Association Between Gender, Age, and Skeletal Class With Mandibular Condyle Morphology: A Retrospective Study.

OBJECTIVES: This study aimed to examine the impact of demographic variables on mandibular condyle morphology, a critical factor in orthodontic treatment and maxillofacial surgery. The investigation focuses on the relationship between gender, age, and skeletal class with the morphological dimensions of the condyle, utilizing panoramic radiography as a diagnostic tool. METHODOLOGY: A retrospective analysis was conducted on 150 panoramic radiographs from individuals stratified into six groups according to gender and skeletal class. Skeletal classes were determined using Steiner and McNamara cephalometry. The Kodak Carestream software (Rochester, NY: Carestream Health) was employed to measure condylar height, width, and morphology. Statistical evaluations included ANOVA, correlation assessments, and multivariate binary logistic regression to discern the differences and associations among the variables studied. RESULTS: The findings revealed notable differences in condylar dimensions between genders across different skeletal classes, with males typically presenting larger condylar dimensions than females. The data also showed a moderate positive correlation between condyle height and width. Round-shaped condyles were the most common form found, with significant gender differences observed in certain skeletal classes. Additionally, logistic regression analysis identified significant associations between gender, age, and condylar width and shape. CONCLUSIONS: The study concludes that demographic factors, such as gender and age, significantly affect mandibular condyle morphology. These factors should be carefully considered in clinical evaluations using panoramic radiography to enhance the precision of diagnoses and the effectiveness of subsequent orthodontic and maxillofacial treatments. The results provide valuable insights for healthcare professionals in regions where more advanced imaging techniques may not be readily available.

Correlation between bacterial type/bacterial quantity and bone loss detected by cone beam computed tomography (CBCT) in primary endodontic infections / Correlación entre el tipo y cantidad de bacterias y la pérdida ósea detectada por Tomografía Computarizada de Haz Cónico (CBCT) en infecciones endodóncicas primarias

Abstract Periapical lesions (PL) of endodontic origin are one of the most common pathological conditions that affect peri-radicular tissues. The main objective of this study was to evaluate the amount and species of microorganisms isolated from necrotic pulps, establish a correlation between these and the size of periapical lesions, and how the amount and species of microorganisms decreased with non-surgical root canal treatment. Twenty-seven patients with a clinical diagnosis of dental pulp necrosis and chronic periapical lesions were selected; a Cone Beam Computed Tomography (CBCT) and microbial samples of the root canal system were taken previous to a disinfection protocol, a post-instrumentation/ disinfection protocol, and a post-medication placement. Samples were processed for colony-forming unit (CFU) counting, Gram staining technique, and bacterial identification by the API-20 Strep/API-20A system. The API system identified 21 species of microorganisms in the pre-instrumentation samples, 11 species in the post-instrumentation samples, and 11 in the post-medication samples. There was a correlation coefficient of 0.598% between the initial size of the lesion and the number of bacteria, with a coefficient of determination up to 35.7%, a correlation coefficient of 0.486% and a determination coefficient of 23.6% between the size of the periapical lesion and the number of CFUs. This study contributes to the knowledge of the amount and species of microorganisms isolated and identified from necrotic pulps, establishes a correlation between the amount and species of microorganisms and the size of the periapical lesions, and shows how the decrease of microorganisms contributes to the healing of PL, corroborating the importance of an adequate disinfection protocol.

Resumen Las lesiones periapicales (LP) de origen endodóncico son la condición patológica más común que afectan los tejidos perirradiculares. El objetivo principal de este estudio es evaluar la cantidad y especie de bacterias aisladas de pulpas necróticas, correlacionar la cantidad y especies bacterianas con el tamaño de la lesión, y cómo disminuyen la cantidad y especies de microorganismos con el tratamiento de conductos. A 27 pacientes con diagnóstico de necrosis pulpar y lesión periapical crónica detectada con CBCT se les tomaron muestras microbianas del sistema de conductos antes y después del protocolo de desinfección y de la medicación intraconducto. Las muestras se procesaron para el recuento de unidades de formación de colonias (UFC), tinción de Gram e identificación mediante el sistema API-20 Strep/API-20A. Se identificaron 21 especies en las muestras pre-instrumentación, 11 en las muestras post-instrumentación y 11 en las muestras post-medicación; se observó un coeficiente de correlación del 0,598% entre el tamaño inicial de la lesión y la cantidad de bacterias, con un coeficiente de determinación hasta el 35,7%, un coeficiente de correlación del 0,486% y un coeficiente de determinación del 23,6% entre el tamaño de la lesión periapical y el número de UFCs. Este estudio contribuye al conocimiento sobre la cantidad y especies de microorganismos aislados e identificados a partir de pulpas necróticas, establece una correlación entre la cantidad y especies de microorganismos y el tamaño de las lesiones periapicales y exhibe cómo la disminución de microorganismos contribuye a la curación de LP, corroborando la importancia de un adecuado protocolo de desinfección.

