Fractal dimension analysis on CBCT scans for detecting low bone mineral density in postmenopausal women.

Purpose: The aim of this study was to compare the fractal dimension (FD) measured at 2 bone sites (second cervical vertebra and mandible) on cone-beam computed tomography (CBCT). The research question was whether FD could serve as an accessory tool to refer postmenopausal women for densitometric analysis. Therefore, the reliability and accuracy of FD were evaluated. Materials and Methods: In total, 103 postmenopausal women were evaluated, of whom 52 had normal bone mineral density and 51 had osteoporosis, according to dual X-ray absorptiometry of the lumbar spine and hip. On the CBCT scans, 2 regions of interest were selected for FD analysis: 1 at the second cervical vertebra and 1 located at the mandible. The correlations between both measurements, intra- and inter-observer agreement, and the accuracy of the measurements were calculated. A P value less than 0.05 was considered to indicate statistical significance for all tests. Results: The mean FD values were significantly lower at the mandibular region of interest in osteoporotic patients than in individuals with normal bone mineral density. The areas under the curve were 0.644 (P=0.008) and 0.531 (P=0.720) for the mandibular and vertebral sites, respectively. Conclusion: FD at the vertebral site could not be used as an adjuvant tool to refer women for osteoporosis investigation. Although FD differed between women with normal BMD and osteoporosis at the mandibular site, it demonstrated low accuracy and reliability.

Dental panoramic indices and fractal dimension measurements in osteogenesis imperfecta children under pamidronate treatment.

OBJECTIVES: To verify radiomorphometric indices and fractal dimension (FD) in dental panoramic radiographs (DPRs) of children with different types of osteogenesis imperfecta (OI) and also to verify the effect of pamidronate (PAM) treatment in such panoramic analyses. METHODS: In this retrospective study, 197 DPRs of 62 children with OI Types I, III and IV who were in treatment with a comparable dosage of intravenous PAM were selected. The mandibular cortical width (MCW), mandibular cortical index, visual estimation of the cortical width and FD of three standardized trabecular and cortical mandibular regions of interest were obtained from the radiographs. Factorial analysis of variance and Fisher test were used to compare FD and MCW measurements in children with different types of OI for different PAM cycles. RESULTS: Children with all types of OI have thinner and more porous mandibular cortices at the beginning of treatment. There were significant differences between MCW and FD of the cortical bone, regarding different types of OI and number of PAM cycles (p = 0.037 and p = 0.044, respectively). FD measurements of the trabecular bone were not statistically different among OI types nor were PAM cycles (p > 0.05). CONCLUSIONS: Children with OI presented cortical bone alterations after PAM treatment. Both MCW and the FD of the cortical bone were higher in children with OI after PAM treatment. It is argued that cortical bone should be considered for analyzing patients with OI, as well as to monitor the progress of PAM treatment.

Fractal dimension and mandibular cortical width in normal and osteoporotic men and women.

OBJECTIVE: To verify whether fractal dimensions (FD) on the mandibular trabecular and cortical bone and mandibular cortical width (MCW) differ between patients with normal bone mineral density (BMD) and osteoporosis. STUDY DESIGN: In this retrospective study, 133 dental panoramic radiographs from men aged >60 years and postmenopausal women with a bone densitometry report of the lumbar spine and hip classified as either normal or osteoporotic were selected. Fractal dimensions of five standardized trabecular and cortical mandibular regions of interest and mandibular cortical width were measured on the panoramic radiographs by an experienced oral radiologist, blinded to the densitometric diagnosis. The following statistical analyses were performed: ANOVA and a forward logistic stepwise regression to verify associations between dental panoramic measurements and the densitometric diagnosis. P values less than .05 indicated statistical significance. MAIN OUTCOME MEASURES: Fractal dimension and mandibular cortical width. RESULTS: Differences were found in the FD values on mandibular cortical bone and MCW between patients with normal BMD and with osteoporosis, but not in the FD values of trabecular bone. The odds of having lower mean values of MCW and FD on cortical bone were 2.16, 3125 and 1005 times in osteoporotic patients, respectively, compared with patients with normal BMD. CONCLUSION: The values of FD analysis on mandibular cortical bone and MCW were lower in women with osteoporosis. A well-adjusted logistic regression model showed that cortical bone measurements might be considered as auxiliary tools to referring patients for DXA exam.

Periostite proliferativa associada a dens in dente

Proliferative periostitis is a disease characterized for successive deposition of layers of subperiosteal bone as a response reaction to a chronic inflammatory stimulation. The affected periosteum forms several rows of reactive bone that are parallel and expand the surface of the altered bone. Dens in dente is a developmental malformation resulting from invagination of the crown before calcification has occurred. They are usually diagnosed upon routine clinical and radiographic examination. An unusual case report of a mandibular dens in dente causing proliferative periostitis is presented. The source of infection was related to dens in dente in mandibular left second premolar's crown, which had apparently communication with periodontal tissues. It was successfully treated by surgical therapy with antibiotic duringthe treatment. After the extraction of the affected tooth, radiographic follow-up showed the decrease of proliferative periostitis, and remodelation of the cortical bone.

A periostite proliferativa é uma doença caracterizada por sucessivas deposições de camadas de osso subperióstica como resposta a um estímulo crônico inflamatório. O periósteo afetado forma sucessivas camadas de osso reacional paralelas entre si e expandem a superfície óssea nesse local. Dens in dente é uma alteração do desenvolvimento resultante de invaginação de esmalte para a dentina antes de sua calcificação ocorrer. Usualmente são diagnosticadas em exames clínicos-radiográficos de rotina. Um relato de caso clínico raro é apresentado sobre dens in dente na coroa do segundo pré-molar inferior causando periostite proliferativa. A fonte de infecção foi o dens in dente que tinha comunicação do meio bucal com a área do periodonto. Foi realizada a extração do dente anômalo associado com uso de antibióticos. As radiografias de controle mostraram diminuição da periostite proliferativa como remodelamento do osso cortical.