外科的矯正治療による開こう症の舌位および頭位の変化 テレメータシステムを用いて解析した３症例

Abstract

Past studies have shown that malposition of the tongue is recognized as a major cause of anterior open bite, and many studies have investigated the relationship between open bite and the tongue. However, no studies have measured changes of the tongue position for a long period after orthognathic surgery. A new wireless telemeter system was developed to measure the tongue position and head posture in skeletal mandibular prognathism with anterior open bite before and after orthognathic surgery.The purpose of this study was to investigate the mechanism of adaptation of the peri-oral soft tissue to the new jaw relationship that had been reconstructed by orthognathic surgery. Data were obtained presurgically and after a debonding period for three cases whose occlusions were stable, and they were compared with the corresponding data of 23 normal occlusions.The results were as follows:1) Change in the tongue-contacting areaThe tongue-contacting area was larger in two cases before orthognathic surgery than that of the normal occlusions. In another case, at the area of the mandible, similar results were obtained, but at the maxilla, the presurgical tongue-contacting area was smaller than that of the normal occlusions.In all cases, the tongue-contacting area before orthognathic surgery became similar to that of normal occlusions by correction of the jaw-relationship and occlusion.2) Change of head postureIn all cases, the head posture was not significantly different from that in normal occlusions. However, the head posture showed a slight backward inclination after orthognathic surgery.The results suggest that head posture and the peri-oral soft tissues, including the tongue, might have adapted to the jaw-relationship and occlusion that is newly reconstructed by orthognathic surgery.