Although many studies on the various aspects of Maxillo-facial bone fractures
have been reported, the author has analyzed locations, age, sex and monthly
distribution of occurrence radiographically.
Special attention was given to the fracture line and eruptive pattern of lower
third molar in the fracture of mandibular angle region.
81 cases from oral surgery department of the Dental Infirmary of the Dental
College of Yonsei Univ. were used for the study.
The results are as follows:
1. The highest incidence of Jaw bone fracture was observed in the age group of
the second decade (35.8%), and male cases (72 cases) were eight times as many as
female (9 cases And two major etiologic factors for jaw bone fracture were fist
blow (37.0%), and traffic accident (30.9%).
In the case of blow, the mandible was most frequently involved.
Middle facial bone were caused most often by traffic accident and middle facial
bone with mandible were most peculiar to fall accidents.
2. In the mandible frature, a single fracture line was abserved in 59.4 percent,
of the cases, double and triple fracture lines appeared in 34.3 percent and 6.3
percent of cases respectively.
The most frequent fractured region was the mandibular angle region (24.5%) and
the left side (42.6%) was more involved compared with right side (37.0%) in all
3. The fracture of the mandibular symphysis was most frequent in cases with a
single fracture line.
The double fracture lines appearing in the right and left anterior regions of one
side and the opposite angle portion were the most frequent combination of
Triple fracture lines were observed in mandibular condylar neck fracture more
than the other regions.
4. 91.3% of the fracture line in the mandibular angle region were associated with
the lower third molar tooth. There were more fracture lines passing distally
(65.2%) then mesially (17.4%) and centrally (17.4%) to the third molar tooth.
5. In the middle facial bone fractures, LeFort type Ⅰ fractures were seen most
frequently (30%) and the least frequent cases were the LeFort type Ⅱ
6. In the monthly distribution of patients with fractures, October appeared the
highest incidence (17.3%) and December was the lowest incidence (3.7%).
Autumn was the most frequent incidence (37.0%) of the year.