Anatomical and morphological findings of the root canal of maxillary premolars and their prevalence: CBCT study in a Mexican population / Hallazgos anatómicos y morfológicos del conducto radicular de premolares maxilares y su prevalencia: estudio CBCT en una población mexicana

SUMMARY: An essential prerequisite to perform any dental procedure is a clear understanding and knowledge of dental anatomy and its possible variations. The root canal system is characterized for a complex morphology, which varies among populations, individuals in the same population and even in the same person. The aim of this study was to evaluate by CBCT the morphology, number, curvature, and length of roots of first and second maxillary premolars in a Mexican population. In this stud 1700 maxillary premolars were evaluated by CBCT scans of patients; the axial, sagittal and coronal sections were analyzed following the longitudinal axis of each tooth. As a result 51.60 % of the maxillary first premolars had a single root, 31.03 % had two roots, 16.29 % had root fusion, and 1.07 % had three roots. 22.3 % of the maxillary first premolars showed mesial curvature, 41.9 % had a distal curvature, and 35.7 % did not show any curvature; and the most prevalent configuration in maxillary first premolars was Type V. 88.9 % of the maxillary second premolars had a single root, 3.9 % had two roots, 6.9 % had root fusion, and 0.11 % had three roots; 37.59 % of the maxillary second premolars showed a mesial curvature and 62.40 % showed a distal curvature; and the most prevalent configuration in maxillary second premolars was Type I. The anatomy of the root canal system is extremely complex and has many anatomical configurations, these clinical situations must be considered previous to performing any endodontic treatment.

RESUMEN: Un requisito esencial previo a la realización de cualquier procedimiento dental es una clara comprensión y conocimiento de la anatomía dental y sus posibles variaciones. El sistema de canales radiculares se caracteriza por una morfología compleja, que varía entre poblaciones, individuos en una misma población e incluso en una misma persona. El objetivo de este estudio fue evaluar mediante CBCT la morfología, número, curvatura y longitud de raíces de primeros y segundos premolares maxilares en una población mexicana. En este estudio se evaluaron 1700 premolares maxilares mediante escaneos CBCT de pacientes; se analizaron los cortes axial, sagital y coronal siguiendo el eje longitudinal de cada diente. El 51,60 % de los primeros premolares maxilares tenían una sola raíz, el 31,03 % tenían dos raíces, el 16,29 % tenían fusión de raíces y el 1,07 % tenían tres raíces. El 22,3 % de los primeros premolares maxilares presentaban curvatura mesial, el 41,9 % presentaban curvatura distal y el 35,7 % no presentaban curvatura alguna; y la configuración más prevalente en primeros premolares maxilares fue el Tipo V. El 88,9 % de los segundos premolares maxilares tenían una sola raíz, el 3,9 % dos raíces, el 6,9 % fusión de raíces y el 0,11 % tres raíces; El 37,59 % de los segundos premolares maxilares presentaban curvatura mesial y el 62,40 % curvatura distal y la configuración más prevalente en segundos premolares maxilares fue el Tipo I. La anatomía del sistema de canales radiculares es extremadamente compleja y tiene muchas configuraciones anatómicas, estas situaciones clínicas deben ser consideradas antes de realizar cualquier tratamiento de endodoncia.

Magnificación en la terapia endodóncica mediante el microscopio operatorio / Magnification in endodontic therapy through the operatory microscope

La microendodoncia involucra la visualización a través de un microscopio operatorio de todas las fases del tratamiento de conductos y procedimientos de cirugía apical y correctiva por parte del endodoncista. Existe sobrada evidencia acerca de las mejoras que puede aportar la magnificación al tratamiento; la literatura demuestra que la capacidad del operador mejora si su visión del campo gana claridad y precisión, ambos recursos pueden ser proporcionados por el microscopio operatorio, aunado a que posibilita diagnósticos más certeros junto con mejoras en el pronóstico, lo que permite evitar posibles complicaciones. La calidad de los tratamientos endodóncicos involucra infinidad de factores, cada uno relevante en sí mismo pero, en determinados casos, el microscopio puede significar la diferencia entre un tratamiento exitoso o un fracaso clínico. En la actualidad, se ha convertido en un tema de lo más relevante, por lo que el objetivo del presente trabajo es revisar la literatura con el fin de ayudar al entendimiento basado en evidencia científica de los criterios que determinan la relevancia del uso del microscopio en el ámbito endodóncico (AU)

Microendodontics involves the visualization through an operating microscope of all phases of root canal treatment and apical and corrective surgery procedures by the endodontist. There is plenty of evidence about the improvements that magnification can provide, the literature shows that the operator's ability improves if his vision of the field gains clarity and precision, both resources can be provided by the operating microscope, added to the fact that it enables more accurate diagnoses together with improvements in the prognosis allowing to avoid possible complications. The quality of endodontic treatments involves countless factors, each relevant in itself, but in certain cases the microscope can mean the difference between a successful treatment or a clinical failure. At present, it has become a very relevant topic, so the objective of this work is to review the literature in order to help understand the criteria that determine the relevance of the use of the microscope in the endodontic field based on scientific evidence (AU)

Dental pain and associated factors in Mexican adolescents and young adults: a cross-sectional study.

