Do intra-articular temporomandibular disorders show an association between physical bite function, self-perceived bite limitation and kinesiophobia? A case-control study.

BACKGROUND

Little is known about the impact of intra-articular temporomandibular disorders (TMDs) on bite function, or how bite impairments in this subgroup relate to self-perceived bite limitation or kinesiophobia. This presents a challenge to practitioners involved in delivering care.

OBJECTIVES

To determine what bite impairments are associated with intra-articular TMDs, and explore how these impairments relate to self-perceived bite limitations and kinesiophobia.

DESIGN

Observational, case-control study.

METHOD: Sixty participants (n = 30 intra-articular TMDs, n = 30 healthy controls) were recruited via convenience sampling. Bite function was explored using pain-free bite force and bite endurance/steadiness (submaximal bite hold) measures. Self-perceived bite function and kinesiophobia were evaluated via the Patient specific functional scale (PSFS) and the Tampa Scale for kinesiophobia of Temporomandibular disorders (TSK-TMD) respectively. Between-group data were compared and associations between physical bite impairments, self-perceived bite limitation and kinesiophobia were explored in the intra-articular TMD group.

RESULTS

Pain-free bite force was significantly impaired in the intra-articular TMD group (-108N, p < 0.01, d = 0.9), and this impairment demonstrated moderate association with degree of kinesiophobia (p < 0.01, r = -0.4). No significant between-group difference was observed for bite endurance or force steadiness (p > 0.05). No association was observed between pain-free bite force and self-perceived bite limitation, or self-perceived bite limitation and kinesiophobia (p > 0.05).

CONCLUSIONS

Impaired pain-free bite force appears to be an important feature of intra-articular TMDs which should be considered within management. Kinesiophobia may be important to consider when assessing bite function in this subgroup. Future research is needed to guide optimal interventions and inform subsequent management guidelines.