Evaluation of Changes in Lip Closing Force After Surgically Assisted Rapid Maxillary Expansion.

OBJECTIVE: Morphological changes in patients subjected to surgical treatment to correct occlusal discrepancies may lead to various functional changes. The aim of the present study was to evaluate changes in lip closing force after surgically assisted rapid maxillary expansion in skeletally mature patients. METHODS: The study involved 7 female and 7 male patients treated with surgically assisted rapid maxillary expansion. Maximum and minimum lip pressures of patients were measured with Lip De CumLDC-110R. The intercanine distance and incisors angulations were measured preoperatively (T0), at the end of the expansion (T1), at the end of the third month of retention (T2), and at the end of the sixth month of retention (T3). RESULTS: The greatest values of maximum and the minimum lip closing force were observed at the end of the expansion period significantly. The intercanine distance and inclinations of incisors measured at the third and sixth months showed a significant decrease. CONCLUSIONS: The present study demonstrated that, following surgically assisted rapid palatal expansion, both the maximum and the minimum lip closing force increases had a tendency to revert to their initial values 6 months after surgery.