OBJECTIVE: To identify the factors associated with the prevalence of dental pain in Mexican adolescents and young adults. MATERIAL AND METHODS: This is a cross-sectional study in which data from 638 Mexican subjects, 16-25 years of age, who were randomly selected from college applicants, were analysed. Questionnaires were administered to collect sociodemographic, economic and behavioural variables. Clinical examinations were carried out to determine the decayed, missing and filled teeth (DMFT) index. The outcome variable was dichotomised as 0 (no dental pain in the last 12 months) or 1 (dental pain in the last 12 months). Statistical analyses included binary logistic regression. RESULTS: Average age was 18.76 ± 1.76 years, and 49.2% of participants were women. Prevalence of dental pain was 34.0%. In the final model, variables significantly (P < 0.05) associated with the experience of dental pain were the use of preventive dental services (OR = 0.34), being a former smoker (OR = 2.37), self-report of very poor/poor oral health (OR = 1.94) or fair oral health (OR = 1.94), self-reported dental disease (OR = 2.06) or gingival disease (OR = 2.84). CONCLUSIONS: The prevalence of dental pain was associated with self-reported oral health status, preventive dental visits and smoking; these results have implications for dental practice. We found that recent experience of dental pain was common in young adults, being reported by one out of three subjects.

Estudio morfológico de canales nasopalatinos en población mexicana mediante tomografía computarizada de haz cónico / Morphological study of nasopalatine canal in Mexican population using cone beam computed tomography

La morfología y dimensiones de ciertas estructuras anatómicas varían de población a población, así como de individuo a individuo; el canal nasopalatino (CNP) es una de estas estructuras, este se encuentra ubicado en la línea media del paladar y aloja el nervio nasopalatino y la rama terminal de la arteria nasopalatina. El propósito de este estudio es determinar la morfología y dimensiones promedio del CNP en la población mexicana mediante tomografía computarizada de haz cónico (CBCT). Se analizaron 120 CBCT de manera coronal, transversal y sagital; y se clasificaron siguiendo los parámetros de Bornstein. Para el análisis estadístico se determinó la normalidad de las variables empleando la prueba de Shapiro Wilk y la significancia estadística mediante la prueba de UMann Whitney. Los resultados mostraron diferencias estadísticas significativas en las variables analizadas del canal nasopalatino entre hombres y mujeres. De acuerdo con los datos obtenidos se puede establecer que la morfología del CNP es muy variable y se recomienda realizar un estudio morfológico y dimensional antes de cualquier intervención quirúrgica relacionada con esta zona.

Certain human structures present different dimensions and morphologies in each population and individual, the nasopalatine canal being one of these. It is located in the midline of the palate, and it contains the nasopalatine nerve and the terminal branch of the nasopalatine artery. The purpose of this study was to analyze and record measurements of the nasopalatine duct in Mexican population by Cone Beam Computed Tomography (CBCT). A total of 120 CBCT coronal, transversal and sagittal views were analyzed. The data were classified according to Bornstein´s parameters. The normality of the variables was determined with the Shapiro Wilk test and the statistical significance was determinate by U-Mann Whitney test. A statistically significant difference was found in the evaluated variables of the nasopalatal canal between men and women. The data obtained determined that the morphology of the nasopalatine canal is variable and a morphological and dimensional analysis before any surgical intervention related with the area is recommended.

Clinical and non-clinical variables associated with preventive and curative dental service utilisation: a cross-sectional study among adolescents and young adults in Central Mexico.

OBJECTIVE: The present study aimed to identify preventive and curative dental health service utilisation (DHSU) in the context of associated clinical and non-clinical factors among adolescents and young adults in Mexico. DESIGN: Cross-sectional study. SETTING: Applicants to a public university in Mexico. PARTICIPANTS: Participants were 638 adolescents and young adults aged 16-25 randomly selected from university applicants. INTERVENTIONS: Data were collected using a self-administered questionnaire filled out by the students. For assessment of dental caries experience, we used the index of decayed, missing and filled teeth. PRIMARY OUTCOME: The dependent variable was DHSU in the previous 12 months, coded as 0=non-use, 1=use of curative services and 2=use of preventive services. RESULTS: The mean age was 18.76±1.76 years, and 49.2% were women. The prevalence of DHSU was 40.9% (95% CI 37.1 to 44.8) for curative services and 22.9% (95% CI 19.7 to 26.3) for preventive services. The variables associated with curative services were age, sex, mother's education, dental pain in the previous 12 months, caries experience, use of self-care devices and oral health knowledge. For preventive services, the variables associated were mother's education, dental pain in the previous 12 months, caries experience, use of self-care devices and self-perception of oral health. CONCLUSIONS: While differences emerged by type of service, a number of variables (sociodemographic and socioeconomic characteristics as well as dental factors) remained in the final model. Greater oral health needs and socioeconomic inequalities remained as predictors of both types of DHSU. Given the differences revealed by our study, oral health policies should refer those seeking dental care for oral diseases to preventive services, and promote the use of such services among the poorer and less educated population groups.

