하악 제3대구치의 유무에 따른 하악 우각부 골절과 과두 골절 발생의 상관관계

Abstract

Purpose : The objective of this study is to evaluate retrospectively the impact of mandibular third molar on the occurrence of angle and condyle fractures.

Methods : This study was a retrospective investigation that used patients’ records and radiographs as data sources. The sample consisted of 440 consecutive patients with mandibular fractures at the department of oral and maxillofacial surgery of Chosun dental hospital between January 2008 and June 2012. Eruption space and depth of a third molar was measured by using the method of Pell and Gregory. Angulation of a third molar was measured by using the method of Shiller.

Results : Of the 144 angle fracture patients, 130 were present the third molar and 14 were not. The ratio of angle fracture when a third molar was present (1.26:1) was found to be greater than when a third molar was not present (0.19:1) (Odds ratio : 6.58) (p<0.001). Of the 141 condyle fracture patients, 84 were present the third molar and 57 were not. The ratio of condyle fracture when a third molar was present (0.56:1) was found to be lower than when a third molar was not present (1.90:1) (Odds ratio : 0.30) (p<0.001). Based on the classification using the eruption space and depth, the ratio of angle fracture was the highest at Class II (1.61:1) and Level B(1.73:1). The ratio of condyle fracture was the highest (1.15:1) when third molar’s root development is not complete. (p<0.05)

Conclusion : In conclusion, increasing the ratio of angle fracture with third molar and the ratio condyle fracture without third molar was considered to be statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of cortical bone at angle than the depth of a third molar. The results of this study demonstrate that a third molar can be a determining factor of angle and condyle fractures.

Key words : mandibular third molar, angle fracture, condyle fracture