Impact of the COVID-19 pandemic on public University laboratories of oral and maxillofacial pathology: A Brazilian multicenter study.

OBJECTIVE: To evaluate the impact of the COVID-19 pandemic on the number of diagnoses of oral and maxillofacial lesions in public laboratories after one year of COVID-19 outbreak in Brazil. MATERIAL AND METHODS: This is a cross-sectional study. Biopsies submitted to histopathologic examination from March 2019 to February 2020 (pre-pandemic period) and from April 2020 to March 2021 (pandemic period) in nine Brazilian public oral pathology laboratories were retrieved and the number of diagnoses, types of lesion, and percentage changes during both periods were analyzed. RESULTS: There were 7389 diagnoses in the pre-pandemic period and 2728 in the pandemic era, indicating a reduction of 63.08%. The reduction was 64.23% for benign lesions and 49.48% for malignant lesions, with a 50.64% reduction in squamous cell carcinoma. The largest decreases were observed in April 2020 and January 2021. CONCLUSION: An important reduction in the diagnoses of benign and malignant lesions was noted in the Brazilian public oral pathology laboratories during the first year of the COVID-19 pandemic.

Anesthetic Efficacy of an Alternative Inferior Alveolar Nerve Block Technique Using an Extra-Short Needle: A Double-Blind Randomized Non-Inferiority Trial.

PURPOSE: Inferior alveolar nerve block (IANB) is a frequently used anesthetic technique for restorative and surgical procedures in the mandible and its success rate usually ranges from 80 to 85%. Thus, this study aimed to compare the anesthetic efficacy of an alternative technique named superficial nerve block (SNB)-which consists of a modified approach using an extra-short needle inserted 10 mm deep and on a higher injection site to the conventional technique (CT) for IANB in healthy individuals. METHODS: About 20 participants received both SNB and CT with 1.8 mL of 2% lidocaine and 1:100,000 epinephrine. Thermal tests were performed 6 times, every 2 min, on the inferior canine and first molar to determine the success rate and anesthesia onset. Assessments were repeated at 20, 40, and 60 min to determine anesthesia duration. Sensitivity of lips and tongue was tested by clamp pressure. Pain perception during injection was assessed by a 100 mm visual analog scale (VAS). RESULTS: The success rate in accordance with anatomical location was molars (SNB = 90%; CT = 85%), canines (SNB = 25%; CT = 70%), lips (SNB = 45%; CT = 95%), and tongue (SNB = 85%; CT = 95%). Significant differences were found for canines (P = .012) and lips (P < .002). Moreover, median anesthesia onset was: molars (SNB = 6 min; CT = 4 min), canines (SNB = 6 min; CT = 6 min), lips (SNB = 10 min; CT = 6 min), and tongue (SNB = 8 min; CT = 4 min), whereas median duration was molars (SNB = 60 min; CT = 60 min), canines (SNB = 20 min; CT = 60 min), lips (SNB = 60 min; CT = 60 min), and tongue (SNB = 60 min; CT = 60 min). A significant difference was found for anesthesia onset on molars (P = .024) and lips (P = .009). Pain scores on VAS were SNB (median = 8.5 mm) and CT (median = 10.0 mm) (P = .398). CONCLUSIONS: In healthy individuals, the anesthetic effects of SNB were noninferior to CT in molars and tongue, although efficacy was considerably inferior in anterior teeth and lips.

Human Dental Pulp Stem Cells in Rat Mandibular Bone Defects.

