Temporomandibular joint function 10-15 years after mandibular setback surgery and six weeks of intermaxillary fixation

Abstract Intermaxillary fixation (IMF) is a classic method for immobilization of the mandible after mandibular fractures and corrective surgery. However, it has been suggested that IMF may be a risk for developing temporomandibular joint (TMJ)-related symptoms, especially when applied for longer periods. Objective: To evaluate the clinical function of TMJs and masticatory muscles 10-15 years after mandibular setback surgery and subsequent six weeks of IMF. The patients' self-reported TMJ and masticatory muscle symptoms were also addressed. Methodology: Thirty-six patients (24 women and 12 men) treated with intraoral vertical ramus osteotomies and subsequent six weeks of IMF, underwent a clinical examination of TMJs and masticatory muscles 10-15 years after surgery and completed a five-item structured questionnaire reporting subjective TMJ-related symptoms. Mean age by the time of clinical examination was 34.1 years (range 27.2–59.8 years). The clinical outcome was registered according to the Helkimo clinical dysfunction index. Descriptive and bivariate statistics were performed and level of significance was set to 5%. Results: Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2), statistically significantly greater in men compared to women (p=0.004). Mean Helkimo dysfunction group was 1.5 (range 1-3, SE 0.10). Eighty-one percent experienced pain on palpation in either the masseter muscle, temporal muscle or both, and 31% experienced pain when moving the mandible in one or more directions. Thirty-one percent reported pain from palpating the TMJs. In the questionnaire, none reported to have pain during chewing or mouth opening on a weekly or daily basis, but 22% reported difficulties with maximum opening of the mouth. Conclusion: Ten to fifteen years after mandibular setback surgery the patient's mandibular range of movement is good. Despite clinically recognizable symptoms, few patients reported having TMJ- or masticatory muscle-related symptoms in their daily life.

摘要 颌间固定（Intermaxillary Fixation, IMF）是下颌骨骨折术后及正颌手术后固定下颌的经典术式。但有研究表明，颌间固定可能会增加颞下颌关节（Temporomandibular Joint, TMJ）相关症状的发病风险，尤其是当固定周期较长时。
研究目的：评估下颌后退手术联合6周颌间固定后10~15年，患者颞下颌关节及咀嚼肌的临床功能状态，并调查患者自我报告的颞下颌关节与咀嚼肌相关症状。
研究方法：纳入36例行口内垂直升支截骨术并术后接受6周颌间固定的患者（其中女性24例，男性12例），于术后10~15年对其颞下颌关节及咀嚼肌进行临床检查，并完成包含5个条目、用于报告主观颞下颌关节相关症状的结构化问卷。患者接受临床检查时的平均年龄为34.1岁（范围27.2~59.8岁）。临床结局依据Helkimo临床功能障碍指数进行记录。采用描述性统计与双变量统计分析，显著性水平设定为5%。
研究结果：术后10~15年，患者平均最大无辅助张口度为50.1mm（范围38~70mm，标准误1.2），男性患者的张口度显著大于女性（p=0.004）。平均Helkimo功能障碍指数分组为1.5（范围1~3，标准误0.10）。81%的患者存在单侧或双侧咬肌、颞肌触诊痛，31%的患者在下颌向一个或多个方向运动时出现疼痛。31%的患者颞下颌关节触诊时存在疼痛。问卷结果显示，无患者每周或每日出现咀嚼或张口时疼痛，但22%的患者自述存在最大张口困难。
研究结论：下颌后退手术后10~15年，患者下颌活动范围仍保持良好。尽管存在临床可识别的症状，但仅有极少数患者在日常生活中报告存在颞下颌关节或咀嚼肌相关症状。