Cranio-Maxillofacial Morphology of Japanese with Completely Third Molor Agenesis

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K20608
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Orthodontics/Pediatric dentistry
• Research Institution: Showa University
• Principal Investigator: HAGA SHUGO 昭和大学, 歯学部, 助教 (00736655)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 永久歯先天欠如 / 第三大臼歯 / 顎骨 / 形態

Outline of Final Research Achievements

Tooth agenesis is frequently noted in Japanese. The purpose of this study was to clarify the characteristics of the maxillofacial morphology of Japanese with complete third molar agenesis (four third molars missing). Furthermore, lateral cephalograms were traced and measured. We evaluated 19 linear and angular measurements, and significant differences were noted in 4 items. Linear measurement items of the maxillary bone showed significantly lower values of S-Ba, which indicates the posterior cranial base length, and N-Ar, which indicates the overall cranial base length, in the subjects with complete third molar agenesis. Angular measurements confirmed significantly higher values of SN-GoGn and SN-GoMe, which indicate variations of the mandibular plane. These results suggest the possibility that the maxillofacial morphology with complete third molar agenesis differs from the morphological characteristics of cases with solely maxillary or mandibular agenesis.

Free Research Field

永久歯先天欠如の遺伝要因と頭蓋顔面形態との関連性の解明