ASSOCIATION OF DENTIGEROUS CYST WITH ...

ASSOCIATION OF DENTIGEROUS CYST WITH
RADIOGRAPHICALLY NORMAL IMPACTED LOWER THIRD
MOLARS: A TREATMENT PERSPECTIVE.
By
Dr. GREESHMA G WALI
DISSERTATION SUBMITTED TO THE
RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES
KARNATAKA, BANGALORE.
IN PARTIAL FULFILLMENT
OF THE REQUIREMENT FOR THE DEGREE OF
MASTER OF DENTAL SURGERY
IN
ORAL AND MAXILLOFACIAL SURGERY
UNDER THE GUIDANCE OF
Dr. SHYLA H.N
Professor and Head of the Department
DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY
A.E.C.S MAARUTI COLLEGE OF DENTAL SCIENCES AND
RESEARCH CENTRE
BANGALORE, KARNATAKA.
2006-2009
i

RAJI GANDHI UNIVERSITY OF HEALTH SCIENCES
BANGALORE, KARNATAKA.
DECLARATION BY THE CANDIDATE
I hereby declare that this dissertation/thesis titled
“ASSOCIATION OF DENTIGEROUS CYST WITH RADIOGRAPHICALLY
NORMAL IMPACTED LOWER THIRD MOLARS: A TREATMENT
PERSPECTIVE” is a bonafide and genuine research work carried out by me under
the guidance of Dr.H.N SHYLA, Professor and Head of Department, Department
of Oral and Maxillofacial Surgery, A.E.C.S Maaruti College of Dental Sciences
and Research Centre,Bangalore,Karnataka.
Date: : :2008 Signature of the candidate
Place: Bangalore Greeshma G Wali
ii

CERTIFICATE BY THE GUIDE
This is to certify that the dissertation titled: “ASSOCIATION OF
DENTIGEROUS CYST WITH RADIOGRAPHICALLY NORMAL
IMPACTED LOWER THIRD MOLARS:A TREATMENT PERSPECTIVE” is
a bonafide research work done by Dr Greeshma G Wali in partial fulfillment of the
requirement for the degree of Masters of Dental Surgery in Oral and Maxillofacial
Surgery.
Date: : :2008
Place: Bangalore Dr SHYLA H.N.
iii
Professor and Head
Department of Oral and Maxillofacial Surgery.
AECS Maaruti College of Dental Sciences and Research Centre,
Bangalore.Karnataka.

ENDORSEMENT BY THE HOD ,PRINCIPAL/HEAD OF THE
INSTITUTION
This is to certify that the dissertation titled “ASSOCIATION OF
DENTIGEROUS CYST WITH RADIOGRAPHICALLY NORMAL
IMPACTED LOWER THIRD MOLARS: A TREATMENT PERSPECTIVE ”
is a bonafide Research work done by Dr GREESHMA G WALI under the guidance
of Dr. H. N. SHYLA Professor and Head of Department,
Department of Oral and Maxillofacial Surgery, AECS Maaruti
College of Dental Sciences and Research Centre, Bangalore,
Karnataka.
Seal and Signature of the HOD Seal and Signature of the
PRINCIPAL
Name : Dr SHYLA H.N . Name: Dr C.S.RAMCHANDRA
Date: : :2008 Date: : :2008
Place: Bangalore Place: Bangalore
iv

COPYRIGHT
Declaration by the Candidate
I hereby declare that the Rajiv Gandhi of Health Sciences, Karnataka shall have
the rights to preserve, use and disseminate this dissertation /thesis in print or
electronic format for academic /research purpose.
Date: : :2008 Signature of the Candidate
Place: Bangalore GREESHMA G WALI
© RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES,
KARNATAKA.
v

ACKNOWLEDGEMENT
First, I thank GOD, THE ALMIGHTY for his blessings at every step .
Never ending gratitude to my parents and brother for their immense support and help.
Thank you mom and dad.
I express gratitude to my Postgraduate guide Dr.Shyla H.N. MDS, Professor and
HOD, who guided me through the study and professional life. Thank You Madam.
I express gratitude to my Co-guide Professor Dr.Ganapathy .K.P MDS, who has
helped me in the study and professional life. Thank you Sir.
Special thanks to Dr Manjunath, Dr Rajkumar, Dr Harish, Dr Pavan, Dr Arvind
Dr Sudhir Krishna.Dept of Oral and Maxillofacial Surgery for their help . A word
of thanks to all the staff nurses. Thanks to all.
I thank our principal Dr C.S.Ramachandra and our Ex Principal
Dr C.K.Chandrashekar, AECS Maaruti Dental College and Research
Centre.Bangalore.
I thank Professor Dr K .P Suresh for the statistical analysis.
I thank Dr Prashant Bobhate for his support and constant encouragement , my
postgraduate colleagues Dr Sridhar V , Dr Arati Rao , all my post graduate juniors
Dr Phani R ,Dr Prateek H ,Dr Gerin T,Dr Harshal ,Dr Balakrishna,
Dr Manjula, who have helped me in my academics.
I sincerely thank Mr R Venkatesh, Honorable secretary and the management of
AECS Maaruti College of Dental Sciences and Research Centre, Bangalore for
providing me an opportunity to study in this esteemed institute and providing all the
facilities required for the study.
Date: : :2008 Signature of the Candidate
Place:Bangalore GREESHMA WALI
vi

BBS : Black Braided Silk
LIST OF ABBREVIATIONS USED
DF-A : Dental follicle lined by stratified squamous epithelium.
DF-B : Dental follicle lined by reduced enamel epithelium.
DF-C : Dental follicle with fragmented epithelium.
DF-X : Dental follicle with no epithelium.
H and E : Hematoxylin and Eosin staining.
ILTM : Impacted lower third molars.
mm : Millimetre.
vii

Background and Objectives:
ABSTRACT
Dentigerous cyst develops in the follicular tissue surrounding the impacted lower
third molar. A study was carried out to know the incidence of Association of
Dentigerous cyst with radiographically normal impacted lower third molars and to
draw the attention of the Oral Surgeons towards the prophylactic removal of impacted
third molars.
Methods:
A prospective study was done on 30 patients with impacted lower third molars which
were indicated for extraction. The follicle tissue surrounding the impacted tooth was
given for histopathologic investigations. Only those teeth with a radiographic finding
of pericoronal space of less than 2.5mm were considered. Two Oral Pathologists
reviewed the slides for any changes suggestive of cystic pathology.
Results:
Pathologic changes suggestive of Dentigerous cyst was found in 7 of the 30 follicular
tissue sent for histopathologic testing .It was found to be statistically
significant.(p

Interpretation and Conclusion:
This study shows statistically high incidence of Dentigerous cyst association with
radiographically normal impacted lower third molar teeth .Hence the Oral and
Maxillofacial surgeons should consider histopathologic evaluation and radiographic
diagnosis in the management of impacted lower third molars. Prophylactic extractions
of normal impacted lower third molars should be considered as a treatment option.
KEY WORDS
Impacted lower third molars, Prophylactic extraction, Dentigerous cyst
ix

CONTENTS
S.No Contents Page No
1. INTRODUCTION 1-3
2. OBJECTIVES 4
3. REVIEW OF LITERATURE 5-20
4. METHODOLOGY 21-31
5. RESULTS 32-46
6. DISCUSSION 47-52
7. CONCLUSION 53
8. SUMMARY 54
9. BIBLIOGRAPHY 55-60
10. ANNEXURE 61-68
x

Table
No
LIST OF TABLES
Title Page No
1 Clinical,Radiographic and Histologic features 31
2 Age distribution of patients studied 32
3 Gender distribution of patients studied 33
4 Follicular space measurements 34
5
Distribution of the type of impacted teeth from
which the follicles were obtained
6 Histopathologic findings 36
7 Incidence of dentigerous cyst according to age 38
8 Incidence of dentigerous cyst according to gender 39
9
10
11
Incidence of dentigerous cyst according to
follicular space
Incidence of dentigerous cyst according to type of
impaction
Incidence of dentigerous cyst according to
histologic findings
12 Definitive Diagnosis 43
xi
35
40
41
42

