Gingival neoplasms: a multicenter collaborative study of 888 patients in Brazil.

BACKGROUND: To evaluate the prevalence and clinicopathological features of a large series of gingival neoplasms in Brazil. MATERIAL AND METHODS:  All gingival benign and malignant neoplasms were retrieved from the records of six Oral Pathology Services in Brazil, during a 41-year period. Clinical and demographic data, clinical diagnosis, and histopathological data were collected from the patients' clinical charts. For statistical analysis, the chi-square, median test of independent samples and the U Mann-Whitney tests were used, considering a significance of 5%. RESULTS:  From 100,026 oral lesions, 888 (0.9%) were gingival neoplasms. There were 496 (55.9%) males, with a mean age of 54.2 years. Most cases (70.3%) were malignant neoplasms. Nodules (46.2%) and ulcers (38.9%) were the most common clinical appearance for benign and malignant neoplasms, respectively. Squamous cell carcinoma (55.6%) was the most common gingival neoplasm, followed by squamous cell papilloma (19.6%). In 69 (11.1%) malignant neoplasms, the lesions were clinically considered to be inflammatory or of infectious origin. Malignant neoplasms were more common in older men, appeared with larger size, and with a time of complaint shorter than benign neoplasms (p<0.001). CONCLUSIONS:  Benign and malignant tumors may appear as nodules in gingival tissue. In addition, malignant neoplasms, especially squamous cell carcinoma, should be considered in the differential diagnosis of persistent single gingival ulcers.

Gingival and alveolar mucosal reactive hyperplastic lesions: a retrospective clinical and histological study of 996 cases.

BACKGROUND: gingival/alveolar mucosal reactive hyperplastic lesions (GRHL), including fibrous hyperplasia (FH), pyogenic granuloma (PG), peripheral ossifying fibroma (POF) and peripheral giant cell lesion (PGCL), are a common group of oral diseases. The aim of the present study was to access the frequency and distribution of the clinical and histological features of these disorders in a Brazilian population. MATERIAL AND METHODS: all specimens diagnosed as GRHL in three Oral Pathology laboratories were selected for the study. Clinical information was retrieved from the laboratory biopsy forms and hematoxylin and eosin stained histological slides were reviewed for analysis of the histological characteristics. RESULTS: final sample was composed of 996 specimens, including 463 FH (47%), 280 PG (28%), 183 POF (18%) and 70 PGCL (7%). Females were more affected by FH, PG, and POF, and most cases affected adults with mean ages ranging from 40 to 53 years. FH, PG, and POF were more common in the upper gingiva/alveolar mucosa. Most PG, POF and PGCL were pedunculated, in contrast with FH (p<0.001). PG, FH and POF were mostly red or normal mucosal in color, while PGCL were mostly red/purple (p<0.001). PGCL were larger, followed by POF, FH and PG (p<0.001). Some histological features were characteristically found in some conditions, but they were also encountered in other lesions with variable frequencies. CONCLUSIONS: Oral medicine specialists, oral pathologists and periodontists are usually the professionals in contact with patients presenting GRHL and it is of upmost relevance that they should be familiarized with their clinical and histological profile.

Adverse reactions to the injection of face and neck aesthetic filling materials: a systematic review.

