Efecto del ultrasonido de baja intensidad (USBI) sobre el movimiento dentario ortodóncico: estudio in vivo en ratas Sprague-Dawley / Effect of low intensity ultrasound (USBI) in the orthodontic dental movement: in vivo study in Sprague-Dawley rats

Este estudio se realizó con el propósito de analizar el efecto de la aplicación de ondas de USBI sobre la velocidad y distancia de movimiento dentario, y su efecto a nivel histológico en ratas Sprague-Dawley. Veintitrés ratas macho Sprague-Dawley fueron parte del experimento, las que fueron divididas aleatoriamente en tres grupos. Cinco ratas fueron utilizadas como control sin movimiento dentario ortodóncico (MDO), nueve ratas fueron sometidas a una aplicación de fuerza ortodóncica sin aplicación de USBI y nueve fueron sometidas a una aplicación de fuerza ortodóncica con USBI. Estas fuerzas ortodóncicas fueron realizadas entre el aspecto mesio vestibular del primer molar superior izquierdo y el incisivo central superior, traccionando el molar hacia mesial, aplicando una fuerza aproximada de 50 gramos durante 21 días, debido a problemas con la sedación estos dos últimos grupos quedaron compuestos de seis y ocho ratas respectivamente. En el grupo MDO sin USBI, se registró una reducción del espacio entre molares e incisivos de 2 mm. En el grupo MDO con USBI dicha reducción fue de 3.4 mm, siendo esta diferencia estadísticamente significativa. Histológicamente el grupo MDO c/USBI mostró un perímetro vascular y espacios medulares aumentados respecto de los otros grupos, no obstante, no se encontraron diferencias significativas en la cantidad de osteoclastos. Fue posible observar y demostrar cuantitativamente que el USBI es una forma de estimulación mecánica eficiente para la aceleración del MDO sobre un período experimental de 21 días, donde se observaron diferencias significativas entre el grupo control, el grupo MDO sin USBI y el grupo MDO con USBI en la magnitud del movimiento dentario. Se observó una mayor vascularidad en el grupo con USBI, expresando perímetros vasculares de mayor tamaño, esto pudo deberse al efecto estimulatorio del ultrasonido sobre la angiogénesis.

The objective of this study was to analyze the effect of USBI wave application on the speed and distance of dental movement, and its effect at histological level in SpragueDawley rats. In this study twenty-three male Sprague-Dawley rats were randomly divided into three groups. Five rats were used as control without orthodontic tooth movement (MDO), nine rats were subjected to an orthodontic force application without USBI application, and nine were subjected to an orthodontic force application with USBI. The orthodontic forces were performed between the vestibular mesio aspect of the first upper left molar and upper central incisor, pulling the molar mesially, applying an approximate force of 50 grams for 21 days. In light of sedation problems these last two groups were composed of six and eight rats respectively. In the MDO group without USBI, there was a reduction in the space between molars and incisors of 2 mm. In the MDO group with USBI this reduction was 3.4mm, this difference being statistically significant. Histologically, the MDO c / USBI group showed a vascular perimeter and enlarged spinal spaces with respect to the other groups, however, no significant differences were found in the amount of osteoclasts. It was possible to quantitatively demonstrate that USBI is a form of efficient mechanical stimulation for MDO acceleration over an experimental 21-day period, where significant differences were observed in tooth movement between the control group, the group without USBI and the group with USBI. A greater vascularity was observed in the group with USBI, expressing larger vascular perimeters, which could be due to the stimulatory effect of ultrasound on angiogenesis.