Graph
No
LIST OF GRAPHS
Title Page No
1 Age distribution of patients studied 32
2 Gender distribution of patients studied 33
3 Follicular space measurements 34
4
Distribution of the type of impacted teeth from
which the follicles were obtained
5-6 Histopathologic findings 36-37
7 Incidence of dentigerous cyst according to age 38
8
9
10
11
Incidence of dentigerous cyst according to
gender
Incidence of dentigerous cyst according to
follicular space measurements
Incidence of dentigerous cyst according to type
of impaction
Incidence of dentigerous cyst according to
histopathologic findings
12 Definitive diagnosis 43
xii
35
39
40
41
42

Photograph
No
LIST OF PHOTOGRAPHS
Title Page No
1 Measuring the pericoronal space 21
2
Orthopentamograph with follicular space
measurements
3 Basic Surgical instruments 24
4 Transalveolar extraction - Incision. 25
5 After flap elevation and buccal bone guttering 25
6 Closure with 3 BBS suture 26
7 Biopsied specimen washed in water 26
8 Biopsied specimen stored in 10% formalin 27
9 Materials used for H and E staining 27
10 H and E staining 28
11 Histologic findings-Stratified squamous epithelium 28
12 Reduced enamel epitheliium 29
13
Odontoid islands
29
14
No epithelial lining seen
xiii
24
30

An impacted tooth is one of the most common complaints of patients
presenting to the Oral and Maxillofacial surgeon for treatment. These are
developmental, pathological medical deformities, characteristics of a modern
civilization. Any teeth in the oral cavity can be impacted but the most commonly
affected tooth is the lower third molar. Various reasons have been put forward as to
why these teeth become impacted. With the gradual transition of eating coarse fibrous
food to refined diets that do not cause attrition of the coronal surfaces of the teeth and
because of timely management of any pathology, full complements of tooth crowns in
their original dimensions are maintained and people lack the shortening of the dental
arch needed to accommodate the eruption of third molars into the space posterior to
the second molars. These teeth are frequently impacted because of skeletal
insufficiency in the area where they erupt. Sometimes there is lack of co-ordination
between the maturation of the permanent tooth and shedding of the primary teeth and
a low co relation between the maxillofacial skeletal growth and third molars 1 .
The formation of a tooth occurs inside a developmental sac known as the
dental follicle or the dental sac which surrounds the papillae of the tooth and enamel.
Damante (2001) has characterized the follicle as being the remnant of tissues that
participate in the odontogenesis and remained circumadjacent to the crown of a tooth
which has not erupted normally. The follicle is responsible for the formation of
cementum and periodontal ligament. Radiographically the pericoronal follicles
present as slight pericoronal radiolucency around the unerupted teeth with a thin radio
opaque border, however enlargement and asymmetry can occur. Consalaro et al
(1987) stated that the transformation of the unerupted teeth into cyst or neoplasm is
related to the constituent structures of the follicular tissue, particularly the reduced
1

enamel epithelium and remnants of dental lamina located in the connective tissue
wall 2 .
Dentigerous cysts are the most common of the developmental odontogenic
cysts of the jaw and account for 20-24% of all the epithelial lined jaw cysts. These
develop around the crown of unerupted teeth and are frequently found around the
crown of mandibular third molar followed by maxillary canine, third molars and
rarely maxillary central incisors. These cysts are usually asymptomatic unless there is
an acute exacerbation therefore these lesions are usually diagnosed during routine
radiographic examination. Despite the importance of radiographic findings, Muller
and Bear stated that the disease condition may be found in minute follicle spaces and
in enlarged radiolucent areas there may be histologically normal tissue, so biopsy is
imperative 2 .The follicular space usually measures up to 2.5mm on intraoral films and
3mm on panoramic films 3 . Knight et al (1991) looked at the prevalence of
Dentigerous cyst and found that 44.7% of 170 impacted teeth examined had
associated Dentigerous cyst, some with little or no radiographic evidence of pathosis.
Aldesperger et al (2000) recently reported that 34% of soft tissue associated with 100
impacted molars, none of which showed radiographic evidence of abnormal
pericoronal pathology, actually showed squamous metaplasia consistent with
Dentigerous cyst. Prevalence of pathologic condition is generally higher than that
assumed from radiographic examination alone 4 .
The advisability of the removal of the asymptomatic impacted third molars by
early prophylactic surgical extraction has been debated in dentistry for many years.
While proponents of the routine surgical extraction of third molars believe that early
extraction is preferable, to the potential for pathological degeneration and disease of
2

the other teeth later in life, clinicians who do not support routine prophylactic removal
feel that there is a lower risk of pathological degeneration and disease compared with
the risks of surgery. If the decision is to extract third molars early before disease
potentially may occur, patients face the certain psychological and physical trauma of
surgery performed at such a young age. If the decision is not to extract third molars
early, the patients face the uncertainty of disease and the likelihood that if extraction
becomes necessary it likely will be more difficult, with the increased possibility of
serious postsurgical morbidity.
As health care workers and dental professionals it is mandatory for us to
improve the health outcomes, quality of life and prevention of 3 rd molars related
morbidity should be conducted in our research. Studies have shown that there is
significant increase in surgical morbidity in removal of third molars in the aged, and
will also consume a large portion of the health care funds 5 .
This study was conducted to know the presence of any pathosis associated
with the radiographically normal follicle surrounding the impacted lower third molar
and advocate this as one of the reasons for prophylactic removal of lower third molar.
3

1. To investigate the incidence of cystic changes specifically related to the
dentigerous cyst in radiographically normal impacted lower third molar teeth.
2. To consider prophylactic removal of impacted lower third molars.
3. To compare the incidence of cystic changes in vertical impactions with
horizontal, mesioangular and distoangular impactions.
4

There are therapeutic and prophylactic indications for the removal of impacted
lower third molars. It is argued by some authors that all impacted lower third molars
should be removed regardless of the absence of symptoms, while other authors think
that reviewing asymptomatic Impacted lower third molar is questionable and yet other
authors consider that prophylactic surgical removal of the impacted lower third molar
is not necessary at all .
Daniel M Laskin (1971) is of the opinion that the complications which arise
from unerupted and impacted third molars are pericoronitis ,periodontitis ,pathologic
resorption, cyst formation ,association with neoplasm ,pathologic resorption of the
second molar, idiopathic pain, involvement in a fracture and crowding in dentition
.According to him the impacted third molar occasionally may remain asymptomatic
throughout the person’s life time ,but his clinical experience has shown that most of
the impacted teeth ultimately give rise to some kind of difficulty, and most of the
times the damage produced by such complications is frequently not reversible even
after the tooth has been extracted 6 .
Robert A Bruce et al (1980) of the Charlmers J .Lyoons Academy conducted
a study on the age of the patients and the morbidity associated with mandibular third
molar surgery. A total of 330 patients were evaluated between the age of 35 to 81
years, the mean being 46.5. The study documented an incidence of lingual nerve
dysesthesia by buccal approach in 1.5% of the cases, Inferior alveolar nerve
dysesthesia in 4.4%,incidence of alveolar osteitis in 13.5% and association with cyst
and tumours in 6.2% cases .Results of the investigations showed that there is a
significant increase in surgical morbidity as the age of the patient increases. If the
third molar has to be extracted, it has to be done when the patient is a young adult 7 .
5

Hinds C Edwards and Karl F Frey (1980) reported a review of 15 cases
who underwent removal of the retained impacted third molars after the 4 th decade of
life. In 15 cases, 9 were histologically diagnosed as Dentigerous cyst, one of which
one was associated with inflammation. A case of Odontogenic keratocyst was
reported, one was reported as non specific infection, 2 cases showed no lesion. One
case showed radiolucent cystic lesion surrounding the impacted third molar and one
case showed post operative surgical complication. Hence the authors concluded that
the third molars which are not functioning ,have inherent hazards such as
development of pathological process like Dentigerous cyst, Odontogenic cyst and that
they should be surgically removed early in life even when clinically symptoms are
absent 8 .
Lysell L and Rohlin M (1988) studied the indications for removal of the
mandibular third molars. The results were based on the data from 870 individuals with
mean age of 27 years.54% of the third molars, which were removed, presented with
no subjective symptoms. Symptoms were frequently in association with fully erupted
or partially erupted molars than the impacted molars which were fully covered by soft
tissue or bone. 27% were removed for prophylactic purpose, 14% for orthodontic
reasons, one fourth for pericoronitis, 13% of the cases had caries and only 3 % of
them were associated with cysts and tumours .Thus the authors suggested that the
third molars which were covered by soft tissue had higher frequency for producing
symptoms and was worth considering for removal rather than removing the bony
impaction until any pathology was detected. Thus the authors concluded that severe
infections, tumours cysts and root resorption which are often said to be the hazard of
6

