ABSTRACT
OBJECTIVES: The present study aimed at performing a histological evaluation of the response of temporal bone tissue to a change of direction of the force vector of the mandible in relation to the base of the skull. MATERIAL AND METHODS: Adult rabbits were assigned into four groups with two control and four experimental animals in each group. experimental animals underwent surgery, which resulted in a change of direction of the force vector on the right temporomandibular joint. Samples were collected after 15, 30, 60 and 90 days for histological analysis. RESULTS: In the two-way analysis of variance, the effect of group and time was statistically significant (p<0.001). Additionally, a statistically significant interaction between group and time was observed (p<0.001). Control animals showed normal growth and development of the temporal region. In the experimental group, the change in direction of the force vector of the mandible induced significant changes in the temporal bone, with a bone modeling process, which suggests growth of this cranial structure. CONCLUSIONS: The methodology used in this experiment allows us to conclude that the change in direction of the force vector of the mandible in relation to the skull base induces remodeling and modeling processes in the temporal bone. The resumption of normal oral functions after bone healing of the mandibular fracture appears to increase cell activation in the remodeling and modeling of the temporal bone structure. The observation of areas of temporal bone modeling shows the relevance of further investigation on the correlation between the joint structures and craniofacial growth and development.
Subject(s)
Animals , Rabbits , Mandible/physiology , Temporal Bone/anatomy & histology , Temporomandibular Joint/physiology , Bone Development/physiology , Skull Base/physiology , Time Factors , Temporal Bone/physiologyABSTRACT
Objective: This in vivo experimental study evaluated the effect of methotrexate on the oral mucosa of mice. Methodology: A total of 28 adult BALB/c mice were randomly assigned into a control and an experimental group. Mice in the experimental group were immuno-suppressed with 2.5 mg/kg of methotrexate for three consecutive days. One mouse from each group was sacrificed each day for 10 days. Samples from ventral mucosal tongue surface were collected and prepared for histomorphometric analysis, by staining with hema-toxylin/eosin. Three microscopic s per section were analyzed, in order to evaluate the mean epithelial cells layer thickness and counting of blood vessels. To eva-luate the existence of inflammatory infiltration, values of 0 and 1 were used for absence or presence, respec-tively. Results: The results showed that the treatment did not induce clinical signs of mucositis in the ventral mucosal tongue region. The histological examination showed that the mean number of blood vessels was si-milar in control and experimental samples (p < 0.001), and that there was absence of inflammatory infiltration. However, the thickness of the epithelial cell layer of experimental samples was significantly lower than in control samples. Conclusion: This study showed that, in the mouse model, methotrexate-induced mucositis histological result in manifestations in the ventral tongue region.