Relationship between masticatory function and internal structure of the mandible based on computed tomography...

Area of Science:

• Osteology
• Biomechanical Engineering
• Dental Anthropology

Background:

• Bone mineral density is crucial for skeletal integrity and function.
• Masticatory function influences bone remodeling in the mandible.
• Computed tomography (CT) enables detailed analysis of bone structure and density.

Purpose of the Study:

• To investigate bone mineral density in human skulls.
• To examine the relationship between dentofacial morphology and masticatory function using CT.
• To assess mandibular bone density changes in rats with experimentally inhibited mastication.

Main Methods:

• Human skulls (n=27) underwent CT scans to measure cortical bone thickness (CBT) and CT value (CV) in molar regions.
• Rats with inhibited molar function (metal cap) were analyzed for cancellous and cortical bone density at 2, 4, and 6 weeks.
• Peripheral quantitative computed tomography (pQCT) was used for bone density measurements in rats.

Main Results:

• Human study: Significant negative correlations found between CV and mandibular angles (gonial, Frankfort-mandibular).
• Animal study: Cancellous bone mineral density declined by week 4 in the hypofunction group.
• Significant bone density loss (up to 38.1% at root apex) observed in rats with reduced mastication.

Conclusions:

• Mandibular bone, including alveolar bone in the molar region, exhibits functional adaptation to masticatory mechanical stress.
• Reduced masticatory load leads to decreased bone mineral density in the mandible.
• Findings highlight the link between oral function and skeletal health in the jaw.