A comparative study of the biocompatibility of two root-end filling materials in rat connective tissue / Estudio comparativo de la biocompatibilidad de dos materiales de retro-obturación en tejido conectivo de rata

The aim of the present study was to examine the short-term biocompatibility of Endosequence Root Repair Material (ERRM) paste and white Mineral Trioxide Aggregate MTA by implanting them into polyethylene tubes in the subcutaneous connective tissue of rats. twenty five male Wistar rats, 3-4 months old, weighing 300-350 g, were used. The tubes were implanted dorsally into the subcutaneous connective tissues of the rats. Five animals were sacrificed at five examination time points: 1, 3, 5, 7 and 15 days. The connective tissues containing the implants were excised. These sections were studied qualitatively and quantitatively using a light microscope. An average value for each group was obtained by averaging the sum of all inflammatory cells counted in 10 randomly selected, separate areas. For the ERRM group: There was a significant increase in the number of inflammatory cells on days 1-3 and on days 5-7 (P ≤ 0.003 and P ≤ 0.024). In the WHITE MTA group, the mean values of the sum of the inflammatory cells during the periods 1-3 days and 5-7 days were statistically significant (P ≤ 0.001 and P ≤ 0.044, respectively) and the XILOPERCHA group: Difference was observed significant in the value of the sum of inflammatory cells during the period of 3-5 days (P ≤ 0.05). According to the results it can be concluded that both, ERRM as MTA, caused an inflammatory reaction, which decreased over time; suggesting that both materials are biocompatible; showing however the presence of a higher organization of collagen fibers around the implants of ERRM.

El objetivo del presente estudio fue evaluar la biocompatibilidad a corto plazo de Material de Reparación de la Raíz Endodóntica (MRRE) y el agregado de trióxido mineral (AgTM), implantándolos dentro de tubos de polietileno en el tejido conectivo subcutáneo de ratas. Se usaron 25 ratas Wistar macho, de 3-4 meses de edad, con peso de 300 a 350 g. Los tubos fueron implantados en el tejido conectivo subcutáneo del dorso de las ratas. Cinco animales fueron sacrificados en cada uno de los siguientes períodos de tiempo: 1, 3, 5, 7, y 15 días. El tejido conectivo con los implantes fue escindido y seccionado. Los cortes se evaluaron cualitativa y cuantitativamente mediante microscopio óptico. Se obtuvo un valor para cada grupo resultado al promediar la suma de las células inflamatorias contadas en 10 áreas separadas seleccionadas aleatoriamente. Para el grupo de MRRE; hubo un incremento significativo en la cantidad de células inflamatorias entre los días 1-3 y 5-7 (p ≤ 0,003 y p ≤ 0,024). En el grupo de AgTM blanco, los valores promedio de la suma de células inflamatorias entre los períodos 1-3 días, y 5-7 días mostraron ser estadísticamente significativos (p≤ 0,001 y p ≤ 0,044 respectivamente) y en el grupo control de Xilopercha se observó diferencia significativa entre los valores de la suma de células inflamatorias entre los períodos de 3-5 días (P ≤ 0,05). De acuerdo a los resultados, puede concluirse que ambos materiales, AgTM y MRRE causaron una reacción inflamatoria que disminuyó a través del tiempo, sugiriendo que ambos materiales son biocompatibles; mostrando sin embargo una mayor organización de fibras colágenas alrededor de los implantes de MRRE.

Incidencia y tipo de istmos en primeros molares permanentes humanos, evaluación in vitro / Incidence and type of isthmus in human permanent first molars, in vitro assessment