impacted third molars were rare as indications and most third molars removed were
symptomatic 9 .
N Bradley et al (1988) presented a case report of a 63 year old man with a 2
month history of dull pain and tenderness associated with horizontally impacted third
lower molar teeth. Radiographic examination showed that there was an ill defined
radiolucency associated with the impacted teeth without any cortical expansion of the
mandible. A clinical diagnosis of Dentigerous cyst was made and the cystic lesion
was exposed under general anesthesia and found to be adherent to the crown of the
teeth, the neurovascular bundle and all parts of the cavity .The cyst was removed
piecemeal. The bony crypt was debrided and closed primarily. Histologically there
was a fibrous walled cyst lined by a non keratinizing stratified squamous epithelium
which had undergone malignant change varying from intra epithelial to infiltrating
squamous cell carcinoma .Malignant change within the squamous epithelium is rare.
Eversole et al (1976) found only 36 well documented cases till the year 1975.
Squamous cell carcinoma arising from an odontogenic cyst occurs at least twice as
commonly in the mandible than the maxilla with a predilection for posterior region of
the mandible 10 .
Eliasson et al (1989) studied the pathological changes related to impacted
third molars in a radiographic investigation of 2128 randomly selected patients.
Pathologic changes were observed in 25 of the 477 maxillary impacted third molars
and in 59 of 734 mandibular impacted third molars. A pathologically widened
pericoronal space (>2.5mm according to Staffne and Gibilison) indicating a
dentigerous cyst was observed in 5 of the 477 maxillary and 43 of the 734 mandibular
impacted third molars. Other changes noted were resorption of the second molars or
7

loss of marginal bone on the distal aspect of the second molars. Thus the risk of
pathologic sequelae, because of impacted third molars is apparently low. Hence
prophylactic surgical removal should be regarded with some reserve, particularly in
view of the high frequency of deep impactions, with greater risk for surgical
complication 11 .
Wovern N.Von and Nielson H.O (1989) carried out a clinical follow up
study on 70 dental students with 130 asymptomatic, non ectopic impacted mandibular
third molars and were followed for 4 years. At the initial visit 26 were impacted in the
soft tissue, 30 were partially impacted in bone, and 74 were completely impacted in
bone. The 4 year follow up revealed that 49 third molars had been removed, the
reason being pericoronitis or caries in 30%, mild symptoms in 39% and for
prophylactic reasons in 31%. Of the remaining 81 third molars: 71% of the soft tissue
impactions, 25% of partial bony impactions and 8% of complete bony impactions
showed complete and normal eruption. The remaining third molars were either static
or had advanced in the degree of eruption. It was concluded that non ectopic,
impacted third molars in the given age group may have a chance to completely erupt.
The treatment for asymptomatic impacted third molars in the young adult may be
observation instead of prophylactic removal 12 .
Ib Sewerin et al (1990) conducted a 4 year radiographic follow up study on
asymptomatic mandibular third molars in young adults. 55 asymptomatic mandibular
third molars in 34 dental students (mean age 20.6 years at the start of the study) were
followed radiographically for 4 years. Based on the clinical evaluation of 55 teeth
involved 20 had almost erupted, 13 were partly erupted and 22 impacted mandibular
third molars. Root development, level of eruption saggital angulation, resorption,
8

pericoronitis /bony pockets, paradental cysts and widening of the periodontal space,
Dentigerous cyst were observed for. The state of 21 teeth had radiographically
changed at the end of the observation period. The most remarkable finding was that
the 15 teeth changed their saggital angulation, all in distal direction, five mesioangular
to vertical, five vertical to distoangular, five mesioangular to distoangular.
Radiographicaly 15 impacted lower third molars moved to a more advanced level of
eruption. No real pathological osseous lesions and no root resorption were observed at
initial or follow up examinations .It is concluded that there are frequent essentially
unpredictable changes in the position of the mandibular third molar after the age of 19
years which may influence the decision of their removal or preservation 13 .
W.G Maxymiw et al (1991) presented a case report of a 72 year old man with
a squamous cell carcinoma of the right mandibular cyst. Before the diagnosis as a cyst
was established, a number of alternatives were explored, because the cyst and
neoplasm may develop independently adjacent to one another and then fuse. The oral
mucosa in the patient was normal. Cystic degeneration of the epithelial neoplasm may
occur but this did not happen since the original biopsy showed no evidence of benign
odontogenic tumour. But there was transition of the cells lining the cyst from a benign
epithelium to that of a carcinoma. An important clinical sign is a firm non tender
enlargement of the jaw. Radiographically odontogenic cysts undergoing malignant
transformation may show margins that are jagged and have indendations and
indistinct borders 14 .
Fukuta Y et al (1991) studied 11 specimens of hyperplastic dental follicles
and were correlated clinicopathologically. Out of these, two cases involved multiple
lesions and other cases showed single lesions. Radiographically the lesions showed
9

various degrees of radiolucency around the crown of impacted tooth. Most of the
cases were diagnosed clinically as dentigerous cyst. The histopathological findings of
the lesions were similar to those of normal dental follicle tissue around the developing
tooth 15 .
Peterson J Larry (1992) in his review mentioned certain indications for the
removal of impacted teeth. They include pericoronitis, periodontal disease, root
resorption, orthodontic considerations, odontogenic cysts and tumours, prosthetic
considerations. To remove asymptomatic impacted teeth, several factors are
considered such as available space in the arch for the tooth to erupt, patient’s age.
Considering all the above mentioned indications, authors concluded that if the
impacted third molar is partially exposed then it should be extracted as soon as
possible. The completely impacted, asymptomatic third molar in a patient older than
35 years can be left intact unless pathology develops 16 .
Mercier P and Preciuos D (1992) conducted a review about risks and
benefits of removal of impacted third molars have mentioned the risk for developing
severe infections, cysts or tumours. Authors point out that an enlarged follicular space
should not be confused with a developing dentigerous cyst especially in growing
individuals. They attribute errors in evaluating the true prevalence of cysts to previous
statements in articles that a space more than 2.5mm represents, in all probability a
cyst with an epithelial lining. They questioned the value of the surveys from
panoramic radiographs, which show major linear distortions, especially in the
horizontal plane. The reported incidence of cyst formation is as follows: Dachi -11%,
Bruce-6.2%, Wordenram-4.5%, Moushed -1.44%, Goldberg-3% including high
incidence of tumours in comparison with lower incidence than other studies 17 .
10

Knutsson Kerstin et al (1992) studied the judgement for the need of
extraction of the 36 impacted third molars among 10 Oral surgeons and 30 general
dental practitioners. The number of mandibular third molar removal proposed by Oral
Surgeons varied from 3-21 of the 36 cases. The mean number of molars proposed for
extraction was 12 for Oral surgeons and 13 for general practitioners. There was no
third molar that all the observers in both the groups agreed should be extracted .The
mean intraobserver agreements within the 2 groups were comparable, 94% for the
oral surgeons and 92% for the general dental practitioners. Authors concluded that
there is great variability between the 2 groups in their judgement on the need for
removal of the asymptomatic mandibular third molar 18 .
Kim Jim and Gary L Ellis (1993) conducted a study to evaluate the incidence
of misdiagnosis of dental follicles and papilla to discuss reasons for this
misinterpretation and the diagnostic pit falls. 847 dental follicles and dental papillae
were studied from 663 patients between the years 1970-1988.The specimens were
submitted to medical pathologists seeking diagnostic consultation. Radiographs were
available for 26 cases which showed follicular width ranging from 2mm-
5.9mm.Histological analysis by medical pathologists contributed with 53.4% of the
specimens being correctly identified in which 16.9% were offered with differential
diagnosis and 9.8 specimens were not given any diagnosis. The most common
incorrect diagnosis was odontogenic myxomas, odontogenic fibroma, ameloblastic
fibroma and odontoma . Dental follicle was commonly misinterpreted as odontogenic
cyst and the papillae as odontogenic myxomas. Hence it was concluded that the
general medical pathologists often are unfamiliar with the dental follicle and need to
11

