Martinho Campolina Rebello Horta

Anatomic variations and lesions of the maxillary sinus detected in cone beam computed tomography for dental implants

OBJECTIVE To evaluate the presence of anatomic variations and lesions of the maxillary sinus in cone beam computed tomography (CBCT) of the maxilla required for dental implant planning. MATERIAL AND METHODS This transversal prevalence study evaluated a sample of 500 consecutive CBCT exams. The inclusion criteria were CBCT exams of the maxilla required for dental implant planning. The CBCT exams were independently evaluated by two oral and maxillofacial radiologists who assessed the presence of anatomic variations and lesions of the maxillary sinus. As most of the CBCT exams did not allow the evaluation of the area close to the maxillary sinus roof, anatomic variations that take place at this site were not assessed. RESULTS The anatomic variations detected were pneumatization (83.2%), antral septa (44.4%), hypoplasia (4.8%), and exostosis (2.6%). The identified lesions were mucosal thickening (≤3 mm in 54.8% and >3 mm in 62.6%), polypoid lesions (21.4%), discontinuity of the sinus floor (17.4%), air-fluid level (4.4%), bone thickening of the maxillary sinus wall (3.8%), antroliths (3.2%), discontinuity of the sinus lateral wall (2.6%), sinus opacification (1.8%), and foreign body (1.6%). CONCLUSION Anatomic variations and lesions of the maxillary sinus were common findings in CBCT exams of the maxilla required for dental implant planning. As some of these conditions can modify dental implant planning and must require specialized treatment, its recognition is noteworthy in dental practice, and especially in implantology. The amount and significance of the anatomic variations and lesions detected in this study reinforces the importance of computed tomography in preoperative dental implant planning.

EBV-1 and HCMV in aggressive periodontitis in Brazilian patients

The purpose of the present investigation was to compare the presence of Epstein-Barr virus type 1 (EBV-1) and of Human Cytomegalovirus (HCMV) in crevicular fluid samples from deep and shallow periodontal pocket sites of Brazilian patients with aggressive periodontitis. A total of 30 systemically healthy patients with aggressive periodontitis participated in the study. Paper points were inserted into 2 gingivitis sites (<3 mm) and into 2 periodontitis sites (>5 mm) in each patient. PCR assay was used to identify genomic copies of HCMV and EBV-1. Twenty-three patients (77%) were positive for EBV-1, while only 2 patients (6%) were positive for HCMV. The McNemar test revealed a positive association between EBV-1 and periodontal lesions (p=0.043). Thirty-four (57%) out of 60 periodontitis sites were positive for EBV-1, whereas 18 (30%) gingivitis sites were positive (p=0.01). Only two sites (6.7%) were positive for HCMV. No positive association was found between HCMV and periodontitis or gingivitis (p=0.479). The elevated occurrence of EBV-1 DNA in periodontal pockets of patients with aggressive periodontitis supports a possible periodontopathic role of this virus.

Expression of epithelial-mesenchymal transition markers at the invasive front of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common malignances. In epithelial-mesenchymal transition (EMT), epithelial cells switch to mesenchymal-like cells exhibiting high mobility. This migratory phenotype is significant during tumor invasion and metastasis. Objective : The aim of this study is to evaluate the expression of the EMT markers E-cadherin, N-cadherin and vimentin in OSCC. Material and Methods : Immunohistochemical detection of E-cadherin, N-cadherin and vimentin was performed on 20 OSCC samples. Differences in the expression of each protein at the invasive front (IF) and in the central/superficial areas (CSA) of the tumor were assessed. Differences in the expression of each protein at the IF of both histologically high- and low-invasive OSCCs were evaluated. Associations among expression of proteins at the IF were assessed. Correlations between the expression levels of each protein at the IF and the tumor stage and clinical nodal status were also evaluated. Results : Reduced expression of E-cadherin was detected in 15 samples (75%). E-cadherin expression was reduced at the IF when compared to the CSA and in high-invasive tumors when compared to low-invasive tumors. All samples were negative for N-cadherin, even though one sample showed an inconspicuous expression. Positive expression of vimentin was observed in 6 samples (30%). Nevertheless, there was no difference in vimentin expression between the IF and the CSA regions or between the low- and high-invasive tumors. Furthermore, no association was observed among protein expression levels at the IF. Finally, no correlations were observed between each protein’s expression levels and tumor stage or clinical nodal status. Conclusions : Reduced E-cadherin expression at the IF and its association with histological invasiveness suggest that this protein is a noteworthy EMT marker in OSCC. Although vimentin was also detected as an EMT marker, its expression was neither limited to the IF nor was it related to histological invasiveness.