BACKGROUND: Adverse reactions, caused during the inflammation and healing process, or even later, can be induced by the injection of dermal filler and can present a variety of clinical and histological characteristics. In this study we aimed to review the adverse reactions associated with the injection of aesthetic filling materials in the face and neck. MATERIAL AND METHODS: The review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Studies published that mentioned adverse reactions in patients with aesthetic filling materials in the face or neck were included. Risk of bias was assessed using the Joanna Briggs Institute appraisal tool. After a 2-step selection process, 74 studies were included: 51 case reports, 18 serial cases, and five cohorts. RESULTS: A total of 303 patients from 20 countries were assessed. Lesions were more prevalent in the lip (18%), nasolabial folds (13%), cheeks (13%), chin (10%), submental (8%), glabella (7%), and forehead (6%). Histopathological analysis revealed a foreign body granuloma in 87.1% of the patients, 3% inflammatory granuloma, 3% lipogranuloma, 2.3% xanthelasma-like reaction, 1% fibrotic reaction, 0.7% amorphous tissues, 0.7% xanthelasma, 0.3% sclerosing lipogranuloma, 0.3% siliconoma, and 0.3% foreign body granuloma with scleromyxedema. In addition, two patients displayed keratoacanthoma and two others displayed sarcoidosis after cutaneous filling. The most commonly used materials were silicone fillers (19.7%), hyaluronic acid (15.5%), and hydroxyethyl methacrylate/ethyl methacrylate suspended in hyaluronic acid acrylic hydrogel (5.6%). All patients were treated, and only 12 had prolonged complications. CONCLUSIONS: There is evidence that adverse reaction can be caused by different fillers in specific sites on the face. Although foreign body granuloma was the most common, other adverse lesions were diagnosed, exacerbating systemic diseases. In this way, we reinforce the importance of previous systemic evaluations and histopathological analyses for the correct diagnosis of lesions.

Ameloblastomas mimicking apical periodontitis: a case series.

BACKGROUND: Ameloblastomas are benign odontogenic tumors that can eventually mimic the clinical and radiological features of apical periodontitis. The aim of the present study was to evaluate the clinical, radiological and histological characteristics from a series of ameloblastomas mimicking apical periodontitis diagnosed in a 14-year period. MATERIAL AND METHODS: all cases histologically diagnosed as ameloblastomas from 2005 to 2018 presenting a clinical diagnosis of periapical lesion of endodontic origin were selected for the study. Clinical, radiological and histological characteristics from all cases were tabulated and descriptively and comparatively analyzed. RESULTS: Twenty cases composed the final sample, including 18 solid and 2 unicystic ameloblastomas. Mean age of the affected patients was in the fifth decade with predilection for males (72%). The most common anatomical location was the posterior mandible (55%) and most cases presented a radiolucent unilocular (80%) well-defined (95%) image. Most cases were asymptomatic, but the presence of local swelling and bone cortical rupture were common. CONCLUSIONS: Ameloblastomas mimicking periapical lesions of endodontic origin are mostly diagnosed in adult males as well-defined radiolucent unilocular lesions producing local swelling and bone cortical rupture.

Nonendodontic periapical lesions: a retrospective descriptive study in a Brazilian population.

BACKGROUND: Several nonendodontic diseases can occur in the periapical region, resembling endodontic inflammatory conditions. Therefore, the aim of the present study was to determine the frequency of nonendodontic periapical lesions diagnosed in a Brazilian population. MATERIAL AND METHODS: The files of two Oral Pathology laboratories were reviewed and all cases including at least one clinical diagnosis of endodontic periapical lesions were selected for the study. After initial selection, demographic and clinical data, clinical diagnosis and final diagnosis were reviewed and tabulated. Final diagnosis included endodontic periapical lesions, and benign and malignant nonendodontic periapical lesions. Data were descriptively and comparatively analyzed among the three groups, with a significance level of 5% (p<0.05). RESULTS: Nonendodontic periapical lesions were identified in 208 (19%) out of the 1.125 registries included in the final sample. Benign nonendodontic periapical lesions (200 cases, 18%) were mostly odontogenic keratocysts, ameloblastomas, nasopalatine cysts, dentigerous cysts, glandular odontogenic cysts, and benign fibroosseous lesions. Malignant nonendodontic periapical lesions (8 cases, 1%) included carcinomas, adenocarcinomas, and melanoma. In general, nonendodontic periapical lesions were more common in males and in the posterior mandible (p>0.05). CONCLUSIONS: The frequency of nonendodontic periapical lesions was high and, although the general distribution was similar to the results from other populations, some features were probably associated with the profile of the studied populations and to the methods applied in the present study. Knowledge on differential diagnosis of endodontic and nonendodontic periapical lesions is essential to avoid unnecessary treatments and diagnostic delay in routine dental practice.

Intraoral soft tissue lipomas: clinicopathological features from 91 cases diagnosed in a single Oral Pathology service.

