Maxillary Interdental Osteotomies Have Low Morbidity for Alveolar Crestal Bone and Adjacent Teeth: A Cone Beam Computed Tomography-Based Study.

PURPOSE: Maxillary segmentation involving interdental osteotomies can have an adverse effect on the interdental crestal bone and adjacent teeth. The purpose of the present study was to evaluate the effect of interdental osteotomies on surrounding osseous and dental structures, including adjacent teeth, using cone beam computed tomography (CBCT), in patients who underwent segmental maxillary osteotomies. PATIENTS AND METHODS: The present retrospective cohort study evaluated interdental osteotomy (IDO) sites between the lateral incisors and canines in patients treated with 3-piece Le Fort I osteotomies. CBCT scans were assessed using Kodac Dental Imaging software at specific intervals: T0 (before surgery), T1 (immediately after surgery), and T2 (a minimum of 11 months after surgery). The statistical analysis using a linear regression model was adjusted to compare the variables at the different intervals. Injury to the dental structures was assessed by radiological evidence of dental damage, the requirement for endodontic treatment, or tooth loss. RESULTS: We evaluated 94 IDO sites in 47 patients in the present study. The mean inter-radicular distance at T0 was 2.5 mm. A statistically significant increase was seen in the inter-radicular distance (between T1 and T0) of 0.72 mm, with a reduction of the alveolar bone crest height (between T2 and T0) of 0.19 mm (P < .001) for the group that underwent IDO. A weak correlation was found for this increase in the inter-radicular distance, with changes in the alveolar crest bone height. The potential complications associated with interdental osteotomies such as iatrogenic damage to the tooth structure, the need for endodontic treatment, and tooth loss were not encountered in any patients. CONCLUSIONS: We found very low morbidity for the interdental alveolar crest and the integrity of teeth adjacent to interdental osteotomies for patients who underwent maxillary segmentation between the lateral incisors and canines.

Quality assurance phantoms for cone beam computed tomography: a systematic literature review.

OBJECTIVES: To undertake a systematic review on quality assurance (QA) phantoms for CBCT imaging, including studies on the development and application of phantoms. METHODS: The MEDLINE (PubMed) bibliographic database was searched until May 2016 for studies evaluating the development and use of phantoms in CBCT image QA. The search strategy was restricted to English language publications using the following combined terms: (Cone Beam CT) OR (Cone Beam Computed Tomography) OR (Cone-Beam Computed Tomography) OR (CBCT) AND (quality OR phantom). It was assessed which of the six image quality parameters stated by the European Commission could be evaluated with each phantom and which of them actually were. RESULTS: The search strategy yielded 37 studies, which had developed and used (25 studies) or only used (12 studies) a phantom in CBCT image QA. According to the literature, in 7 phantoms, it is possible to evaluate 4 or more image quality parameters while in 11 phantoms, merely 1 parameter can be evaluated. Only two phantoms permit the evaluation of the six image quality parameters stated by the European Commission. The parameters, which can most often be evaluated using a phantom, are image density values, spatial resolution and geometric accuracy. The SEDENTEXCT phantom was used most frequently. In two studies, all quality parameters suggested by the European Commission were evaluated. CONCLUSIONS: QA phantoms rarely allow all image quality parameters stated by the European Commission to be evaluated. Furthermore, alternative phantoms, which allow all image quality parameters to be evaluated in a single exposure, even for a small field of view, should be developed.

Concomitant treatment of mandibular ameloblastoma and bilateral temporomandibular joint osteoarthritis with bone graft and total joint prostheses.

Temporomandibular joint (TMJ) osteoarthritis is a degenerative disease that can create clinical problems in the masticatory musculature, jaws, occlusion, and other associated structures and is commonly accompanied by inflammatory changes and pain. Many cases of TMJ dysfunction can be managed with nonsurgical therapies, but patients with irreversible TMJ damage may require surgical intervention for repair or reconstruction. Despite various methods of TMJ reconstruction, the patient-fitted total joint prostheses may be the best option to achieve good outcomes. Multicystic ameloblastoma is a benign odontogenic neoplasm of the jaws that is found most often in the mandible, in the region of the molars, and the ramus. Ameloblastomas usually progress slowly, but are locally invasive and may cause significant morbidity and sometimes death. This report describes a case of concomitant treatment of recurrent mandibular ameloblastoma and severe bilateral TMJ osteoarthritis treated by resection of the tumor, reconstruction with bone grafting, and bilateral TMJ reconstruction in a 63-year-old woman.