Clinical, histological and immunohistochemical features of ectomesenchymal chondromyxoid tumor

OBJECTIVE Ectomesenchymal chondromyxoid tumor is a rare oral soft tissue neoplasm that should be differentiated from other neural and chondromyxoid entities. The aim of this study was to report the clinical, histological, and immunohistochemical features of 3 additional cases of this condition. METHODS Clinical data were obtained from the clinical records and all cases were evaluated through light microscopy and immunohistochemistry to cytokeratins, vimentin, S100 protein, desmin, smooth muscle actin, and glial fibrilary acidic protein. RESULTS All 3 cases affected the tongue as a long-lasting submucosal swelling and were managed through conservative surgery. They all showed myxoid and chondroid histological patterns, and vimentin, S100, and glial fibrilary acidic protein immunoexpression. CONCLUSIONS These findings reinforce the typical features of ectomesenchymal chondromyxoid tumor previously described, helping to confirm and establish the clinical, histopathological, and immunohistochemical profile of this uncommon lesion.

Odontogenic tumours in children and adolescents: a collaborative study of 431 cases

This study describes the oral and maxillofacial pathological characteristics of a series of odontogenic tumours in children and adolescents from three Brazilian reference centres. The records were reviewed for all odontogenic tumours in patients up to 18 years old based on criteria proposed by the World Health Organization (WHO) in 2005. Data concerning sex, age, skin colour and tumour location were collected and plotted. Four hundred and thirty one odontogenic tumours in children and adolescents were found, accounting for 37.5% of the total number of odontogenic tumours diagnosed. Benign tumours were predominant (99.8% of the cases), and odontoma was the most frequent type (41.4%), followed by keratocystic odontogenic tumours (25.5%) and ameloblastoma (14.6%). Odontogenic tumours were rarely detected in early childhood, and their prevalence increased with age. An almost equal distribution was observed with respect to sex and the site of the lesions. This study is the largest reported retrospective analysis describing odontogenic tumours in children and adolescents to date. The authors detected some variation in the relative frequency of odontogenic tumours compared with similar reports. Additional studies should be conducted based on the new WHO classification and predetermined age parameters to enable comparative analysis among different worldwide populations.

Cell proliferation and apoptosis in ameloblastomas and keratocystic odontogenic tumors

A high proliferative activity of the odontogenic epithelium in ameloblastoma (AM) and keratocystic odontogenic tumor (KOT) has been demonstrated. However, no previous study has simultaneously evaluated cell proliferation and apoptotic indexes in AM and KOT, comparing both lesions. The aim of this study was to assess and compare cell proliferation and apoptotic rates between these two tumors. Specimens of 11 solid AM and 11 sporadic KOT were evaluated. The proliferation index (PI) was assessed by immunohistochemical detection of Ki-67 and the apoptotic index (AI) by methyl green-pyronine and in situ DNA nick end-labelling methods. KOT presented a higher PI than AM (p<0.05). No statistically significant difference was found in the AI between AM and KOT. PI and AI were higher in the peripheral cells of AM and respectively in the suprabasal and superficial layers of KOT. In conclusion, KOT showed a higher cell proliferation than AM and the AI was similar between these tumors. These findings reinforce the classification of KOT as an odontogenic tumor and should contribute to its aggressive clinical behavior.

Laminin-5 gamma 2 chain expression is associated with intensity of tumor budding and density of stromal myofibroblasts in oral squamous cell carcinoma.

BACKGROUND Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide. Laminin-5 gamma 2 chain (laminin-5 γ2) is a protein associated to a migratory phenotype in epithelial neoplastic cells. Stromal myofibroblasts also play a significant role in tumor invasion, due to its ability to modify the extracellular matrix. Tumor budding is a morphologic marker of tumor invasion. The aim of this study was to evaluate the expression of laminin-5 γ2 in OSCC and its association with intensity of tumor budding and density of stromal myofibroblasts. METHODS Paraffin-embedded archival samples of 57 OSCC patients were evaluated. Immunohistochemistry was employed to detect laminin-5 γ2, alpha smooth muscle actin (marker of stromal myofibroblasts), and multicytokeratin (to identify OSCC cells in tumor budding evaluation). Laminin-5 γ2 expression and its association with intensity of tumor budding and density of stromal myofibroblasts were analyzed. Association among intensity of tumor budding and density of stromal myofibroblasts was also evaluated. RESULTS Higher laminin-5 γ2 expression was associated with high-intensity tumor budding (P < 0.05) and with higher density of stromal myofibroblasts (P < 0.05). Moreover, high-intensity tumor budding was associated with higher density of stromal myofibroblasts (P < 0.05). CONCLUSIONS In OSCC, higher laminin-5 γ2 expression is associated with high-intensity tumor budding and with higher density of stromal myofibroblasts, suggesting that this expression is related to the establishment of an invasive phenotype of neoplastic cells and a permissive environment for tumor invasion in this neoplasia.

