Abstract
AIM: This experimental study investigated the association between masticatory hypofunction and mandibular morphological dimensions and internal bone characteristics. METHODS: Twentyfour 21-day-old male Wistar rats were randomly divided into two groups, according to the diet consistency. The control group (CG) was fed a solid diet (pellets) and the experimental group (EG) received a powdered diet during 50 days. All animals were euthanized and their mandibles removed and processed for histomorphometric analysis. A calibrated examiner performed linear and angular measurements (mandibular body length and height, mandibular lengths, ramus depth and height, mandibular base depth, mandibular head and gonial angle) on photographs, estimated bone density in the mandibular ramus region on digital radiographs and assessed the area of cortical and trabecular bone tissue in the second molar region, in 5-µm-thick serial cuts stained with Cason's Trichrome. Measurements for the study groups were compared using Mann-Whitney test (α=0.05). larvae to induce experimental candidiasis, and after 24 hours, the survival rate was assessed. RESULTS: some of the macroscopic dimensions evaluated on photographs were significantly smaller in EG compared to CG, specifically mandibular ramus height (10.77 mm vs. 11.11 mm, p=0.0375), mandibular body length (21.67 mm vs. 22.36 mm, p=0.0165) and height (4.24 mm vs. 4.54 mm, p=0.0016), as well as mandibular base depth (1.24 mm vs. 1.47 mm, p=0.0325). The relative mineral bone density was significantly decreased in EG (1.04) compared to CG (1.25), p<0.001. Rats in the EG also presented smaller trabecular and cortical bone area (2.36 mm2) than those in CG (3.16 mm2), p<0.001. CONCLUSIONS: Based on the above-mentioned measurements, it may be concluded that masticatory hypofunction induced by a powdered diet affected mandibular morphology and was associated with significantly reduced bone content.
Highlights
The adoption of a soft diet is related to histological, morphological and biochemical alterations in muscle fibers, which in turn impair the normal development of masticatory muscles[1,2] and mandibular growth . 1,3-4 experimental studies using botulinum neurotoxin type A to induce masticatoryBraz J Oral Sci. 12(3):205-211206 Effects of masticatory hypofunction on mandibular morphology, mineral density and basal bone area muscle atrophy reported decreased craniofacial growth and development[5,6].When bone is subjected to mechanical load, areas of tension and compression are generated in different regions, resulting in bone deposition and resorption as part of the remodeling process[7,8]
Results: some of the macroscopic dimensions evaluated on photographs were significantly smaller in experimental group (EG) compared to control group (CG), mandibular ramus height (10.77 mm vs. 11.11 mm, p=0.0375), mandibular body length (21.67 mm vs. 22.36 mm, p=0.0165) and height (4.24 mm vs. 4.54 mm, p=0.0016), as well as mandibular base depth (1.24 mm vs. 1.47 mm, p=0.0325)
It was hypothesized that mechanical load arising in the mandibular ramus during mastication would generate the physiologic stimulus for bone remodeling and mandibular growth
Summary
The adoption of a soft diet is related to histological, morphological and biochemical alterations in muscle fibers, which in turn impair the normal development of masticatory muscles[1,2] and mandibular growth . 1,3-4 experimental studies using botulinum neurotoxin type A to induce masticatoryBraz J Oral Sci. 12(3):205-211206 Effects of masticatory hypofunction on mandibular morphology, mineral density and basal bone area muscle atrophy reported decreased craniofacial growth and development[5,6].When bone is subjected to mechanical load, areas of tension and compression are generated in different regions, resulting in bone deposition and resorption as part of the remodeling process[7,8]. The adoption of a soft diet is related to histological, morphological and biochemical alterations in muscle fibers, which in turn impair the normal development of masticatory muscles[1,2] and mandibular growth . 206 Effects of masticatory hypofunction on mandibular morphology, mineral density and basal bone area muscle atrophy reported decreased craniofacial growth and development[5,6]. When bone is subjected to mechanical load, areas of tension and compression are generated in different regions, resulting in bone deposition and resorption as part of the remodeling process[7,8]. The mandibular ramus exhibits a posterior concave and anterior straight border, which favors the development of compression and tension loads during mastication. It was hypothesized that mechanical load arising in the mandibular ramus during mastication would generate the physiologic stimulus for bone remodeling and mandibular growth. Bone curvatures tend to amplify the functional stimulus produced by mechanical loads[9,10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