This study aimed to evaluate the use of human dental pulp stem cells (hDPSCs) in non-critical-sized mandibular bone defects in rats. hDPSCs from permanent teeth were isolated and engrafted in mandibular bone defects in rats for 7, 14, and 28 days; bone defects without cells formed the control group. Samples were evaluated by scanning electron microscopy (SEM), light microscopy (hematoxylin and eosin staining), and the regeneration area was measured by the Image J program. Before surgery procedures, the human dental pulp cells were characterized as dental pulp stem cells: fusiform morphology, plastic-adherent; expression of CD105, CD73, and CD90; lack of expression of CD45 and CD34, and differentiated into osteoblasts, adipocytes, and chondroblasts. The results indicated that within 7 days the control group presented a pronounced bone formation when compared with the treated group (p < 0.05). After 14 days, the treated group showed an increase in bone formation, but with no statistical difference among the groups (p > 0.05). In the final evaluated period there was no difference between the control group and the treated group (p > 0.05). There was a significant difference between 7 and 14 days (p < 0.05) and between 7 and 28 days (p < 0.05) in the treated group. In conclusion, there is no evidence that the use of hDPSCs in the conditions of this study could improve bone formation in non-critical-sized mandibular bone defects.

Primary intraosseous carcinoma of the maxilla arising from an odontogenic keratocyst: a case report and review of the literature.

A 47-year-old man was referred for treatment of a painful lesion of 5 months' duration located on the left side of the maxilla. A small perforation in the buccal cortex was observed during the intraoral examination. Cone beam computed tomography (CBCT) showed an extensive, well-delimited radiolucent lesion extending from the alveolar ridge to the nasal cavity. An incisional biopsy was performed, and a cystic lesion consistent with an odontogenic keratocyst (OKC) was observed microscopically. The initial treatment option was decompression to be followed by enucleation. However, 3 months after decompression of the lesion, the patient returned because there was a significant increase in the size of the perforation. A destructive lytic lesion that involved the left side of the maxilla and crossed the midline was evident in the CBCT. The examination of a second incisional biopsy specimen showed epithelial neoplasia comprising islands and projections toward the surface. There was abundant keratin deposition, resulting in the formation of pearls and plugs. A diagnosis of primary intraosseous carcinoma arising from an OKC was confirmed, and the patient underwent a maxillectomy. After 1 year of follow-up, there were no signs of recurrence.

A Rare Case of Mucoepidermoid Carcinoma ex Pleomorphic Adenoma arising in Minor Salivary Gland: Histopathological and Immunohistochemical Analysis.

Mucoepidermoid carcinoma ex pleomorphic adenoma (MCxPA) is a rare salivary gland tumor predominantly found in major salivary glands. A case of MCxPA involving the soft tissue and bone of the retromolar region of a 26-year-old man is presented. The histopathological features revealed a neoplasm with predominance of pleomorphic adenoma (PA) elements, and presence of mucoepidermoid carcinoma malignant epithelial cells in several areas. Histochemical and immunohistochemical studies were positive for periodic acid Schiff, alcian blue, cytokeratins 7, 13, 14, and 19, Bcl-2, c-erbB-2, FGF-2 and maspin in the malignant areas. The patient underwent a partial resection of the left side of the mandible with neck dissection and MCxPA diagnosis was confirmed.

Immunohistochemical expression of Rho GTPases in ameloblastomas.

Rho GTPases are proteins that regulate cell cycle, shape, polarization, invasion, migration, and apoptosis, which are important characteristics of normal and neoplastic cells. Rho GTPases expression has been reported in normal tooth germ and several pathologies; however, it has not been evaluated in ameloblastomas. The aim of this study was to analyze the expression and distribution of RhoA, RhoB, Rac1, and Cdc42 Rho GTPases in solid and unicystic ameloblastomas. Three-micrometer sections from paraffin-embedded specimens were evaluated by using an avidin-biotin immunohistochemical method with antibodies against the proteins mentioned above. RhoA and RhoB staining was observed in a high number of cells (P < 0.05) and greater intensity in non-polarized ones. Rac1 was not observed, and Cdc42 did not show any statistical differences between the number of non-polarized and basal positive cells (P > 0.05). Upon comparing the studied ameloblastomas, a higher number of positive cells in the unicystic variant was observed than that in the solid one (P < 0,05). The results obtained suggest that these GTPases could play a role in the ameloblastoma neoplastic epithelial cell phenotype determination (polarized or non-polarized), as well as in variant (solid or unicystic) and subtype (follicular or plexiform) determination. Furthermore, they could participate in solid ameloblastoma invasion mechanisms.

