Study on frequency of dental developmental alterations in a Mexican school-based population

BACKGROUND: The aim of this study was to know the distribution of dental developmental alterations in the population requesting stomatological attention at the Admission and Diagnosis Clinic of our institution in Mexico City. MATERIAL AND METHODS: We reviewed the archives and selected those files with developmental dental alterations. Analyzed data were diagnoses, age, gender, location and number of involved teeth. RESULTS: Of the 3.522 patients reviewed, 179 (5.1%) harbored 394 developmental dental alterations. Of them, 45.2% were males and 54.8% were females with a mean age of 16.7 years. The most common were supernumeraries, dental agenesia and dilaceration. Adults were 30.7% of the patients with dental developmental alterations. In them, the most common lesions were agenesia and supernumeraries. Mesiodens was the most frequently found supernumerary teeth (14.7%). CONCLUSIONS: Our finding that 30.7% of the affected patients were adults is an undescribed and unusually high proportion of patients that have implications on planning and prognosis of their stomatological treatment

MUC-1 expression in pleomorphic adenomas using two human milk fat globule protein membrane antibodies (HMFG-1 and HMFG-2).

UNLABELLED: Pleomorphic adenoma (PA) is the most common salivary gland tumor and its microscopic features and histogenesis are a matter of debate. Human milk fat globule protein membrane (HMFG) monoclonal antibodies (MoAbs) comprise a set of antibodies against the mucin 1 (MUC-1) protein detected in several salivary gland tumors. OBJECTIVE: The aim of this study was to assess the immunoexpression of the PA neoplastic cells to MUC-1 protein using HMFG-1 and HMFG-2 MoAbs, contrasting these results with those from normal salivary gland tissue. MATERIAL AND METHODS: Immunohistochemical detection of MUC-1 protein using HMFG-1 and HMFG-2 MoAbs was made in 5 mm thick, paraffin embedded slides, and the avidin-biotin method was used. RESULTS: Positivity to HMFG-1 and HMFG-2 MoAbs was found in ductal, squamous metaplastic and neoplastic myoepithelial cells, keratin pearls and intraductal mucous material. Two kinds of myoepithelial cells were identified: classic myoepithelial cells around ducts were negative to both MoAbs, and modified myoepithelial cells were positive to both MoAbs. This last cellular group of the analyzed tumors showed similar MUC-1 immunoexpression to ductal epithelial cells using both HMFG antibodies. Intraductal mucous secretion was also HMFG-1 and HMFG-2 positive. CONCLUSIONS: Our results showed there are two kinds of myoepithelial cells in PA. The first cellular group is represented by the different kinds of neoplastic myoepithelial cells and is HMFG-positive. The second one is HMFG-negative and represented by the neoplastic myoepithelial cells located around the ducts.

Scanning Electron Microscopic Study on the Fibrillar Structures within Dentinal Tubules of Human Dentin.

INTRODUCTION: Pulp biology is central to the whole tooth, and knowledge on its microstructure is changing with new studies. This study presents certain microfibrillar structures found within the dentin tubules of human teeth connecting dentin tubules and odontoblastic processes. METHODS: We analyzed the crowns of 30 noncarious, human teeth. They were fixed; demineralized; and, later, processed and reviewed by means of scanning electron microscopy. RESULTS: In the predentin layer, we found numerous fine fibrillar structures connecting the odontoblastic process and the wall of the dentinal tubule. In the inner dentinal third, we observed structures forming a dense microfibrillar network of variable thickness and diameters. These microstructures were very thin and numerous in this area, and their number decreased as more external dentin levels were examined. CONCLUSIONS: According to the review of the literature and our findings, these microfibrillar structures may be an unrecognized support system that holds and secures the odontoblastic process within the dentinal tubule.

Toxicity test of a dental commercial composite.

BACKGROUND: International rules must be followed for testing biosecurity in dental materials. A new brand of restorative material appeared in the market and regulations indicated that it should be tested for toxicity. OBJECTIVES: The aim of this study was to determine the 90-day sub chronic toxicity of one triethylene glycol dimethacrylate containing composite (MEDENTAL Light-Cure Composite™) orally administered to rats according to Organization for Economic Co-Operation and Development no. 48 guidelines and the requirements specified in the ISO 10993-11. MATERIAL AND METHODS: Wistar rats ate the polymerized composite during 90 days and were observed to determine changes in their behavior, eye and skin signs and other attitudes such as aggressiveness, posture, walking and response to handling. After 90 days were sacrificed to ascertain blood alterations, we did special hematological tests and assessed microscopic slides from 33 different organs. RESULTS: We recorded no significant changes in clinical behavior of the animals. Microscopic review of the H&E stained slides obtained from the analyzed organs showed no abnormal inflammatory or cytological changes and all hematological special tests were within normal limits. CONCLUSIONS: Results of this study show that under our experimental conditions the MEDENTAL Light-Cure Composite™ does not produce inflammatory or cytological changes suggestive of toxicity. Key words:Dental materials, composite resin, toxicity, inflammation, TEGDMA.