BACKGROUND: intraoral soft tissue lipomas are relatively uncommon mesenchymal neoplasms. Few papers have been published comparing the clinicopathological features of these tumors in different populations. The aim of the present study was to analyze the clinicopathological features from intraoral soft tissue lipomas diagnosed in a Brazilian population. MATERIAL AND METHODS: all cases diagnosed as intraoral soft tissue lipomas in an Oral Pathology laboratory from 2005 to 2019 were retrieved and descriptively analyzed; statistical analysis was performed for comparison of the clinical and demographic parameters. RESULTS: 91 intraoral lipomas were retrieved, including 56 lipomas, 30 fibrolipomas, 2 spindle cell lipomas, 2 angiolipomas, and 1 chondrolipoma. Mean age of the patients was 62.2 years and females represented 57.1% of the sample. Mean time of complaint was 45.4 months and mean size of the lesions was 16.2 millimeters. Buccal mucosa (38.8%), lower lip (18.8%) and tongue (16.5%) were the most commonly affected locations. Fibrolipomas were more common in females (p=0,037) and presented as smaller lesions (p=0,011) in comparison to lipomas. CONCLUSIONS: report of clinicopathological data from intraoral lipomas aid in establishing their differential diagnostic criteria and clinical profile in this specific location.

Bending, buckling and torsional resistance of rotary and reciprocating glide path instruments.

AIM: To evaluate the bending, buckling and torsional resistance of ProGlider (PG) (Dentsply Sirona, Ballaigues, Switzerland), R-Pilot (RP) (VDW, Munich, Germany) and WaveOne Gold Glider (WOGG) (Dentsply Sirona). METHODOLOGY: Ninety instruments were used: 30 PG (size 0.16, .02v taper), 30 RP (size 0.125, .04 taper) and 30 WOGG (size 0.15, .02v taper). The bending resistance test was performed on 10 randomly selected instruments of each system according to ISO 3630-1 specifications. For the buckling resistance test, a loading was applied in the axial direction of each instrument using a universal test machine, with a 20 N cell and 15 mm min-1 speed, in the axial direction. When a lateral elastic displacement of 1 mm occurred, the force was registered. The torsional resistance test was performed according to ISO 3630-1 specifications. Statistical analysis was performed using one-way anova and post hoc Student-Newman-Keuls test (P < 0.05). RESULTS: WOGG had the lowest bending resistance, whilst RP had the highest bending resistance (P < 0.05). RP also had the highest buckling resistance, and WOGG had the lowest (P < 0.05). PG had intermediate results regarding bending and buckling resistance, with significant differences to RP and WOGG (P < 0.05). RP had the highest torsional strength and the lowest angular deflection when compared to PG and WOGG (P < 0.05). No differences in the torsional strength and angular deflection were observed between WOGG and PG (P> 0.05). CONCLUSION: The glide path instruments had different behaviours in term of bending, buckling and torsional resistance.

Effects of alcohol and nicotine consumption on the development of apical periodontitis in rats: a correlative micro-computed tomographic, histological and immunohistochemical study.

AIM: To evaluate the effects of alcohol and nicotine, when used alone or simultaneously, in the development of apical periodontitis induced in rats, using a correlative analytic approach with micro-CT, histological and immunohistochemical analysis. METHODOLOGY: Twenty-eight male Wistar rats were arranged into four groups: Control, Nicotine, Alcohol and Alcohol + Nicotine. The alcohol groups were exposed to self-administration of a 25% alcohol solution, whilst the other groups drunk only filtered water. The nicotine groups received daily intraperitoneal injections of a solution with 0.19 µL of nicotine per mL, whilst the other groups received saline solution. The pulps of the left mandibular first molars were exposed for 28 days to induce periapical lesions. Throughout the experiment, drug administration was maintained, and the animals had their weight and solid and liquid consumption measured. After euthanasia, the mandibles were removed and the area, volume and major diameter of the periapical lesions were measured using micro-computed tomography images. The samples were submitted to histopathological evaluation and immunohistochemistry for RANKL and PTHrP. Statistical analysis was undertaken with a significance level of 5%. Nonparametric data were analysed using the Kruskal-Wallis test followed by Dunn's test, whilst one-way anova followed by Tukey's test was performed for parametric data. RESULTS: The alcohol groups had lower solid and liquid consumption and gained less weight when compared to the nonalcohol groups (P < 0.05). The Alcohol + Nicotine group had lesions with significantly larger volume and area when compared to the other groups (P < 0.05), whilst the Alcohol or Nicotine groups had significantly larger lesions than the control group (P < 0.05). There was no significant difference in the largest diameter of the lesions amongst groups (P > 0.05). The experimental groups had greater inflammatory response scores than the control group (P < 0.05), and the representative samples had more pronounced immunoreaction against RANKL and PTHrP antibodies. CONCLUSIONS: Alcohol and nicotine consumption exacerbated the inflammatory response and the development of periradicular lesions in rats. The association of both substances enhanced their harmful effects.