Expression of extracellular matrix proteins in adenomatoid odontogenic tumor.

Altered expression of extracellular matrix (ECM) components has been reported in several pathologies; however, few ECM proteins have been evaluated in adenomatoid odontogenic tumor (AOT). The aim of this study was to analyze the expression and distribution of the ECM proteoglycans: biglycan and decorin; and glycoproteins: osteonectin, osteopontin, bone sialoprotein and osteocalcin in the AOT. Three-micrometer sections from paraffin-embedded specimens were evaluated employing a streptavidin-biotin immunohistochemical method with the antibodies against the proteins previously cited. Only the osteonectin was expressed in the epithelial cells. The eosinophilic amorphous material and the connective tissue showed expression of all components studied. The calcification foci expressed only osteopontin. In conclusion, the low expression of the components studied in neoplastic epithelial cells suggests that the epithelial cells act probably as stimulators of the expression by the stroma, which in turn can act as agonist or antagonist of the tumor growth. These results suggest that the components studied probably have a key role in the biological behavior of the AOT.

Hybrid ameloblastoma and central giant cell lesion: Challenge of early diagnosis.

Hybrid lesions encompass the occurrence of different entities in one lesion. A 67-year-old woman was referred to the Oral and Maxillofacial Surgery Service for treatment of mandibular Central Giant Cell Lesion (CGCL) previously diagnosed. Intraoral examination revealed edentulism and a painless swelling extending from the alveolar ridge to the buccal vestibule with hard consistency covered by normal mucosae, with unknown duration. Panoramic radiograph revealed a large, multilocular and well-defined radiolucent lesion extending from the region of left mandibular lateral incisor teeth to right mandibular first molar with no evidence of osseous perforation. Initially, a treatment with intralesional injection of corticosteroids was performed. After 18 months of treatment, an increase in size of the osteolytic lesion was noted. An incisional biopsy was carried out and the microscopic examination revealed a unicystic ameloblastoma associated to CGCL. It was performed marsupialization and later the enucleation of residual lesion. The follow-up remains being performed. Key words:Hybrid lesion, central giant cell lesion, ameloblastoma.

Dystrophic calcification and respiratory metaplasia in the epithelial lining of odontogenic cysts: a study of 362 odontogenic cysts in a Brazilian population and literature review.

PURPOSE: Main study: undertake a histological study of odontogenic cysts (OC) to determine the prevalence of dystrophic calcification and metaplasia to respiratory epithelium on a Brazilian population. LITERATURE REVIEW: to review the literature for studies that investigated the prevalence of respiratory metaplasia and dystrophic calcification on OC. METHODS: Main study: a retrospective histopathological evaluation was made of the archives from a pathology laboratory. A total of 362 cases diagnosed as OC were identified; they were analyzed by two expert observers to determine the presence of dystrophic calcification and respiratory metaplasia. The association with sex, age and anatomic location was performed through statistical analysis. LITERATURE REVIEW: a critical literature review was undertaken. Two main electronic databases (PubMed and LILACS) were searched. Retrospective studies of histological evaluation that determined the prevalence of epithelial metaplasia and dystrophic calcification on OC, with at least 10 cases, were included; their findings were summarized and discussed. RESULTS: Main study: the histological evaluation of OC revealed the presence of respiratory epithelium in 25 cases (6.9%) and dystrophic calcification in 24 cases (6.6%). Positive association was found to dystrophic calcification on residual cyst and age; respiratory metaplasia on OC and sex; respiratory metaplasia on residual cyst and gnatic bone; respiratory metaplasia in OC and gnatic bone; dystrophic calcification in OC and anatomic site of mandible. LITERATURE REVIEW: eleven studies were included in the literature review, and respiratory metaplasia ranged from 0.0% to 19.2% while dystrophic calcification ranged from 2.5% to 40.5%. CONCLUSIONS: the histological evaluation of this study found 6.9% of prevalence of respiratory metaplasia and 6.6% of dystrophic calcification, which is in accordance with the literature reviewed. Therefore, these phenomena must be taken into account in routine diagnosis services.

