Alveolar Bone

In this review we discuss the historical perspective of stem cell populations from oral tissues in light of our current understanding of stem cell biology. Stem cells and their niches have been identified in the periodontium starting from the late 1970s. Applying new criteria for the identification and characterization reveals that oral tissues comprise a multipotent primitive neural crest-like stem cell population capable of differentiating into neural crest derived cell lineages of the cranial-facial zone. This population supplies cells to a more restricted stem cell type with tissue specific epigenetic memory that differentiates into cell lineages characteristic of their tissue origin. We believe that the microenvironment plays an essential role in maintaining stem cell populations and directing their migration and differentiation, and that this factor needs to be considered for utilization of stem cell-based therapy for periodontal regeneration and regenerative dental medicine.

The objective of this study was to determine whether dietary boron (B) affects the strength, density and mineral composition of teeth and mineral density of alveolar bone in rabbits with apparent obesity induced by a high-energy diet. Sixty female, 8-month-old, New Zealand rabbits were randomly assigned for 7 months into five groups as follows: (1) control 1, fed alfalfa hay only (5.91 MJ/kg and 57.5 mg B/kg); (2) control 2, high energy diet (11.76 MJ and 3.88 mg B/kg); (3) B10, high energy diet + 10 mg B gavage/kg body weight/96 h; (4) B30, high energy diet + 30 mg B gavage/kg body weight/96 h; (5) B50, high energy diet + 50 mg B gavage/kg body weight/96 h. Maxillary incisor teeth of the rabbits were evaluated for compression strength, mineral composition, and micro-hardness. Enamel, dentin, cementum and pulp tissue were examined histologically. Mineral densities of the incisor teeth and surrounding alveolar bone were determined by using micro-CT. When compared to controls, the different boron treatments did not significantly affect compression strength, and micro-hardness of the teeth, although the B content of teeth increased in a dose-dependent manner. Compared to control 1, B50 teeth had decreased phosphorus (P) concentrations. Histological examination revealed that teeth structure (shape and thickness of the enamel, dentin, cementum and pulp) was similar in the B-treated and control rabbits. Micro CT evaluation revealed greater alveolar bone mineral density in B10 and B30 groups than in controls. Alveolar bone density of the B50 group was not different than the controls. Although the B treatments did not affect teeth structure, strength, mineral density and micro-hardness, increasing B intake altered the mineral composition of teeth, and, in moderate amounts, had beneficial effects on surrounding alveolar bone.

Background. The esthetic replacement of teeth has become an important standard for implant dentistry. While defining this goal has not been difficult, the ability to restore implants esthetically has been fraught with obstacles and sometimes has not been attainable. The purpose of ...

The aim of this study was to determine anatomical variations in the radiographic distance between the cemento-enamel junction and the alveolar crest with respect to ethnic heritage and gender in New Zealand dental students. Digitized bitewing films of 123 second-year New Zealand dental students were examined with a computer imaging program on a desktop computer screen. The race of parents and grandparents was obtained by questionnaire. The mean distance from the cemento-enamel junction to the alveolar crest across the sample was 0.97 mm. Eighteen (14.6%) of the participants had measurements >2 mm, of whom 17 were Asians. Asians had a significantly larger mean distance than did non-Asians (1.10 mm compared to 0.83 mm; P <0.001). Gender was not a significant variable. Students of Asian origin had a significantly greater distance between the cemento-enamel junction and the alveolar crest. It remains to be determined whether this is anatomical or disease related.

Study Design. The trial was a randomized, double-blind, placebo-controlled, parallel-group study conducted among 279 subjects, each of whom required oral surgery for the removal of a minimum of one impacted mandibular third molar. Subjects were instructed to rinse twice daily with ...

Osteonecrosis of the jaws (ONJ) is a significant complication of antiresorptive medications, such as bisphosphonates and denosumab. Antiresorptive discontinuation to promote healing of ONJ lesions remains highly controversial and understudied. Here, we investigated whether antiresorptive discontinuation alters ONJ features in mice, employing the potent bisphosphonate zoledronic acid (ZA), or the RANKL inhibitor OPG-Fc, utilizing previously published ONJ animal models. Mice were treated with veh, ZA or OPG-Fc for 11 weeks to induce ONJ, and antiresorptives were discontinued for 6 or 10 weeks. Maxillae and mandibles were examined by μCT imaging and histologically. ONJ features in ZA and OPG-Fc groups included periosteal bone deposition, empty osteocyte lacunae, osteonecrotic areas and bone exposure, each of which substantially resolved 10 weeks after discontinuing OPG-Fc, but not ZA. Full recovery of TRAP+ osteoclast numbers occurred after discontinuing OPG-Fc, but not ZA. Our data pr...