consider clinical, radiological features as well as histologic observation for
discriminating dental follicles from odontogenic cysts and tumours 19 .
Brickley M et al (1993) carried out a study to compare clinical treatment
decisions for removal of the lower third molar with National Institute of Health
Consensus criteria. 72 consecutive patients were evaluated. Indications for removal
were follicular cysts, caries pericoronitis, root resorption, internal and external
resorptions and periodontal diseases. Of the 139 third molars, 79 were partially
erupted, 55 were unerupted , 5 fully erupted .A total of 42 teeth did not have a valid
indication for removal when National Institute of Health consensus criteria were used
, of which 27 third molars were scheduled for surgery 20 .
Girod S C et al (1993) described three cases in which large cysts developed
over a period of 3 year displacing the third molars. Among these, two cases were
diagnosed as dentigerous cysts and one was odontogenic keratocyst .Initially when
radiographs were taken these impacted teeth were asymptomatic .At later years they
developed a large cyst. The cases presented illustrate the need for further research to
calculate the risks when asymptomatic teeth are left in place. With increase in age the
morbidity associated with infection, general anesthesia and surgery is likely to
increase. These factors have to be considered when the patients are advised about
advantages and disadvantages of third molar removal 21 .
Kahl B et al (1994) conducted a long term radiographic follow up study of
251 adults who were orthodontically treated. Radiographs showed 113 clinically
asymptomatic impacted third molars in 58 patients. Radiographic assessment revealed
contact of impacted third molars with the second molars and reduced bone height on
the distal aspect of maxillary second and mandibular second molar as well as
12

pathologically widened pericoronal spaces of the maxillary and mandibular third
molars. Most of the maxillary and 2/3rds of the mandibular impacted third molars
showed normal pericoronal spaces. Widened pericoronal spaces were measured in 6
maxillary and 20 mandibular third molars, but there were no changes suggesting
cystic pathology 22 .
Sheperd J P ,Brickley M (1994) on surgical removal of the third molars
,suggested that in any case the prophylactic removal should be abandoned and surgery
should be carried out in cases only where National Institute of Health Consensus
criteria exists. The indications for removing third molars was the subject of a National
Institutes of Health consensus conference held in the United States in 1979 .The
consensus criteria are ,recurrent pericoronitis, caries , not amenable to restorative
measures ,dentigerous cyst ,internal and external resorption and periodontal diseases
to which the third molar was contributing factor 23 .
Daley D Tom et al (1995) made an attempt to identify epidemiological
features that would assist in differential diagnosis of dentigerous cyst and dental
follicles. The study group comprised of 1662 dentigerous cyst and 824 dental follicles
which showed considerable overlap in age distribution and site predilection and
therefore were of minimal use in reaching a final diagnosis. Hence the authors
concluded that identifying a cystic cavity at the time of surgery may be the only
reliable way to arrive at a definitive diagnosis 24 .
Osaki Tokio et al (1995) carried out a study to determine the clinical
characteristics of infections caused by impacted third molars in elderly persons. 41
patients were 60 years of age who showed pathologic changes such as pericoronitis,
secondarily infected dentigerous cyst, osteomyelitis and abscesses. They concluded
13

that retained impacted third molars with overlapping of other factors occasionally
cause oral infections in older persons. So management of impacted third molars in
younger patients has to be done even when it is asymptomatic to prevent probable
clinically disastrous conditions in the elderly 25 .
Linden Van Der Wyanand et al (1995) conducted a retrospective survery of
1001 panoromic radiographs with impacted lower third molars. Radiographically
authors studied various changes associated with the third molars like caries, widening
of the pericoronal space, height of the cementoenamel junction to the alveolar bone
between the second and third molars, type of impaction, odontogenic neoplasm and
cyst. Radiolucent space of 3 mm between the tooth and follicle was considered as
cystic change. No odontogenic neoplasm or cysts were seen in the study group. Thus
the low rates did not offer support for the likely presence of pathologic conditions to
be an indication for the third molar removal 26 .
Brooks S.L Woolfolk (1996) examined 1318 consecutive records of impacted
third molars with detailed information on age ,gender of the patients ,number and
status of the third molars Follow up radiographs for any change in the status of these
teeth were evaluated including the follicle width and any associated pathology. There
were 2110 third molars including 1589 erupted ,521 impacted teeth ,out of which
117 subjects with 216 impacted teeth was evaluated thoroughly. The average follow
up time was 11.8 years. Out of 216 teeth only 33 underwent some change in the
interval. Two cases were suspected as cysts, which increased in size and two
periodontal defects. A 61 years old male had a large dentigerous cyst at the time of
the first examination. Thus the authors concluded that routine extraction of
asymptomatic impacted third molars cannot be justified due to low prevalence and
14

incidence of pathology associated with these teeth in adults. They recommended a
periodic follow up examinations for those impacted teeth left in place 27 .
A literature review was conducted by Song et al (1997) to evaluate the
appropriateness of prophylactic removal of impacted third molars where in 12
published reviews were analyzed and the authors concluded that in the absence of
good evidence to support prophylactic removal, there appears to be little justification
for the removal of pathology free impacted third molars 28 .
Kostopoulom O et al (1998) investigated intra observer reliability of Oral
surgeons and dental practitioners regarding removal of asymptomatic third molars. 36
asymptomatic third molar cases were given for assessment with detailed history of
each patient in two occasions. Significant correlations were found between initial and
repeat assessments. There was little agreement about the need for removal .Authors
concluded that treatment decisions about whether or not to remove asymptomatic
third molars were not made on rational basis. It is inferred that until high quality
evidence of disease prediction is published, decisions to remove third molars
prophylactically cannot be made reliably 29 .
Glosser J.W, Campbell J.H (1999) studied 96 specimens of dental follicles,
which were radiographically normal impacted third molars. They considered
pericoronal radiolucency larger than 2.5mm as radiographic pathology. Three
different pathologists analyzed the excised dental follicles. They agreed that any soft
tissue specimen with squamous epithelium spreading along the surface of the follicle
would be deemed cystic. Cystic changes were seen in tissues from patients as young
as 16 years and as old as 38 years, but most occurred in 20-25 years of age. In the 96
specimens 31 had dentigerous cyst like changes. This was the only pathologic change
15

found in any specimen. While only 25% of the specimen from the maxillae were
cystic, nearly 37% of the mandibular specimens had undergone cystic changes. They
concluded that, though higher incidence of cysts than expected were found, the
importance of this is not yet clear and they suggested that both the definitions and
diagnostic importance of Dentigerous cyst should perhaps be reconsidered. Additional
histological criteria like immunohistochemistry and histomorphometric studies may
aid in confirming the diagnosis 30.
According to KSC Ko (1999) et al dentigerous cyst are the most common
odontogenic cyst of the jaws. They are commonly associated with impacted lower
third molars. Bilateral Dentigerous cysts are rare and occur in association with a
developmental syndrome .Its occurance in non syndromic impacted lower third
molars is rare and only 11 cases have been reported till date. Syndrome associated
could be Cleidocranial dysplasia or Morteaux lammy syndrome. They are frequently
discovered radiographically after there is an impacted or, unerupted tooth 31 .
Guven A et al (2000) conducted a retrospective analysis to determine the
incidence of development of cysts and tumors around third molars and discuss the
issues relating to the removal of asymptomatic, impacted third molars. 9994 impacted
third molars removed in 7582 patients, formed the basis of the study .The analysis
revealed 231 cysts (2-31%) and 79 tumors (0.02%), including 7 benign tumors (.77%)
and 2 malignant tumors (.02%). The incidence of cysts and tumors around impacted
third molars was found to be 3.10% in this study 32 .
John Adelsperger et al (2000) conducted a study to histologically evaluate
soft tissue pathosis in pericoronal tissues of impacted third molars that did not exhibit
pathologic pericoronal radiolucency. One hundred impacted third molars without the
16

