Qu Siwei, Shen Sile, Ji Kai, Zhou Yang, Chen Jian, Wang Chengyuan
Plastic Surgery Department, China-Japan Friendship Hospital, No. 2 Cherry Garden East Street, Chaoyang District, Beijing, 100029, China.
Aesthetic Plast Surg. 2025 Mar;49(5):1205-1216. doi: 10.1007/s00266-024-04607-9. Epub 2024 Dec 28.
Congenital hypoplasia of the depressor labii inferioris muscle can lead to Asymmetrical crying facies(ACF). The objective of this research was to examine the alterations in both static and dynamic facial symmetry following the resection of the depressor labii inferioris on the healthy side through an intraoral approach.
Patients exhibiting palsy of the depressor labii inferioris muscles were included in the study. smile modiolus angle, excursion, and exposure of teeth were assessed on both sides before and after resection of the depressor labii inferioris using Emotrics photographic analysis.
Thirty-six patients were included. Before the resection of the depressor labii inferioris, the modiolus excursion of the closed-mouth smile is significantly asymmetric (p = 0.001), and after the operation, it becomes symmetric (p= 0.185). The change of symmetry with modiolus angle and teeth exposure in an open-mouth smile are the most significant. The surgery can turn the obvious skew lip (p<0.0001) into an almost symmetrical (modiolus angle: p = 0.321; teeth exposure: p = 0.368) expression. The teeth exposure significantly reduced on the healthy side (p<0.01).
ACF patients have asymmetry both in closed-mouth and open-mouth smiles. Resection of the depressor labii inferioris muscle offers a treatment that rapidly improves the symmetry of closed-mouth and open-mouth smiles.
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降下唇肌先天性发育不全可导致不对称哭泣面容（ACF）。本研究的目的是通过口内入路切除健康侧的降下唇肌后，观察静态和动态面部对称性的变化。
纳入表现为降下唇肌麻痹的患者。在切除降下唇肌前后，使用Emotrics摄影分析法评估两侧的笑涡角度、偏移度和牙齿暴露情况。
共纳入36例患者。切除降下唇肌前，闭口微笑时笑涡偏移度明显不对称（p = 0.001），术后变为对称（p = 0.185）。开口微笑时笑涡角度和牙齿暴露的对称性变化最为显著。手术可将明显歪斜的嘴唇（p < 0.0001）转变为几乎对称的表情（笑涡角度：p = 0.321；牙齿暴露：p = 0.368）。健康侧的牙齿暴露明显减少（p < 0.01）。
ACF患者在闭口和开口微笑时均存在不对称。切除降下唇肌提供了一种能快速改善闭口和开口微笑对称性的治疗方法。
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