Evaluation of changes in trabecular alveolar bone during growth using conventional panoramic radiographs

Micro-computed tomography assessment of bone structure in aging mice

High-resolution computed tomography (CT) is widely used to assess bone structure under physiological and pathological conditions. Although the analytic protocols and parameters for micro-CT (μCT) analyses in mice are standardized for long bones, vertebrae, and the palms in aging mice, they have not yet been established for craniofacial bones. In this study, we conducted a morphometric assessment of craniofacial bones, in comparison with long bones, in aging mice. Although age-related changes were observed in the microarchitecture of the femur, tibia, vertebra, and basisphenoid bone, and were more pronounced in females than in males, the microarchitecture of both the interparietal bone and body of the mandible, which develop by intramembranous ossification, was less affected by age and sex. By contrast, the condyle of the mandible was more affected by aging in males compared to females. Taken together, our results indicate that mouse craniofacial bones are uniquely affected by age and sex.

Assessment of the changes in alveolar bone quality after fixed orthodontic therapy: A trabecular structure analysis

Background. Tooth displacement changes the periodontium. The aim of orthodontic treatment is desired tooth movement with minimum side effects on the alveolar bone quality. The aim of the present study was to assess changes of alveolar trabeculation in children, young adults and adults and the two genders.

Methods. In this cross-sectional study, 63 patients who had been treated in Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran, were chosen with convenient sampling method. They were divided into three groups based on their age. Their digitized panoramic radiographs (PRs) were evaluated at six interdental sites from the mesial aspect of the mandibular second molars to the distal aspect of the mandibular first premolars using a visual index. The trabeculation pattern was assigned as either dense (score 3), dense-sparse (score 2) or sparse (score 1). Data were imported to SPSS. Mean of the scores before treatment (score B) and mean of them after treatment (score A) were compared for each group with paired t-test. Changes between score B and sore A of the groups were compared using one-way ANOVA and post hoc tests.

Results. Mean score A was significantly higher than mean score B in children (P = 0.001). In contrast, mean score A was significantly lower than mean score B in young adults (P = 0.003).

Conclusion. Orthodontists should be cautious when treating young adults and adults regarding the probable, yet possibly temporary, negative effects of orthodontic therapy on the alveolar bone quality.

Alveolar bone loss in osteoporosis: a loaded and cellular affair?

Maxillary and mandibular bone mirror skeletal bone conditions. Bone remodeling happens at endosteal surfaces where the osteoclasts and osteoblasts are situated. More surfaces means more cells and remodeling. The bone turnover rate in the mandibular alveolar process is probably the fastest in the body; thus, the first signs of osteoporosis may be revealed here. Hormones, osteoporosis, and aging influence the alveolar process and the skeletal bones similarly, but differences in loading between loaded, half-loaded, and unloaded bones are important to consider. Bone mass is redistributed from one location to another where strength is needed. A sparse trabeculation in the mandibular premolar region (large intertrabecular spaces and thin trabeculae) is a reliable sign of osteopenia and a high skeletal fracture risk. Having dense trabeculation (small intertrabecular spaces and well-mineralized trabeculae) is generally advantageous to the individual because of the low fracture risk, but may imply some problems for the clinician.

Five-year alveolar bone level changes in women of varying skeletal bone mineral density and bone trabeculation

OBJECTIVES

To investigate alveolar bone level changes in women with varying skeletal bone mineral density (BMD) and bone trabeculation.

STUDY DESIGN

In a prospective, longitudinal study of 128 women (22-75 years of age), BMD (dual x-ray absorptiometry), and periapical radiography were performed in 1996 and 2001. The mandibular trabecular bone was assessed as dense, mixed, or sparse. Mandibular alveolar bone level was measured with a Schei ruler and related to BMD (osteoporotic, osteopenic, or normal) and trabeculation.

RESULTS

After 5 years, the total bone level score was significantly decreased (P = .001). No significant differences were found in the total bone level scores between the different BMD groups. The greatest decreased total bone level score in 1996 was found in the group with dense trabeculation (0.71 in the dense group vs. 0.31 in the nondense group, P = .005), and similarly in 2001 (0.75 in the dense group vs. 0.39 in the nondense group, P = .020). Five-year changes in the total bone level scores did not differ between trabeculation groups (P = .37).

CONCLUSIONS

The small group of women with dense mandibular trabecular bone seems to suffer a greater decrease in alveolar bone height compared with other women, including women with osteoporosis.

Mandibular bone structure, bone mineral density, and clinical variables as fracture predictors: a 15-year follow-up of female patients in a dental clinic

OBJECTIVE

To compare three mandibular trabeculation evaluation methods, clinical variables, and osteoporosis as fracture predictors in women.

STUDY DESIGN

One hundred and thirty-six female dental patients (35-94 years) answered a questionnaire in 1996 and 2011. Using intra-oral radiographs from 1996, five methods were compared as fracture predictors: (1) mandibular bone structure evaluated with a visual radiographic index, (2) bone texture, (3) size and number of intertrabecular spaces calculated with Jaw-X software, (4) fracture probability calculated with a fracture risk assessment tool (FRAX), and (5) osteoporosis diagnosis based on dual-energy-X-ray absorptiometry. Differences were assessed with the Mann-Whitney test and relative risk calculated.

RESULTS

Previous fracture, gluco-corticoid medication, and bone texture were significant indicators of future and total (previous plus future) fracture. Osteoporosis diagnosis, sparse trabeculation, Jaw-X, and FRAX were significant predictors of total but not future fracture.

CONCLUSION

Clinical and oral bone variables may identify individuals at greatest risk of fracture.