Dental Germ Tumor: An Unusual, Cystic, Mixed Epithelial-Mesenchymal Odontogenic Tumor.

Although odontogenic lesions have been extensively described and studied, anomalous, challenging cases occasionally come to the attention of the pathologist. Here, we report the clinical and microscopic characteristics of an unusual cystic lesion of odontogenic origin. A 16-year-old male presented with swelling and pain to palpation of the right mandible as well as numbness of the right lower lip. Radiographically, the corresponding lesion was well-defined and radiolucent with internal radiopaque foci. It extended from the right first premolar posteriorly, approaching the angle of the mandible, and involved the mandibular first molar which was impacted and displaced. The second and third right mandibular molars were also impacted and displaced. The patient was treated by excisional biopsy under general anesthesia. The histopathologic examination revealed the presence of multicystic areas lined by a thin, non-keratinizing squamous epithelium that resembled the epithelial lining of a dentigerous cyst. In continuity with the cystic lining, areas of myxoid tissue reminiscent of dental papilla were observed. The myxoid tissue formed structures that were surfaced by an epithelium comprising a basal layer of ameloblast-like cells with reverse polarity of the nuclei. Above the basilar cells, additional layers of epithelial cells composed a structure resembling the enamel organ. Subjacent to the basilar ameloblast-like cells, a condensation of mesenchymal cells with polarized nuclei opposite to the ameloblast-like cells was present. These mesenchymal cells resembled odontoblasts. In addition, numerous mineralized structures amongst the odontogenic epithelial tissue were present. To date, the patient remains well and without evidence of recurrence after 36 months of follow-up.

Imaging and histomorphometric evaluation of mandible and tibia of rats treated with bisphosphonates.

OBJECTIVES: To evaluate the mandible and tibia of rats treated with bisphosphonates (BPs) by imaging and histomorphometric analysis. STUDY DESIGN: Thirty-four rat specimens (Rattus norvegicus, Wistar strain) were distributed into 3 groups: (1) 12 rats treated with zoledronic acid; (2) 12 rats treated with clodronate; and (3) the control group, containing 10 rats that received saline. All bones were exposed to cone beam computed tomography (CBCT). The images were analyzed to determine bone density (BD), using the software OsiriX 7.0. Histological slides were prepared from the specimens and the proportion of bone volume (BV) was quantified using the software Adobe Photoshop CC. RESULTS: There was no statistically significant difference in BD either between the drug groups or between mandible and tibia. BV between BPs and control group did not show a significant difference. However, comparing the two bones, the mandibles in the control group displayed higher BV than did the tibiae in the same group. CONCLUSION: According to our results, we conclude that (1) BD was not altered by bone type or by type of BP administered, and (2) treatment with zoledronic acid or clodronate did not affect BV in the mandible or tibia of test groups.

A multicenter study of biopsied oral and maxillofacial lesions in a Brazilian pediatric population.

The aim of this study was to investigate the prevalence of oral and maxillofacial lesions among children from representative regions of Brazil. A retrospective descriptive study was conducted. Biopsy records comprising the period from 2000 to 2015 were obtained from the archives of three Brazilian oral pathology referral centers. A total of 32,506 biopsy specimens were analyzed, and specimens from 1,706 children aged 0-12 years were selected. Gender, age, anatomical location and histopathological diagnosis were evaluated. Descriptive statistics was carried out. Likelihood ratio tests were used to evaluate the association between the categorical variables. The level of significance was set at 0.05. The post-hoc test was used to identify the subgroups that significantly differed from one another, and the Bonferroni correction was applied. A total of 1,706 oral and maxillofacial lesions were diagnosed in pediatric patients, including 51.9% girls. Oral mucocele was the most prevalent reactive/inflammatory lesion (64%). The most commonly affected sites were the lips (34.5%) and mandible (19.9%). A significant association was observed between age and the group of lesions of the oral cavity (p < 0.001), and between age and anatomical location (p < 0.001). Pediatric oral and maxillofacial lesions were frequent and showed wide diversity, with the prevalence of mucocele. Knowledge of oral lesions is important for pediatric dentists worldwide, since it provides accurate data for the diagnosis and oral health of children.