Mandibular trabecular structures in alveolar ridge preservation using different grafting materials after tooth extraction / Estructura trabecular mandibular en preservación de reborde alveolar utilizando diferentes materiales de injerto después de la exodoncia

The aim was to describe the star volume analysis in ridge preservation using different grafting materials. Bilateral extraction of the first mandibular molars of sixteen male rabbits was performed, divided at random into four groups (n= 4 in each group) according to graft, using: blood clot (G1), xenograft (G2), pure phase beta-tricalcium phosphate (G3) and biphasic calcium phosphate (60 % HA / 40 % beta-TCP) (G4). Rabbits were euthanized at 4, 6, or 8 wk post-extraction; the trabecular bone structures was evaluated by star volume analysis. The Levene test was used to analyze variance, as was the independent sample t-test. A P-value of < 0.001 was used to establish a statistically significant. The star volume analysis of the mandibular trabecula shows that the marrow space star volume (V*m.space) was higher than the trabecular star volume (V*tr). At 6-week post-extraction, new trabecular bone was evident. At 8-week post-extraction V*tr increase in all groups and the V*m.space diminish, suggesting coarsening of the internal architecture. In G2, some trabecular bone was observed in the central region. In G3, most of the socket regions were occupied by newly formed and loose trabecular bone and in the G4, the sockets were almost entirely filled with trabecular bone. Star volume analysis is adequate to analysis of bone patterns formation using bone substitutes.

El objetivo de esta investigación fue describir el volumen estrella en preservación alveolar utilizando diferentes injertos óseos. La exodoncia bilateral del primer molar mandibular de 16 conejos machos fue realizada, dividiéndolos en 4 grupos (n= 4 en cada grupo) de acuerdo al injerto utilizado, siendo: coágulo sanguíneo (G1), xenoinjerto (G2), beta-tricalcio fosfato puro (G3) y fosfato de calcio bifásico (60 % HA / 40 % beta-TCP) (G4). Los conejos fueron sometidos a eutanasia a las 4, 6 u 8 semanas post exodoncia; el trabeculado óseo fue evaluado por medio del volumen estrella. La prueba de Levene fue utilizado para el análisis de varianza y luego la prueba t-test para muestras independientes. El valor de P menor a 0.001 fue establecido como significancia estadística. El análisis del volumen estrella del trabeculado mostró que el espacio medular de volumen estrella (V*m.space) fue mayor que trabeculado (V*tr). A 6 semanas post exodoncia, nuevo trabeculado óseo fue evidente. A las 8 semanas post exodoncia V*tr aumenta en todos los grupos y el V*m.space disminuye, sugiriendo un engrosamiento de la arquitectura interna. En el grupo G2, algún trabeculado óseo fue observado en la región central. En el G3, la mayoría del alveolo fue ocupado por nuevo hueso y perdió trabeculado óseo y en G4, el alveolo fue ocupado casi enteramente por hueso trabecular. El análisis de volumen estrella es adecuado para analizar el modelo de formación ósea utilizando sustitutos óseos.

Estudio clínico e histológico de aloinjerto de hueso liofilizado en alvéolos pos extracción: presentación de caso clínico / Clinical and histological study of bone freeze drying allograft in postextraction sockets: report of a clinical case

Objetivos: evaluar las respuestas clínicas e histológicas y determinar la calidad del hueso obtenido por medio del aloinjerto utilizado en un alvéolo posextracción en el que se realizó una técnica de preservación del volumen alveolar, a fin de colocar implantes. Caso clínico: una paciente de 47 años recibió un tratamiento de preservación del volumen alveolar posextracción mediante aloinjerto de hueso liofilizado (matriz ósea UNC en polvo) contenido por una lámina ósea cortical (matriz ósea UNC en membrana). A los 120 días, se tomó biopsia y se colocaron implantes. La muestra se observó con microscopía óptica. Conclusión: histológicamente, se identificaron restos de partículas y de lámina ósea, e intensos fenómenos de angiogénesis y neoformación ósea. La observación clínica permitió visualizar los márgenes nítidos del reborde y verificar la conservación del volumen ósea en el lugar en el que se realizó la fijación primaria de los implantes. La técnica de preservación con los biomateriales citados permite la colocación del implante en una posición adecuada, con resultados funcionales y estéticos.