Stromal myofibroblasts in focal reactive overgrowths of the gingiva

Focal reactive overgrowths are among the most common oral mucosal lesions. The gingiva is a significant site affected by these lesions, when triggered by chronic inflammation in response to microorganisms in dental plaque. Myofibroblasts are differentiated fibroblasts that actively participate in diseases characterized by tissue fibrosis. The objective of this study was to evaluate the presence of stromal myofibroblasts in the main focal reactive overgrowths of the gingiva: focal fibrous hyperplasia (FFH), peripheral ossifying fibroma (POF), pyogenic granuloma (PG), and peripheral giant cell granuloma (PGCG). A total of 10 FFHs, 10 POFs, 10 PGs, and 10 PGCGs from archival specimens were evaluated. Samples of gingival mucosa were used as negative controls for stromal myofibroblasts. Oral squamous cell carcinoma samples, in which stromal myofibroblasts have been previously detected, were used as positive controls. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin (α-sma). Myofibroblast immunostaining was qualitatively classified as negative, scanty, or dense. Differences in the presence of myofibroblasts among FFH, POF, PG, and PGCG were analyzed using the Kruskal-Wallis test. Stromal myofibroblasts were not detected in FFH, POF, PG, or PGCG. Consequently, no differences were observed in the presence of myofibroblasts among FFH, POF, PG, or PGCG (p > 0.05). In conclusion, stromal myofibroblasts were not detected in the focal reactive overgrowths of the gingiva that were evaluated, suggesting that these cells do not play a significant role in their pathogenesis.

Dentoskeletal effects of 3 maxillary expanders in patients with clefts: A cone-beam computed tomography study.

INTRODUCTION The purpose of this study was to evaluate the skeletal and dental changes in the maxillae of patients with clefts treated with 3 expanders: hyrax, fan-type, and inverted mini-hyrax supported on the first premolars. METHODS Thirty patients with unilateral cleft lip and palate with transverse maxillary deficiency were divided into 3 groups, according to the type of expander that they used. Cone-beam computed tomography images were taken before and 3 months after expansion, and the paired t test was used to evaluate the changes in each group. RESULTS The subjects in the inverted mini-hyrax group showed significant forward displacement of the maxilla (P <0.05). On the transversal plane, the hyrax group showed greater expansion in the posterior region than in the anterior region (P <0.05). However, the fan-type and the inverted mini-hyrax groups showed significantly greater maxillary expansion anteriorly than posteriorly (P <0.05). There was a greater tendency for buccal inclination of the supporting teeth when the fan-type was used. The cleft and the noncleft sides expanded symmetrically with all appliances, and there was no difference in dental tipping between these sides (P >0.05). CONCLUSIONS The hyrax expander showed better results for cleft patients requiring anterior and posterior maxillary expansion. The inverted mini-hyrax most effectively restricted posterior expansion, optimizing anterior expansion without causing as much buccal tipping of the supporting teeth as did the fan-type.

Periapical Repair in Dog Teeth: Root Canal Adhesive Filling by Using the Resilon System

INTRODUCTION New filling biomaterials with better physicochemical properties would create a favorable biologic environment for the healing of periapical tissues. The aim of this study was to evaluate periapical repair after biomechanical preparation and root filling with an adhesive system compared with the gold standard material (gutta-percha+sealer) in dog teeth. METHODS The pulp of 25 root canals was removed. The apical cementum layer was perforated, and the root canals were prepared up to size #60 K-file followed by step-back shaping with the #90 K-file and filled by the lateral condensation technique. In the experimental group (n=15), the Resilon System (Pentron Clinical Technologies, Wallingford, CT) was used. As a control material (n=10), gutta-percha cones and pulp canal sealer were used. After 60 days, the animals were killed, and 10 histologic parameters were evaluated. Differences among the groups were analyzed by using the Mann-Whitney and Fisher exact tests. RESULTS In radiographic and histologic evaluations, most fillings were slightly short of the apex. Progressive regenerative stages were observed; however, there was a reduced prevalence of biologic foraminal closure. No significant differences were observed between the 2 biomaterials with regard to any of the parameters evaluated (P>.05). CONCLUSIONS The Resilon System shows periapical biocompatibility equivalent to the gold standard material.