Juan Carlos Hernández-Guerrero

Clinico-Pathologic Study of Odontogenic Cysts in a Mexican Sample Population

BACKGROUND Odontogenic cysts are uncommon lesions that frequently behave agressively and attain a large size. Unfortunately, information on the relative incidence of these cysts from different populations is not abundant. In Mexico, for example, only a few examples have been reported. The aim of this study was to ascertain the frequency of odontogenic cysts in a Mexican sample and to compare these data with previously reported studies from other countries. METHODS The files of the Oral and Maxillofacial Pathology Diagnosis Service at the School of Dentistry at the Universidad Nacional Autónoma de México (UNAM) were reviewed and all accessions of odontogenic cysts were listed. Clinical and radiographic data were recorded and microscopic slides evaluated according to the most recent World Health Organization (WHO) classification (1992). RESULTS Three hundred and four cases of odontogenic cysts (55.9% male predominance) were found. The most frequent odontogenic cysts were the following: periapical cyst (38. 8%); dentigerous cyst (35.5%), and odontogenic keratocyst (18.8%). Periapical cyst was more frequent in females, and maxillary anterior teeth were most commonly involved. Dentigerous cysts appeared in males at a rate of 64.8%, this cyst found more frequently between the 1st and 2nd decades of life and in the molar zone. Odontogenic keratocyst was more frequent in males (59.6%), between the 2nd and 4th decades of life and more common in the molar zone. CONCLUSIONS More than 50% of the sample were aggressive cysts (dentigerous and keratocyst). Our results suggest that Mexican patients develop aggressive odontogenic cysts more commonly than other populations. Our figures point to the need for a precise diagnosis in order to institute the correct surgical procedure, prevent recurrence, and forestall more extensive tissue destruction.

Bebidas embotelladas como fuentes adicionales de exposición a flúor

ResumenObjetivo . Evaluar y notificar la concentracion de fluoruroen bebidas embotelladas que se consumen en la ciudad deSan Luis Potosi, S.L.P., Mexico y su implicacion como factorde riesgo a fluorosis dental. Material y metodos . Seestudio el contenido de algunos productos de las dos com-panias refresqueras mas importantes de Mexico y de otrasdos locales. Las muestras se recolectaron de 10 lotesdiferentes en el caso de los refrescos y de cinco lotes en elde los jugos, con tres muestras por lote, durante tres me-ses. La determinacion de concentracion de fluoruro serealizo mediante el metodo del electrodo de ion selectivo. Resultados . La concentracion de fluor de muestras dediferentes plantas de companias nacionales presentarondiferencias estadisticas significativas entre grupos ( p < 0.05).La comparacion de resultados entre companias nacionalesy locales tambien mostro diferencia estadistica significativa( p < 0.05). Los diferentes jugos presentaron concentracionesde fluor elevadas.

In vitro effect of sodium fluoride on antioxidative enzymes and apoptosis during murine odontogenesis

Excessive fluoride ingestion has been identified as a risk factor for fluorosis and oxidative stress. The oxidative stress results from the loss of equilibrium between oxidative and antioxidative mechanisms that can produce kinase activation, mitochondrial disturbance and DNA fragmentation, resulting in apoptosis. Actually many people are exposed to no-adverted fluoride consumption in acute or chronic way. The aim of this study was to determine the effect of sodium fluoride on first molar germ in relation to its effect on antioxidative enzymes immunoexpression and apoptosis. Thirty first molar germs from 1-day-old Balb/c mice were cultured for 24 h with sodium fluoride (0 mM, 1 mM and 5 mM). Immunoexpression determination of CuZnSod, MnSod, catalase, Bax, Bid, caspase 8, caspase 9, caspase 3 and TUNEL assay were performed. Cellular disorganization in ameloblast and odontoblast-papilla zones was observed. CuZnSod and MnSod immunoexpression decrease in experimental groups. Caspase 8, caspase 3, Bax, Bid increase expression and more TUNEL positive cells in both experimental groups than control, suggest that apoptosis induced by fluoride is related to oxidative stress due to reduction of the enzymatic antioxidant.