RESUMEN: El conocimiento de la complejidad anatómica del sistema radicular de conductos generada por conductos accesorios, deltas apicales e istmos, aumenta la probabilidad de éxito en el tratamiento endodóntico, dado que dichos sitios pueden ser un reservorio de microorganismos y materia orgánica que pueden limitar la acción de los instrumentos, las sustancias irrigantes y los medicamentos intraconducto. El objetivo de este estudio fue determinar la incidencia y el tipo de istmos presentes en los distintos segmentos de raíces mesio-vestibulares de molares superiores y mesiales de molares inferiores. Se recolectaron setenta y dos primeros molares extraídos, treinta y seis superiores y treinta y seis inferiores a los cuales se les tomó radiografías y se les estudiaron distintas variantes anatómicas como número de conductos, curvatura y configuración radicular; posteriormente se les eliminó la corona y las raíces mesio-vestibulares de superiores y mesiales de inferiores se incluyeron en resina epóxica y con un disco de diamante se hicieron cortes transversales en cada raíz dejando cinco secciones de un mm iniciando desde el extremo apical hasta el cervical, se tiñeron con cristal violeta y se analizó la presencia de istmos y su clasificación bajo microscopio estereoscópico. Los resultados mostraron una alta incidencia de istmos asociada a raices de configuración aplanada. Entre más cerca del ápice, más baja la incidencia de istmo tanto en las raices mesiovestibulares del primer molar superior como en las raices mesiales del primer molar inferior; la más alta incidencia de istmos se dio aproximadamente a siete mm del ápice y la clase de istmo más frecuentemente encontrada fue la clase II en ambos tipos de raíz.

SUMMARY: The profound knowledge of the root canal anatomical complexity generated by accessory canals, apical deltas and isthmuses, increases the likelihood of success in endodontic treatment, given that such sites may be a reservoir of microorganisms and organic matter that may limit the action of instruments, irrigant substances and intracanal medications. The objective of this study was to determine the incidence and type of isthmus in the various segments of mesio-buccal roots of first upper molars and mesial root of first lower molars. Seventy-two extracted first molars, thirty-six upper and thirty-six lower were radiographed and different anatomic variants such as number of canals, curvature and root configuration were studied. Later, mesio-buccal and mesial roots were cut and embedded in resin and sectioned with a diamond disc, five serial horizontal sections were made perpendicular to the root long axis. These were stained with crystal violet and examined under stereomicroscope in order to determine the presence of isthmuses and their classification. Results showed a high incidence of isthmus associated with roots of flattened configuration. The closer to the apex, the lower the incidence of isthmus observed in both in the upper and lower roots; the isthmus were most frequently found at 7 mm from the apex, the type of isthmus found more frequently was type II in both types of root.

Condrosarcoma periosteal mandibular / Mandibular periosteal chondrosarcoma

Los condrosarcomas son neoplasias malignas con diferenciación cartilaginosa, la mayoría de localización intraósea y en huesos largos; su incidencia en cabeza y cuello es baja y más aún, su localización periosteal y mandibular. Se presenta un caso de neoplasia maligna productora de matriz condroide, periosteal, de alto grado, recidivante y localizada en mandíbula.

The chondrosarcomas are malignant neoplasms characterized by cartilaginous differentiation, mainly located intraosseously, and in large bones. Their incidence in head and neck is rare and even more so when it is periosteal or located in the jaw. A case of a malignant tumor producing chondroid matrix, periosteal, of high-grade, recurrent and localized in the jaw is presente.

Expression of enamel proteins in rough endoplasmic reticulum and golgi complex in human dental germs / Expresión de proteínas del esmalte en retículo endoplásmico rugoso y complexo golgiensis en gérmenes dentales humanos

Tooth enamel is the hardest tissue in the body. The organic matrix configuration is provided by the main proteins amelogenin, ameloblastin and enamelysin (MMP20), an enzyme that helps to shape the matrix. The aim of this study was to determine by histochemistry the expression of amelogenin and enamelysin through the rough endoplasmic reticulum in the late stages of amelogenesis, and its expression in the Complexus golgiensis (Golgi complex / Golgi apparatus) in the early stages in human fetuses. In early stages a colocalization of both proteins inside the Golgi apparatus was found, being more evident the relationship between Golgi and amelogenin (99.92 %). In the late stage, a colocalization of both proteins and rugged endoplasmic reticulum was found. With enamelysin being more evident in relation with rough endoplasmic reticulum (99.95 %). Our findings demonstrated the presence of amelogenin and enamelysin in odontoblast and ameloblast. However, the presence of these two proteins in odontoblast remains unknown.

El esmalte dental es el tejido más duro del cuerpo. La configuración de la matriz orgánica es proporcionada por las proteínas principales amelogenina, ameloblastina y enamelisina (MMP20), una enzima que ayuda a dar forma a la matriz. El objetivo de este estudio fue determinar mediante histoquímica la expresión de amelogenina y enamelisina a través del retículo endoplasmático rugoso en las últimas etapas de la amelogénesis , y su expresión en el Complexo golgiensis en las primeras etapas de formación en fetos humanos. En las primeras etapas se observó colocalización de ambas proteínas en el interior del Complexo golgiensis, siendo más evidente la relación entre Golgi y amelogenina (99,92 %). En la última etapa, se identificó una colocalización de ambas proteínas y retículo endoplásmico rugoso. Resulto más evidente la enamelisina en relación con el retículo endoplasmático rugoso (99,95 %). Nuestros resultados demostraron la presencia de amelogenina y enamelisina en odontoblastos y ameloblastos, sin embargo se desconoce la presencia de estas dos proteínas en odontoblastos.