evidence of abnormal pericoronal radiolucency were removed and the pericoronal
tissues were submitted for histopathologic examination. Specimens were fixed and
processed stained with hematoxylin and eosin and then evaluated by 2 Oral
Pathologists. A subset of both the diseased and healthy tissues underwent additional
evaluation for the presence of proliferating cell nuclear antigen for assessment of
cellular activity. Of the specimens, 34% showed squamous metaplasia suggestive of
cystic change similar to that found in Dentigerous cyst. Soft tissue pathosis was
significantly higher in patients over the age of 21 years. Thus he concluded that the
radiographic appearance may not be a reliable indicator of the absence of disease
within a dental follicle 33 .
Damante J H and Fleury R N (2001) verified the relationship between the
radiographically measured width of the pericoronal space and the microscopic
features of the small Dentigerous cysts and Paradental cysts. One hundred and thirty
unerupted and thirty partially erupted teeth were radiographed and extracted. The
radiographic width of the pericoronal space of the specimens ranged from.1mm to
5.6mm. 68.4% of the unerupted teeth showed reduced enamel epithelium in the
follicles .Inflammation was present in 36.1% of the cases ,20% showed stratified
squamous epithelium and 13% showed no epithelium .In case of partially erupted
teeth most frequent epithelium was the hyperplastic stratified squamous epitheliumin
found in 68.4% of the cases and reduced enamel epithelium in 68.5% of the
cases.Inflammation was present in 82.8% of the cases.No epithelium was seen in
11.4% of the cases.The authors concluded that the final differential diagnosis between
small dentigerous cysts or paradental cysts and pericoronal follicle depends on
17

clinical and or surgical findings, such as the presence of bone cavitation and cystic
content 34 .
Rakprasitkul (2001) conducted a study to determine whether the incidence
of pathologic conditions affecting the pericoronal tissue of unerupted third molars
justifies their routine removal .The pericoronal tissue of 104 unerupted teeth was
submitted for histological examination after surgical removal of the teeth .He found
that the incidence of normal follicle tissue was 41.35% and the incidence of
pathologic tissue was 58.65% (dentigerous cyst ,50.96%. chronic nonspecific
inflammatory tissue ,4.81%.odontogenic keratocyst,1.92%.ameloblastoma,.96%).The
incidence of pathologic conditions was higher than the normal conditions in all third
molar positions. In younger patients, normal tissue was more commonly found, but in
patients older than 20 years, the incidence of pathologic tissue was higher than the
incidence of normal tissue. He concluded that the unerupted third molars should be
removed before pathologic changes can occur in the pericoronal tissue. This justifies
the routine removal of unerupted third molars from patients older than 20 years 35 .
FCS Chu et al (2003) conducted a study on 3853 impacted teeth in 2115
patients and found that mandibular third molars were the commonly impacted teeth
(82.5%) followed by maxillary third molars (15.6%) and maxillary canine (0.8%
.Caries and periodontal diseases were commonly seen in relation to the impacted third
molars where as cystic pathology and root resorption were rarely observed 36 .
Richard Werkmester et al (2005) conducted a 5 year retrospective study on
316 patients who had received in-patient treatment for deep abscess formation, cyst
formation or mandibular angle fracture in relation to lower third molars. A
radiological analysis was done to determine whether major pathological changes
18

associated with lower third molars was associated with the position of the impacted
teeth. Third molar position was studied in, inpatient and outpatient group .The
outpatient group consisted of 300 patients .The relationship between the positions and
pathologies was analyzed statistically using a new position score. The study revealed
that the highest score corresponds to a leading aberrant position of the tooth and is
associated significantly with cyst formation 37 .
Wasiu Lanre Adeyemo et al (2006) after a critical review of literature
concluded that there are well established indications for removal of impacted lower
third molars. According to them although ILTM’s may sometimes be associated with
pathologies, this occurs in a relatively small proportion of patients. Patients with
ILTM’s are more likely to have an angle fracture than those without impacted lower
third molars. But there is emerging evidence that ,the presence of ILTM’s helps to
prevent condylar fractures which are more severe ,are more difficult to treat and have
great risk of long lasting complications that the angle fracture. According to them the
prophylactic removal of ILTM’s in the absence of specific medical and surgical
conditions should be discontinued 38 .
G H L Saravana et al (2008) conducted a study to find out the incidence of
histological abnormalities in soft tissues that are associated with impacted lower third
molars with no pericoronal cystic lesions (

The literature gives us an idea about the merits and demerits of an impacted
lower third molar. Controversy still persists with respect to the incidence of
pathologic conditions associated with these teeth. It is clear that Dentigerous cyst can
achieve significant dimensions and cause marked tissue destruction. So the clinician
has to investigate all the teeth that fail to erupt at the expected time and promptly start
appropriate assessment and management of the suspected cystic lesions.
20

A prospective study was conducted to know the incidence of Dentigerous cyst
in the follicle around the lower third molars with no radiographic or clinical evidence
of cystic changes. This study was conducted in the Department of Oral and
Maxillofacial Surgery, AECS Maaruti College of Dental Sciences and Research
Centre, Bangalore. The study comprised of 30 patients with impacted lower third
molars which were indicated for extraction for various reasons .These patients did not
have any clinical or radiographic evidence of cystic pathology. The follicle tissue
surrounding the crown of these impacted lower third molar was given for
histopathological examination.
Inclusion Criteria:
1. Impacted lower third molar indicated for extraction.
2. Impacted lower third molars with a follicular space of less than 2.5mm.
3. Third molars with two roots, fused roots or conical roots in which the long axis of
the root can be appropriately determined will be considered.
4. Age group-20-30 years.
Exclusion Criteria:
1. Follicular space greater than2.5mm will not be considered.
2. Impacted teeth with dilacerated roots or curved roots where in the long axis of the
teeth cannot be determined.
3. Patients with any systemic disorder.
21

Radiographic Technique:
Orthopantomograph of all the subjects were taken using Panoramic X –ray machine.
Patients chin and occlusal plane was positioned properly. The mid sagittal plane was
centered within the focal trough of the X ray unit. Standard exposure time was used.
Orthopantamograph with minimum distortions were considered.
The contours of the tooth and of the pericoronal space were traced on the tracing
paper using the X ray viewer. The widest point of the follicular space was measured
using a graduated scale. Two perpendicular lines(AA’ and BB’) were drawn on the
image of the impacted teeth .One line passing through the long axis of the tooth and
other line passing through the centre of the crown. Starting from the intersection of
the two lines, a ruler will be moved to the widest of the follicular space where
measurements were done with a caliper ruler. Subjects who had a follicular space of
more than 2.5mm were excluded from the study .After meeting the inclusion and
exclusion criteria an informed consent of the patient was taken for surgical removal of
impacted lower third molars 34 .
Photograph : 1
22

Surgical Procedure:
The transalveolar extraction of the impacted lower third molar was carried out under
Local anesthesia maintaining strict asepsis. The standard Wards incision was given
with a No 15 blade. A mucoperiosteal flap was elevated, if any coronal follicle tissue
was found, it was carefully dissected out using blunt forceps and preserved. The bone
surrounding the impacted teeth i.e, on the buccal and the distal aspect was removed
with bur under copious saline irrigation .Few cases required sectioning of the teeth .It
was also done using a bur under copious saline irrigation. The tooth was gently
elevated from the socket taking care not to damage the follicular tissue. After the
tooth was removed, the follicle was enucleated from the socket attachment and then
washed with water. The surgical site was irrigated and closed with 3-0 silk sutures.
Histopathologic Technique:
The excisional biopsy specimens were obtained after transalveolar extraction of the
impacted lower third molar. They were washed in water and immediately fixed in
10% neutral formalin solution, processed and 5microns thick sections were obtained
from the paraffin embedded blocks using a rotary microtome. The sections were then
stained using Hemetoxylin and Eosin. Two Oral Pathologists who were involved in
the routine diagnostic histopathologic investigations reviewed the slides. To reduce
the interobserver discrepancy same set of slides were given to both the Oral
Pathologists.
23

The findings observed by the Oral Pathologists were-
• Non keratinizing stratified squamous epithelium
• Reduced enamel epithelium
• Fragmented epithelium
• Absence of epithelium
• Underlying connective tissue with Odontoid Island
24

Photograph 2: Follicular space measurement
Photograph 3: Basic Surgical Instruments
25

Photograph 4: Transalveolar extraction. Incision
Photograph 5: Mucoperiosteal flap
26

Photograph 6: Closure with 3BBS suture
Photograph 7: Biopsied follicle tissue washed in water
27

Photograph 8: Biopsied follicle stored in 10% Formalin
Photograph 9: Materials used for H and E staining
28

Photograph 10: H and E staining
Photograph 11: Histologic findings-Stratified Squamous epithelium
29

Photograph 12: Reduced enamel epithelium
Photograph 13: Odontoid islands in dense fibrous connective tissue
30