Changes in morphology of alveolar buccal walls following atraumatic internal root fragmentation / Cambios en la morfología de las paredes alveolares bucales después de fragmentación radicular interna atraumática

The buccal alveolar wall represents the most important structure to provide shape and volume of the alveolous following tooth extraction. The aim of the study was the evaluation of buccal alveolar bone structures following minimally invasive surgery. In 15 patients (3 male, 12 female), aged 20­67 years, 3 central incisors, 5 lateral incisors, and 7 bicuspids were removed using flapless enucleation. The enucleation comprised endoscopically assisted mesiodistal root sectioning with inward fragmentation of the oral and apical parts followed by internal reduction of the buccal root lamella. Buccal bone height before extraction was 10.61 mm, following extraction 10.50 mm. Crestal width of the buccal bone plate was 1.11 mm before and 1.40 mm after tooth removal. Apical buccal bone width before was 0.66 mm and after extraction 0.40 mm. Gingival height was 13.58 mm before and 13.56 mm following extraction. Following transalveolar enucleation, the buccal alveolar bone wall remains unchanged concerning height and crestal width.

La pared alveolar bucal representa la estructura más importante para proveer la forma y el volumen de los alveólos dentales posterior a la extracción dental. El objetivo del estudio fue evaluar las estructuras de hueso alveolar bucal después de la cirugía mínimamente invasiva. En 15 pacientes (3 hombres, 12 mujeres), con edades entre 20 a 67 años, 3 incisivos centrales, 5 incisivos laterales y 7 premolares fueron removidos utilizando enucleación sin colgajo. La enucleación comprende el seccionamiento mesio-distal de la raíz dental endoscópicamente asisitido a través de fragmentación interna de la porción lingual y apical radicular y posteriomente una reducción interna de la lamela de raíz bucal. La altura ósea bucal antes de la extracción fue 10,61 mm y después de la extracción fue 10,50 mm. La anchura de la cresta ósea bucal fue 1,11 mm y 1,40 mm después de la extracción del diente. El grosor del hueso apical antes de la extracción fue 0,66 mm y 0,40 mm después de la extracción. La altura gingival fue 13,58 mm antes de la extracción y 13,56 mm después de la extracción. Después de la enucleación transalveolar, la pared del hueso alveolar bucal se mantiene sin cambios en relación con la altura y del grosor del reborde alveolar.

Técnica de preservación del volumen alveolar post-extracción utilizando hueso liofilizado y lámina ósea cortical / Preservation techniques of alveolar post-extraction volume using liophilisate bone and cortical bone sheets

Se evaluó la eficacia del hueso liofilizado humano (Matriz Ósea UNC en Polvo) injertado en cavidades alveolares post-extracción, recubierto por una lámina ósea cortical (Matriz Ósea UNC en membrana), en el tratamiento de preservación del perfil volumétrico del reborde alveolar.La metodología de trabajo se fundamentó en: 1) El estudio de una casuística de 27 casos clínicos en pacientes de ambos sexos que poseían elementos dentarios unirradiculares con indicación de extracción. Se injertó en las cavidades óseas resultantes hueso liofilizado, contenido in situ mediante una lámina ósea cortical parcialmente desmineralizada. Los pacientes fueron evaluados clínica y radiográficamente, mediante modelos de estudio, Rx convencional y radiovisiografía que permitieron mensurar las modificaciones producidas por resorción durante un año. Se realizaron controles pre y post-operatorios, a los 7, 15, 30, 60, 90, 120, 180 y 360 días. A los modelos de yeso preliminares y a los obtenidos a los 120 y 360 días se les efectuaron cortes transversales en las zonas de estudio y se los escaneó. Las imágenes obtenidas se procesaron mediante un analizador de imágenes (Image Pro-Plus). Los datos se analizaron estadísticamente con software específico (SPSS). El estudio demostró que las mayores modificaciones dimensionales del reborde se observaron sobre el área superficial del alvéolo y en los primeros 4 meses post-extracción. La lámina cortical presentó características físicas, estructurales y biológicas que le permitieron actuar como barrera física oclusiva, minimizando los fenómenos de inhibición celular heterotípica y favoreciendo los procesos osteogénicos por el mecanismo de osteopromoción...

