Evaluation of tongue strength and symptoms of oral dysphagia in patients accompanying temporomandibular disorder

Introduction
The aim of this study was to compare functional restriction of the jaw, swallowing difficulty, tongue strength and endurance, and quality of life in temporomandibular disorder (TMD) patients with and without oral dysphagia (OD) and in healthy individuals.

Material and methods
The TMD group with 20 patients with TMD, and the TMD-OD group with 20 TMD patients with Eating Assessment Tool-10 (EAT-10) ≥ 3, and presence of pain and difficulty in swallowing as well as control group comprising 20 healthy volunteers were included in this case-control study. Evaluations were made of pain severity, pain history, maximum mouth opening, Jaw Function Limitation Scale-20 (JFLS-20), and the Swallowing related-Quality of Life questionnaire (Swal-QoL). Additionally, the tongue strength and endurance were measured with the Iowa Oral Performance Instrument (IOPI).

Results
The history of pain, JFLS, EAT-10 values were significantly higher, and the SwalQoL were significantly lower in the TMD-OD group compared to the patients with the TMD group (p 0.05). The IOPI values of the TMD and TMD-OD groups were determined to be significantly lower than those of the healthy group (p<0.05).

Conclusions
Functional restriction of the jaw, swallowing difficulty, and Swal-QoL showed a difference in the patients with TMD-OD compared to the patients with TMD only. The tongue strength and endurance values of the patients were different from those of the healthy control group.