Objective: Vertical dimension must be increased gradually in patients undergoing full mouth restorative therapy and any adverse symptoms during the process must be monitored. Occlusal splints are the best way to increase the vertical dimension in a patient. The present study is aimed to analyse the effect of different splints on the condylar position, verical dimension and EMG activity of masseter and anterior temporalis. Methodology: Patients with moderate to severe attrition were included in this randomized cross over study and were constituted into four groups (n=10). Canine to canine splint and full arch splint at both 1 mm (Group A, C) and 4mm (Group B, D) vertical dimension were made. The surface EMG activity of anterior temporalis and masseter muscle and Lateral cephalograms for condylar position assesmentwere recorded bilaterally pre and postoperatively after the insertion of the splints.
Results:The mean EMG values (μV ) Masseter reduced from 263.10±24.7 to 147.15 ±12.77μV with the use of canine to canine 1mm splint , 134.7 ±14.72μV with the use of canine to canine 4mm splint, 145.47 ±26.86μV with the use of full arch 1mm splint, 139.04 ±28.21μV with the use of full arch 4mm splint. with a statistical significance (p<.001). Condylar position did not show a significant statistical difference (p>0.05).
Conclusion:The occlusal splints were effective in reducing the masticatory muscle hyperactivity. The reduction in muscle activity was more at increased vertical dimension of 4mm when compared to 1mm splint. The splints were similar in positioning the condyles.