Human efficacy lyophilized bone (UNC Bone Matrix Powder) grafted post-extraction alveolar sacs, covered by a cortical bone plate (UNC Bone Matrix membrane), in the treatment volume preservation ridge profile was evaluated. The working methodology was based on: 1) The study of a case series of 27 clinical cases in patients of both sexes who had single-rooted tooth elements indicating extraction. It was grafted bone cavities in the resulting lyophilized bone content in situ by a partially demineralized cortical bone plate. Patients were evaluated clinically and radiographically, using study models, and conventional Rx radiovisiography that allowed mensurar resorption induced changes for a year. Pre and post-operative controls at 7, 15, 30, 60, 90, 120, 180 and 360 days were performed. A preliminary plaster models and those obtained at 120 and 360 days transects were conducted in the study areas and were scanned. The images obtained were processed by an image analyzer (Image Pro-Plus). The data were statistically analyzed with software (SPSS) .The study showed that older flange dimensional changes were observed on the surface area of the alveoli and in the first 4 months post-extraction. The cortical sheet submitted physical, structural, and biological characteristics that allowed him to act as occlusive physical barrier, minimizing heterotypic cellular inhibition phenomena and processes favoring osteogenic mechanism osteopromoción...

Avaliação da inclinação axial dos dentes posteriores e sua respectiva morfologia alveolar nos diferentes padrões faciais: uma visão por meio da tomografia computadorizada de feixe cônico / Evaluation of the axial inclination of posterior teeth and their respective alveolar morphology in different facial patterns: a vision by cone beam computed tomography

O objetivo deste estudo foi comparar, por meio de tomografia computadorizada de feixe cônico, a inclinação axial dos dentes posteriores e a morfologia óssea alveolar mandibular entre indivíduos com diferentes padrões faciais. Para isso, foram utilizadas 58 tomografias de indivíduos maiores de 14 anos de idade não tratados ortodonticamente. Os indivíduos foram divididos em 3 grupos de acordo com o padrão facial avaliado pelo índice VERT de Ricketts: Grupo 1: composto por 18 indivíduos com padrão braquifacial, com idade média de 21,58 anos (d.p.=7,43); Grupo 2: composto por 23 indivíduos com padrão mesofacial, com idade média de 19,14 anos (d.p.=5,19); e Grupo 3: composto por 17 indivíduos com padrão dolicofacial, com idade média de 19,09 anos (d.p.=6,89). Foi realizada uma avaliação quantitativa das tábuas ósseas vestibular e lingual dos dentes pósteroinferiores, em tomografias de feixe cônico. As medidas utilizadas foram: altura do osso mandibular vestibular e lingual, largura mandibular cervical e média, inclinação mandibular, inclinação da face vestibular, largura do molar, angulação do molar e ângulo dente/osso. A comparação intergrupos foi realizada com a utilização do teste ANOVA a um critério de seleção e teste de Tukey quando necessário. Para verificar se existe correlação entre o padrão facial e as variáveis estudadas foi utilizado o teste de correlação de Pearson. Os resultados demonstraram que os indivíduos braquifaciais apresentaram uma menor inclinação mandibular quando comparados aos indivíduos mesofaciais e dolicofaciais. Houve diferença significante da altura mandibular vestibular entre os três grupos avaliados, sendo que esta foi menor no grupo braquifacial, intermediária no grupo mesofacial e maior no grupo dolicofacial. A altura mandibular lingual foi menor no grupo braquifacial em comparação aos grupos mesofacial e dolicofacial. A largura mandibular média foi maior nos indivíduos braquifaciais em relação aos mesofaciais.

