Bone quality assessment in patients with healing mandibular fracture sites: a computed tomography investigation.

The objective of this retrospective study was to assess the bone quality of healing mandibular fracture sites by measuring the Hounsfield units (HU) on computed tomographic (CT) images obtained presurgery and postsurgery in patients treated with rigid internal fixation (RIF). The HU values of healing fracture sites were compared to those of corresponding nonfractured (control) sites on the opposing side and cervical vertebrae sites in the same patients. In total, 31 patients with 45 mandibular fractures treated with RIF underwent presurgical and postsurgical CT examinations. The scans performed after surgery (1, 3, 6, 12, or 18 months) were taken only when there was a need for radiographic evaluation due to a complaint of discomfort from the patient or when the surgeon needed to verify the postsurgical outcome, and each patient underwent only a single postsurgical CT. At the presurgical CT examination, the HU values were lower in the fracture sites than in the control sites. At 3 months postsurgery, the HU values in the fracture sites had increased as the mandibular bone healed. At 6 months postsurgery, the HU values in the fracture sites were higher than those of the control sites. At 12 and 18 months postsurgery, the HU values of both sites were similar. The HU values of the cervical vertebrae remained constant with time. These results suggest that, in patients who have been treated with RIF for mandibular bone fracture, HU values measured by CT vary across time, expressing the physiologic bone healing process.

Assessment of the correlation between mandibular radiomorphometric patterns and dual-energy X-ray absorptiometry measurements for screening bone mineral density.

The objective of this study was to investigate the correlation between scores for femoral and lumbar spine bone mineral density (dual-energy X-ray absorptiometry [DXA]) and visual, qualitative mandibular bone pattern assess¬ments (mandibular cortical index, trabecular bone pattern, and visual mandibular cortical width) as well as age and body mass index. Three trained observers evaluated 200 panoramic radiographs and 200 femoral and lumbar spine DXA measurements from 100 male and 100 female participants. The κ test showed an acceptable agreement among observers (0.73; P = 0.003). The Shapiro-Wilk test revealed that the variables were not normally distributed, so the Spearman correlation test was used. The mean age of the sample was 60.7 (13.9) years, and 86.0% of the patients were White. There were inverse correlations between the mandibular cortical index and the spine T-score in men, women, and the total sample as well as between the spine Z-score in the total sample. An inverse correlation was observed between the trabecular bone pattern and the spine T- and Z-scores in women and the total sample. The results also showed inverse correlations between the visual mandibular cortical width and all parameters analyzed in men, women, and the total sample except for the femur T-score and spine T- and Z-scores in men. Body mass index was correlated with all DXA parameters. Age was inversely correlated with femur T-scores in men and women but not with spine DXA values in men. The results suggest that qualitative assessments of radiomorphometric patterns on panoramic radiographs correlate with DXA values and therefore are suitable for screening patients at risk of developing low bone mineral density.

Assessment of mandibular cortical index in patients with hepatic cirrhosis: A case-control study.

AIMS: To assess the presence of alterations suggestive of reduced bone mineral density (BMD) by using mandibular cortical index (MCI) in panoramic radiographs of cirrhotic individuals and to evaluate their relationship with other characteristics of hepatic cirrhosis (HC). METHODS AND RESULTS: This is an observational case-control study assessing the medical records of 165 cirrhotic patients matched by sex and age with healthy individuals. MELD (model of end stage liver disease) score, etiology, complications, comorbidities, and serum levels of vitamin D were collected. MCI was used to obtain BMD. Binary logistic regression was used to test associations and the risk estimates were expressed in odds ratio. Most of the sample consisted of men (73.93%) with median age of 56 years old. In the study group, the mean value of MELD was 16.5 and hepatitis C was the main etiology of HC (33.9%). Cirrhotic individuals are 3.99 times more likely to present alterations suggestive of reduced BMD (p < .01). There was no statistical significance in the association of MCI with levels of vitamin D, comorbidities, etiology or cirrhosis complications. CONCLUSIONS: MCI suggestive of reduced BMD is more likely to be identified in panoramic radiographs of cirrhotic individuals than of healthy ones.

Avaliação das características de lesões odontogênicas por meio da ressonância magnética de 3Teslas e tomografia computadorizada multislice / Assessment of odontogenic lesions imaging features in magnetic resonance imaging and multislice computed tomography

