Date of Award


Document Type

Scholarly Project

Degree Name

Master of Physical Therapy (MPT)


Physical Therapy

First Advisor

Henry C. Wessman


Joint Instability; Temporomandibular Joint


The purpose of this study was to determine whether people with generalized joint hypermobility also demonstrate hypermobility at the temporomandibular joint. In addition, an attempt was made to determine the relationship between general joint mobility, gender, temporomandibular joint symptoms, and oral parafunction.

Forty-seven physical therapy students worked in pairs under supervision to measure and record: 1) the Beighton hypermobility criteria, 2) maximum mandibular range of motion, and 3) a questionnaire of temporomandibular joint dysfunction and oral parafunctional habits.

The mean Beighton score for males was 1.21 and for females 2.14. Twelve out of the forty-seven subjects (15.5%) had a Beighton score greater than or equal to four. The mean maximal mandibular opening for all subjects was 53.68 mm. The mean maximal opening for males was 58.00 and for females 50.75 mm.

The T test for independent samples revealed that males have a greater maximal opening of the mandible (p = .05). Calculation of the Pearson coefficient for the variables of mandibular opening, generalized mobility, symptoms, and oral parafunctions revealed a strong correlation between gender and maximal mandibular opening values (p = .001). Because of this strong viii relationship, a partial correlation was calculated controlling for gender. The adjusted data indicated that generalized joint hypermobility is positively correlated with maximum mandibular opening at the .05 level ( p = .008). It also revealed that oral parafunctional activities are inversely correlated to maximum opening (p = .039).

The results of this study indicate a significant relationship between generalized joint hypermobility and maximum mandibular opening. Further investigation is warranted to determine a standardized system for quantifying generalized joint laxity and to define the clinical criteria for hypermobility of the temporomandibular joint.