両顎矯正手術における舌圧と口唇閉鎖力の評価：後方視的研究

Evaluation of tongue pressure and lip closing force in bimaxillary orthognathic surgery: A retrospective study.

抄録

本研究の目的は、顎矯正手術を受けた骨格クラスⅡおよびクラスⅢの患者と対照群における舌圧と口唇閉鎖力の変化を定量的に比較することである。最大舌圧と口唇閉鎖力は、術前と術後6ヵ月および12ヵ月に測定した。時間経過の変化を分析し、グループ間で比較した。対照群には40人の骨格性I級咬合ボランティア（男性20人、女性20人）、II級群には20人の女性患者、骨格性III級群には40人の患者が参加し、それぞれ男性20人、女性20人の2群に性差で分けられた。舌圧の経時的変化は、群間、群間で有意差はなかった。しかし、術後の口唇閉鎖力は、Class III群の女性および男性では対照群と比較して徐々に高くなったが、Class II群では観察されなかった。術前後の舌圧と口唇閉鎖力には有意な相関があり（p=0.001）、これらの相関は時間の経過とともに増加した。顎矯正術後の最大舌圧に有意な増加はみられなかったが、それに関連して口唇周囲筋力の増加がみられた。このことは、口腔周囲筋力の増加が、術後の顎形態の安定により寄与する可能性を示唆している。

The purpose of this study was to quantitatively compare changes in tongue pressure and lip closing force among skeletal Class II and Class III patients, who had undergone orthognathic surgery, and a control group. Maximum tongue pressure and lip closing forces were measured preoperatively and at 6 and 12 months postoperatively. Time-course changes were analyzed and compared among the groups. The control group involved 40 skeletal Class I occlusion volunteers (20 male and 20 female), the Class II group involved 20 female patients, and the skeletal Class III group involved 40 patients, who were subdivided by sex into two groups comprising 20 males and 20 females, respectively. Time-course changes in tongue pressure were not significantly different between and within groups. However, postoperative lip closing forces became gradually higher in the Class III group female and male subjects compared with the control group, although this was not observed in the Class II group. There were significant correlations between tongue pressure and lip closing force before and after surgery (p = 0.001), and these correlations increased over time. Although there was no significant increase in maximum tongue pressure after orthognathic surgery, there was an associated increase in perioral muscle strength. This suggests that an increase in perioral muscle strength may contribute more to the stability of postoperative jaw morphology.