Oral splint therapy in patients with Meniere's disease and temporomandibular disorder: a long-term, controlled study

Purpose To assess the effect of oral splint therapy on audio-vestibular symptoms in patients with Meniere's disease (MD) and temporomandibular disorder (TMD). Methods Retrospective case-control study. Treatment group: 37 patients with MD and TMD who received gnatological treatment. Control group: 26 patients with MD and TMD who had never received gnatological treatment. The number of vertigo spells in 6 months (primary endpoint), pure-tone audiometry average (PTA), MD stage, functional level, Dizziness handicap Index (DHI), Tinnitus handicap Index (THI) and Aural Fullness Scale (AFS) were compared at baseline and after 24 months according to groups. Analysis of Covariance was used to determine the treatment effect. Results Groups were comparable for demographic, clinical data, baseline PTAs and the number of vertigo spells. Analysis of covariance showed a significant effect of gnathological treatment on number of vertigo spells (eta(2)(p) = 0.258, p < 0.001), PTA (eta(2)(p) = 0.201, p < 0.001), MD stage (eta(2)(p) = 0.224, p < 0.001), functional level (eta(2)(p) = 0.424, p < 0.001), DHI (eta(2)(p) = 0.421, p < 0.001), THI (eta(2)(p) = 0.183, p < 0.001), but not for AFS (eta(2)(p) = 0.005, p = 0.582). The treatment group showed vertigo control of class A in 86.5% and class B in 13.5% of patients. In the control group, vertigo control was of class A in 19.2% of patients and class B in 11.5%, class C in 30.8%, class D in 11.5%, class E in 19.2% and class F in 7.7%. Classes of vertigo control differed significantly (X-2 test, p < 0.001). Conclusions Oral splint therapy could represent a viable treatment in patients with TMD and uncontrolled MD disease. The effects are maintained at least after 2 years.