No abstract available.

Purpose: The objective of the present study was to evaluate the prevalence of dental implants positioning errors and their associations with adjacent structures and anatomical variations by means of cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of 207 patients (584 dental implants) were evaluated by 2 oral radiologists. The distance between the implant and the adjacent teeth/implants was measured and classified as adequate (≥1.5 mm and ≥3 mm, respectively) or inadequate. The presence of thread exposure, cortical perforation, implant dehiscence, implant penetration into adjacent structures, and anatomical variations was also recorded. The incisor canal diameter and the depth of the concavity of the submandibular fossa were measured in order to evaluate their correlations with the frequency of implant penetration in these structures. Descriptive analyses, the Fisher exact test, and Spearman correlation analysis were performed (α= 0.05). Results: The overall prevalence of positioning errors was 82.9%. The most common error was the inadequate distance between the implant and the adjacent teeth/implants. The presence of anatomical variations did not significantly influence the overall prevalence of errors (P>0.05). There was a positive correlation between the diameter of the incisor canal and the frequency of implant penetration in this structure (r= 0.232, P<0.05). Conclusion There was a high prevalence of dental implant positioning errors, and positioning errors were not associated with the presence of anatomical variations. Professionals should be aware of the space available for implant placement during the preoperative planning stage.

No abstract available.
Dentigerous Cyst*

OBJECTIVES: Metastasis of melanoma to the head and neck mucosa is a very unusual condition. The aim of this study was to report four cases of patients with metastatic melanoma in the head and neck mucosa treated at a single institution. METHODS: Clinical data were obtained from the medical records. All cases were histologically reviewed to confirm the diagnosis, and immunohistochemical reactions were performed in the cases submitted to biopsy. RESULTS: All patients were males and the mean age was 40.5 years old. The sites of the metastatic tumors were gingival mucosa, floor of the mouth, oropharynx, and larynx. Two tumors appeared as submucosal nodules with normal color; one lesion was a blackish nodular lesion, and one was shown to be an ulcerated lesion. The size of tumors ranged from 2.0 to 4.0 cm. All patients had developed systemic disease at time of diagnosis of metastatic tumor in the head and neck mucosa. Survival rates ranged from 2 to 19 months after the diagnosis of the metastatic mucosal melanoma in the head and neck region. CONCLUSION: Although rare, patients with melanoma must be closely and regularly followed up, with careful routine examination of head and neck, because metastatic tumors in this region seem to be part of a lethal widespread metastatic disease.
Biopsy ; Diagnosis ; Head and Neck Neoplasms ; Head* ; Humans ; Larynx ; Male ; Medical Records ; Melanoma* ; Mouth ; Mucous Membrane* ; Neck* ; Neoplasm Metastasis* ; Oropharynx ; Survival Rate ; Ulcer

Osteoma is a benign osteogenic tumor composed of cancellous or compact bone, classified as peripheral, central, or extraskeletal. Peripheral osteomas are uncommon. Excluding the maxillary sinuses, the maxilla is a rare site for osteomas. The purpose of this report was to describe clinicopathological and radiological features of two peripheral osteomas occurring in the jaws, one located in the mandible and another in the edentulous maxillary alveolar ridge. The tumors were asymptomatic and were fully excised without any complications or recurrence. The lesions were submitted to histopathological analysis and diagnosed as peripheral osteoma, compact type.
Alveolar Process ; Durapatite ; Jaw ; Mandible ; Maxilla ; Maxillary Sinus ; Osteoma ; Recurrence

PURPOSE: Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. RESULTS: An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). CONCLUSION: In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles.
Anatomic Variation ; Cone-Beam Computed Tomography* ; Dental Implants ; Humans ; Linear Models ; Male ; Mandible ; Prevalence