Photograph 14: No Epithelium lining seen
31

Table No 1
32

Percentages
Table 2: Age distribution of patients studied
Age in years Number %
18-20 5 16.7
21-25 17 56.7
26-30 8 26.7
Total 30 100.0
Mean ± SD 23.10±2.87
Graph 1: Age distribution of patients studied
60
55
50
45
40
35
30
25
20
15
10
5
0
16.7
56.7
18‐20 21‐25 26‐30
Age in years
33
26.7

60
50
40
30
Table 3: Gender distribution of patients studied
Gender Number %
Male 18 60.0
Female 12 40.0
Total 30 100.0
Graph 2: Gender distribution of patients studied
20
10
0
Male
60%
34
Female
40%

No of cases
50
45
40
35
30
25
20
15
10
5
0
Table no 4: Follicular space measurements
Follicular space Number of patients
1.0 21
1.50 6
2.0 3
Total 30
Graph 3: Follicular space measurements
6
35
3 0

Table 5: Distribution of the type of impacted teeth from which the follicles were
obtained
Type of impaction
Number
(n=30)
1.Distoangularly impacted teeth 6 20.0
2.Horizontally impacted teeth 6 20.0
3.Mesioangularly impacted teeth 11 36.7
4.Vertically impacted teeth 7 23.3
Graph 4: Distribution of the type of impacted teeth from which the follicles were
obtained
Percentages
50
45
40
35
30
25
20
15
10
5
0
1 2 3 4
Radiographic interpretations
36
%
1.Distoangularly impacted teeth
2.Horizontally impacted teeth
3.Mesioangularly impacted teeth
4.Vertically impacted teeth

Histopathological findings
HISTOPATHOLOGICAL OBSERVATION
Table 6: Histopathological findings
Number
(n=30)
% 90%CI
DF-A 7 23.3 13.2-37.9
Others 23 76.7 62.1-86.8
DF-B 5 16.7 8.4-30.5
DF-C 6 20.0 10.7-34.3
DF-X 12 40.0 26.7-54.9
Graph 5: Histopathological findings
Others
76.7%
37
DF‐A
23.3%

Percentages
50
45
40
35
30
25
20
15
10
5
0
Graph 6: Histopathologic findings
16.7
20
DF‐B DF‐C DF‐X
Others
38
40

% of Dentigerous cyst
Age in years
STATISTICAL ANALYSIS
Table 7: Incidence of dentigerous cyst according to age
Number of
patients
Dentigerous cyst
No %
P value
18-20 5 1 20.0 0.861
21-25 17 6 35.3 0.242
26-30 8 0 0.0 -
Total 30 7 23.3 -
Graph 7: Incidence of dentigerous cyst according to age
50
45
40
35
30
25
20
15
10
5
0
20
35.3
18‐20 21‐25 26‐30
Age in years
39
0

Table 8: Incidence of dentigerous cyst according to gender
Gender
Number of
patients
Dentigerous cyst
No %
P value
Male 18 5 27.8 0.652
Female 12 2 16.7 0.589
Total 30 7 23.3 -
% of Dentigerous cyst
Graph8: Incidence of dentigerous cyst according to gender
30
25
20
15
10
5
0
27.8
Male Female
Gender
40
16.7

Table 9: Incidence of dentigerous cyst according to follicular space
Follicular space
Number of
patients
Dentigerous cyst
No %
P value
1.0 21 6 28.6 0.565
1.50 6 - - -
2.0 3 1 33.3 0.682
Total 30 7 23.3 -
Graph 9: Incidence of dentigerous cyst according to follicular space
% of Dentigerous cyst
50
45
40
35
30
25
20
15
10
5
0
28.6
1.0 1.50 2
0
FOLLICULAR SPACE
41
33.3

Table 10: Incidence of dentigerous cyst according to type of impaction
Type of Impacted teeth
Number
Dentigerous cyst
(n=30) No %
P value
1.Distoangularly impacted teeth 6 2 33.3 0.562
2.Horizontally impacted teeth 6 2 33.3 0.562
3.Mesioangularly impacted teeth 11 - - -
4.Vertically impacted teeth 7 3 42.9 0.219
% of Dentigerous cyst
Total 30 7 23.3 -
Graph 10: Incidence of dentigerous cyst according to type of impaction
50
45
40
35
30
25
20
15
10
5
0
1 2 3 4
Radiographic interpretations
42
1.Distoangularly impacted teeth
2.Horizontally impacted teeth
3.Mesioangularly impacted teeth
4.Vertically impacted teeth

Table 11: Incidence of dentigerous cyst according to Histopathological findings
Histopathogical
findings
Number of
patients
Dentigerous cyst
No %
P value
DF-A 7 7 100.0

Definitive diagnosis
Table 12: Definitive diagnosis
Number
(n=30)
% 90%CI
Dentigerous cyst(P value

1. Z-test for a proportion (Binomial distribution) was used for this study.
Objective: To investigate the significance of the difference between the assumed
proportion and the P0 and the observed proportion P
2. 90% Confidence Interval
(! p p0!
) 1/
2n
Z
p q / n
− −
=
P ± 1.64* SE(P), Where SE(P) is the Standard error of proportion = P*Q/√n
3.Significant figures
+ Suggestive significance 0.05

An in vivo prospective study was done to know the incidence of histologic changes
suggesting cystic pathology of radiographically normal IMLT. It was conducted on 30
patients with ILTM, indicated for extraction and the follicle surrounding the crown
was given for histopathological testing.
The clinical, radiographical and histopathological parameters is given in Table No-1
Hematoxylin and Eosin staining showed stratified squamous epithelium, fibrous
connective tissue with odontoid islands suggestive of Dentigerous cyst in 7 slides.
Maximum of them were found in vertically impacted teeth followed by distoangular
and horizontally impacted teeth.
46

The incidence of impacted or embedded teeth accounts for between
14% - 96% of the population. Among this 98% of the impacted teeth are the third
molars. Only 50% of the third molars erupt into the oral cavity 1 .
The mandibular third molar tooth germ is usually radiographically seen by the
age of 9 years and cusp mineralization is completed by 2 years .Initially the tooth is
located in the anterior border of the ramus with the occlusal surface facing anteriorly.
The level of the tooth germ is approximately at the occlusal plane of the erupted
dentition. Crown formation is completed by age of 14 years and the roots are
approximately 50% formed by 16 years of age and by 18 years the root is completely
formed with an open apex. By 24 years of age ,95% of all the molars will complete
their eruption 40 .Changes in the axial inclination of the impacted lower third molar
takes place between 16-18 years of age when the roots of these teeth move abruptly
forward in the bone indicating the approach of the tooth to the adult axial position.
Ledyard studied 375 tracings of the lateral roetgenograms of right and left jaws of
orthodontic patients .Measurements were made on the tracings from the distal aspect
of the lower first molar on the occlusal plane to the anterior border and posterior
border of the ramus .These curves leveled off after 14 years of age and there was little
growth after that. Ledyard concluded that, after 15 or 16 years of age, further growth
in the retromolar region is negligible and a comparison of the tooth and bone structure
at this time would determine if sufficient space is present for the third molar to erupt.
Sicher stated that the lower third molar faces upward and forward during its
development, if insufficient space is present for its pre eruptive rotation and it starts
to erupt in the direction of its abnormally inclined long axis,its crown moves towards
the crown or the root of the second molar and is arrested in its movement 41 .
47

