하악후퇴수술후 연조직측모의 예측에 관한 연구

PREDICTION OF SOFT TISSUE PROFILE CHANGES AFTER MANDIBULAR SET-BACK SURGERY

본 교실에서 하악지시상골절단술을 시행한 악전돌증환자 15명(남자 5명, 여자 10명)을 대상으로 술전교정치료전(T1), 술직전(T2), 술직후(T3), 술후 6개월(T4), 술후 18개월(T5)의 변화를 관찰하여 경조직 변화에 따른 연조직의 변화와 그 관련성을 검토하여 다음과 같은 결론을 얻었다. 1. 하악의 연조직, 경조직은 술후 후방, 상방으로 위치하였다. 하악의 평균 이동량은 Pog에서 8.17mm였다. 술후 18개월의 관찰에서 하악의 경조직은 비록 적은 양의 변화가 있기는 하였으나 통계적으로 비교적 안정적인 위치를 유지하고 있었다. 2. 상, 하순연조직은 술후-장기관찰간에 변화가 있었으나 하악을 덮은 연조직은 술후-장기관찰간에 별다른 변화가 없었다. 상순 일부(Ls, stms)와 대부분의 하악연조직은 하악후퇴수술로 인하여 후, 상방으로 움직였으며 술후 6개월에서 술후 18개월간에는 비교적 안정적이었다. 18개월후 B 와 Pog 의 경조직 이동에 대한 연조직 이동비율은 84.7%, 74.7% 였다. 3. 하악후퇴수술후 하악연조직위치를 장기적으로 예측하는 것은 경조직을 예측하는 것보다 더 어려우며 유의성도 적었다. 이것은 술후 환자의 안모를 정확히 예측해내기는 어려을 뿐 아니라 통상 1 : 1 비율의 변화를 적용시키는 컴퓨터 안모예측 시스템을 이용할 때 주의를 요한다는 것 의미하는 것으로 보인다.

We usually accept 1 : 1 ratio soft tissue change in mandibular set-back surgery. But we cannot sure whether we can use this ratio as a long term predictor after surgery. We investigated the change of hard tissue and its effects to soft tissue and examined the predictability of cephalometric analysis in short term and long term follow-up periods in mandibular set-back surgery. Subjects were 15 patients (5 male, 10 female) performed mandibular set-back procedure only by BSSRO with tigid fixation. Cephalometric data were obtained before orthodontic tretment, immediated before surgery and immediate after surgery, 6 months, and 18 months after surgery consecutively. Differences in soft and hard tissue changes among the time intervals were examined using analysis of vatiance (ANOVA) : the association between immediate surgical change in chin landmarks and subsequent short and long term soft and hard tissue changes were examined using linear regression analysis 1. Soft tissue mandibular structures were positioned posteriorly and superiorly after surgery. Average mandibular set-back were 8.17mm at Pog. The horizontal and vertical hard tissue mandibular changes were stable for 18 months after surgery. Although there was a small degree of change, soft tissue and hard tissue remain relatively stable after surgery and there was no clinically discernable changes between 6 months and 18 months post-operatively. 2. some part of upper lip (Ls & stms) and most part of mandibular soft tissue moves postero-superiorly mandibular set-back. The ratio of horizontal changes of hard tissue to soft tissue at Inf. labial sulcus(B ), Pogonion(Pog ) were 84.7%, 74.7% after 18 months, respectively. 3. Predictability of the soft tissue change is less certain than hard tissue and this predictability is decreased over time. These result suggests that we cannot predict the surgical outcomes exactly. It is recommendable that the oral surgeon should be careful in using the computerized surgical prediction software program as a predictor of long term soft tissue change.