Actinic cheilitis and lip squamous cell carcinoma: Literature review and new data from Brazil.

BACKGROUND: To investigate the prevalence of malignant and potentially malignant lesions of the lip in an oral pathology service and to compare these data with a literature review. MATERIAL AND METHODS: A total of 3173 biopsy reports and histopathological records were analyzed. Cases with a histological diagnosis of actinic cheilitis (AC) with or without epithelial dysplasia, in situ carcinoma, or lip squamous cell carcinoma (LSCC) were included. A comprehensive literature review was conducted to investigate the prevalence of AC and/or LSCC. RESULTS: 124 cases (3.91%) were included, 75 (60.5%) had some degree of epithelial dysplasia and 31 (25.0%) were LSCC. Clinically, most of the lesions were diagnosed as AC (50.8%); however, eight cases clinically reported as AC were histologically diagnosed as LSCC. Regarding clinical characteristics, most individuals were fair-skinned male, with mean age of 54.3±12.3 years, and with a history of long-term solar exposure. Furthermore, 18 articles were selected from the literature, showing that the lower lip was predominantly affected and that most individuals were males, fair-skinned, and older than 40 years. CONCLUSIONS: Since most of the cases diagnosed clinically as AC presented some degree of epithelial dysplasia, it is important to emphasize the value of biopsy and the histological evaluation of this lesion. Key words:Actinic cheilitis, Precancerous conditions, In situ carcinoma, Oral diagnosis, Mouth neoplasms.

Effect of organic silicon, methylsulfonylmethane, and glucosamine sulfate in mandibular bone defects in rats.

Organic silicon (OS), glucosamine sulfate (GS), and methylsulfonylmethane (MSM) have been related to bone and connective tissue health and have been considered as basic therapy for osteoarthrosis disorders. Therefore, the aim was to analyze the effect of the association of these three components in mandibular bone defects in rats. Nine rats were used for histocompatibility test. In each animal was implanted the composition (70% OS, 15% GS, 15% MSM) and gutta percha (control) under the dorsal subcutaneous tissue. The samples were collected at 7, 14, and 21 days post-surgery and inflammatory events analyzed. In sequence, the composition was engrafted in mandibular bone defects of nine rats; bone defects without treatment were the control group. Analyses were performed at 7, 14, and 28 days post-surgery and samples were evaluated by scanning electron microscopy (SEM). For the histocompatibility test, both groups had a moderate inflammatory process at 7 days post-surgery and mild inflammatory process at 14 and 21 days. But in SEM analysis, the composition promotes an extensive reabsorption in cortical and crest alveolar bone, and great tooth root reabsorption. In conclusion, although the composition had positive result in the histocompatibility test, its direct application in mandibular bone defects caused intense resorption.

Temporo-spatial analysis of Osterix, HNK1 and Sox10 during odontogenesis and maxillaries osteogenesis.

Cell differentiation is essential for maxillaries and tooth development. Facial mesenchymal tissue is formed by neural crest cells (NC). These cells are highly migratory, giving rise to various cell types, considered with a high level of plasticity, indicating that they contain progenitor cells with a great power of differentiation. In this study, it was analyzed the presence of NC cell progenitors and mesenchymal stem cells (MSC) during maxillaries osteogenesis and odontogenesis in rats. Histological slides were collected in two phases: embryonic age of 15 and 17 days; 2, 4 and 7 days after birth. Immunohistochemistry for MSC markers (Osterix) and NC cells (Sox10, HNK1) was performed. The results showed positive expression for Osterix and HNK1 in undifferentiated ectomesenchymal cells in early and late stages; Sox10 was present only in early stages in undifferentiated cells. All markers were present in differentiated cells. Although the experiments performed do not allow us to explain a possible role for Osx, HNK1 and Sox10 in both differentiated and undifferentiated cells during osteogenesis and odontogenesis, it had shown important results not yet described: the presence of HNK1 and Sox10 in osteoblasts and odontoblasts in late development stages and in the tooth germ epithelial cells and ameloblasts.

