Gabriella Lopes de Rezende Barbosa

Prevalence and characteristics of pneumatization of the temporal bone evaluated by cone beam computed tomography.

The aim of this study was to determine the prevalence and characteristics of pneumatization of the glenoid fossa and articular eminence by means of cone beam computed tomography (CBCT) images. CBCT images of 658 patients (1316 joints) were evaluated to determine pneumatization in the articular eminence (PAT) and roof of the glenoid fossa (PGF). Age and gender were recorded for all patients and, for the cases of pneumatization, laterality and type (unilocular or multilocular) were noted. Its prevalence was correlated with gender, age and laterality by statistical analyses. 21.3% of individuals presented with PAT and 38.3% presented with PGF. Considering the temporomandibular joint, PAT was in 15.5% and PGF in 30.2%. Of PAT cases, 54.3% were unilateral and 45.7% bilateral; 3.4% were unilocular and 96.6% were multilocular. In the PGF cases, 42.5% were unilateral and 57.5% bilateral; 0.02% was unilocular and 99.8% were multilocular. There was no statistical difference regarding gender and age; but there was statistical difference regarding laterality, with higher frequency on the left side. In conclusion, there was a significant prevalence of PAT and PGF in the studied population; their prevalence seems higher than has been previously supposed.

Difference in maxillary sinus volumes of patients with cleft lip and palate

BACKGROUND AND OBJECTIVE Sinus disease is noted to be common in patients with cleft lip and palate. Many have wondered if anatomic differences are a cause or at least a contributor of this. In this sense, comparisons of sinus volumes of patients with different craniofacial clefts may be helpful to determine possible differences from normal. Thus, the present study aimed to evaluate and compare the maxillary sinus volume of patients with unilateral (UCLP) and bilateral (BCLP) cleft lip and palate to control, i.e. non-cleft patients, using cone beam computed tomography (CBCT) images. METHODS The sample consisted of 30 subjects with UCLP, 15 with BCLP and 15 control individuals (non-cleft). Each maxillary sinus was assessed three-dimensionally, segmented and its volume was calculated. The comparison between right and left sinus was performed by Student t-test, and the differences between the control and cleft groups were calculated using ANOVA. RESULTS No statistical differences were found when the sides were compared (p>0.05). In relation to the assessment among groups, all comparisons had statistically significant differences (p<0.05), with the UCLP group presenting the lowest sinus volume. CONCLUSION UCLP individuals present maxillary sinuses with smaller volumes, without differences found between the cleft and non-cleft side. BCLP subjects also present a reduction in the volume when compared to a control sample, but the average sinus volume is larger than in UCLP patients.

Volumetric nasal cavity analysis in children with unilateral and bilateral cleft lip and palate

Children with cleft lip and palate (CLP) often suffer from nasal obstruction that may be related to effects on nasal volume. The objective of this study was to compare side:side volume ratios and nasal volume in patients with unilateral (UCLP) and bilateral (BCLP) clefts with age‐matched controls.

Three-dimensional evaluation of nasopharyngeal airways of unilateral cleft lip and palate patients.

The aim of this study was to compare the volume of nasopharyngeal airways of patients with unilateral cleft lip and palate (UCLP) with a control (noncleft) group of subjects.

Comparison of different methods to assess alveolar cleft defects in cone beam CT images

OBJECTIVES This study aimed to evaluate the accuracy of three different methods for assessing the volume of cleft defects in CBCT images. The influence of field of view (FOV) and voxel sizes was also assessed. METHODS Using three radio-opaque plastic skulls, unilateral defects were created to mimic alveolar clefts and were filled with wax following the contralateral side contours. They were scanned in a CBCT unit using four different acquisition protocols, varying FOV and voxel sizes. Using three different methods, the defect/wax volume was evaluated on the images by defining: (1) the width, height and facial-palatal length of the defect in maximum intensity projection; (2) the areas of the defect on axial slices; and (3) the threshold and segmentation of the region of interest. The values obtained from each method using different acquisition protocols were compared with the real volume of the wax (gold standard) using ANOVA and Tukeys test. RESULTS Methods 2 and 3 did not differ from the gold standard (p > 0.05). Conversely, Method 1 presented statistically significant overestimated values (p < 0.01). No differences were found among the different FOV and voxel sizes (p > 0.05). CONCLUSIONS CBCT volumes proved reliable for the volumetric assessment of alveolar cleft defects, when using Methods 2 and 3 regardless of FOV and voxel sizes. It may be possible to improve surgical planning and outcomes by knowing the exact volume of grafting material needed prior to the surgical intervention.

