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.

Expression of stem cell markers Nanog and Nestin in lip squamous cell carcinoma and actinic cheilitis.

Cancer stem cell (CSC) proteins have been observed in several lesions and are associated with tumor beginning, evolution, and resistance to treatment. OBJECTIVES: To investigate the presence of NANOG, NESTIN, and ß-tubulin in lip squamous cell carcinoma (LSCC), actinic cheilitis (AC), and normal epithelium (NE). MATERIALS AND METHODS: Thirty cases of LSCC, thirty cases of AC (both analyzed according to the WHO classification and AC according to the binary classification), and twenty cases of NE were submitted to an immunohistochemical study. RESULTS: NANOG was more expressed in the nuclei of AC compared to NE (p = 0.007), as well as in high-risk AC cases (p = 0.017) and well-differentiated LSCCs (no significance). There was an accumulation of nuclear NANOG from mild to moderate and severe ACs. NESTIN was significantly less present in NE compared to AC (p = 0.001) and LSCC (p = 0.003). There was a higher expression in severe dysplasia or high-risk AC and well-differentiated LSCC. These results indicate an upregulation of NANOG and NESTIN in the early stages of carcinogenesis. ß-tubulin was intensely present in all lesions. CONCLUSION: The results suggest an upregulation of NANOG and NESTIN in the biological behavior these diseases, mainly in the transformation from AC to LSCC.

Immunoexpression of SOX-2 in oral leukoplakia.

OBJECTIVE: This study was conducted to correlate and compare the immunoexpression of sex-determining region Y-box 2 (SOX-2) in oral leukoplakia (OL) lesions with that in normal buccal mucosa (control). MATERIALS AND METHODS: In this observational study, OL with low-risk (n = 34) and high-risk (n = 33) dysplasia and control samples (n = 25) were subjected to immunohistochemical analysis for SOX-2. In the epithelium, SOX-2 positive and negative cells, as well as semiautomatic segmentation of the immunopositive nuclear area were counted. Statistical tests included chi-square, one-way analysis of variance, Tukey, and Games-Howell. The level of significance was 5%. RESULTS: Groups with OL lesions (low and high-risk) showed higher mean numbers of SOX-2 positive cells (63.47 ± 25.70 and 68.18 ± 21.17) compared to the control group (45.85 ± 27.38) (p = 0.00). Groups with OL lesions (low and high-risk) exhibited higher mean positive nuclear area (0.24 ± 0.47 and 1.09 ± 2.06) compared to the control group (0.00 ± 0.01) (p = 0.01). CONCLUSION: Oral leukoplakia lesions showed a higher expression of SOX-2, suggesting its contribution to the pathogenesis of OL.

Immunohistochemical expression of DNA methyltransferases 1, 3a, and 3b in actinic cheilitis and lip squamous cell carcinomas.

BACKGROUND: Epigenetic modifications, including DNA methylation of tumor suppressor genes carried out by DNA methyltransferases (DNMTs), are important events in carcinogenesis. Although there are studies concerning to its expression in several cancer types, DNMTs expression pattern is not known in photoinduced lip carcinogenesis. The aim of this study was to investigate the immunoexpression of DNMTs 1, 3a, and 3b in lip precancerous lesion (actinic cheilitis) and cancer. METHODS: Thirty cases of actinic cheilitis (AC), thirty cases of lip squamous cell carcinoma (LSCC), and twenty cases of non-neoplastic tissue (NNT) were selected for immunohistochemical investigation of DNMTs 1, 3a, and 3b. RESULTS: Nuclear DNMT 1 immunoreactivity was significantly higher in the LSCC group (68.6%) compared with NNT (47%), and nuclear DNMT 3b was higher in LSCC (70.9%) than in NNT (37.9%) and in AC (44%). Only DNMT 3a showed both higher nuclear and cytoplasmic expression in AC (35.9% and 35.5%, respectively) than in NNT (4.4% and 16.1%, respectively) and LSCC (8.8% and 13.2%, respectively) (P < 0.05). CONCLUSIONS: The results suggested that DNMT 3a could play a key role in the methylation process of initial steps of UV carcinogenesis present in AC while DNMT 3b could be responsible for de novo methylation in already established lip cancer.