Influence of scan mode (180°/360°) of the cone beam computed tomography for preoperative dental implant measurements.

OBJECTIVE: The aim of this study was to evaluate the effect of scan mode of the cone beam computed tomography (CBCT) in the preoperative dental implant measurements. MATERIAL AND METHODS: Completely edentulous mandibles with entirely resorbed alveolar processes were selected for this study. Five regions were selected (incisor, canine, premolar, first molar, and second molar). The mandibles were scanned with Next Generation i-CAT CBCT unit (Imaging Sciences International, Inc, Hatfield, PA, USA) with half (180°) and full (360°) mode. Two oral radiologists performed vertical measurements in all selected regions; the measurements of half of the sample were repeated within an interval of 30 days. The mandibles were sectioned using an electrical saw in all evaluated regions to obtain the gold standard. The intraclass correlation coefficient was calculated for the intra- and interobserver agreement. Descriptive statistics were calculated as mean, median, and standard deviation. Wilcoxon signed rank test was used to determine the correlation between the measurements obtained in different scan mode with the gold standard. The significance level was 5%. RESULTS: The values of intra- and interobserver reproducibility indicated a strong agreement. In the dental implant measurements, except the bone height of the second molar region in full scan mode (P = 0.02), the Wilcoxon signed rank test did not show statistical significant difference with the gold standard (P > 0.05). CONCLUSIONS: Both modes provided real measures, necessary when performing implant planning; however, half scan mode uses smaller doses, following the principle of effectiveness. We believe that this method should be used because of the best dose-effect relationship and offer less risk to the patient.

In vitro comparison of cone beam computed tomography with different voxel sizes for detection of simulated external root resorption.

The present study compared the efficacy of cone beam computed tomography using different voxel sizes in the diagnosis of simulated external root resorption. The presence or absence of simulated defects on buccal, mesial and distal root surfaces of 20 premolars was evaluated. The defects were small (0.26 mm in diameter and 0.08 mm deep), medium (0.62 mm in diameter and 0.19 mm deep) and large (1.05 mm in diameter and 0.24 mm deep), equally distributed on each root surface. Images were obtained using Classic i-CAT cone beam computed tomography with different voxel sizes: 0.12, 0.20, 0.25 and 0.30 mm. Five oral radiologists evaluated the images. Accuracy, sensitivity, specificity, positive and negative predictive values were determined. The sensitivity decreased and specificity increased as voxel size increased. Accuracy values were the highest for the smallest voxel size (0.12 mm). The results for voxel sizes 0.20 mm and 0.25 mm were similar. Positive and negative predictive values were similar in all protocols, except with 0.30 mm, in which they were the lowest. In conclusion, external root resorption was more easily diagnosed when a smaller voxel size was used.

Lingual accessory mental foramen: a report of an extremely rare anatomical variation.

The presence of accessory foramina and canals in the mandible is frequently overlooked in clinical procedures. It is important to note that these anatomical variations may only be pre-surgically detected on imaging exams, and such detection may directly influence therapeutic success. We describe a previously unreported case of accessory mental foramen located in the lingual cortical bone of the mandible.

Síndrome de Goldenhar: relato de caso / Goldenhar’s syndrome: a case report

A Síndrome de Goldenhar é uma condição rara, geralmente de ocorrência esporádica, caracterizada por microssomiahemifacial, dermóide epibulbar, más formações do pavilhão auditivo e anomalias vertebrais. Existem também relatos deassociações da síndrome com outras condições sistêmicas. Os autores relatam um caso de Síndrome de Goldenhar empaciente do sexo feminino, 28 anos, sem antecedentes familiares, que apresentava microssomia hemifacial, o quecomprometia os músculos da mastigação, a expressão facial e os ossos da face (mandíbula, maxila e zigomático) do lado esquerdo, presença de broto auricular, história médica de dermóide epibulbar e fissura lateral de face, ipsilateralmente. Na avaliação sistêmica, foram encontrados ectopia do rim esquerdo e discreto espessamento dos folhetos mitrais, com refluxo mitral de grau leve.