Expresión de tuftelina en gérmenes dentales humanos / Expression of tuftelin in human dental germs

La tuftelina es una proteína secretada en la matriz adamantina en desarrollo durante la formación del esmalte. Su función continúa sin esclarecerse, aunque se presume que juega un papel importante en la biomineralización de esmalte y dentina, así como en el desarrollo del órgano dental. Con el presente estudio se identificó su localización en las diferentes estructuras de gérmenes dentales de fetos humanos, conforme a los resultados se observó su expresión en el estadio pre-secretor observándose en el citoplasma de los ameloblastos, retículo estrellado, papila dental, así como en el estrato intermedio; en el secretor se identificó principalmente en la unión amelodentinaria, y en la superficie externa del esmalte, observando una marcada expresión de la proteína en la porción basal del proceso odontoblástico, pero no en la matriz extracelular de la dentina. De acuerdo a los resultados obtenidos se puede considerar que su expresión se presenta tanto en la amelogénesis, como en la odontogénesis en tejidos sin mineralizar.

The tuftelin is a secreted protein in the adamantine matrix in developing during the enamel formation. Its function continues unclarified, although it plays a role in the biomineralization of the dental organ. With the present studio the location was identified in the different structures of dental germs from human fetuses, according to the results it was observed the expression in the pre-secretor stage being observed in the cytoplasm of ameloblasts, stellate reticulum, dental papilla, also in the intermediate stratum; in the secretor it was mainly identified in the amelodentinal junction and in the outer surface of enamel, observing a marked expression of the protein in the basal portion of the odontoblastic process, but not in the extracellular matrix of the dentine. According to the results obtained it can be considered that its expression occurs in both amelogenesis and odontegenesis in unmineralized tissues.

Eficacia antimicrobiana del primer ortodóncico adicionado con nanopartículas de plata: Estudio transversal in vitro / Antimicrobial efficacy of orthodontic primer added with silver nanoparticles: Cross-sectional in vitro study

Se evaluó la eficacia antimicrobiana de las nanopartículas de plata (NPsAg) incorporadas al adhesivo (primer) colocado en el esmalte dental adyacente a la aparatología ortodóncica fija (brackets). Se realizó un estudio experimental in vitro en 40 premolares, los cuales se dividieron en dos grupos con brackets, uno cementado con primer convencional y otro adicionado con NPsAg; se colocaron en medios de cultivo, previamente inoculados con Streptococcus mutans, y se tomaron muestras para hacer cultivos y conteo de unidades formadoras de colonias (UFC) al día 1, 15 y 30. Se observó una disminución de la presencia de Streptococcus mutans en las muestras a los 15 días de colocado el primer con la agregación de nanopartículas, aunque tal efecto se redujo a los 30 días. Esta reducción del efecto de las nanopartículas puede deberse a la inexistencia de limpieza mecánica, lo cual favoreció la agregación bacteriana sobre el biofilm, afectando su efecto antimicrobiano. Esto sugiere la necesidad de realizar estudios in vivo que permitan observar el comportamiento de los biomateriales en el medio bucal. Las NPsAg agregadas al primer resultan una herramienta eficaz para prevenir la desmineralización del esmalte alrededor de la aparatología ortodóncica fija.

The antimicrobial efficacy of the silver nanoparticles (NPsAg), incorporated into the adhesive (primer) placed in the enamel adjacent to fixed orthodontic appliances (brackets), was evaluated. An experimental study was performed on 40 premolars in vitro, which were divided into two groups with brackets, one cemented with conventional primer and another added with NPsAg, placed in culture media previously inoculated with Streptococcus mutans, and sampled for culturing and counting colony forming units (UFC) on days 1, 15 and 30. A decrease in the presence of Streptococcus mutans in the samples after 15 days with nanoparticle aggregation was observed, and a reduction in the effect of said nanoparticles after 30 days. This reduction of the nanoparticles effects can be due to the absence of mechanical cleaning, which favored the bacterial aggregation on the biofilm, affecting its antimicrobial effect. This suggest the need for realizing studies in “vivo” which will allow the observation of the behavior of the biometals on the buccal medium. The NPsAg added to the primer are an effective tool to prevent the demineralization of the enamel around the fixed orthodontic appliances.

