This report surveys the experience in 150 patients (54 male patients and 96 female patiens) who underwent sagital splitting osteotomy of mandibular ramus (Obwcgeser-Dal Pont's method) between 1972 and 1986. We divided the period into three terms (the former term group, the middle term group, the latter term group), and surveyed operation time, blood loss, operative technique, anethesic time and so forth.
The results were as follows:
1) Operation time
The average operation time of all cases was 141.0±32.7 minutes. However, the average of the former term group was 156.9±36.9 minutes, the middle was 132.0±28.6 minutes, and the latter was 137.1±28.6 minutes.
The operation time had been reduced in recent years.
2) Blood loss
The average blood loss of all case was 508.5±405.3ml. But, the average of the former was 761.0±518.9ml, the middle was 486.4±338.9 ml, the latter was 385.0±297.4ml.
We rarely needed blood transfusion in recent years as a result of the reduction of blood loss and the improvement of operating techniques.
3) Correlation between operation time and blood loss
In recent years, there was positive correlation, and we found that the reduction in operation time was related to the decrease in the blood loss.
4) The others
No postoperative vomiting and airway obstruction occurred, and none of the patients returned to the room with endotracheal intubation.