Immunoexpression of bone resorption biomarkers in apical periodontitis in diabetics and normoglycaemics.

AIM: To compare the immunoexpression of RANK, MMP-9 and PTHrP in apical periodontitis lesions of diabetic and normoglycaemic individuals. METHODOLOGY: Primary chronic apical periodontitis lesions associated with teeth indicated for extraction in 13 type 2 diabetic individuals and 13 normoglycaemic individuals who were screened for the glycaemic index and glycated haemoglobin (HbA1c) were analysed. Individuals with other systemic diseases and users of anti-inflammatories and/or antibiotics in the previous 3 months were excluded. Silanized slides with paraffin sections were used for immunohistochemical reactions and stained with haematoxylin and eosin for histopathological classification. The images were analysed with an optical microscope, and the slides were subdivided into five large fields assigning scores (0-2), according to the number of positive markings for each antibody. Fisher's exact test evaluated the parameters: gender, type of lesion, location and position in the arch. Nonparametric Mann-Whitney test was used for age, HbA1c values and comparison of marker expression. The chi-squared test was used to associate the expression of the markers. And the Spearman's coefficient correlated the markers with the size of the periapical lesion. RESULTS: The samples consisted of 69% periapical granulomas and 31% periapical cysts in each group. RANK expression was considered weak/moderate and strong in, respectively, 62% and 38% of the cases in both groups. MMP-9 expression was weak/moderate and strong in, respectively, 38% and 62% of the cases from the diabetic group, in comparison with 38% and 38% in the normoglycaemics (24% cases from this group were negative). In contrast, PTHrP expression was negative, weak/moderate and strong in, respectively, 46%, 46% and 8% of the cases from the diabetic group, in comparison with 38% negative and 62% weak/moderate in normoglycaemics. Quantitative analysis revealed that there were no significant differences in the immunoexpression of RANK (P = 0.26), MMP-9 (P = 0.17) and PTHrP (P = 0.43) between the groups. There was no significant correlation between the expression of bone resorption markers and the macroscopic size of the periapical lesions (P > 0.05). CONCLUSIONS: The bone resorption mediators analysed had similar immunoexpression in the periapical lesions of diabetic and normoglycaemic individuals.

Clinicopathological and ultrastructural characterization of periapical actinomycosis.

BACKGROUND: The aim of the present study was to analyze the clinicopathological and the ultrastructural features of periapical actinomycosis (PA) cases. MATERIAL AND METHODS: Data from the files of an oral pathology laboratory were retrieved and the findings of histopathological analysis were evaluated. Hematoxylin-eosin (HE), a modified Brown & Brenn, and Grocott stains as well as ultrastructural analysis using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were utilized. RESULTS: Six cases were obtained, 4 females and 2 males, with a mean age of 34 year-old. Two cases were symptomatic, lower teeth and the anterior region were more commonly affected, and all cases were characterized by periapical radiolucencies. All cases presented sulfur granules with a ray-fungus or club-shaped pattern of the Splendore-Hoeppli phenomenon in HE-stained sections, with filamentous gram-positive bacteria aggregates highlighted by the modified Brown & Brenn stain. SEM analysis revealed abundant packed rod-like and filamentous bacteria associated with an extracellular amorphous material. EDX analysis showed predominant picks of calcium and sulfur in actinomycotic colonies. CONCLUSIONS: Our findings suggest that PA manifests either clinically and radiologically as a non-specific and heterogeneous condition and that the actinomycotic colonies consist in a calcium- and sulfur-rich matrix. Furthermore, the results highlight the importance of submitting periapical specimens after surgical removal to histopathological analysis.