The aim of this study was to compare, with cone beam computed tomography, the axial inclination of posterior teeth and mandibular alveolar bone morphology among individuals with different facial patterns. For this, 58 CT scans of untreated individuals orthodontically aged more than 14 years were used. The subjects were divided into 3 groups according to the facial pattern evaluated by the VERT index by Ricketts: Group 1 comprised 18 individuals with brachyfacial pattern, with a mean age of 21.58 years (s.d.=7.43); Group 2 comprised 23 individuals with mesofacial pattern, with a mean age of 19.14 years (s.d.=5.19); and Group 3 comprised 17 individuals with dolichofacial pattern, with a mean age of 19.09 years (s.d.=6.89). A quantitative assessment of the buccal and lingual bone plates of the mandibular posterior teeth were made in cone beam CT scans. The variables measured were: buccal and lingual mandibular height, cervical and middle mandibular width, mandibular inclination, inclination of the buccal surface, molar width, molar angle and tooth/bone angle. The intergroup comparison was performed by one-way ANOVA and Tukey test when necessary. To check whether there is a correlation between facial pattern and the variables studied, the Pearson correlation test was used. The results showed that the brachyfacial subjects had a smaller mandibular angle when compared to mesofacial and dolichofacial individuals. There was significant difference in the buccal mandibular height between the three groups, and this was smaller in the brachyfacial group, intermediate in the mesofacial group and larger in the dolichofacial group. Lingual mandibular height was smaller in brachyfacial group when compared to mesofacial and dolichofacial groups. The mean mandibular width was greater in brachyfacial than in mesofacial subjects.

Avaliação da inclinação axial dos dentes posteriores e sua respectiva morfologia alveolar nos diferentes padrões faciais: uma visão por meio da tomografia computadorizada de feixe cônico / Evaluation of the axial inclination of posterior teeth and their respective alveolar morphology in different facial patterns: a vision by cone beam computed tomography

O objetivo deste estudo foi comparar, por meio de tomografia computadorizada de feixe cônico, a inclinação axial dos dentes posteriores e a morfologia óssea alveolar mandibular entre indivíduos com diferentes padrões faciais. Para isso, foram utilizadas 58 tomografias de indivíduos maiores de 14 anos de idade não tratados ortodonticamente. Os indivíduos foram divididos em 3 grupos de acordo com o padrão facial avaliado pelo índice VERT de Ricketts: Grupo 1: composto por 18 indivíduos com padrão braquifacial, com idade média de 21,58 anos (d.p.=7,43); Grupo 2: composto por 23 indivíduos com padrão mesofacial, com idade média de 19,14 anos (d.p.=5,19); e Grupo 3: composto por 17 indivíduos com padrão dolicofacial, com idade média de 19,09 anos (d.p.=6,89). Foi realizada uma avaliação quantitativa das tábuas ósseas vestibular e lingual dos dentes pósteroinferiores, em tomografias de feixe cônico. As medidas utilizadas foram: altura do osso mandibular vestibular e lingual, largura mandibular cervical e média, inclinação mandibular, inclinação da face vestibular, largura do molar, angulação do molar e ângulo dente/osso. A comparação intergrupos foi realizada com a utilização do teste ANOVA a um critério de seleção e teste de Tukey quando necessário. Para verificar se existe correlação entre o padrão facial e as variáveis estudadas foi utilizado o teste de correlação de Pearson. Os resultados demonstraram que os indivíduos braquifaciais apresentaram uma menor inclinação mandibular quando comparados aos indivíduos mesofaciais e dolicofaciais. Houve diferença significante da altura mandibular vestibular entre os três grupos avaliados, sendo que esta foi menor no grupo braquifacial, intermediária no grupo mesofacial e maior no grupo dolicofacial. A altura mandibular lingual foi menor no grupo braquifacial em comparação aos grupos mesofacial e dolicofacial. A largura mandibular média foi maior nos indivíduos braquifaciais em relação aos mesofaciais...