Fluoride Consumption and Its Impact on Oral Health

Objective The purpose of this study was to evaluate caries and dental fluorosis among Mexican preschoolers and school-aged children in a non-endemic zone for fluorosis and to measure its biological indicators. Methods DMFT, DMFS, dmft, dmfs, and CDI indexes were applied. Fluoride urinary excretion and fluoride concentrations in home water, table salt, bottled water, bottled drinks, and toothpaste were determined. Results Schoolchildren presented fluorosis (CDI = 0.96) and dental caries (DMFT = 2.64 and DMFS = 3.97). Preschoolers presented dmft = 4.85 and dmfs = 8.80. DMFT and DMFS were lower in children with mild to moderate dental fluorosis (DF). Variable fluoride concentrations were found in the analyzed products (home water = 0.18–0.44 ppm F, table salt = 0–485 ppm F, bottled water = 0.18–0.47 ppm F, juices = 0.08–1.42 ppm F, nectars = 0.07–1.30 ppm F, bottled drinks = 0.10–1.70 ppm F, toothpaste = 0–2,053 ppm F). Mean daily fluoride excretion was 422 ± 176 μg/24 h for schoolchildren and 367 ± 150 μg/24 h for preschoolers. Conclusions Data from our study show that, despite values of excretion within an optimal fluoride intake range, the prevalence of caries was significant in both groups, and 60% of the 11- to 12-year-old children presented with dental fluorosis. In addition, variable fluoride concentrations in products frequently consumed by children were found.

Fluorosis en dentición temporal en un área con hidrofluorosis endémica

OBJETIVO: Determinar la prevalencia de fluorosis dental en la poblacion infantil de la ciudad de San Luis Potosi, y su asociacion con la concentracion de fluor en agua de consumo y de orina. Asimismo, desarrollar, validar y probar un indice especifico para fluorosis en denticion temporal. MATERIAL Y METODOS: Se efectuo un estudio transversal analitico, de mayo de 1997 a enero de 1999, en tres jardines de ninos, seleccionados al azar, en tres areas de riesgo en San Luis Potosi. Se seleccionaron 100 ninos de edades entre tres y seis anos. El indice especifico de fluorosis para dientes temporales fue validado mediante la cuantificacion de concentraciones de fluor en esmalte de dientes con y sin fluorosis. Para estimar la asociacion entre las concentraciones de fluor en agua y orina y el grado de fluorosis dental se utilizo la prueba estadistica Kruskal-Wallis. En el caso de la asociacion entre el area de riesgo y el desarrollo de fluorosis dental se utilizo ji2 de Mantel-Haenszel. RESULTADOS: La prevalencia de fluorosis en denticion temporal fue de 78%, la cual tuvo patrones diferentes de presentacion, siendo los dientes posteriores los mas afectados en ambos maxilares y la coloracion predominante fue blanco mate. Se encontro una correlacion (r=0.93) entre la concentracion de fluor en esmalte de dientes temporales y el indice de fluorosis para denticion temporal (IFDDT). Se encontraron asociaciones entre la concentracion de fluor en el agua de consumo y orina con el grado de fluorosis dental (Kruskal-Wallis, p=0.00001) y entre el area de riesgo y el grado de fluorosis (ji² de Mantel-Haenszel p=0.00001). CONCLUSIONES: El IFDDT identifica y gradua adecuadamente la fluorosis en denticion temporal. Es importante detectar el primer efecto toxico de exposicion a fluor para ser usado como predictor de fluorosis en denticion permanente y fluorosis esqueletica.

Fluoride content in table salt distributed in Mexico City, Mexico.