Immunohistochemical expression of matrix metalloproteinase-1, matrix metalloproteinase-2 and matrix metalloproteinase-9, myofibroblasts and Ki-67 in actinic cheilitis and lip squamous cell carcinoma.

Matrix metalloproteinases (MMPs), myofibroblasts (MFs) and epithelial proliferation have key roles in neoplastic progression. In this study immunoexpression of MMP-1, MMP-2 and MMP-9, presence of MFs and the epithelial proliferation index were investigated in actinic cheilitis (AC), lip squamous cell carcinoma (LSCC) and mucocele (MUC). Thirty cases of AC, thirty cases of LSCC and twenty cases of MUC were selected for immunohistochemical investigation of the proteins MMP-1, MMP-2, MMP-9, α-smooth muscle actin (α-SMA) and Ki-67. The MMP-1 expression in the epithelial component was higher in the AC than the MUC and LSCC. In the connective tissue, the expression was higher in the LSCC. MMP-2 showed lower epithelial and stromal immunostaining in the LSCC when compared to the AC and MUC. The epithelial staining for MMP-9 was higher in the AC when compared to the LSCC. However, in the connective tissue, the expression was lower in the AC compared to other lesions. The cell proliferation rate was increased in proportion to the severity of dysplasia in the AC, while in the LSCC it was higher in well-differentiated lesions compared to moderately differentiated. There were no statistically significant differences in number of MFs present in the lesions studied. The results suggest that MMPs could affect the biological behaviour of ACs and LSCCs inasmuch as they could participate in the development and progression from premalignant lesions to malignant lesions.

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.

Accuracy of MRI, CT, and Ultrasound imaging on thickness and depth of oral primary carcinomas invasion: a systematic review.

OBJECTIVES: The aim of this study was to perform a systematic review to assess the sensitivity, specificity, and accuracy of magnetic resonance imaging (MRI), computed tomography (CT), and intraoral ultrasound (US) to determine the depth of invasion (DOI) and/or tumor thickness (TT) in oral cavity cancers, with histopathological evaluation as the gold standard. METHODS: Articles whose primary objective was to evaluate the accuracy (sensitivity and specificity) of MRI, CT, and US imaging to assess DOI and/or TT were searched in six major electronic databases, in addition to three grey literature databases. The methodological quality of the selected studies was evaluated by using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. RESULTS: Twelve studies met the inclusion criteria and underwent qualitative analysis: six studies on MRI, three on US, and one on CT. The accuracy values for MRI ranged from 67 to 83%, with sensitivity values above 80% and specificity above 75%. For US, mean values of sensitivity ranged from 91 to 93%. For CT, accuracy was 75%. CONCLUSIONS: For the application of US, CT, MRI, good accuracy was reported in DOI and/or TT, as evaluated in the preoperative period. US offered advantages for detection of small lesions.

The challenging diagnosis of low-grade myofibroblastic sarcoma: A case report and literature update.

Low-Grade Myofibroblastic sarcoma (LGMS) is categorized as an extremely rare malignant neoplasia of myofibroblasts, which has only recently become more widely studied. Our patient was referred for evaluation of a nodule involving the palate. The histopathological analysis showed a mesenchymal tumor formed for stellate-shaped cells. Negativity for Laminin, Desmin, Collagen IV, CK pool, CD34, S100, and ALK1, discarded epithelial, endothelial, neural, and inflammatory origin. On the other hand, the positivity for Calponin and SMA demonstrated myofibroblastic and smooth muscle differentiation. The diagnosis of LGMS was endorsed and the patient was submitted for medical treatment. To date, only 18 cases describing patients diagnosed with intrabuccal LGMS have been reported in the scientific literature. Here, we introduce a rare report and for the first time, also provide an update of the literature and a clear review regarding the immunohistochemical panel to diagnose this entity, once the histopathological diagnosis is still challenging.

