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MALAYSIAN DENTAL JOURNALMalaysian Dental Journal (2008) 29(2) 113-118©2008 The Malaysian Dental AssociationPosterior Teeth Mesialization With Mini-implants In An Oligodontia PatientWey MC. Wey Mang Chek, BDS (Malaya), FDSRCS (England), MOrthRCS (Edin), MOrth (HK), Senior Lecturer inOrthodontics, Faculty of Dentistry, Universiti MalayaWu CL. BDS (HK), MOrth (HK), MOrthRCS (Edin), FHKAM (Dental Surgery), FCDSHK (Orthodontics), PrivateOrthodontic Specialist, Hong KongWong WK. BDS (HK), MOrth (HK), PhD (HK), FRACDS, MOrthRCS (Edin), FHKAM (Dental Surgery), FCDSHK(Orthodontics), Associate Professor in Orthodontics, Faculty of Dentistry, University of Hong KongZamri R. DDS (Indon), MDent Sci (Leeds)), MOrth RCS (Eng), MOrth RCS (Edin), FFDRCSI, Associate Professor inOrthodontics, Faculty of Dentistry, Universiti MalayaHägg U. DDS (Lund), Cert Comp Orth (Sweden), Odont Dr (Lund), Hon FDSRCS (Edin), FHKAM (Dental Surgery),FCDSHK (Orthodontics), Chair Professor in Orthodontics, Faculty of Dentistry, University of Hong KongSUMMARYA case report of a 16 year old male oligodontia patient who presented with a Class I malocclusion on a skeletalI base. He had multiple missing teeth of upper lateral incisors and all premolars except for lower right firstpremolar. Treatment involved fixed appliance with the aid of mini-implants to mesialize posterior teeth in orderto reduce the number of prosthodontic replacement of the remaining missing teeth planned for the future. Theapplication of the mini-implants in the sequence of treatment is presented.Key wordsorthodontic mini-implant, mesialize posterior teeth, oligodontiaIntroductionDefinitionHypodontia is a developmental absence of only afew teeth, while oligodontia denotes congenital absenceof many teeth 1 . It is the most common craniofacialmalformation 2 . If six or more permanent teeth are missing,the term oligodontia is used 3 .Prevalence and EtiologyHypodontia involving four or more congenitallymissing permanent teeth excluding third molars is relativelyless common than that involving less number of teeth andreported to have a prevalence of 0.08 – 0.5% 4,5,6,7 , andthis has been found to be usually associated with somegeneral systemic condition. The prevalence of hypodontiain the permanent dentition among a Chinese populationhas been reported to be 6.9%, frequently involving thelower incisor, representing 60% of all missing teeth,followed by maxillary second premolars at 10% andmaxillary lateral incisors at 8% 8 . The etiology is broadand includes environmental factors such as infection 9 ,trauma, drugs, chemotherapy or radiotherapy at youngage 10 , genetic factors 11,12 and associated with conditionssuch as ectodermal dysplasia, cleft lip and palate, Down’ssyndrome and hemifacial microsomia 13 .Features and Presenting ProblemsMalocclusions related to absence of teeth arecommon, such as rotations, tilting, drifting and spaces.Microdontia is a frequent association, significantly inhypodontia involving six or more congenitally missingteeth 14,15 . Other dental anomalies are transposition ofpermanent teeth 16 , impaction of permanent teeth 17,18 ,taurodontism 19 and ankylosis 20 . A significant retroclinationof incisors and an increased interincisal angle werealso observed with increasing severity of hypodontia 21 .Some studies have reported flat or concave facial profile,obtuse naso-labial angle, retrognathic maxilla, reducedanterior face height and mandibular plane angle in severehypodontia with absence of six or more teeth 4,22,23 .113