The aim of this study was to compare, with cone beam computed tomography, the axial inclination of posterior teeth and mandibular alveolar bone morphology among individuals with different facial patterns. For this, 58 CT scans of untreated individuals orthodontically aged more than 14 years were used. The subjects were divided into 3 groups according to the facial pattern evaluated by the VERT index by Ricketts: Group 1 comprised 18 individuals with brachyfacial pattern, with a mean age of 21.58 years (s.d.=7.43); Group 2 comprised 23 individuals with mesofacial pattern, with a mean age of 19.14 years (s.d.=5.19); and Group 3 comprised 17 individuals with dolichofacial pattern, with a mean age of 19.09 years (s.d.=6.89). A quantitative assessment of the buccal and lingual bone plates of the mandibular posterior teeth were made in cone beam CT scans. The variables measured were: buccal and lingual mandibular height, cervical and middle mandibular width, mandibular inclination, inclination of the buccal surface, molar width, molar angle and tooth/bone angle. The intergroup comparison was performed by one-way ANOVA and Tukey test when necessary. To check whether there is a correlation between facial pattern and the variables studied, the Pearson correlation test was used. The results showed that the brachyfacial subjects had a smaller mandibular angle when compared to mesofacial and dolichofacial individuals. There was significant difference in the buccal mandibular height between the three groups, and this was smaller in the brachyfacial group, intermediate in the mesofacial group and larger in the dolichofacial group. Lingual mandibular height was smaller in brachyfacial group when compared to mesofacial and dolichofacial groups. The mean mandibular width was greater in brachyfacial than in mesofacial subjects...

Particulate bone matrix usage for alveolar bone conservation. A histomorphometric study / Particulate bone matrix usage for alveolar bone conservation. A histomorphometric study.

UNLABELLED: Different filling materials have been used in an attempt to repair bone loss situations. OBJECTIVE: The present study aimed to examine the effect of a bone matrix in post - extraction remodelling of the alveolar bone, and to perform a histomorphometric analysis of the residual alveolar ridges in Wistar rats. MATERIAL AND METHODS: Both rat first lower molars were extracted and the right alveoli were filled with particles of a bone matrix with mineral components (MO - UNC) (experimental group, EG). The left alveoli were used as a control group (CG). The animals were sacrificed at 0 hr., 15, 30 and 60 days after extraction, and the samples were processed. Histological sections were made at the level of the mesial alveolus of the first lower molar. Repair of the alveoli was histologically evaluated and a histomorphometric study of total alveolar volume (TAV), height of the buccal plate (Bh), height of the lingual plate (Lh) and percentage of osseointegration (OI) of the particles was performed to compare the residual ridges of CG with those of the EG. Statistical analysis of the data was performed. RESULTS: In the cases of the experimental group, newly - formed bone tissue was identified around the MO - UNC particles (osseointegration). Histomorphometric data indicate that, at 60 days post - extraction, TAV was significantly greater for EG when compared with CG (p <0.05) and the percentage of osseointegration of the particles increased as a function of time (57.6

, for EG at 15, 30 y 60 days respectively). CONCLUSIONS: The bone matrix (MO - UNC) evaluated in this study is an osteoconductive material that prevents the collapse of post - extraction alveolar bone.

Location of the mandibular foramen according to the amount of dental alveoli / Localización del foramen mandibular según la cantidad de los alvéolos dentales

The aim of this study was to analyze the anatomotopographic location of the mandibular foramen in the right and left ramus, and to verify the influence of the amount of dental alveoli on the foramen position. Thirty-five adult dry human mandibles of Araraquara Dental School, UNESP - São Paulo State University were assessed, with or without dental alveoli. Measurements were obtained, using a ruler and a digital caliper. The following distances were measured: FI - distance between the lowest point of the mandibular incisure and the mandibular foramen (F point); FB - distance between the mandibular base and F point; FP - distance between the posterior margin of the ramus and F point; FA - distance between the anterior margin of the ramus and F point; FT - distance between the apex of the retromolar trigone and F point. The Mann-Whitney test was used to compare each measurement according to hemi-arch, and the Kruskal-Wallis test was used to analyze the influence of the presence of alveoli on the measures. For multiple comparison, Dunn's method was used. There was no statistically significant difference in the location of the mandibular foramen when compared to the right and left hemi-arches. The amount of dental alveoli influenced, significantly, only on FA and FP distances. Thus, it was concluded that the right and left mandibular ramus showed symmetry in the location of the mandibular foramen, and the amount of alveoli influenced on the distances of the anterior and posterior margins of the mandibular ramus, in relation to the mandibular foramen.