OBJECTIVE The aim of this study was to analyze table salt available in Mexico Citys market to identify the fluoride concentrations and to compare these with the Mexican regulations. METHODS We analyzed 44 different brands of table salt. All samples were purchased at random in different stores, supermarkets, and groceries from Mexico Citys metropolitan area and analyzed in triplicate in three different laboratories (nine determinations per sample) with an Orion 720 A potentiometer and an Orion 9609 BN ion-specific electrode. RESULTS Fluoride concentration in the samples varied from 0 ppm to 485 ppm. It was found that fluoride concentration varied widely among the analyzed brands. Also, we found that fluoride concentration in 92 percent of the analyzed samples did not match with that printed on the label. Only 6.8 percent of the analyzed samples contained fluoride concentrations that meet Mexican and WHO regulations. CONCLUSIONS The broad variation in the analyzed samples suggests that Mexican Public Health authorities must implement more stringent regulation guidelines and procedures for controlling the distribution of salt and its fluoride concentration for human consumption.

erbB expression changes in ethanol and 7, 12- dimethylbenz (a) anthracene-induced oral carcinogenesis

Objetive: The aim of this study was to determine erbB expression in normal mucosa, oral dysplasia, and invasive carcinomas developed in the hamster’s buccal pouch chemical carcinogenesis model. Study design: Fifty Syrian golden hamsters were equally divided in five groups (A-E); two controls and three experimental group exposed to alcohol, DMBA, or both for 14 weeks. Number of tumors per cheek, volume, histological condition, erbB expression were determined and results were analyzed by the Mann–Whitney U and Dunn’s test. Results: Control groups and those exposed to alcohol (A, B and C respectively) only presented clinical and histological normal mucosa; while those exposed to DMBA or DMBA plus alcohol (D and E groups) developed dysplasia and invasive carcinomas. erbB2, erbB3, and erbB4 increased their expression in alcohol-exposed mucosa, dysplasia, and invasive carcinomas. We observed a similar expression level for erbB2 in dysplasia and carcinomas; while, erbB3 and erbB4 were similar only in carcinomas. Conclusion: The DMBA and alcohol can be considered as carcinogen and promoter for oral carcinogenesis. The erbB expression is different according to their histological condition, suggesting differential participation of the erbB family in oral carcinogenesis induced by alcohol and DMBA. Key words:erbB, 7,12- dimethylbenz(a)anthracene, oral squamous cell carcinoma.

Maxillomandibular giant osteosclerotic lesions

Abstract Giant Osteosclerotic Lesions (GOLs) are a group of rarely reported intraosseous lesions. Their precise diagnosis is important since they can be confused with malignant neoplasms. Objective This retrospective study aimed to record and analyze the clinical and radiographic Giant Osteosclerotic Lesions (GOLs) detected in the maxillomandibular area of patients attending to our institution. Materials and Methods: Informed consent from the patients was obtained and those cases of 2.5 cm or larger lesions with radiopaque or mixed (radiolucid-radiopaque) appearance located in the maxillofacial bones were selected. Assessed parameters were: age, gender, radiographic aspect, shape, borders, size, location and relations to roots. Lesions were classified as radicular, apical, interradicular, interradicular-apical, radicular-apical or located in a previous teeth extraction area. Additionally, several osseous and dental developmental alterations (DDAs) were assessed. Results Seventeen radiopacities in 14 patients were found and were located almost exclusively in mandible and were two types: idiopathic osteosclerosis and condensing osteitis. GOLs were more frequent in females, and in the anterior and premolar zones. 94.2% of GOLs were qualified as idiopathic osteosclerosis and one case was condensing osteitis. All studied cases showed different osseous and dental developmental alterations (DDAs). The most common were: Microdontia, hypodontia, pulp stones, macrodontia and variations in the mental foramina. Conclusions GOLs must be differentiated from other radiopaque benign and malignant tumors. Condensing osteitis, was considered an anomalous osseous response induced by a chronic low-grade inflammatory stimulus. For development of idiopathic osteosclerosis, two possible mechanisms could be related. The first is modification of the normal turnover with excessive osseous deposition. The second mechanism will prevent the normal bone resorption, arresting the osseous breakdown process.