Investigating Oral Behaviors and Function Performances for TMD Patients

Objectives: Patients with TMD experience various clinical symptoms, including limited mouth opening, pain, which in turn affects chewing ability. It has been reported that oral behaviors such as grinding and clenching are risk factors for TMD. The aim of this study is investigating oral behaviors and function performances for TMD patients.
Methods: This study was a cross-sectional study. From July to September 2023, the participants were diagnosed with TMD and aged between 20 to 65 years old recruited from the dental outpatients of the medical centre. Data collection included Maximum Mouth Opening (MMO), Oral Behavior Checklist (OBC), perceived chronic pain and interference, the chewing ability was determined by a color-changeable chewing gums. T-test and Spearman rank correlation were used for the data analysis.
Results: A total of 42 participants averaged 35.88±11.69 years old and 78.6% were women. The 54.8% participants were TMJ combine Myalgia in TMD subgroup type. The chewing ability is 6.55±1.19. The worst pain score in the past 6 months is 5.23±3.68. The MMO with painless is 37.33±5.34mm, and 71.4% of the patients had a MMO≧40mm. Participants reported "Clench teeth together during waking hours" was significantly higher MMO than who was not. Patients who "Press tongue forcibly against teeth" had worse chewing ability (P=0.039), β=-0.320. "Hold or jut jaw forward or to the side" was negatively correlated with the MMO under no pain, tolerable pain, tolerable pain with the application of external force (P<0.005); "Hold jaw in rigid or tense position" was positively correlated with both perceived chronic pain and disturbance (P<0.001).
Conclusions: We found that the activities, moving the jaw and keeping the jaw in a tense position, had a negative impact on the MMO of TMD patients. It also increased the perceived chronic pain and interference.