DNA methylation in oral squamous cell carcinoma: from its role in carcinogenesis to potential inhibitor drugs.

DNA methylation is one of epigenetic changes most frequently studied nowadays, together with its relationship with oral carcinogenesis. A group of enzymes is responsible for methylation process, known as DNA methyltransferases (DNMT). Although essential during embryogenesis, DNA methylation pattern alterations, including global hypomethylation or gene promoter hypermethylation, can be respectively associated with chromosomal instability and tumor suppressor gene silencing. Higher expression of DNA methyltransferases is a common finding in oral cancer and may contribute to inactivation of important tumor suppressor genes, influencing development, progression, metastasis, and prognosis of the tumor. To control these alterations, inhibitor drugs have been developed as a way to regulate DNMT overexpression, and they are intended to be associated with ongoing chemo- and radiotherapy in oral cancer treatments. In this article, we aimed to highlight the current knowledge about DNA methylation in oral cancer, including main hyper/hypomethylated genes, DNMT expression and its inhibitor treatments.

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.

Atypical presentation of oral basaloid squamous cell carcinoma.

AIM: The purpose of this report is to present the clinical and histological features of a basaloid squamous cell carcinoma (BSCC) occurring in the retromolar trigone of a 59-year-old man and to relate its immunohistochemical characteristics. BACKGROUND: BSCC is an aggressive distinct variant of squamous cell carcinoma (SCC) requiring recognition as a separate entity from SCC due to its peculiar behavior. CASE REPORT: A clinical examination revealed a 12x07x07 mm nodular mass with a rubbery consistency, defined borders, covered by reddish mucosa and an absence of bleeding upon palpation. Histologically, nests and cords of closely packed, moderately pleomorphic basaloid cells with nuclear palisading along the periphery of the neoplastic nests surrounded by a fibrous stroma were found. SUMMARY: Since this tumor can mimic other neoplasms such as adenoid cystic carcinoma, neuroendocrine carcinoma, and basal cell adenocarcinoma, histological features are essential to differentiate between them. Furthermore, immunohistochemical testing can provide valuable diagnostic information that can have a profound impact on treatment options and the prognosis. CLINICAL SIGNIFICANCE: BSCC needs to be differentiated from other neoplasms as early as possible because of its adverse prognosis. Clinicians are advised to conduct a mucosal evaluation during oral examinations and take a thorough medical history which could ultimately save the life of a patient.

Effects of sclerosing agents on head and neck hemangiomas: A systematic review.

BACKGROUND: The aim of this study was to systematically review the literature for studies that investigated the effects of sclerosing agents on head and neck hemangiomas. MATERIAL AND METHODS: Clinical trials, cohort studies, and descriptive studies were considered eligible and selected in a two-phase process. Six main electronic databases, in addition to three grey literature databases, were searched. Risk of bias (RoB) was assessed using the "Meta-Analysis of Statistics Assessment and Review Instrument" checklist. From fifty-six considered eligible, five were finally included. RESULTS: One article were judged at low, one at moderate, and three at high RoB. The sclerosing agents investigated were sodium tetradecyl sulphate (n=2), ethanolamine oleate (n=1), pingyangmycin (n=1) and bleomycin (n=1). Overall, good results were achieved on the treatment of head and neck hemangiomas with intralesional sclerotherapy. Most commonly reported adverse effects included pain, swelling, fever, necrosis, transient facial palsy, and anorexia. CONCLUSIONS: Considering the limited number of included studies, intralesional sclerotherapy on the management of HN hemangiomas presented overall good results with minor adverse reactions, especially in regards to smaller lesions. Key words:Sclerotherapy, sclerosing solutions, vascular neoplasms, hemangioma.