Oral potentially malignant disorders: clinical-pathological study of 684 cases diagnosed in a Brazilian population.

BACKGROUND: The frequency and distribution of oral potentially malignant disorders (OPMD) may vary among different populations. The aim of the present study was to evaluate the clinical-pathological characteristics of OPMD diagnosed in a Brazilian oral pathology laboratory over a period of 11 years. MATERIAL AND METHODS: All cases diagnosed as leukoplakia, speckled leukoplakia, erythroplakia, and actinic cheilitis from 2005 to 2015 were analyzed. Clinical information was obtained from laboratory forms and histological information was obtained from histological slides stained with hematoxylin and eosin. RESULTS: the final sample was comprised of 684 cases, of which 292 were males and 392 were females. The mean age was 58 years. The anatomical site most often involved was the lateral border of the tongue (23%), followed by the lower lip (20%), and by the buccal mucosa/vestibule (18%). Leukoplakia accounted for 82% of the sample (564 cases). The mean size of the leukoplakia and speckled leukoplakia lesions was 13 mm (ranging from 1 to 100 mm) and 15 mm (ranging from 5 to 30 mm), respectively (p=0.460). Males reported smoking and drinking alcohol more frequently than females (p=0.001 and p<0.0001, respectively). In half of the cases, dysplasia was not histologically detected, while slight dysplasia was detected in 28% of the cases. The lesions from patients aged from 41 to 80 years presented moderate and severe dysplasia more often than lesions from patients in other age groups. CONCLUSIONS: OPMD were more common in females in their sixties. Females were more frequently affected in all anatomical sites, except for the lips. Leukoplakia lesions were the most common OPMD, followed by actinic cheilitis. The lateral border of the tongue was the most affected anatomical site. OPMD located in the floor of the mouth/sublingual mucosa and lesions from older patients presented severe epithelial dysplasia with greater frequency.

Peri-implant peripheral giant cell lesions: report of 13 new cases and comparative histological and immunohistochemical analysis with peripheral and central giant cell lesions.

BACKGROUND: Few cases or peri-implant peripheral giant cell lesions (PGCL) have been reported in the literature. The aim of this study was to report 13 new cases of peri-implant PGCL and compare the expression of smooth muscle actin, Bcl-2 protein, GLUT-1, CD68, osteoprotegerin, receptor activator of nuclear factor kappa-B, Ki-67 and CD34 in these cases with PGCL and central giant cell lesions (CGCL). MATERIAL AND METHODS: Clinical data were retrieved from the laboratory records and histological analysis was performed using HE-stained slides. Immunohistochemical reactions for the above mentioned antibodies were performed and digitally scored. RESULTS: Peri-implant PGCL mostly affected the posterior mandible of adult females. CD68 and Bcl-2 expressions were higher in conventional PGCL and CGCL than in peri-implant PGCL ( p=0.033 for CD68 and p<0.0001 for Bcl-2). Microvessel density was higher in conventional peripheral than in central and peri-implant PGCL ( p=0.002). Proliferative index of the mononuclear cells showed no statistically significant differences comparing the three groups but it was higher in peri-implant PGCL. CONCLUSIONS: The current study demonstrated that peri-implant PGCL is more common in the posterior mandible of adult females. There were some differences in microvessel density, proliferative activity and expression of CD68 and Bcl-2 among conventional PGCL, peri-implant and CGCL. Further studies are encouraged to better understand these early findings.

Benign epithelial oral lesions - association with human papillomavirus.

