Methods: In a double blind randomized parallel trial, 40 consenting patients were selected from the dental faculty pool of TMD patients. Two splint designs were made; an ordinary stabilization (Michigan type, type “a”) or a NTI (Nociceptiv trigeminal inhibition, type “b”) splint. All patients were treated by one operator. A separate examiner assessed joint and muscle tenderness by palpation and bite opening prior to splint therapy, and after 2 and 6 weeks and 3 months splint use. Additionally, the patients reported on a VAS scale headache and TMD-related pain and comfort of splint use. Commentaries were also invited. The differences in splint design were not described to the patients and their allocated splint design was unknown to the examiner.
Results: Eighteen patients have been observed over 3 months and form the basis of these preliminary findings. Muscle tenderness and self-reported pain was less with the type a splint (p< .05, Wilcoxon sign rank test), but not for the type b splint. A reduction of headache was reported for the type b splint (p=.04), but not for the type a splint. There were no changes for joint pain and bite opening.
Few differences between the two splints have been noted. The patients with a type a splint reported less pain at 14 days (p= .03, Mann-Whitney U test), headache at 6 weeks (p= .02) and had less tender muscles at 3 months (p= .009). Comfort of use was identical for both splint designs.
Conclusion: The preliminary observations indicate that splint treatment using the Michigan type and the NTI splint types were comparable over 3 months.