A multicenter study of biopsied oral and maxillofacial lesions in a Brazilian pediatric population

Abstract The aim of this study was to investigate the prevalence of oral and maxillofacial lesions among children from representative regions of Brazil. A retrospective descriptive study was conducted. Biopsy records comprising the period from 2000 to 2015 were obtained from the archives of three Brazilian oral pathology referral centers. A total of 32,506 biopsy specimens were analyzed, and specimens from 1,706 children aged 0-12 years were selected. Gender, age, anatomical location and histopathological diagnosis were evaluated. Descriptive statistics was carried out. Likelihood ratio tests were used to evaluate the association between the categorical variables. The level of significance was set at 0.05. The post-hoc test was used to identify the subgroups that significantly differed from one another, and the Bonferroni correction was applied. A total of 1,706 oral and maxillofacial lesions were diagnosed in pediatric patients, including 51.9% girls. Oral mucocele was the most prevalent reactive/inflammatory lesion (64%). The most commonly affected sites were the lips (34.5%) and mandible (19.9%). A significant association was observed between age and the group of lesions of the oral cavity (p < 0.001), and between age and anatomical location (p < 0.001). Pediatric oral and maxillofacial lesions were frequent and showed wide diversity, with the prevalence of mucocele. Knowledge of oral lesions is important for pediatric dentists worldwide, since it provides accurate data for the diagnosis and oral health of children.

Comparison of effects of zoledronic acid and clodronate on the bone structure: imaginological and histomorphometrical study in vivo.

OBJECTIVES: To compare histologically and imaginologically the bone structure of rats' mandibles treated with bisphosphonates (BPs) and rats that did not receive BPs. METHODS: Thirty-four rat specimens (Rattus novergicus, Wistar strain) were divided into three groups: (i) 12 rats treated with zoledronic acid; (ii) 12 rats treated with clodronate; and (iii) the control group, containing 10 rats that received saline solution. All individuals were exposed to cone beam computed tomography (CBCT). The images were processed and analyzed to obtain the Hounsfield scores, using the software OsiriX 7.0. Sixty-eight histological slides were obtained from the specimens and stained with hematoxylin and eosin (HE). Using the software Adobe Photoshop CS6, the histological areas containing non-vital bone were identified and quantified. RESULTS: Non-vital bone presented positive association with the zoledronic acid and clodronate groups. Statistically, no significant difference in bone density was observed among the groups. CONCLUSIONS: Based on the results, the BP therapy alone was sufficient to induce osteonecrosis. In addition, the CBCT was not a sensible method for detection of the early signs of bone modification in individuals under BP therapy.

Demographic profile of oral nonodontogenic cysts in a Brazilian population.

OBJECTIVES: The purpose of this study was to determine the clinical and demographic characteristics of oral non-odontogenic cysts (ONOC) in a Brazilian population over a 53-year period and to compare this data with the literature. STUDY DESIGN: A total of 20.391 biopsies records were evaluated, from April/1959 to August/2012. Cases of oral developmental cysts were selected. Data regarding age, gender, time of evolution, and anatomic site of all cases were collected. The data were analyzed by descriptive statistics. RESULTS: Among 20.391 oral biopsies, 71 (0.35%) met the criteria of ONOC. Females accounted for 50.70% of all cases. The mean age observed was 38.14 years (range: 5-88 years). Nasopalatine duct cysts, oral lymphoepithelial cysts and epidermoid cysts were the most common ONOC, accounting for 63 cases (88.73%). Nasopalatine duct cysts occurred in 31 cases (43.66%), followed by 22 patients with oral lymphoepithelial cysts (30.99%) and 10 cases of epidermoid cysts (14.08%). Nasopalatine duct cysts revealed predominance among males (58.06). Oral lymphoepithelial cysts were more commonly observed in tongue (50%). Epidermoid cysts were most frequently found in the buccal mucosa (40.00%). CONCLUSIONS: The differential diagnosis of ONOC is based on the clinical, radiological, and histological findings. It is difficult to establish an epidemiological profile of ONOCs, considering the low frequency of these lesions and the divergences in the demographic and clinical presentation data among different populations.