Estudio transversal comparativo de la relación maxilo-mandibular de McNamara aplicadas a sujetos mexicanos / Transversal comparative study of McNamara maxillofacial mandibular ratio applied in Mexican subjects

Las características antropológicas entre diversas razas en las cuales se incluyen etnia, sexo y edad en el mundo varían, es preciso analizar que un estudio establecido para una población no puede ser usado para otra, ya que presenta formas y características diferentes; es por esto que existe la necesidad de realizar estudios en diversas razas comparándolos con las normas establecidas. El objetivo fue comparar la relación maxilo-mandibular de McNamara aplicadas en sujetos mexicanos. Se analizaron 60 radiografías laterales de cráneo con trazados de McNamara. Se identificaron diferencias en los patrones genéticos de crecimiento de los caucásicos y los mexicanos. Nuestros resultados muestran un crecimiento típico de los pacientes clase II esqueletal con maxilar hipotónico posteroanteriormente, una mandíbula disminuida y poca altura vertical, esto como consecuencia de una falta de crecimiento del tercio medio facial por una pobre ventilación aérea.

The anthropological characteristics between different races in which ethnicity, sex and age vary in the world, and it becomes necessary to analyze a set for one population study that cannot be used for another, with different shapes and characteristics. There is a need for studies in different races for comparison with established standards. The objective of the research was to compare the McNamara maxilla-mandibular relationship applied in Mexicans subjects and analyze 60 lateral radiographs of the skulls with McNamara traces. Genetic differences in growth patterns of Caucasians and Mexicans were identified. Our results show typical growth of skeletal class II patients with hypotonic posterior jaw, and jaw with diminished vertical height caused by a lack of midface growth the result of poor air flow.

Lip projection analysis in brachycephalic, dolichocephalic and mesocephalic individuals of a Mexican population.

The aim of this study was to examine the lip projection of brachycephalic, dolichocephalic and mesocephalic Mexican patients and to analyze the relationship between dental protrusion and the lip position, to identify if a labial soft tissue projection exists and to determine what features predominated in this study. A total of 120 lateral radiographs of the skull were randomly selected from patients aged 16-25 years. The linear and angular data were measured, the values of the upper and lower lip projection relative to Ricketts E-line, Steiner S-line and Arnett TV-line were collected. The angles to be analyzed were the nasolabial, mandibular plane and interincisal, and the mentolabial groove depth. The statistical significance was determined by the Student t-test. A significant difference between mesocephalic and brachycephalic patients was observed measuring the angle between the Frankfurt plane and the mandibular plane (P<0.001). Between dolichocephalic and mesocephalic individuals significant differences were observed in the lower lip to E-line (P<0.031), lower lip to S-line (P<0.010), the interincisal angle (P<0.032) and the mandibular´s plane (P<0.001). A statistical significant difference was shown between brachycephalic and dolichocephalic individuals: lower lip to E-line (P<0.001), upper lip to S-line (P<0.037), lower lip to S-line (P<0.001), interincisal angle (P<0.034) and the angle between the mandibular´s plane (P<0.001). Lip soft tissue projection will depend on the population studied; we found some significant differences when compared with the cephalometric norms.

Antimicrobial efficacy of orthodontic primer added with silver nanoparticles. Cross-sectional in vitro study. / Eficacia antimicrobiana del primer ortodóncico adicionado con nanopartículas de plata. Estudio transversal in vitro.

The antimicrobial efficacy of the silver nanoparticles (NPsAg), incorporated into the adhesive (primer) placed in the enamel adjacent to fixed orthodontic appliances (brackets), was evaluated. An experimental study was performed on 40 premolars in vitro, which were divided into two groups with brackets, one cemented with conventional primer and another added with NPsAg, placed in culture media previously inoculated with Streptococcus mutans, and sampled for culturing and counting colony forming units (UFC) on days 1, 15 and 30. A decrease in the presence of Streptococcus mutans in the samples after 15 days with nanoparticle aggregation was observed, and a reduction in the effect of said nanoparticles after 30 days. This reduction of the nanoparticles effects can be due to the absence of mechanical cleaning, which favored the bacterial aggregation on the biofilm, affecting its antimicrobial effect. This suggest the need for realizing studies in "vivo" which will allow the observation of the behavior of the biometals on the buccal medium. The NPsAg added to the primer are an effective tool to prevent the demineralization of the enamel around the fixed orthodontic appliances.

Análisis Morfológico del Grosor Labial en Individuos Mesofaciales y Braquifaciales en una Población Mexicana / Morphological Analysis of Lip Thickness in Mesofacial and Braquifacial Patients of a Mexican Population

