engleski

Comparison of mandibular bone density and radiomorphometric indices in wearers of complete or removable partial dentures

Objectives To examine bone mineral density (BMD) and linear radiomorphometric parameters of the mandible in elderly patients with different types of dentures. Methods Patients had mandibular complete dentures (CDs) or Kennedy Class I removable partial dentures (RPDs) in the mandible ; all patients had CDs in the maxilla. The age and sex distributions of patients with CDs and of those with RPDs were not significantly different. Three parameters were measured in dental panoramic radiographs (DPRs) from a total of 136 patients: thicknesses of the mandibular cortex below the mental foramen, the antegonion, and the gonion. Mandibular BMD was measured densitometrically using DPRs and a copper step wedge. All BMD values were expressed relative to the step wedge thickness. Results There was a significant difference between patients with CDs and those with RPDs for all the radiomorphometric indices measured (P < 0.001) ; specifically, radiomorphometric indices were higher in RPD wearers. Mandibular BMD values in RPD wearers were higher than those of patients with CDs, and BMD was significantly higher under the saddle in RPD wearers (P < 0.05). Conclusions These results support the hypothesis that occlusal forces that are transmitted directly to the mucosa beneath mucosa-borne dentures may cause overloading, which may cause bone resorption ; by contrast, under tooth and mucosa-borne dentures, occlusal forces are transmitted not only to mucosa but also to the periodontal ligament of the abutment teeth, thereby reducing the transmission of force to the mucosa, which prevents overload. Greater chewing forces might thus be achieved with tooth and mucosa-borne dentures, which may stimulate bone growth at the mandibular cortex.

Mandible - Residual ridge resorption - Linear radiomorphometric index - Bone mineral density

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