After the formation of enamel, the crown of the tooth is surrounded by
reduced enamel epithelium and by ectomesenchyme. These two structures together
form the dental follicle, which may be the reason for several types of diseases after
and during odontogenesis 34 .
In the impacted third molar that is left intact in the jaw, the follicle may
undergo cystic degeneration and form a dentigerous cyst. The follicular sac may also
develop into odontogenic tumours. These pathological entities usually occur under 40
years of age 40 . Dentigerous cysts are the most common of the developmental
odontogenic cysts of the jaws and account approximately for 20-24% of all the
epithelium lined jaw cyst. It develops around the crown of the unerupted teeth by
expansion of the follicle when the fluid collects or a space occurs between the reduced
enamel epithelium and the enamel of the impacted teeth. These cysts are often
asymptomatic and sometimes there may be acute inflammatory exacerbation,
therefore these lesions are usually diagnosed on routine radiographic examination.
Swelling, pain, tooth displacement mobility and sensitivity may be present if the cyst
reaches the size larger than 2 cms. Radiograph of the dentigerous cyst usually shows a
well defined unilocular radiolucency with a sclerotic border surrounding the crown of
the impacted teeth 42 .
Histologically the dentigerous cyst consists of a fibrous wall lined by non
keratinized stratified squamous epithelium consisting of myxoid tissue,odontogenic
remanants and rarely sebaceous cells 4 .
The present study was carried out to analyze early pathologic changes
associated with the dental follicle of asymptomatic impacted lower third molars. The
study group consists of 30 subjects with their impacted lower third molars indicated
48

for extraction. 30 follicular tissues were obtained with a maximum follicular space of
2.5mm .Among these subjects, 18 male and 12 female subjects had impacted lower
third molars in the ratio of 1.5:1. The incidence of dentigerous cyst in males (27.8%)
to females (16.7%) was in the ratio of 1.6:1.These histologic findings were similar to
the findings in the study conducted by John et al (2000).He reported an incidence of
1.5:1. Ragezzi and Sciuba (1993) also reported an incidence of 1.6:1 male to
female 33 .The subjects based on gender were selected randomly. The age group ranged
from 18 to 30 years .Young adults were considered for the study, because studies have
shown that as age increases there will be an increase in pathologic changes 7 . The
eruption of lower third molars begins between the age group of 17.5 to 20 years, with
a mean of 19.5 years for Asian Indian population 44 . Time of eruption varies
considerably between populations ranging from 14 years in Nigerians to 24 years in
the Greek, with males 3-6 months ahead of the females. Considering this observation,
according to Faiez N Hattab, the average age of eruption of the lower third molar is
20 years and may continue in some patients until the age of 25 years 45.
The third molars with a pericoronal space of 2.5 or less was considered in this
study because a space less than 2.5mm is considered non pathologic 33 .The incidence
of cystic changes was high in the follicle space between 0-1 mm. According to
Stephens et al a pericoronal space of more than 2.5mm is probably a cyst 41 .Glosser
and Campbell defined radiographic pathology as a pericoronal space of more than
2.5mm or larger 30 .
Shear suggests that some unerupted teeth have a slightly dilated follicle in the
pre eruptive phase but this does not signify a cyst .It is cystic only if the pericoronal
radiolucency is between 3-4mm.
49

Studies comparing both radiological and histological findings suggested that
the incidence of Dentigerous cyst associated with ILTM is higher than reported by
radiographic studies alone. A study conducted by Timucin B et al on radiographically
normal impacted teeth, that is with a pericoronal space of less than 2.5mm showed
that 50% of them had cystic changes 43 .
Hence the present study was designed to histologically evaluate the
pathological changes associated with normal radiographic pericoronal spaces in
ILTM’s.
Histologically two different Oral Pathologists analyzed the dental follicles
independently. The presence of lining epithelium was noted in 60.3% of the follicles
in foci, or segments or in a continous pattern. Out of this reduced enamel epithelium
was present in 16.7% of the follicles. Damante J and Fleury R.N found 68.4% of the
follicles with reduced enamel epithelium lining. No epithelial lining was seen in 40%
of the cases in the present study. Damante J H and Fleury R .N found 13% of the
follicles with no epithelium.
The loss of epithelium may be because of the ameloblastic attachment of the
enamel cuticle, which detach from parts of the specimen during the surgical
treatment 34 .According to Glosser and Campbell (1999) the histologic definition of a
dentigerous cyst is any soft tissue specimen which is lined with stratified squamous
epithelium spreading along the surface of the follicles 30 .
In the present study 23.3% of the follicles were lined with stratified squamous
epithelium resembling cyst like changes .Curran et al studied histologic changes in
non pathologic follicular tissue. Pathologically significant lesions were diagnosed in
50

32.9% of the cases with dentigerous cyst being the highest (77.5%) 4 . According to
Knights et al (1991) surgical removal of the follicular tissue,especially in patients
older than 25 years may reveal a non keratinized stratified squamous epithelial lining
,which in itself is not a diagnostic of a Dentigerous cyst 24 . But in this present study,
histologic findings suggestive of Dentigerous cyst were found in the patients aged
between 19- 25 years. According to Daley et al (1995) a true cyst will exhibit a fluid
filled cavity that allows the surgeon to separate the Dentigerous cyst from at least a
portion of the enamel surface of the impacted tooth. He has recommended some
guidelines for the diagnosis of a Dentigerous cyst.
1. Pericoronal radiolucency larger than 4mm in greatest width.
2. Histologically non keratinized stratified squamous epithelium.
3. A surgically demonstrable cystic space between enamel and overlying tissue 24 .
In the present study the incidence of cystic changes in the follicle
tissue was compared between the different types of impacted teeth. 2 cases of
horizontally impacted, 2 cases of distoangularly impacted and 3 of vertically impacted
teeth were diagnosed as cystic. Timucin et al in his study also found higher incidence
of pathological changes in the vertically impacted teeth. Eliasson and Heimdall
reported higher incidence of pathological changes in horizontal impacted third molars
in their radiographic study 43 . In a study conducted by Richard et al cyst development
was seen in 86% of the cases which were completely or severely impacted and 14% in
partially impacted teeth. Cyst changes were more in distoangular, followed by
vertical, horizontal and then mesioangular 37 .
51

Thus the above data suggests that there is statistically significant incidence of
Dentigerous cyst changes in the radiographically normal impacted lower third molars.
It also suggests that the absence of radiographic feature is not reflective of the absence
of the disease. All the above mentioned data suggest that early removal of the ILTM
when they are asymptomatic should be considered.
52

The present study was carried out to evaluate any pathologic changes
associated with radiographically normal impacted lower third molars. The study
group consisted of 30 patients with impacted lower third molars which were indicated
for extraction. Excisional biopsy of the follicle surrounding these teeth was done and
the tissue sent for histopathologic testing. Subjects were between the age 18-30 years
of which 60% were males and 40% females.
• 7 (23.3%) of the 30 follicles showed histologic changes suggestive of
dentigerous cyst.
• Of the 7 follicles which showed histologic changes suggestive of dentigerous
cyst, 3 of them were from vertically impacted teeth.
As this study shows statistically high incidence of Dentigerous cyst in
radiographically normal impacted lower third molars, attention should be given to
asymptomatic ILTM Prophylactic removal, an intervention undertaken to prevent
disease has been a subject of controversy for many years. The reason being the
imbalance between the advantages and disadvantages associated with the surgical
procedure. Thus keeping in mind that prevention is better than cure; prophylactic
removal of the impacted lower third molars should be considered.
53

The follicular sac surrounding the tooth is interpreted in the radiograph as
pericoronal radiolucency .The width of this radiolucency is of utmost importance to
differentiate between a normal and abnormal dental follicle.
According to Miller and Bean (1994) disease conditions may be found in
miniature follicular spaces and in enlarged radiolucent areas there may be
histologically normal tissues ,so biopsy is imperative .This study evaluated the co
relation between radiographic and histomorphologic features of pericoronal follicles
of unerupted lower third molars 46 .
30 follicule tissues surrounding the radiographically normal impacted lower
third molars were given for histopathologic testing .These teeth did not have any
clinical or radiographical findings which suggested an associated cystic pathology.
It was found that 7 out of the 30 biopsied follicle tissues had changes
suggestive of Dentigerous cyst .That accounts to 23.3% which is statistically
significant. This proves the importance of careful evaluation of the clinical and
radiographic findings along with histopathologic testing which most of the times is
neglected.
These findings also suggest that prophylactic extraction of impacted lower
third molars should be given consideration.
54

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60

ANNEXURE –I
CASE HISTORY PROFORMA
Name of the Patient: OP .No:
Age:
Sex:
Occupation:
Address:
Chief Complaint:
History of Present illness:
Past Medical History:
Past Dental History:
Family History:
Personal History:
General physical examination:
Extra Oral examination:
Intra Oral examination:
Investigations:
Radiograph advised:
Radiographic interpretation:
Treatment plan:
61

