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中固定下颌的经典术式，但有研究提示，长期应用颌间固定可能增加颞下颌关节（temporomandibular joint, TMJ）相关症状的发病风险。
研究目的：评估下颌后退术后接受6周颌间固定的患者，在术后10~15年时的颞下颌关节及咀嚼肌临床功能状态，并分析患者自我报告的颞下颌关节与咀嚼肌症状情况。
研究方法：本研究纳入36例接受口内垂直升支截骨术（intraoral vertical ramus osteotomies）及术后6周颌间固定的患者（24例女性，12例男性），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、针对主观颞下颌关节相关症状的结构化问卷调查。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）。临床结局依据赫尔基莫临床功能障碍指数（Helkimo clinical dysfunction index）进行登记。采用描述性及双变量统计分析，显著性水平设定为5%。
研究结果：术后10~15年时，患者的平均无辅助最大开口度为50.1mm（范围38~70mm，标准误1.2），男性患者的该指标显著高于女性（p=0.004）。平均赫尔基莫功能障碍评分为1.5（范围1~3，标准误0.10）。81%的患者在咬肌、颞肌单侧或双侧触诊时出现疼痛，31%的患者在下颌向一个或多个方向运动时出现疼痛；31%的患者在触诊颞下颌关节时主诉疼痛。问卷调查结果显示，无患者每周或每日出现咀嚼或开口时疼痛，但22%的患者报告存在最大开口困难。
研究结论：下颌后退术后10~15年，患者的下颌运动范围良好。尽管存在可被临床检出的症状，但仅有少数患者在日常生活中报告有颞下颌关节或咀嚼肌相关不适症状。