MUC-1 expression in pleomorphic adenomas using two human milk fat globule protein membrane antibodies (HMFG-1 and HMFG-2)

Pleomorphic adenoma (PA) is the most common salivary gland tumor and its microscopic features and histogenesis are a matter of debate. Human milk fat globule protein membrane (HMFG) monoclonal antibodies (MoAbs) comprise a set of antibodies against the mucin 1 (MUC-1) protein detected in several salivary gland tumors. Objective The aim of this study was to assess the immunoexpression of the PA neoplastic cells to MUC-1 protein using HMFG-1 and HMFG-2 MoAbs, contrasting these results with those from normal salivary gland tissue. Material and Methods Immunohistochemical detection of MUC-1 protein using HMFG-1 and HMFG-2 MoAbs was made in 5 mm thick, paraffin embedded slides, and the avidin-biotin method was used. Results Positivity to HMFG-1 and HMFG-2 MoAbs was found in ductal, squamous metaplastic and neoplastic myoepithelial cells, keratin pearls and intraductal mucous material. Two kinds of myoepithelial cells were identified: classic myoepithelial cells around ducts were negative to both MoAbs, and modified myoepithelial cells were positive to both MoAbs. This last cellular group of the analyzed tumors showed similar MUC-1 immunoexpression to ductal epithelial cells using both HMFG antibodies. Intraductal mucous secretion was also HMFG-1 and HMFG-2 positive. Conclusions Our results showed there are two kinds of myoepithelial cells in PA. The first cellular group is represented by the different kinds of neoplastic myoepithelial cells and is HMFG-positive. The second one is HMFG-negative and represented by the neoplastic myoepithelial cells located around the ducts. .

Review of the literature on necrotizing sialometaplasia and case presentation.

The aim of this article is to report a case of necrotizing sialometaplasia with long-term follow-up. A case of necrotizing sialometaplasia in a 37-year-old man with clinical documentation on the progress during a 2-year follow-up is presented. Data from an extensive review of the literature including clinical, imagenologic, and microscopic features are provided. Information on diagnostic and prognostic factors is offered and comprehensibly discussed. The importance of identification and diagnosis of this entity during the review of the slides from the first biopsy is stressed and the exclusive performance of an incisional biopsy is debated. The presented clinical photographs reveal the clinical changes of the lesion from the beginning of the lesions up to 2 years follow-up, documenting the complete long-term clinical course and the healing process of this entity.

Presence of matrix vesicles in the body of odontoblasts and in the inner thirdof dentinal tissue: A scanning electron microscopyc study

Objectives: The aim of this report is to present the results of a scanning electron microscopic study on the presence of matrix vesicles (MVs) found in human dentine. Study Design: Dentin tissue from 20 human bicuspids was analyzed by means of scanning electron microscopy. Results: MVs were found as outgrowths of the cellular membrane of the odontoblastic body, the more proximal portion of the odontoblastic process before entering the dentinal tubule and in the odontoblastic process within the inner third of the dentin. Size of MVs varied depending on location. In the inner third of dentin, they were seen indiverse positions; as membranal outgrowths, deriving from the odontoblastic process, lying free in the intratubular space and attached to the dentinal wall. Sometimes, they were seen organized forming groups of different size sand shapes or as multivesicular chains running from the surface of the odontoblastic process to the tubular wall. MVs were present in places never considered: 1) the body of odontoblasts; 2) the most proximal part of the odontoblastic processes before entering the circumpulpal dentine and also: 3) in the inner third of dentinal tissue. Conclusions: According to our results, MVs not only participate during mantle dentin mineralization during early dentinogenesis, they also contribute during the mineralization process of the inner dentin (AU)

Presence of matrix vesicles in the body of odontoblasts and in the inner third of dentinal tissue: a scanning electron microscopic study.

