A study on the change of occlusal contacts and lateral cephalometric variables after stabilization splint therapy in temporomandibular disorder patients

Abstract

Objectives: The aim of this study is to assess the relationship between possible occlusal change after stabilization splint therapy and the research diagnostic criteria for temporomandibular disorders (RDC/TMD) Axis I diagnoses and lateral cephalometric variables.

Methods: Clinical and radiographic records of 47 patients treated by occlusal splint therapy after diagnosed as TMD based on RDC/TMD Axis I were reviewed. The number of occluding teeth was recorded and lateral cephalogram was taken at pre-treatment and 6-month post-treatment. They were divided into two groups. The control group consists of patients whose number of occluding teeth did not decrease after wearing stabilization splint for 6 months (19 females and 4 males). And occlusal-loss group consists of patients whose number of occluding teeth decreased (19 females and 5 males). The difference of RDC/TMD diagnoses and cephalometric variables were compared between two groups.

Results: In the control group, RDC group I, muscle disorders, was 39.1% (9/23), group II, disc displacements, was 17.4% (4/23), group III OA, osteoarthritis/osteoarthrosis, was 73.9% (17/23), and group III pain, arthralgia, was 82.6% (19/23). In the occlusal-loss group, group I was 41.7% (10/24), group II was 41.7% (10/24), group III OA was 70.8% (17/24), and group III pain was 83.3% (20/24). The frequency of RDC groups was not different between two groups, analyzed by binomial logistic regression. Pre-treatment cephalometric variables were not different between two groups. However, articular angle(S-Ar-Go), AB to mandibular plane and ODI decreased and gonial angle (Ar-Go-Me) increased significantly in the occlusal-loss group, implying clockwise rotation of the mandible, between pre-treatment and 6-month post-treatment, while none of cephalometric variables showed any statistical difference in the control group.

Conclusions: 1. Change in the number of occluding teeth was not related to the RDC/TMD diagnoses. 2. Cephalometric values changed only in the occlusal-loss group as a result of mandibular clockwise rotation. 3. None of cephalometric variables before the stabilization splint therapy was statistically different between the control and occlusal non-loss group.