BACKGROUND: The presence of human papilloma virus in benign oral lesions has been studied by different techniques obtaining extremely variable results. The objective of this study was to determine the presence of human papillomavirus in 83 cases of benign hyperplastic epithelial oral lesions. MATERIAL AND METHODS: Eighty-three oral lesions with clinical or histopathological features suggestive of HPV infection were retrieved from the files of four oral pathology services. Demographic data were obtained from patient's medical charts. All cases had available clinical image, H&E preparations and paraffin blocks with enough tissue for HPV detection by in situ hybridization, and immunohistochemical reactions for Ki67. RESULTS: Episomal positivity for wide spectrum HPV was observed in 24% of the cases; most of them (70%) HPV 6/11 positive. HPV 16/18 was not detected. Condyloma acuminatum was the most common lesion associated with HPV (75%), followed by verruca vulgaris (15%), squamous papilloma and multifocal epithelial hyperplasia, 5% each. Koilocytes were identified in all the HPV positive cases. Ki67 showed an abnormal proliferation pattern in 90% of the HPV positive cases; most of them (70%) showing groups of proliferating cells in focal superficial regions, and in 20% positivity was seen almost in the whole thickness of the epithelium. HPV negative cases showed Ki67 positive cells restricted to the basal layer. CONCLUSIONS: Regarding oral lesions associated with HPV, condyloma is the most common lesion expressing low-risk subtypes. The etiology of squamous papilloma remains controversial as HPV was found in 1.9% of the cases. The identification of koilocytes and the pattern of expression of Ki67 reflect HPV infection and are helpful for classification. Papillary oral lesions not associated to HPV deserve further studies to better clarify its etiology.

Primordial odontogenic tumor: Subepithelial expression of Syndecan-1 and Ki-67 suggests origin during early odontogenesis.

Primordial odontogenic tumor (POT) is composed of variably cellular myxoid connective tissue, surrounded by cuboidal to columnar odontogenic epithelium resembling the inner epithelium of the enamel organ, which often invaginates into the underlying connective tissue. The tumor is delimited at least partially by a thin fibrous capsule. It derives from the early stages of tooth development. Syndecan-1 is a heparan sulfate proteoglycan that has a physiological role in several cellular functions, including maintenance of the epithelial architecture, cell-to-cell adhesion and interaction of cells with extracellular matrix, and with diverse growth factors, stimulating cell proliferation. Ki-67 is considered the gold standard as a cell proliferation marker. The aim of this study was to examine the expression of Syndecan-1 and Ki-67 proliferation index in POT and normal tooth germs to better understand the biological behavior of this tumor. Results showed that Syndecan-1 was more intensely expressed in subepithelial mesenchymal areas of POT, in a pattern that resembles the early stages of tooth development. The cell proliferation index (4.1%) suggests that POT is a slow growing tumor. Syndecan-1 expression in tooth germs in late cap and early bell stages was similar to POT, showing immunopositivity in subepithelial mesenchymal condensed areas. The immunohistochemical findings showed a pattern in which the population of subepithelial mesenchymal cells exhibited greater proliferative activity than the central portion of the dental papilla.

What happens to unprepared root canal walls: a correlative analysis using micro-computed tomography and histology/scanning electron microscopy.

AIM: To microscopically examine the cleanliness of root canal walls that remained unprepared as revealed by micro-CT. METHODOLOGY: The root canals of 10 freshly extracted mandibular premolars with necrotic pulps and apical periodontitis along with the mesiobuccal canals of 11 mandibular molars with vital pulps were prepared using Reciproc instruments R40 and R25, respectively, and 2.5% sodium hypochlorite irrigation. Specimens were scanned in micro-CT before and after preparation, and the unprepared areas were identified. The outer root surface corresponding to the untouched areas was marked on each root third to guide further analysis using histological (for teeth with vital pulps) and scanning electron microscopic (SEM; for necrotic teeth) examination. In the teeth with vital pulps, the root canal area occupied by tissue remnants was calculated. In SEM analysis of teeth with necrotic pulps, scores were attributed for the amount of debris on the untouched areas. RESULTS: The proportion of unprepared areas in the mesiobuccal molar canals was 18.1% and 9.6% over the full canal length and apical canal, respectively. In premolars, corresponding figures were 34.6% and 17.6%, respectively. Histological analysis of canals with vital pulps revealed tissue remnants over the untouched walls almost exclusively in the apical canal. SEM analysis of the canals with necrotic pulps revealed debris along the untouched walls in all root canal thirds. CONCLUSION: The areas that remain untouched by Reciproc instruments used with 2.5% NaOCl irrigation as revealed by micro-CT analysis were usually covered with debris, in the form of pulp tissue remnants, bacteria and dentine chips, especially in the apical root canal.