ANNEXURE II
CONSENT FORM FOR ORAL AND MAXILLOFACIAL SURGERY
Patient name: _____________________Age_______________Sex_______________
1. My condition has been explained to me as
:______________________________
2. The procedure necessary to treat the condition has been explained to me and I
understand the nature of the treatment to
be:______________________________
3. I have been informed of the possible alternate methods of treatment (if any)
including_______________________________________________________
I understand that these forms of treatment or no treatment at all are choices
that I have made and the risks of these choices have been presented to me.
4. My Doctor has explained to me that there are inherent and potential risks and
side effects associated with my proposed treatment and in this specific
instance they include ,but are not limited to:
a. Post operative discomfort and swelling that may require several days of at
home recovery.
b. Prolonged or heavy bleeding that may require additional treatment.
c. Injury or damage to adjacent teeth or fillings
d .Post operative infection that may require additional treatment.
e.Stretching of the corners of the mouth that may cause cracking or bruising
and may heal slowly.
62

f. Restricted mouth opening during healing sometimes related to swelling and muscle
soreness, and sometimes related to stress in the jaw joints, especially when TMJ
problems already exist.
g. A decision to leave a small piece of root in the jaw when its normal removal
would require extensive surgery or risk other complications.
h. Fracture of the jaw (usually only in more complicated extractions or
surgery)
i. Injury to the nerve underlying the teeth, resulting in pain, numbness tingling
or other sensory disturbances in the chin lip, cheek instances, permanently.
j. Dry socket (loss of blood clot from the extraction socket site)
k. Allergic reactions (previously known) to any medications used in the
treatment.
l. It has been explained to me that during the course of the treatment
unforeseen conditions may be revealed that may require changes in the
procedure noted in paragraph 2 above. I authorize my doctor and staff to use
professional judgment to perform such additional procedures that are desirable
to complete my surgery.
m. The anesthesia which will be used for my surgery is: Local Anesthesia.
n. It has been explained to me, and I fully understand that a perfect result is
not or cannot be guaranteed.
o. I certify that I have been informed about all the above points in my own
language, and I fully understand this consent for surgery, have had my
questions answered and that all blanks were filled prior to my signature.
63

Patients Signature Patients thumb impression Date
Witness Signature Date
Doctors Signature Date
64

ANNEXURE III
CONSENT FORM FOR BIOPSY PROCEDURE
Patients Name:___________________________________________________
Age:________________________Sex:______________________________
In your case the area of concern is: _________________________________
It is planned to
a) Remove the suspected tissue totally .If the biopsy report is suspicious ,it
may be necessary to return to the area to remove additional tissue to obtain a
margin of safety.
b) I understand that a biopsy requires incision in my mouth which will require
stitches, and sometimes the removal of bone tissue. It has been explained that
there are certain risks associated with the surgery, including (but not limited
to)
1. Post operative discomfort and swelling that may require several days of at
home recuperation.
2. Prolonged or heavy bleeding that may require additional treatment
3. Post operative infection that may require additional treatment.
4. Stretching of the corners of the mouth that may cause cracking or bruising
and may heal slowly.
5. Restricted mouth opening during healing: sometimes related to swelling and
muscle soreness and sometimes related to stress on the jaws joints, especially
when TMJ problem.
6. Reactions to medications, anesthetics, sutures etc.
65

7. Injury to sensory nerve branches in the area of biopsy which may result in pain or a
tingling and numb feeling in the lip, chin, tongue, cheek gums or teeth or in areas of
the skin of the face. Usually this disappears slowly over several weeks or months, but
occasionally the effects may be permanent.
8. There is always a possibility of the lesion recurring in the same area, even when it
appears to be totally removed.
9. Others: _________________________________________________________
10. It has been explained that during the course of the treatment unforeseen conditions
may be revealed that may require changes in the procedure noted in the paragraph 2
and 1 above. I authorize my doctor and staff to use professional judgment or perform
such additional procedures that are desirable to complete my surgery.
11. The anesthesia which will be used for my surgery is: local anesthesia.
I certify that I have been informed about all the points in my own language, and I
Fully understand that this consent for surgery, have had my questions answered and
that all the blanks were filled prior to the signature
Patients signature Patients thumb impression Date
Witness signature Date
Doctors signature Date
66

ANNEXURE –IV
HEMATOXYLIN AND EOSIN STAINING PROCEDURE
a.Dewaxing was done by keeping microslides with tissue sections for 5 mins in two
changes of Xylene.
b.Hydrated through descending grades of alcohol 90%,70%. In each alcohol the slides
were kept for 5 minutes.
c. Sections were kept under running water for 5 minutes.
d.Stained with hematoxylin for 9 mins
e.Kept under running tap water for 5 minutes
f. Differentiation was done by dipping it in 1% acid alcohol for 1 second
g.Kept in Lithium carbonate for 5 mins.
h .Washed under running tap water for 15 minutes . Stained with eosin for 30 seconds
i.Dehydrated by using ascending grades of alcohol 70%, 90% each for 2 minutes.
j.Clearing of the microslide was done by keeping it in xylene for 5 minutes . Drying
of the slide done.
k.Slide was mounted with cover slips by using Distrene dibutylene phthalate
xylene.(DPX).
67

Table 1
S.No Age Sex Chief Complaint Provisional Diagnosis Radiographic
interpretation
Follicular
space
1 19 M Pain in the right lower back region of the jaw pericoronitis with 48 Horizontally impacted 48 1mm DF-A
2 22 F Pain in the left lower back region of the jaw Pericoronitis with 38 Vertically impacted 38 1mm DF-A
3 18 F General Check up Impacted 48 Mesioangularly impacted 48 1mm DF-B
4 21 F Pain in the lower left back region of the jaw Pericoronitis with 38 Horizontally impacted 38 1.5mm DF-B
5 27 M Pain in the lower left back region of the jaw Pericoronitis with 38 Mesioangularly impacted 38 1mm DF-C
6 20 F Pain in the lower left back region of the jaw Pericoronitis with 38 Mesioangularly impacted 38 1.5mm DF-X
7 21 F Pain in the left lower back region of the jaw Pericoronitis with 38 Distoangularly impacted 38 1mm DF-X
8 23 M Referred from Dept Of Orthodontics Impacted 38 Distoangularly impacted 38 1mm DF-X
9 20 M Referred from Dept Of Orthodontics Impacted 38 Mesioangularly impacted 38 1mm DF-X
10 22 M General Check up Impacted 38 Distoangularly impacted 38 1mm DF-A
11 30 M Pain in upper front region of the jaw Pericoronitis with 48 Vertically impacted 48 1mm DF-X
12 22 F Pain in the right lower back region of the jaw Pericoronitis with 48 Mesioangularly impacted 48 1mm DF-B
13 21 F Referred from Dept Of Orthodontics Impacted 48 Vertically impacted 48 2mm DF-A
14 22 F Pain in the lower left back region of the jaw Pericoronitis with 38 Vertically impacted 38 1mm DF-X
15 27 M Pain in the lower left back region of the jaw Pericoronitis with 38 Horizontally impacted 38 1.5mm DF-B
16 24 M Patient referred from Dept of Orthodontics Impacted 38 Horizontally impacted 38 2mm DF-X
17 24 M Patient referred from Dept of Orthodontics Impacted 48 Horizontally impacted 48 1mm DF-A
18 21 F Pain in the lower left back region of the jaw Pericoronitis with 38 Mesioangularly impacted 38 1mm DF-X
19 21 M Pain in the lower left back region of the jaw Pericoronitis with 48 Horizontally impacted 48 1mm DF-C
20 26 M Pain in the lower left back region of the jaw Pericoronitis with 38 Vertically impacted 38 1mm DF-X
21 26 M Pain in the lower left back region of the jaw Pericoronitis with 38 Distoangularly impacted 38 1mm DF-C
22 22 M Pain in the lower right region of the jaw Pericoronitis with 38 Mesioangularly impacted 48 1mm DF-C
23 23 M General Check up Impacted 38 Distoangularly impacted 38 1mm DF-A
24 27 M Pain in the right lower back region of the jaw Pericoronitis with 48 Mesioangularly impacted 48 1mm DF-X
25 20 F General Check up Impacted 38 Distoangularly impacted 38 1.5mm DF-C
26 23 F General Check up Impacted 38 Mesioangularly impacted 38 1.5mm DF-B
27 23 F Pain in the lower right back region of the jaw Pericoronitis with 48 Mesioangularly impacted 48 2mm DF-C
28 26 M Pain in the lower left back region of the jaw Pericoronitis with 38 Vertically impacted 38 1mm DF-X
29 27 M Pain in the right lower back region of the jaw Pericoronitis with 48 Mesioangularly impacted 48 1.5mm DF-X
30 25 M General Check up Impacted 48 Vertical impacted 48 1mm DF-A
31
Histologic
findings