OBJECTIVES: The aim of this report is to present the results of a scanning electron microscopic study on the presence of matrix vesicles (MVs) found in human dentine. STUDY DESIGN: Dentin tissue from 20 human bicuspids was analyzed by means of scanning electron microscopy. RESULTS: MVs were found as outgrowths of the cellular membrane of the odontoblastic body, the more proximal portion of the odontoblastic process before entering the dentinal tubule and in the odontoblastic process within the inner third of the dentin. Size of MVs varied depending on location. In the inner third of dentin, they were seen in diverse positions; as membranal outgrowths, deriving from the odontoblastic process, lying free in the intratubular space and attached to the dentinal wall. Sometimes, they were seen organized forming groups of different sizes and shapes or as multivesicular chains running from the surface of the odontoblastic process to the tubular wall. MVs were present in places never considered: 1) the body of odontoblasts; 2) the most proximal part of the odontoblastic processes before entering the circumpulpal dentine and also: 3) in the inner third of dentinal tissue. CONCLUSIONS: According to our results, MVs not only participate during mantle dentin mineralization during early dentinogenesis, they also contribute during the mineralization process of the inner dentin.

Multiple supernumeraries in a non-syndromic patient.

Presence of supernumerary teeth (ST) in non-syndromic patients is an exceptional event. The aim of this article is to present an unusual case of a non-syndromic 12 years old girl with 12 ST In the reported case supernumeraries were found in three quadrants and the most common ST were bicuspids. All ST were surgically excised and occlusion and functionality was restored with prosthetic appliances. ST are an exceedingly uncommon event in the Pediatric Clinic. An extensive review of the literature dealing on non-syndromic cases comprising 10 or more ST and a discussion about the origin of the ST is presented.

Scanning electron micrographic features of a giant submandibular sialolith.

To recognize recently appearing mineralization phenomena, one must study the external surface of the sialoliths, since it is not possible to study them in the central portions of sialoliths. The authors examined the external surface of a sialolith by scanning electron microscopy and analyzed its microstructures. The study revealed the presence of numerous microstructures of different shapes (nodular, laminar, reticular, microgranular, and multinodular) and variable size arranged in a haphazard fashion. The diverse microstructures encountered strongly suggest that different mechanisms of mineralization occur during growth and development of the sialoliths.

Clinicopathological and immunocytochemical study of multifocal epithelial hyperplasia.

PURPOSE: We present the clinicopathological findings after reviewing 52 patients affected by multifocal epithelial hyperplasia (MEH), previously known as focal epithelial hyperplasia and the results of an immunocytochemical study. PATIENTS AND METHODS: We reviewed the clinical files and microscopic slides from 52 MEH-affected patients and new slides were immunostained with a polyclonal antibody against high molecular weight cytokeratins. RESULTS: More than 95% of the patients were in poverty (<200 dollars monthly family income). Females comprised 71.1% of the MEH patients, 69.3% were in the first and second decades and buccal mucosa, lips, and tongue were more frequently affected. Ninety-two percent of the patients had a direct relative with similar lesions. In hematoxylin and eosin-stained slides, prominent multiple nucleoli were observed. Immunocytochemical study showed differences in immunostaining between lesional and normal cells. Cells with strongly immunostained cytoplasm were seen in the prickle layer of the lesional epithelium as well as in the clinically normal neighboring epithelial tissue. Cytokeratin-negative mitosis-like cells and koilocytes were identified within the lesions. CONCLUSIONS: The name "multifocal epithelial hyperplasia" is more accurate than those previously proposed designations, because it is more precise to describe the clinical and microscopic features of the disease. Also, our results suggest that mitosis-like cells and koilocytes are degenerated cells unable to synthesize cytokeratins and that cells with strongly immunostained cytoplasm represent epithelial cells showing an altered cytokeratin metabolic profile.

Immunoexpression of the HLA-DR class II molecule in cells from inflamed dental pulp.

BACKGROUND: Despite that the role of inflammatory cells in chronic inflammatory reactions of pulpal origin (CIRPOs) has been extensively studied, function of the HLA-DR+ cells (HLA-DR+ Cs) is poorly understood. The aim of this study was to quantify their number and clarify their role in these lesions. METHODS: We studied 11 CIRPOs immunostained with an anti-HLA-DR class II monoclonal antibody and the number and location of the HLA-DR+ Cs quantified. CIRPOs were divided in periapical granulomas (PGs), epithelized granulomas (EGs) and periapical cysts (PCs). RESULTS: HLA-DR+ Cs were observed within epithelium, inflammatory infiltrate and close to blood vessels. In PGs, they account for 19-256 cells/mm2, in EGs they were 20-494 cells/mm2 and in PCs quantification numbered 39-316 cells/mm2. CONCLUSIONS: Our results suggest that HLA-DR+ Cs present antigens to lymphocytes, collaborating in initiation, regulation, development and perpetuation of CIRPOs. Also, these results suggest that these cells have an active role during initiation of epithelial proliferation in PGs and that they are partially responsible for cystic transformation from EGs to periapical cysts. They may also play an active role in bone resorption.

