Introduction: To check the morphological changes of the masseter muscle after surgical extraction of inferior molar teeth. Methods: 24 Wistar rats had samples of their masseter muscles analysed in the Optical Microscope (OM). The rats were randomly divided into three groups as follows: GI-15, GII-30, GII-60 days after surgical extraction of inferior molar teeth. Each group had 5 experimental and 3 normal control rats for OM observation. The OM allowed the morphometric study of the masseter muscle. The morphometric study was based on the measurement of the fiber’s area by AXION-VISION software. ANOVA test was applied for data analysis. Results: No alteration was detected in all morphometric analysis of the masseter muscle. Conclusion: The masseter muscle adapts to the occlusal modification caused by the extraction of the molar teeth during the analysed periods.