Clinical and genetic analysis of patients with cherubism.

OBJECTIVE: To describe the clinical and genetic features of patients with cherubism. MATERIAL AND METHODS: A descriptive analysis of 14 cases from nine different families was carried out. Clinicopathological, imaging, and follow-up data were retrieved from patients' medical files and correlated with the genetic profile of each patient. Genomic DNA isolated from buccal mucosa cells was subjected to direct sequencing analysis of the SH3BP2 gene. RESULTS: Females were more affected than males (8:6), and the mean age at diagnosis was 8.6 years (range 3-30 years). Eleven patients exhibited simultaneous bilateral involvement of the maxilla and mandible. Two patients did not have a familial history of cherubism. Progressive growth pattern was found in six patients and stable lesions were observed in other seven patients, whereas in one patient, complete spontaneous remission was documented during the follow-up (31 years). Mutations were found in 13 cases and included the typical heterozygous missense mutations R415Q, P418T, and P418H at exon 9 of SH3BP2. No correlation between the mutations and the clinical manifestations was observed. CONCLUSION: Three different point mutations in the SH3BP2 gene were detected with variable clinical involvement. Genotype-phenotype association studies in larger population with cherubism are necessary to provide important knowledge about molecular mechanisms related to the disease.

Primordial odontogenic tumor: An immunohistochemical profile.

BACKGROUND: Primordial Odontogenic Tumor (POT) is a recently described odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla, covered by cuboidal to columnar epithelium that resembles the internal epithelium of the enamel organ, surrounded at least partly by a delicate fibrous capsule. The purpose of this study was to investigate the possible histogenesis and biological behavior of this rare tumor by means of a wide immunohistochemical analysis of its epithelial and mesenchymal components. MATERIAL AND METHODS: The immunoexpression of twenty-three different antibodies were evaluated in four cases of POT. RESULTS: The epithelial cells that cover the periphery of the tumor showed immunopositivity for Cytokeratins 14 and 19, while Amelogenin, Glut-1, MOC-31, Caveolin-1. Galectin-3, PITX2, p53, Bax, Bcl-2, Survivin and PTEN were variably expressed in focal areas. The mesenchymal component of the tumor was positive for Vimentin, Syndecan-1, PITX2, Endoglin (CD105), CD 34, Cyclin D1, Bax, Bcl-2, Survivin and p53. PTEN and CD 90 showed a moderate positivity. BRAF V600E and Calretinin were negative in all samples. Cell proliferation markers (Ki-67, MCM-7) were expressed in <5% of the tumor cells. CONCLUSIONS: According to these immunohistochemical findings, we may conclude that POT is a benign odontogenic tumor in which there is both epithelial and mesenchymal activity during its histogenesis, as there is expression of certain components in particular zones in both tissues that suggests this tumor develops during the immature (primordial) stage of tooth development, leading to its inclusion within the group of benign mixed epithelial and mesenchymal odontogenic tumours in the current World Health Organization classification of these lesions.

Comparative histological and immunohistochemical study of ameloblastomas and ameloblastic carcinomas.