As lesões odontogênicas constituem achados relativamente frequentes na prática odontológica e são frequentemente investigadas inicialmente por meio de exames radiográficos bidimensionais. Todavia, tais exames apresentam limitações inerentes à sua técnica. Por conta disso, técnicas de imagem avançadas como a tomografia computadorizada multislice e a ressonância magnética podem e devem ser aplicadas para o estudo das lesões odontogênicas, otimizando hipóteses diagnósticas. Assim, o objetivo desta pesquisa foi estudar, por meio da ressonância magnética em imagens ponderadas em T1, STIR e difusão, e por meio da tomografia computadorizada multislice, considerando a escala de Hounsfield, os 3 tipos de lesões odontogênicas: o ameloblastoma, o queratocisto odontogênico e o cisto dentígero. O ameloblastoma também foi analisado considerando-se seus conteúdos internos (sólido e cístico) isoladamente. Para tal, foram estudadas retrospectivamente 71 imagens. Como resultado, observou-se que, por meio das imagens em ressonância magnética, especialmente ponderadas em STIR, foi possível a diferenciação do conteúdo sólido do ameloblastoma do seu próprio conteúdo cístico e do queratocisto odontogênico; e a diferenciação do conteúdo cístico do ameloblastoma do cisto dentígero. Ademais, os valores do coeficiente de difusão aparente são úteis na diferenciação dos conteúdos císticos entre os ameloblastomas de queratocistos odontogênicos e de cistos dentígeros. Por meio dos valores da escala de Hounsfield, foi possível a diferenciação dos ameloblastomas (considerando seus conteúdos sólidos e císticos em uma mesma análise) de cistos dentígeros e dos queratocistos odontogênicos. Os parâmetros analisados por meio destas técnicas avançadas de imagem possuem correspondência com os conteúdos internos das lesões estudadas, do ponto de vista histopatológico.

Imaging features of Stafne bone defects on computed tomography: An assessment of 40 cases.

PURPOSE: This study was performed to assess and describe the imaging features of 40 cases of Stafne bone defects (SBDs) on computed tomographic (CT) examinations. MATERIALS AND METHODS: This study collected data, including age and sex, from 40 patients with SBDs who underwent CT exams. The imaging features of the SBDs were assessed in terms of their location, average size, the relationship of their contour with the cortical plate of the lingual mandible, bone margins, degree of internal density, shape, topographic relationship between the defect and the mandibular edge, the distance from the SBD to the base of the mandible, and the Ariji classification (type I, II, and III). RESULTS: The average age was 57.3 years (range, 28-78 years), and the patients were predominantly male (70%). In all cases (100%), the posterior unilateral lingual SBD variant was observed. Within the Ariji classification, type I was the most common (60%). Among the most frequently observed radiographic characteristics were thick sclerotic bone margin across the entire defect contour, completely hypointense internal content, an oval shape, and continuity with the mandibular base with discontinuity of the mandibular edge. CONCLUSION: This study showed that posterior SBDs could present with an oval or rounded shape, complete hypodensity, and thick sclerotic margins. Likewise, SBDs could appear almost anywhere, with minor differences from the classic SBD appearance. It is fundamental for dental practitioners to know the imaging features of SBDs, since they are diagnosed primarily based on imaging.

Assessment of Hounsfield unit in the differential diagnosis of odontogenic cysts.

OBJECTIVES: The purpose of this study was to evaluate the usefulness of Hounsfield unit (HU) assessment with multislice-CT in the differentiation of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs). METHODS: In total, 307 odontogenic cysts (RCs, DCs and OKCs) were included in this study. Cysts with lesion diameter <10 mm, cysts with artefacts affecting measurement of HU values, cysts involving infection and recurrent cysts were regarded as exclusion criteria. Images were acquired in three different types of CT scanners: Aquilion ONE, Discovery CT750 HD and SOMATOM Definition Flash. Differences in HU values among scanners and among types of odontogenic cysts were assessed using one-way analysis of variance; multiple comparisons were performed post hoc, using the Tukey-Kramer honestly significant difference test. RESULTS: In total, 164 cysts were analysed in this study (64 RCs, 57 DCs and 43 OKCs). Regardless of the type of lesion, the Aquilion ONE scanner demonstrated a significant difference in HU value, compared with the Discovery CT750 HD scanner. Regardless of CT scanner model, HU values significantly differed between DCs and OKCs (p < 0.0001), as well as between OKCs and RCs (p < 0.0001). CONCLUSIONS: HU values were found to vary among CT scanners and should always be associated with other lesion imaging features while interpreting and elaboration diagnostic hypothesis. Notably, the results suggested that OKCs might be able to be differentiated from DCs and RCs by using HU values.

Assessment of osteoporotic alterations in type 2 diabetes: a retrospective study.

OBJECTIVES: To analyze the influence of Type 2 diabetes on bone mineral density (BMD) and panoramic radiomorphometry in postmenopausal females, comparing with results from non-diabetic postmenopausal females. METHODS: A total of 228 postmenopausal females (mean age: 59.51 ± 11.08 years) were included in this study. Demographics, T scores and Z scores from peripheral dual X-ray absorptiometry (DXA) and mandibular cortical index (MCI) from panoramic radiographs were assessed. Mean comparison between results for diabetics and non-diabetics was carried out with the Student's t-test. In addition, non-parametric correlations between MCI and DXA results were carried out with Spearman's test, at a level of significance of 5%. RESULTS: Mean Z score values were significantly higher in diabetics than in non-diabetics (p = 0.001). T and Z score values were also significantly correlated with MCI (r = 0.428, p = 0.001, and r = 0.356, p = 0.022, respectively). CONCLUSIONS: Within the limitations of this study, the present results suggest that Type 2 diabetes might increase BMD in postmenopausal females.