The studies about bone resorption contributed greatly to the advancement of rehabilitation with dental implants and Buccomaxillo facial Surgery and Traumatology. This phenomenon leads to a more superficial localization of the mandibular canal in relation to the alveolar ridge when teeth are lost, limiting and hindering the installation Bone tissue, of implants, as well as other surgical procedures. This anatomical study aimed to analyze and interpret the distances from the mandibular canal to the alveolar ridge, in groups of dentate individuals and toothless, comparing them statistically, so 20 adult male cadavers divided into two groups, namely group A, formed by 10 dentate and group B, consisting of 10 toothless individuals. All their teeth were dissected and then, were checked the measurements of the distances between the roof of the mandibular canal and the alveolar ridge. The averages found were enlightening to say that bone resorption has consequences for treatment and surgery for dental implants, due to the decreasing bone support for the implantation and other surgical procedures, increasing the risk of injury to the inferior alveolar neurovascular bundle.

Twelve adult male Wistar rats (220 g average weight) were divided in 3 experimental groups: GI-15. GII-30 and GIII-60 days, after mandibular molar extraction, with three experimental animals and one control per group. Qualitatively, ultrastructural changes of protein filaments from myofibrils of these muscles and ipsilateral to the extractions were observed. Ultrastructure asymmetry and disorganization of Z line and I band, in the experimental group GII, of Medial Pterigoid muscle (MPT) were observed. The temporomandibular dysfunction, stimulated by the unilateral extractions of mandibular molars in rats may lead to modifications in the Z line and I band, which showed to be sensitive to this dysfunction. Changes in the MPT muscle, probably related to its own functional characteristics and major participation in the dynamics of mastication, compared to Masseter were also observed. However, the muscular fibres seem to adapt to the new conditions along the experiment.

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.