1957 年 24 巻 4 号 p. 389-398
This is a statistical observation of 214 patients who visited our clinic with jaw fractures during the period from April 1934 to February 1957.
The results are summarized as follows:
1) The rate of frequency of fractures at mandibles and maxillae was three to one.
2) Fractures were found more in males than in females.
3) Fractures were found particularly often in the males of 20-30 years of age. However, 11.7% of all fractures were observed in the children under 9 years of age.
This frequency was very high in comparison with the reports of foreign observers.
4) The greatest part of the causes of those fractures were traffic accidents, and the next was labour accidents. Pathologic fractures due to chronic diseases were 6 cases and a fracture occured at tooth extraction.
5) The frequency of fractures was higher in May, June, September and October than in other months.
6) The fractures due to traffic accidents were frequent at 10-12 o'clock a.m. and 4-6 o'clok p.m. and those due to labour accidents were frequent at 10-12 o'clock a.m. and 2-4 o'clock p.m.
7) The direction of the fracture lines in mandibles are not always parallel with the axes of the teeth.
Most of them ran obliquely from supro-anterior to infro-posterior. Some of them ran paraller to the tooth axes. The smallest part of them ran from supro-posterior to infroanterior.
Most of the fractures lines beginning at the alveolar region between right and left cuspids ended at the lower edges below right or left 1 st bicuspids.
Those beginning at the wisdom teeth ended at mandibular angles.
Subcondyle fractures, coronoid fractures and a part of fractures in mental regions occured by the indirect shocks.
8) Most of chosen cases were successfully treated by traction gum elastics and the open reduction were used for old fractures.
9) For the fixation, the multiple loop wiring with 18-8 stainless steel have been applied since 1952 with good results.
10) Recently, severe infective complication is rare due to application of antibiotics.