Presencia del cuarto molar. Revisión de la literatura / Presence of the fourth molar. Literature review

Resumen: El cuarto molar, también llamado distomolar, es una variante de número y forma que se presenta como una alteración durante la odontogénesis, pueden ser eumórfico o dismórfico, único o múltiple, erupcionado o retenido, de forma unilateral o bilateral y se puede presentar en ambos maxilares. La etiología es desconocida, pero existen varias teorías que justifican el desarrollo de esta alteración dentaria como la duplicación de la lámina dental, su proliferación horizontal o hiperactividad de ésta; otros factores pueden ser los hereditarios, la división completa del germen dentario o regresión filogenética. El cuarto molar se encuentra en un espacio muy importante, que al desconocer su existencia o técnica adecuada para su extracción, las posibilidades de tener severas complicaciones transy postoperatorias son altas. Se realiza una revisión bibliográfica de diferentes artículos y textos en diferentes años para determinar de forma más clara el origen y formación de este diente supernumerario.

Abstract: Fourth molars, also called distomolars, are a variant in shape and number appearing as alterations during odontogenesis. They can be eumorphic or dismorphic, single or multiple, erupted or impacted, unilateral or bilateral, and can appear in both jaws. They are of unknown etiology, but there are several theories to justify these tooth alterations such as dental lamina duplication, its horizontal proliferation or its hyperactivity. Other factors can be hereditary factors, full division of tooth bud or phylogenetic regression. Fourth molars are found in a very important space, and when their own existence or the suitable extraction techniques are unknown, severe complications can frequently occur during and after surgery. A literature review was undertaken, examining different articles and texts of different years, in order to better determine the origins and formation of this supernumerary tooth.

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

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.

Prevalence trends of oral squamous cell carcinoma. Mexico City’s General Hospital experience

Objective: Recent reports suggest an increase in oral squamous cell carcinoma (OSCC) frequency. To improve programs in public health, it is necessary to understand the epidemiological conditions. The aim of this study was to analyze the trend in gender, age, anatomic zone and OSCC stage from Mexico City’s General Hospital patients from 1990 to 2008.Study design: A retrospective review of all OSCC cases diagnosed by the Pathology Department of the Mexico City General Hospital was performed. Demographic data, in addition to anatomic zone and histological degree of differentiation were obtained. Central tendency, dispersion and prevalence rate per 100,000 individuals were determined. Results: A total of 531 patients were diagnosed with OSCC; 58.4% were men, giving a male: female ratio of 1.4:1, and the mean age was 62.5 ± 14.9 years. The predominant anatomic zone was the tongue (44.7%), followed by the lips (21.2%) and gums (20.5%). The most frequent histological degree was moderately differentiated in 325 cases (61.2%). The rates of OSCC prevalence showed similar (..) (AU)

Prevalence trends of oral squamous cell carcinoma. Mexico City's General Hospital experience.

OBJECTIVE: Recent reports suggest an increase in oral squamous cell carcinoma (OSCC) frequency. To improve programs in public health, it is necessary to understand the epidemiological conditions. The aim of this study was to analyze the trend in gender, age, anatomic zone and OSCC stage from Mexico City's General Hospital patients from 1990 to 2008. STUDY DESIGN: A retrospective review of all OSCC cases diagnosed by the Pathology Department of the Mexico City General Hospital was performed. Demographic data, in addition to anatomic zone and histological degree of differentiation were obtained. Central tendency, dispersion and prevalence rate per 100,000 individuals were determined. RESULTS: A total of 531 patients were diagnosed with OSCC; 58.4% were men, giving a male:female ratio of 1.4:1, and the mean age was 62.5 ± 14.9 years. The predominant anatomic zone was the tongue (44.7%), followed by the lips (21.2%) and gums (20.5%). The most frequent histological degree was moderately differentiated in 325 cases (61.2%). The rates of OSCC prevalence showed similar patterns in terms across time. A significant correlation (P = 0.007) between anatomic zone and age was observed. CONCLUSION: According to our results, the prevalence of OSCC does not show important variations; however, a relationship between age and anatomic zone was observed. These data could be used as parameters for the diagnosis of OSCC as well as for the development and dissemination of preventive programs for the early detection of oral cancer.

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.

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)