El objetivo fue determinar las diferencias de grosor y proyección labial en hombres y mujeres mesofaciales y braquifaciales mexicanos a través del análisis de Arnett & Bergman. Se evaluaron 120 radiografías laterales de cráneo usando mediciones lineales y angulares de la cefalometría de tejidos blandos. Se evaluaron las dimensiones: plano oclusal, ángulo interincisal, grosor del labio superior e inferior, ángulo nasolabial, gap interlabial, proyección del labio superior e inferior, plano vertical nasion-menton. Para el análisis estadístico se realizó una prueba ANOVA usando el software minitab versión 15 para determinar las diferencias entre los grupos. No se encontraron diferencias estadísticamente significativas en el plano oclusal del incisivo superior e inferior, en el ángulo interincisal, ángulo nasolabial, gap interlabial y proyecciones de labio superior e inferior. Se encontraron diferencias estadísticamente significativas en mujeres: grosor del labio superior (p0,007), grosor del labio inferior (p0,001) y en el plano vertical nasion-menton (p0,001); mientras que para hombres se identificó diferencia significativa en: grosor del labio inferior (p0,033), proyección de labio inferior (p0,039) y en el plano vertical nasion-menton (p0,001). Estas medidas muestran que las diferencias del biotipo facial se identifican en cambios de los tejidos blandos. Existe una diferencia en el grosor de los labios entre los individuos mesofaciales y braquifaciales.

The mean of this study was to determinate the differences between lip thickness and lip projection in mesofacial and brachyfacial patients of a Mexican population using the Arnett & Bergman cephalometric analysis. 120 cephalograms were evaluated using linear and angular measurements of the soft tissue analysis. In this study it was evaluated: occlusal plane with the upper incisive, occlusal plane with the upper incisive, interincisal angle, upper and lower lip thickness, nasolabial angle, interlabial gap, upper and lower lip projection and true vertical plane from nasion-menton. The ANOVA test was performed using Minitab (15 version) statistical analysis software to indicate the differences between the groups. No statistical significance was found in the occlusal plane with the upper and lower incisive, interincisal angle, nasolabial angle, interlabial gap and upper and lower lip projection. Statistical significance was found in women: upper lip thickness (p0.007), lower lip thickness (p0.001) and true vertical plane from nasion-menton (p0.001) and a statistical significance in men: lower lip thickness (p0.033), lower lip projection (p0.039) and true vertical plane from nasion-menton (p0.001). This measurement shows soft tissue differences between the facial growth patterns. A lip thickness difference was found between mesofacial and brachyfacial individuals.

Expression of Mmp-20 in dental germs of human fetus / Expresion de Mmp-20 en gérmenes dentales de fetos humanos

During experiments in animal studies, it has been observed that enamelysin (MMP-20) is expressed during tooth development in the late secretory stage of amelogenesis but not in the mature enamel.The aim of this research was to determine the location of MMP-20 in human tooth germs in the different structures of the enamel organ.The detection of MMP-20 was performed by immunohistochemistry in 20 specimens obtained from human fetuses. Immunostaining of MMP-20 was observed from the presecretor stadium in stellate reticulum and intermediate stratum and in the basal portion of ameloblasts in the secretory stage in stellate reticulum, stratum intermedium, secretory ameloblasts, odontoblasts and dental papilla. The results of this research show the location of MMP-20 in tooth germ development in humans and provides the foundation for future research about the process of dental organ formation.

En estudios realizados en animales de experimentación se ha observado que la enamelisina (MMP-20) se expresa durante el desarrollo dental durante el estadio de secreción tardío de la amelogénesis pero no en el esmalte maduro. El objetivo de la presente investigación fue determinar la localización de MMP-20 en gérmenes dentarios humanos en las diferentes estructuras del órgano del esmalte. Se analizaron 20 especímenes obtenidos de fetos humanos, efectuando la detección de MMP-20 por Inmunohistoquímica. Se observó inmunolocalización de MMP-20 desde el estadio presecretor en retículo estrellado y estrato intermedio, así como en porción basal de ameloblastos; en el estadio secretor en retículo estrellado, estrato intermedio, ameloblastos secretores, odontoblastos y papila dental. Los resultados de la presente investigación muestran la localización de la MMP-20 en el desarrollo del germen dentario en humanos y aporta las bases para futuras investigaciones acerca del proceso de formación de los órganos dentales.

Amelogenin and enamelysin localization in human dental germs.

Odontogenesis is extensively studied in animal models but less understood in human. In early amelogenesis, amelogenin constitutes 90% of enamel organic matrix, which is degraded by enamelysin and replaced by hydroxyapatite crystals. Here, amelogenin and enamelysin distribution changes during amelogenesis were shown by co-localization experiments by confocal microscopy. Early bell stage showed more amelogenin labeling than enamelysin, as free immune-reactive granular patches towards basal membrane between ameloblast and odontoblast. Increased amelogenin expression and secretion towards extracellular matrix formation region was found. Enamelysin distribution was perinuclear in early bell stage. During late bell stage, a decreasing amelogenin labeling in contrast with enamelysin increasing along the cells was found, suggesting specific temporal amelogenin degradation. Enamelysin was located initially around nuclei and later was found in all the ameloblast and stellate reticulum cytoplasm. Amelogenin was observed inside ameloblast, stellate reticulum, and intermediate stratum cells in the enamel as well as in the newly formed dentin extracellular matrix. In contrast, in dentin more amelogenin than enamelysin was found located close to the periphery.