Sialolitiasis de glándula sublingual: presentación de un caso clínico y revisión de la literatura / Sialolithiasis of sublingual gland: report of a clinical case and review of the literature

La sialolitiasis es una enfermedad de presentación esporádica que se manifieta con mayor frecuencia en pacientes de sexo masculino y se asocia principalmente con las glándulas salivales mayores. Clínicamente, el sitio afectado presenta aumento de volumen, de consistencia dura, móvil, fácilmente desplazable y a veces doloroso. En este artículo se reporta un caso de uon paciente masculino de 20 años de edad con un sialolito de un año de evolución, localizado en una de las glándulas sublinguales. Se llevó a cabo la remoción quirúrgica del cálculo, sin ninguna complicación y se realizó el examen microscópico. Se efectúa seguimiento del paciente y al año no se encontró evidencia clínica o radiográfica de recurrencia. En la discusión se analizan las principales características clínicas de esta enfermedad, su tratamiento, pronóstico y se hace énfasis en que su tratamiento debe de ser realizado por un cirujano maxilofacial experimentado

Hiperplasia multifocal del epitelio. Reporte de nueve casos / Multifocal epithelial hyperplasia. Report of nine cases

La hiperplasia multifocal del epitelio (HME) conocida tambiéncomo hiperplasia epitelial focal, enfermedad de Heck ó hiperplasiamultifocal del epitelio por papiloma virus, se caracterizapor la aparición de lesiones múltiples en la mucosa de la cavidadbucal en población pediátrica y se asocia a la presencia del viruspapiloma humano. El objetivo de este estudio fue conocer lascaracterísticas clínico-patológicas de los casos diagnosticadosde esta enfermedad en el Servicio de Dermatología del HospitalManuel Gea González. Se revisaron los archivos de estainstitución y se seleccionaron los casos diagnosticados comoHME. Se encontraron 9 casos. La mayoría de los pacientesfueron menores de 20 años (67%) y del sexo femenino (78%),todos los casos presentaron lesiones múltiples y siempre huboparientes directos con lesiones similares. Los lugares que seafectaron con mayor frecuencia fueron: mucosa bucal, labioinferior, paladar y comisuras. La HME es una condición de lamucosa de la cavidad bucal que solamente necesita tratamientode aquellas lesiones que representan un problema cosmético óaquellas que se traumatizan secundariamente. Las demás remitiránconforme avanza la edad del paciente. Se sugiere usarel nombre de hiperplasia multifocal del epitelio pues describemejor las características clínico-patológicas y microscópicasde la enfermedad

Multifocal epithelial hyperplasia (MEH) is also known as focalepithelial hyperplasia, Heck’s disease or multifocal papillomavirus-induced epithelial hyperplasia. It is characterised by thepresence of multiple lesions in the oral mucosa of children andit has been associated with the presence of the human papillomavirus.The aim of this study was to determine the clinicopathologicalfeatures of the cases diagnosed as MEH in theService of Dermatology of the Hospital Manuel Gea González(SDHMGG). The files of the SDHMGG were reviewed and allcases diagnosed as MEH were retrieved. Nine MEH cases werefound. Most of the patients were 20 year-old or younger (67%)and females were more commonly affected (78%). All patientspresented multiple lesions and always, close relatives with similarlesions were found. Lesions were located most commonly inthe buccal mucosa, lower lip and comissures. MEH is a soft tissueintraoral condition that needs treatment solely of the traumatisedlesions or those with cosmetic problems. Remaining lesions willdisappear with the age of the patients. It is suggested that thisentity should be named multifocal epithelial hyperplasia sincethis name describes better the clinico-pathological and microscopicfeatures of the disease

Multifocal epithelial hyperplasia. Report of nine cases.

Multifocal epithelial hyperplasia (MEH) is also known as focal epithelial hyperplasia, Heck's disease or multifocal papillomavirus-induced epithelial hyperplasia. It is characterised by the presence of multiple lesions in the oral mucosa of children and it has been associated with the presence of the human papillomavirus. The aim of this study was to determine the clinico-pathological features of the cases diagnosed as MEH in the Service of Dermatology of the Hospital Manuel Gea González (SDHMGG). The files of the SDHMGG were reviewed and all cases diagnosed as MEH were retrieved. Nine MEH cases were found. Most of the patients were 20 year-old or younger (67%) and females were more commonly affected (78%). All patients presented multiple lesions and always, close relatives with similar lesions were found. Lesions were located most commonly in the buccal mucosa, lower lip and commissures. MEH is a soft tissue intraoral condition that needs treatment solely of the traumatised lesions or those with cosmetic problems. Remaining lesions will disappear with the age of the patients. It is suggested that this entity should be named multifocal epithelial hyperplasia since this name describes better the clinico-pathological and microscopic features of the disease.