Immunolocalization of bone morphogenetic protein 2 during the early healing events after guided bone regeneration.

OBJECTIVE: The objective of this study was to evaluate the immunolocalization of bone morphogenetic protein 2 (BMP-2) after autogenous block grafting covered or not with an e-PTFE membrane. STUDY DESIGN: Forty-eight rats were divided into 2 groups, autogenous block graft (B) and autogenous block graft + e-PTFE membrane (MB), and were evaluated by immunohistochemistry at baseline and 3, 7, 14, 21, and 45 days. RESULTS: The largest number of positive cells in the recipient bed was observed after 3 days in both groups. At the graft border, the largest number of positive cells was seen after 7 days in group B and after 14 days in group MB. The highest proportion of staining in the graft was observed after 3 days in group B and after 21 days in group MB. CONCLUSIONS: High proportions of stain were related to intense revascularization and osteogenesis. Except for the interface, BMP-2 staining occurred later in group MB than in group B in all structures analyzed.

Incidência de anormalidades histológicas em tecido correspondente ao espaço pericoronário de terceiros molares inclusos e semi-inclusos / Incidence of the soft tissue changes around unerupted or impacted third molars

Introdução: O Folículo Pericoronário envolve a coroa do germe dental durante seu desenvolvimento. Quando o dente permanece incluso, alterações do folículo podem originar doenças, como cistos e tumores odontogênicos. Objetivo: Analisar as alterações histológicas no tecido mole circundante a terceiros molares inclusos e semi-inclusos, independentemente de alterações patológicas aparentes em suas radiografias correspondentes, além de relacionar o diagnóstico histológico com o diagnóstico radiográfico dos casos. Material e Método: A partir de terceiros molares extraídos de 26 pacientes, foram analisados espécimes histológicos de folículos pericoronários por dois examinadores calibrados. O diagnóstico histopatológico obtido foi relacionado ao radiográfico, sendo este realizado por meio de radiografias periapicais e, quando necessário, complementado por radiografias panorâmicas. Resultado: Dos 37 folículos pericoronários avaliados, 30% mostraram alterações histológicas compatíveis com cistos dentígeros; 51% eram folículos normais, e 19% continham apenas fragmentos de mucosa. Radiograficamente, 100% dos casos demonstraram características de folículos sem alterações. Conclusão: Esses dados exemplificam que anormalidades podem estar presentes nos tecidos pericoronários sem que haja evidências clínicas e radiográficas. O exame histopatológico provê um diagnóstico mais preciso e deve ser considerado para a construção do diagnóstico definitivo. .

Introduction: Dental follicles remain adjacent to the crown of an unerupted or impacted tooth. Changes in dental follicles can occur and form a solitary cyst around the crown of the tooth, deemed dentigerous cysts. Objective: The aim of this study was to determine the incidence of soft tissue changes around unerupted or impacted third molars. Material and Method: Pericoronal tissue of patients who were referred to our clinic for removal of third molars for a variety of reasons was examined histopathologically. Follicular spaces were measured from periapical and panoramic radiographs by each author independently. Result: Of the 37 specimens submitted for histopathologic examination, 19 normal follicular tissues (51%), 11 arrangements typical of a cyst (30%) and 7 normal tissues of oral mucous (11%) were found. Conclusion: Cystic changes may be encountered in the histopathologic examination of radiographically normal unerupted or impacted third molar follicles. .