BACKGROUND: This study aimed to compare the histological and immunohistochemical characteristics of ameloblastomas (AM) and ameloblastic carcinomas (AC). MATERIAL AND METHODS: Fifteen cases of AM and 9 AC were submitted to hematoxilin and eosin (H&E) and immunohistochemical analysis with the following antibodies: cytokeratins 5,7,8,14 and 19, Ki-67, p53, p63 and the cellular adhesion molecules CD138 (Syndecan-1), E-cadherin and ß-catenin. The mean score of the expression of Ki-67 and p53 labelling index (LIs) were compared between the groups using the t test. A value of p<0.05 was considered to be statistically significant. RESULTS: All cases were positive for CKs 5, 14 and 19, but negative for CKs 7 and 8. CKs 5 and 19 were positive mainly in the central regions of the ameloblastic islands, while the expression in AC was variable in intensity and localization. CK14 was also variably expressed in both AM and AC. Ki-67 (P=.001) and p53 (P=.004) immunoexpression was higher in AC. All cases were positive for p63, but values were higher in AC. CD138 was mainly expressed in peripheral cells of AM, with a weak positivity in the central areas, while it was positive in most areas of ACs, except in less differentiated regions, where expression was decreased or lost. E-cadherin and ß-catenin were weakly positive in both AM and AC. CONCLUSIONS: These results shows that Ki-67, p53 and p63 expression was higher in AC as compared to AM, suggesting that these markers can be useful when considering diagnosis of malignancy, and perhaps could play a role in malignant transformation of AM. Pattern of expression of CKs 5 and 19 in AC were different to those found in AM, suggesting genetic alterations of these proteins in malignant cells. It was confirmed that CK19 is a good marker for benign odontogenic tumors, such as AM, but it is variably expressed in malignant cases.

Influence of oestrogen deficiency on the development of apical periodontitis.

AIM: To evaluate the effects of a long period of oestrogen deficiency on the development of apical periodontitis in rats. METHODOLOGY: Wistar rats (n = 24), 3 months old, evaluated by vaginal cytology, were included in the study. Twelve animals were ovariectomized (OVX group) and the other 12 were sham operated (control group). One hundred and twenty days after castration, the pulps of the left mandibular first molars were exposed to induce the development of apical periodontitis. Body mass was verified on a weekly basis. Following 21 and 40 days of lesion induction, the animals were sacrificed. Blood was collected for biochemical analysis, and mandibles were removed for radiographic analysis. Comparative analysis of the data was performed by the nonparametric Kruskal-Wallis and Dunn's multiple-comparisons tests. The t-test was applied to compare the oestrogen levels between control and OVX groups. RESULTS: Radiographs revealed that apical periodontitis lesions were significantly larger in the 40-day OVX group when compared with both 40-day (P < 0.05) and 21-day (P < 0.001) control groups. Serum oestrogen levels were significantly lower in the OVX group (P < 0.01), confirming the efficacy of castration. Oestrogen deficiency resulted in significantly greater body mass gain (P < 0.01) in 40-day OVX group when compared with 40-day control group. Serum concentrations of calcium were similar between groups (P > 0.05). Alkaline phosphatase levels, although higher in the OVX groups (21 and 40 days), were not significantly different. CONCLUSIONS: Ovariectomized rats had significantly larger apical periodontitis lesions after 40 days of pulp exposure when compared with controls. These findings suggest that bone alterations as a result of long periods of oestrogen deficiency can influence the progression of apical periodontitis.

Allelic loss in amalgam-associated oral lichenoid lesions compared to oral lichen planus and mucosa.

BACKGROUND: The amalgam-associated oral lichenoid lesion (AAOLL) shows clinical and histopathological features similar to oral lichen planus (OLP). Molecular researches to improve knowledge of pathogenesis and clinical behavior of AAOLL are still scarce. OBJECTIVE: We investigated for the first time the use of loss of heterozygosity (LOH) as a molecular approach for genetic characterization of AAOLL in comparison with OLP and evaluated the cell proliferation index. MATERIALS AND METHODS: The sample comprised nine AAOLLs, 10 OLPs, and eight NOMs matched by patients' gender and age. LOH was assessed using polymorphic microsatellite markers at chromosomes 9p (D9S157, D9S162, D9S171), 11q (D11S1369), and 17p (TP53, AFM238WF2). Cell proliferation was assessed by immunohistochemical expression of Ki-67 (MIB-1). The association between LOH and Ki-67 was investigated. RESULTS: Loss of heterozygosity occurred in 5/9 AAOLLs and in 2/10 OLPs in at least one marker each, while NOM showed no LOH. Cell proliferation index in AAOLL ranged from 2 to 23%. There was no association between cell proliferation and LOH, independent of the marker. CONCLUSION: Our study shows that the profile of molecular changes in AAOLL and OLP, evaluated by LOH and Ki-67 expression, is similar. Additional studies including larger samples should be performed to confirm or to refute our findings.