El objetivo de este trabajo fue evaluar la posición anátomo-topográfica del foramen mandibular en ambas ramas de la mandíbula y verificar la influencia de la cantidad de alvéolos dentales en la posición del foramen. Se evaluaron 35 mandíbulas humanas secas de individuos adultos de la Facultad de Odontología de Araraquara, Universidade Estadual Paulista - UNESP, con o sin alvéolos dentales. Se utilizó regla y calibrador digital para realizar las mediciones de las distancias entre: el punto más profundo de la incisura de la mandíbula y el foramen mandibular (FI); base de la mandíbula y el foramen (FB); margen posterior de la rama mandibular y el foramen mandibular (FP); margen anterior de la rama mandibular y el foramen (FA) y la distancia entre el vértice del trígono retromolar y el foramen mandibular (FT). Para la comparación de cada medida según hemiarcada se realizó el test de Mann-Whitney y para la influencia de la presencia de alvéolos en las medidas se utilizó el test de Kruskal-Wallis y para comparación múltiple el método de Dunn. No hubo diferencia estadística significativa en la localización del foramen mandibular al comparar el hemiarco mandibular derecho con el izquierdo. La cantidad de alvéolos dentales interfirió, de manera significativa, sólo en las distancias FA y FP. Se concluyó que las ramas mandibulares derecha e izquierda presentan simetría en el posicionamiento del foramen mandibular y la cantidad de alvéolos interfirió en las distancias de las márgenes anterior y posterior de la rama mandibular en relación con el foramen de la mandíbula.

Dentoalveolar heights in skeletal class I normodivergent facial patterns

To determine the dentoalveolar heights [mm] in skeletal class I normodivergent facial pattern and compare the same heights in male and female subjects. Cross-sectional observational study. Orthodontics Clinic, The Aga Khan University Hospital, Karachi, from July to October 2009. Eighty one subjects were selected from the orthodontic record at the Aga Khan University Hospital Karachi.The inclusion criteria were an age range of 12 to 30 years and skeletal class I normodivergent facial pattern with exclusion criteria of prior orthodontic treatment, restored teeth and craniofacial anomalies/syndromes. The pre-treatment cephalographs of the patients were traced manually on acetate paper by the principal investigator. The various land marks were marked and the parameters were recorded. Mean and standard deviations were determined. Independent sample t-test was used to find gender dimorphism. The mean age of the sample was 15.8 +/- 3.4 years. Mean ANB angle for the entire sample was 2.6° +/- 1.2° and for angle SN-MP was 31.5° +/- 2.5°. Descriptive analysis presented mean value of upper anterior, upper posterior, lower anterior and lower posterior dentoalveolar heights to be 28.5 +/- 2.7 mm, 22.9 +/- 2.6 mm, 41.3 +/- 2.9 mm and 31.5 +/- 3.2 mm respectively. Male subjects had significantly greater mean values for lower anterior and posterior dentoalveolar heights [p=0.02 and 0.05 respectively]. The mean dentoalveolar heights for the skeletal class I normodivergent sample were established. No gender dimorphism was found for upper dentoalveolar heights however, lower anterior and lower posterior were significantly greater in males as compared to females. All the values of dentoalveolar heights for male subjects were greater than female subjects

Morphometrical and morphological study of mental foramen in dry dentulous mandibles of South Andhra population of India.

