Association between temporomandibular disorders and abnormal head postures

This study examines the possible correlation between the prevalence of temporomandibular disorders (TMD) and different head postures in the frontal and sagittal planes using photographs of undergraduate students in the School of Dentistry at the Universidade de Brasília - UnB, Brazil. In this nonrandomized, cross-sectional study, the diagnoses of TMD were made with the Research Diagnostic Criteria (RDC)/TMD axis I. The craniovertebral angle was used to evaluate forward head posture in the sagittal plane, and the interpupillary line was used to measure head tilt in the frontal plane. The measurements to evaluate head posture were made using the Software for the Assessment of Posture (SAPO). Students were divided into two study groups, based on the presence or absence of TMD. The study group comprised 46 students and the control group comprised 80 students. Data about head posture and TMD were analyzed with the Statistical Package for the Social Sciences, version 13. Most cases of TMD were classified as degenerative processes (group III), followed by disk displacement (group II) and muscle disorders (group I). There was no sex predominance for the type of disorder. No association was found between prevalence rates for head postures in the frontal plane and the occurrence of TMD. The same result was found for the association of TMD diagnosis with craniovertebral angle among men and women, and the group that contained both men and women. Abnormal head postures were common among individuals both with and without TMD. No association was found between head posture evaluated in the frontal and sagittal planes and TMD diagnosis with the use of RDC/TMD.

本研究以巴西巴西利亚大学（Universidade de Brasília, UnB）牙科学院本科生的影像资料为研究对象，探讨颞下颌关节紊乱病（temporomandibular disorders, TMD）患病率与额状面、矢状面不同头位姿势之间的潜在关联。本研究为非随机横断面研究，采用研究诊断标准（Research Diagnostic Criteria, RDC）/颞下颌关节紊乱病轴I标准完成TMD的诊断。以颅颈角评估矢状面的前伸头位，以瞳孔间线测量额状面的头倾斜程度。头位姿势的评估采用姿势评估软件（Software for the Assessment of Posture, SAPO）完成。根据是否罹患TMD，将受试者分为两组：病例组纳入46名学生，对照组纳入80名学生。采用社会科学统计软件包13.0版（Statistical Package for the Social Sciences, version 13）对头位姿势与TMD相关数据进行分析。多数TMD病例被归类为退行性病变（Ⅲ组），其次为关节盘移位（Ⅱ组）与肌肉紊乱（Ⅰ组）。各类TMD均无性别偏好。未发现额状面头位姿势患病率与TMD发生存在关联；无论针对男性、女性还是全体受试者，TMD诊断与颅颈角之间均未发现显著关联。无论是否罹患TMD，受试者中异常头位姿势均较为常见。采用RDC/TMD标准进行评估时，未发现额状面与矢状面的头位姿势与TMD诊断存在关联。