Prosthetic Rehabilitation of Child Victim of Avulsion of Anterior Teeth with Orthodontic Mini-Implant

The treatment of choice in cases of avulsed permanent teeth is the immediate reimplantation. However, this conduct does not always work favorably, either by failures in the initial approach or by inappropriate interventions. In this sense, the aim of this study is to present an alternative prosthetic rehabilitation with the use of orthodontic mini-implants in the anterior region. This case reports a ten-year-old child with history of avulsion of superior central incisors. The therapeutic approach was planned to promote physiological teeth contacts and acceptable esthetics and phonetics. First, the occlusal-gingival insertion of two orthodontic mini-implants was performed in the alveolar ridge, and, immediately after that, two provisional crowns were attached to the implants. The interventions achieved satisfactory cosmetic and functional results. After one-year follow-up, the adjacent periodontal tissues remained without signs and/or symptoms of inflammation. The provisional crowns presented no mobility and fractures. During radiographic examination, a healthy bone tissue appearance was observed. The simplicity of mini-implant installation makes them a promising alternative for temporary prosthetic rehabilitation of patients undergoing growth and development. The technique provides positive aesthetic and functional results that may reflect on self-esteem and social inclusion of children and adolescents.

Micro-CT evaluation of the radioprotective effect of resveratrol on the mandibular incisors of irradiated rats

The purpose of this study was to perform a microcomputed tomographic evaluation of the radioprotective effect of resveratrol on the volume of mandibular incisors of irradiated rats. A second aim was to make a quantitative assessment of the effect of x-ray exposure on these dental tissues. Twenty adult male rats were divided into four groups: control, irradiated control, resveratrol, and irradiated resveratrol. The resveratrol groups received 100 mg/kg of resveratrol, whereas the irradiated groups were exposed to 15 Gy of irradiation. The animals were sacrificed 30 days after the irradiation procedure, and their mandibles were removed and scanned in a microcomputed tomography unit. The images were loaded into Mimics software to allow segmentation of the mandibular incisor and assessment of its volume. The results were compared by One-way ANOVA and Tukeys post hoc test, considering a 5% significance level. The irradiated groups showed significantly diminished volumes of the evaluated teeth, as compared with the control group (p < 0.05). The resveratrol group presented higher values than those of the irradiated groups, and volumes similar to those of the control group. High radiation doses significantly affected tooth formation, resulting in alterations in the dental structure, and thus lower volumes. Moreover, resveratrol showed no effective radioprotective impact on dental tissues. Future studies are needed to evaluate different concentrations of this substance, in an endeavor to verify its potential as a radioprotector for these dental tissues.

Vertical Measurements for Planning Palatal Mini-implants in Lateral Radiography and Cone Beam Computed Tomography

Objective: To compare palatal bone height measurements in the region of first premolars for planning palatal mini-implant insertion on conventional lateral radiography (CLR), cone beam computed tomography (CBCT), and reformatted virtual lateral radiography (VLR). Materials and Methods: One hundred ten images of CLR, VLR, and CBCT from the same patient were used. Linear measurements corresponding to the relevant dimension of available bone on upper first premolar site were performed between the hard palate floor and the nasal floor. The Friedman test compared the measurements of all imaging modalities. Intraobserver and interobserver agreement was calculated with the intraclass correlation coefficient (ICC). Results: The ICC values showed excellent intraobserver and interobserver agreement. VLR examination resulted in measurements statistically different from both CBCT and CLR images (P < 0.05), being underestimated when compared with these techniques, and the values found on CLR did not show statistically significant differences from the CBCT images (P > 0.05). Conclusions: The measurements for planning palatal mini-implants at the level of first premolars are comparable on CLR and multiplanar reconstructions of CBCT, whereas underestimated in reformatted examinations (VLR).