Safdar N, Meechan J G
Department of Oral Surgery, Dental School, University of Newcastle Upon Tyne, U.K.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1995 Jun;79(6):680-4. doi: 10.1016/s1079-2104(05)80299-9.
This study attempted to relate the incidence of fractures at the mandibular angle with the presence and state of eruption of lower third molars.
The records and radiographs of 200 patients with mandibular fractures were examined. The presence and degree of impaction of lower third molars were assessed for each patient and related to the occurrence of fractures of the mandibular angle. Data were analyzed by chi-square statistic and the Student's t test.
The incidence of angle fractures was found to be significantly greater when unerupted lower third molars were present (p < 0.001). Bilateral unerupted third molar teeth predisposed to a fracture at the angle significantly more than unilateral unerupted third molars (p < 0.01). Furthermore, the amount of bony space occupied by an unerupted third molar tooth directly related to the weakness of that area of bone (p < 0.001).
This study provides clinical evidence to suggest that unerupted third molar teeth weaken the mandibular angle both quantitatively and qualitatively.
本研究试图将下颌角骨折的发生率与下颌第三磨牙的萌出情况及状态联系起来。
检查了200例下颌骨骨折患者的病历和X光片。评估了每位患者下颌第三磨牙的阻生情况及程度，并将其与下颌角骨折的发生情况相关联。数据采用卡方统计和学生t检验进行分析。
发现存在未萌出的下颌第三磨牙时，角部骨折的发生率显著更高（p < 0.001）。双侧未萌出的第三磨牙比单侧未萌出的第三磨牙更容易导致角部骨折（p < 0.01）。此外，未萌出的第三磨牙所占骨间隙的大小与该区域骨质的薄弱程度直接相关（p < 0.001）。
本研究提供了临床证据，表明未萌出的第三磨牙在数量和质量上都会削弱下颌角。
