Cone beam computed tomography devices in the evaluation of buccal bone in anterior teeth.

OBJECTIVE: To determine the accuracy of various cone beam computed tomography (CBCT) devices in assessing the buccal bone in anterior teeth. MATERIAL AND METHODS: A skull encased in tissue equivalent material was imaged with six CBCT devices: 3D Accuitomo 170 (J. Morita, Japan), CS 9000 3D (Carestream Dental, France), CS 9300 (Carestream Dental, France), Eagle 3D (Dabi Atlante, Brazil), i-CAT Classic (Imaging Sciences International, USA) and Orthophos XG 3D (Sirona Dental System, USA). The exposure and acquisition protocols were determined using the manufacturer's guidelines, the voxel size adjusted as close as possible to 0.2 mm. Cross-sectional images were evaluated randomly, and the buccal bone was assessed. RESULTS: The statistics were calculated based on a logistic regression model with the significance level set at 5%. All CBCT devices showed high accuracy; however, observers noted that the accuracy and sensitivity of CS 9300 device were slightly superior. CONCLUSION: The diagnostic performance of all CBCT devices was high for the evaluation of buccal bone in anterior teeth. When the clinical usefulness of an imaging modality is equivalent, the choice of appropriate imaging should be directed towards the modality that delivers the least radiation dose to the patient for a specific diagnostic task.

Cone beam computed tomography assessment of the pterygomaxillary region and palatine canal for Le Fort I osteotomy.

The aim of this study was to evaluate the anatomical linear measurements of the descending palatine canal and the pterygomaxillary fissure for Le Fort I preoperative planning. Seventy-five patients, comprising 46 females (61.3%) and 29 males (39.7%), underwent multi-slice computed tomography examinations performed for preoperative orthognathic surgical planning. The images were categorized according to sex, craniofacial side, and skeletal and craniofacial patterns. The anterior length between the descending palatine canal and the lateral wall of the piriform rim showed a higher mean value for males compared to females (P=0.0121). The posterior distance also showed a difference between the sexes and the highest mean was observed in females (P=0.0295). Comparing the posterior width for the skeletal patterns, a statistical difference was observed between classes I and III (P=0.0371), and classes II and III (P=0.0094). Regarding the craniofacial patterns, the brachycephalic (P=0.0078) and mesocephalic (P=0.0015) groups showed a greater posterior width in females. In conclusion, the patient's sex and aspects of the skeletal pattern and craniofacial pattern have an influence on the pterygomaxillary area and descending palatine canal anatomy. A preoperative computed tomography analysis involving this evaluation could reduce the risk of surgical complications.

Biometric parameters of the temporomandibular joint and association with disc displacement and pain: a magnetic resonance imaging study.

The aim of this study was to evaluate the relationship between biometric parameters of the components of the temporomandibular joint (TMJ), articular disc displacement, and TMJ pain. Magnetic resonance imaging (MRI) examinations of 185 patients were assessed (39 males and 146 females (370 TMJs), mean age 41.3 years, range 18-79 years). The antero-posterior length of the condyle was measured in its medial and lateral regions, as well as the transverse length of the condyle. Possible associations between linear measurements of the condyle, presence of disc displacement, and joint pain were tested. Although pain was more commonly reported among patients with disc displacements, this association was not statistically significant. We found statistically significant associations showing that the antero-posterior length of the condyle at the lateral pole (D1L), the antero-posterior length of the condyle at the medial pole (D1M), and the transverse length of the condyle (D2) were higher among patients without disc displacements when compared to those with unilateral or bilateral displacements. This study showed that disc displacement was associated with smaller condyles in the antero-posterior and transverse dimensions when compared to condyles in subjects with normal disc position.

Evaluation of panoramic radiomorphometric indices related to low bone density in sickle cell disease.

SUMMARY: In sickle cell disease, erythroid hyperplasia causes trabecular destruction leading to low bone density. This condition could be suspected by the radiomorphometric indices and your diagnosis becomes relevant in a multidisciplinary context of health care for sickle cell subjects, providing prognostics and contributing to determine adequate therapeutic and preventive actions. INTRODUCTION: The aim of this study was to assess the risk of low bone density in subjects with sickle cell disease (SCD) through analysis of panoramic radiographic exams by radiomorphometric indices. METHODS: Seventy-eight Brazilian subjects with SCD took part in this study and were subdivided into four groups: (I) 31 SCD subjects aged under 40 years; (II) 13 SCD subjects aged 40 years or more; (III) 12 normal subjects aged under 40 years; and (IV) 22 normal subjects aged 40 years or more. In the panoramic radiographs, the mandibular cortical index (MCI) classification, increased spacing of the trabecular bone, panoramic mandibular index (PMI), and mental index (MI) were evaluated. Exact Fisher's test was used to compare age between the different groups. Descriptive analysis of the data was performed to evaluate the simple visual estimation of low bone density (increased bone trabecular space and MCI), and a one-way analysis of variance (Bonferroni criteria) was used to compare the means of the quantitative indices (PMI and MI). The significance level was p < 0.05. RESULTS: In the MCI classification, C2 was more prevalent, especially in groups I and IV. Increased spacing of the trabecular bone was more frequent in groups I and II. MI did not show a statistically significant difference among the groups. PMI showed a statistically significant difference only between groups III and IV. CONCLUSIONS: The radiomorphometric indices applied in the present study can be used on panoramic radiographs to detect the presence of low bone density in SCD subjects.

Hybrid lesion: central giant cell granuloma and benign fibro-osseous lesion.

Hybrid lesions comprise elements of different pathologies in one lesion. Hybrid lesions comprising central giant cell granulomas (CGCG) with fibro-osseous components are rare, with only six maxillomandibular cases reported in the literature. We report a case of a hybrid lesion in a 38-year-old woman who presented with a swelling in the mandibular parasymphysis, on the left side. Panoramic and occlusal radiographs and CT showed a mixed lesion with expansion of the buccal cortical plate that pointed to the diagnosis of ossifying fibroma (OF). Complete excision of the lesion was performed, and the anatomopathological examination showed features of both CGCG and a fibro-osseous lesion. Clinical, imaging and histopathological features indicate a hybrid lesion of CGCG and OF. The patient remains asymptomatic after 30 months of follow-up.

Mandibular ramus-related Stafne's bone cavity.

Mandibular bone depressions located on the lingual/buccal aspect of the mandibular ramus are the rarest variants of the so-called Stafne's bone cavities, or major salivary gland-related depressions, with only 17 cases reported in the literature including both clinical cases and archaeological specimens. We report the case of a 14-year-old male patient who sought clinical assistance complaining of a hard expansion on the lower left premolar-molar region. Apart from a unilocular radiolucent lesion between the lower left second premolar and first molar, a panoramic radiograph showed another radiolucent lesion located in the right mandibular ramus, at the level of the mandibular foramen. Computed tomography (CT) revealed an expansile lesion in the left mandibular body, later diagnosed as a simple bone cyst through surgical exploration. The three-dimensional CT volume rendering reconstructed image showed that the second lesion, located on the lingual aspect of the ascending ramus, was an actual cortical bone defect, which was diagnosed as a mandibular ramus-related Stafne's bone cavity. Considering the young age of the patient, the size of the defect, the recognizedly slow development of mandibular bone defects and, above all, the location of the bone defect under discussion, we believe it to have a congenital rather than a developmental origin (i.e. it was caused by a focal failure during intramembranous ossification of the mandible). If this is the case, mandibular bone depressions should not be seen exclusively as salivary gland-related bone defects.