Avaliação do metabolismo epitelial em cistos radiculares pela técnica de AgNORS / Epithelial metabolism evaluation in radicular cysts by the AGNOR technique

Introdução: A formação do Cisto Radicular (CR) está associada à proliferação dos restos epiteliais de Malassez por estímulos inflamatórios, provenientes da proliferação bacteriana do canal radicular de um dente não vital. Quando o dente é removido, esse cisto passa a ser denominado Cisto Residual (CRe). O tratamento de escolha para o CR é endodôntico, com o objetivo de eliminar a inflamação presente no periápice. No entanto, em alguns casos, o cisto pode continuar a crescer, necessitando de tratamento cirúrgico, o que ocorre na maioria dos casos de CRe. Objetivo: Avaliar o metabolismo do epitélio de revestimento de CR e CRe, utilizando a quantificação das AgNORs, e verificar a influência da presença de inflamação sobre o crescimento desses cistos. Material e método: Vinte casos de CR e dez de CRe foram submetidos à técnica de AgNOR. A análise quantitativa das NORs foi realizada utilizando-se o software 'Contando células'. O teste estatístico pós-hock de Newman-keuls foi realizado para a comparação do número médio de AgNORs entre CR e CRe, e entre áreas inflamadas e não inflamadas. Resultado: Diferença estatisticamente significante (p=0,0094) foi observada entre áreas inflamadas (1,86±0,26) e não inflamadas (1,65±0,20). Na comparação entre CR (1,81±0,28) e CRe (1,73±0,16), não houve diferença estatisticamente significante (p=0,37). Conclusão: A inflamação interfere no metabolismo epitelial de CR e CRe, o que reflete a ação de fatores de crescimento na proliferação do epitélio, contribuindo para o crescimento do cisto, independentemente da presença do fator etiológico associado com a origem da lesão. .

Introduction: Radicular Cyst (RC) development is associated with the activation and proliferation of epithelial rests of Malassez. This occurs due to inflammatory stimuli resulting from bacteria proliferation in the root canal of a non-vital tooth. When the tooth is removed, the cyst becomes known as Residual Cyst (ReC). The RC common treatment is the endodontic therapy, with the aim of eliminating the inflammation in the periapical region. Nonetheless, this treatment is not always effective and the cyst may continue to grow, what happens in most cases of ReC. Objective: To evaluate the metabolism of the RC and ReC epithelial lining through the technique of AgNOR quantification and of the influence of the presence of inflammation in the growth of these cysts. Material and method: 20 cases of RC and 10 of ReC, were processed by the AgNOR technique. The AgNOR quantitative analysis was performed using the "Counting cells" software. The statistical post-hock Newman-Keuls test was applied to compare the RC and ReC mean number of AgNORs in inflamed and non-inflamed areas. Result: Statistically significant difference (p=0.0094) was observed between inflamed (1.86±0.26) and non-inflamed (1.65±0.20) areas. No statistically significant difference (p=0.37) was observed in the comparison between RC (1.81±0.28) and ReC (1.73±0.16). Conclusion: Inflammation interferes in the epithelial metabolism of RC and ReC, reflectings the action of growth factors in epithelial proliferation and contributing to the growth of the cyst, regardless the presence of the etiologic factor associated with the injury origin. .

Idiopathic hyperplasia of the sublingual glands in totally or partially edentulous individuals.

OBJECTIVE: To determine the possible etiologic factors associated with the development of idiopathic hyperplasia of the sublingual gland (IHSG). STUDY DESIGN: Fifty partially or totally edentulous patients were divided into 2 groups, each with 25 subjects, matched by sex. Group 1 was made up of patients with IHSG, whereas group 2 consisted of patients without IHSG. Patients of both groups were investigated with respect to the use of prostheses, systemic medication, systemic diseases, smoking habits, alcohol consumption, and xerostomia. In addition, patients of group 1 were examined by occlusal radiography, and in 6 of them, a biopsy of the sublingual gland swelling was taken for histopathologic investigation. The Fisher exact test was used, with significance set for P < or = .05. RESULTS: The comparative analysis revealed no statistical difference between the 2 groups concerning all factors investigated (P > .05). Radiographic examination did not detect any presence of salivary calculi; the histopathologic findings revealed either chronic sialadenitis (4 cases) or normal glandular tissue (2 cases). CONCLUSION: Our clinical and histopathologic analyses confirm that IHSG is a harmless condition for which no surgical treatment is required. The etiologic investigation did not find any local or systemic factors significantly associated with the development of IHSG. The absence of posterior teeth remains as the only known predisposing factor to be strongly linked to this condition.