Evaluation of Cross-sectional Thickness and Activity of Masseter, Temporalis, Orbicularis Oris and Mentalis Muscles in Normal, High and Low Angle Cases and its Correlation with Craniofacial Morphology

Abstract

The dynamic aspect of the oral cavity, i.e. muscle tissue, cannot be excluded from consideration, as the bony foundation which supports the teeth is powered and remodeled by muscles. Aims and objectives: The study was to correlate the thickness and activity of masseter, temporalis, orbicularis oris and mentalis muscles with craniofacial morphology in high angle, low angle cases with that of normal angle cases. Materials and methods: For selection of sample, the lateral cephalograms were taken in natural head position and 14 craniofacial parameters were analyzed for each subject and accordingly divided into high, low and normal angle cases. Ultrasonographic and electromyographic study were carried out for all subjects. Results: Statistical analysis of results showed that there exist significant differences in cross-sectional thickness and activity of masseter muscle. It was more in low angle cases and less in high angle cases. Conclusion: A positive correlation was found between masseter muscle thickness and activity with cephalometric parameters like—OB, PFH and RH and negative correlation was found with ADH, ī to MP, TFH and LFH.