Orthodontic Diagnosis (Chephalomerty) - Pharos University in ...

FACULTY OF DENTISTRY
PHAROS UNIVERSITY
ORTHODONTIC DEPARTMENT
Orthodontic
Diagnosis
)(Chephalomerty
PART 3
CEPHALOMETRY
Enjy
Dr. Khaled AboulAzm
BDS, MS, PHD
Orthodontic Course Director
Dr.Khaled AboulAzm 2010

Orthodontic Diagnosis (Chephalomerty)
Dr.Khaled AboulAzm
2010
Cephalometric radiography is a standardized
method of production of skull radiographs,
which are useful in making measurements of
the cranium and the orofacial complex.
The radiograph thus obtained is called a
cephalogram.
Posterior-Anterior (Frontal view)
Assessment of transverse conditions
(assymetry)
WORD DERIVATION
• Cephalo=Head
• Metric=Measurement
Cephalometrics introduced for use by
orthodontists by Dr. Broadbent in 1931
Original purpose: Research on growth
patterns of the craniofacial complex. Soon
thereafter, it was shown that they could
also be used to evaluate dentofacial
proportions and clarify the anatomic basis
for a malocclusion
Purpose of Cephalometrics
Views
Lateral (Profile view)
Assessment of A-P & Vertical conditions
(prognatism, vertical growth)
A. An aid to diagnosis
Diagnosis of craniofacial deformity help in
identifying, locating and quantifying the
nature of the problem, the most important
result being a differentiation between
skeletal and dental malrelationships.
B. Treatment planning
By helping in diagnosis and prediction of
craniofacial morphology and future growth,
cephalometries help in developing a clear
treatment plan. Even prior to starting
orthodontic treatment an orthodontist can
predict the final position of each tooth
within a given patient's craniofacial I
skeleton to achieve aesthetic and more
stable results.
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Orthodontic Diagnosis (Chephalomerty)
Dr.Khaled AboulAzm
2010
C. Evaluation of treated cases
Serial cephalograms permit the orthodontist
to evaluate and assess the progress of
treatment and also helps in guiding any
desired change.
D. Study of craniofacial growth
Serial cephalogram studies have helped in
providing information regarding
• The various growth patterns.
• The formation of standards, against which
other cephalograms can be compare
E. Medico-legal documentation
OBTAINING THE CEPHALOGRAM
Cephalometric apparatus consists of head
holding device (cephalostat). An x-ray
source and a cassette holder.
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Orthodontic Diagnosis (Chephalomerty)
Dr.Khaled AboulAzm
2010
What Are We Trying to
Accomplish?
F. Find out skeletal classification
Antroposterior
Is the patient class I,II,III skeletal
Vertical
Does the patient have a skeletal open bite
growth pattern, or a deep bite growth
pattern, or a normal growth
G. Find out angulation of incisors
Are the maxillary/mandibular
incisors proclined, retroclined or
normal
H. Consider soft tissue
Facial profile
Are the lips protrusive, retrusive,
or normal
COMMONLY USED
CEPHALOMETRIC LANDMARKS
• Nasion (N): junction of nasal and frontal
bones
Orbitale (O): lowest point on lower margin
of orbit
Point A (Subspinale) : most concave portion
of premaxilla
Point B (Supramentale) : most concave
portion of symphysis
Pogonion (Pog): most anterior portion of
symphysis
Menton (M): lowermost portion of
symphysis
Gnathion (Gn): most anterior inferior
portion of symphysis
Gonion (Go): most inferior posterior portion
of the angle of the mandible
COMMONLY USED PLANES IN
CEPHALOMETRICS
Frankfort Horizontal Plane (FH)
• Extends from the upper border of the
external auditory canal to the upper
border of the lower orbital rim
• Porion (Po): superior point of external
auditory meatus
Sella Turcica (S): midpoint of the pituitary
fossa
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Orthodontic Diagnosis (Chephalomerty)
Dr.Khaled AboulAzm
2010
Porion-Orbitale
Mandibular Plane
Line drawn from Gnathion (Gn) to
Gonion (Go)
Sella-Nasion Plane (SN)
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Orthodontic Diagnosis (Chephalomerty)
Dr.Khaled AboulAzm
2010
Cephalometric Analysis
I.Skeletal relation
A. Antroposterior relation
1. SNA
Evaluates A-P position of the maxilla
relative to the cranial base
Norm=82 degrees
• >82 deg=maxillary protrusion
• 79 deg=mandibular protrusion
• 3 deg=skeletal Cl II tendency
Therefore the outcomes of the skeletal
antroposterior analysis are to evaluate
skeletal patterns (bone-to-bone relations)
• Does the patient have a Class I, Class
II or Class III skeletal pattern?
• Is the problem due to a prognathic
maxilla, a retrognathic maxilla, a
prognathic mandible, a retrognathic
mandible or a combination of these?
•

Orthodontic Diagnosis (Chephalomerty)
Dr.Khaled AboulAzm
2010
• Mean 61°
B. Vertical relation
1. FrankFurt Mandibular plane angle (FMA)
• Angle formed by mandibular plane and
Frankfurt plane
• Increase angle –vertical growth
pattern( long face tendency)
• Decreased angle –horizontal growth
pattern( deep bite)
• (Avrage 25°)
• Increase FMA-high anlgle case
(vertical growers)
2. Y(growth) Axis
• Anlgle by Y axis( S-Gn) and FH plane
• Indicate the type of growth of the
mandible
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Orthodontic Diagnosis (Chephalomerty)
Dr.Khaled AboulAzm
2010
Dental analysis
1. Upper incisor ( 1:SN )
• Increased –proclined upper incisors
• Decresed –retroclined upper incisors
2. lower incisor( 1:SN )
• Increased –proclined lower incisors
• Decresed –retroclined lower incisors
3. Interincisal angle
Soft tissue analysis
Esthetic Plane (E-plane)
• Tip of nose to tip of soft tissue chin
• In balance face
• Lower lip should fall 0-4 mm behind
line
• Upper lip a little further posterior to
the line.
• Angle formed by the long axis of
upper and lower incisor
• Increased –retruded incisors
• decreased –protruded incisors
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