Frequency of supernumerary teeth in Mexican population.

Supernumerary teeth (ST) are a not uncommon developmental anomaly which appears in 0.3 to 3.8 percent of the population. We studied the corresponding radiographs from 2241 patients, both sexes who seeked dental attention at the Outpatient Clinic of the División de Estudios de Posgrado e Investigación, Facultad de Odontología, UNAM in Mexico City. Of them, we found 72 patients (3.2%) with 102 ST. Of the 72 patients, 39 were males (54.2%) and 33 females (45.8%). Mesiodens was the most common ST (48.6%), followed by supernumerary premolars (26.4%), supernumerary laterals (11.1%) and fourth molars (9.7%). This series includes cases with one, two and three ST and one case comprising 10 ST. Our results suggest that frequency of ST in the population studied differs in some aspects with previously reported series and that frequency of ST shows different rates depending the population studied. As our results demonstrate, it is encouraged the need to have panoramic radiographs of all patients attended in dental offices, clinics and schools of Dentistry in order to detect and diagnose undiscovered pathologies.

Frecuencia de dientes supernumerarios en una población Mexicana / Frequency of supernumerary teeth in Mexican population

Los dientes supernumerarios (DS) son una anomalía del desarrollo que no se observa con frecuencia (del 0.3 al 3.8% de la población). En este estudio, se analizaron las ortopantomografías correspondientes a 2241 pacientes, de ambos sexos quienes acudieron a la Clínica de Admisión de la División de Estudios de Posgrado e Investigación, Facultad de Odontología, UNAM en la ciudad de México D.F. De ellos, se encontraron 72 pacientes (3.2%) con 102 DS. De los 72 pacientes, 39 fueron hombres (54.2%) y 33 mujeres (45.8%). El mesiodens fue el más común de los DS (48.6%), seguido por lo premolares supernumerarios (26.4%), laterales supernumerarios (11.1%) y cuartos molares (9.7%). En esta serie se incluyen casos con uno, dos, tres DS y un caso con 10 DS. Nuestros resultados sugieren que la frecuencia de DS en la población estudiada es diferente en algunos aspectos a la que se reporta en otras series. Como demuestran nuestros resultados, se aconseja que se tomen radiografías panorámicas a todos los pacientes que se atiendan en los consultorios dentales, clínicas y facultades ó escuelas de Odontología, para poder detectar procesos patológicos ocultos (AU)

Supernumerary teeth (ST) are a not uncommon developmental anomaly which appears in 0.3 to 3.8 percent of the population. We studied the corresponding radiographs from 2241 patients, both sexes who seeked dental attention at the Outpatient Clinic of the División de Estudios de Posgrado e Investigación, Facultad de Odontología, UNAM in Mexico City. Of them, we found 72 patients (3.2%) with 102 ST. Of the 72 patients, 39 were males (54.2%) and 33 females (45.8%). Mesiodens was the most common ST (48.6%), followed by supernumerary premolars (26.4%), supernumerary laterals (11.1%) and fourth molars (9.7%). This series includes cases with one, two and three ST and one case comprising 10 ST. Our results suggest that frequency of ST in the population studied differs in some aspects with previously reported series and that frequency of ST shows different rates depending the population studied. As our results demonstrate, it is encouraged the need to have panoramic radiographs of all patients attended in dental offices, clinics and schools of Dentistry in order to detect and diagnose undiscovered pathologies (AU)

Importance of mast cells in human periapical inflammatory lesions.

The role of mast cells (MCs) in periapical inflammatory lesions is not well understood. The objective of this work was to quantify MC numbers in human periapical lesions with the aim to clarify their role in the pathogenesis of these lesions. We analyzed the slides of 64 human periapical inflammatory lesions stained with pH 8.0 toluidine blue technique, quantified the number of MCs, and evaluated any correlation with age, gender, size, and location. The results of this study suggest that MCs were more numerous in females (p < 0.01); MC numbers were higher in biopsies from granulomas with proliferating epithelium and lower in biopsies from chronic apical abscesses; MC counts did not correlate with patients' age or size. MCs were observed more commonly in areas containing inflammatory infiltrate and degranulation was a frequent finding in these zones. Our results suggest that MCs play an active role in the pathogenesis of the periapical inflammatory lesions. The potential role of MCs related with the initiation, development, and persistence of the periapical inflammatory process are discussed.