Background: Mental foramen (MF) is an anatomical structure of particular importance in local anesthesia and surgical procedures in terms of achieving effective mandibular nerve blocks and avoiding injuries to the neurovascular bundles. Aim: To determine the morphometry and morphology of MF in south Andhra population of India, hitherto unreported. Materials and Methods: Ninety dry dentulous mandibles of both sexes were examined for position, size, shape and number of MF. Results: Various parameters investigated are, the horizontal distance between (1) symphysis menti and MF was 27.2 mm on right and 27.7 mm on the left, (2) MF and posterior border of ramus was 70.7 mm on both sides, vertical distance between (3) MF and inferior border of mandible was16.5 mm on right and 14.3 mm on left, (4) alveolar crest and MF was 13.7 mm on right and 16.4 on left, (5) distance between the MF and below the apex of premolar socket was +2.8 mm on right and +3.5 mm on left and above the socket was -2.8 mm on right and -2.7 mm on left. Occurrence of MF below the second premolar tooth was found to be highest (73.2%). Average size of MF was larger on left and its way of exit was in postero-superior direction. Shape of MF was round in 79% and oval in 21% and double MF was found in 8.9% of mandibles. Conclusions: In the present study, most common position of MF was found below the apex of second premolar in 73.2% and between the second premolar and first molar in 19% of mandibles. The other morphometrical findings of this study may be implicated by dental practitioners and maxillofacial surgeons.

Histological evaluation of bone regeneration means freeze dried bone allograft (FDBA) in post exodontia sockets / Evaluación histológica de la regeneración ósea en alvéolos post exodoncia mediante uso de freeze dried bone allograft (FDBA)

Within oral rehabilitation alveolar ridge preservation following extraction is important. This research study shows a histological, histochemical and histomorphometrical evaluation in two cases of post extraction ridge-socket preservation performed with FDBA. In two patients dental extraction procedures were performed and sockets were immediately filled with FDBA. Six months later a biopsy of grafted area was obtained and rehabilitated through dental implant. Grafted bone samples were treated for histological and histochemical analysis. Bone tissue area was measured. Laboratory analysis of three samples showed inactive bone surfaces, neither osteoblasts nor osteoclasts were found, only osteocyte and osteogenous cells were observed. These findings do not mean that tissue is metabolically inactive, rather bone genesis develop from a tissue matrix with the potential to generate undifferentiated osteocytes, and a micro environment with proteins such as bone morphogenetic proteins (BPM). Inactive biomaterial particles were not observed. Samples showed 0 percent and 30 percent bone tissue respectively. Considering histological differences between this and other research studies, it is necessary to develop further investigation to increase knowledge of processes involved in bone regeneration as well as bone quality, considering the variability that could be seen in each patient.

Dentro de la rehabilitación oral, es importante preservar el reborde alveolar post exodoncia. Se expone un análisis histológico, histoquímico e histomorfométrico de dos casos clínicos de terapias de regeneración ósea de alvéolos post extracción mediante FDBA. En dos pacientes se extrajeron piezas dentarias destruidas y se indujo regeneración ósea mediante FDBA. Seis meses después, se obtuvo una biopsia del injerto y mediante un implante de titanio fue rehabilitado. Para el análisis Histológico e Histomorfométrico, las muestras fueron tratadas con las técnicas Hematoxilina-Eosina, Azul de Alcián, Masson, Von Kossa y colorante Picrosirius de Junqueira.Se midió el área total de tejido, así como el área de tejido óseo. Las superficies de hueso de las muestras se observaron inactivas, no fueron encontrados osteoblastos ni osteoclastos, sólo osteocitos y células osteógenas, lo que no significa que el hueso esté en estado quiescente, sino mas bien a que su génesis ocurre a partir de la matriz de tejido donde se encuentran células con potencialidad de formar osteocitos indiferenciados y un microambiente con proteinas de la familia de factor de crecimiento transformante beta. No fueron encontradas partículas de biomaterial inactivo. En las muestras se cuantificó 0 por ciento y 30 por ciento de hueso mineralizado. Dadas las diferencias histológicas encontradas con otros estudios, es necesario profundizar el conocimiento en los procesos involucrados en la regeneración ósea dependiendo del biomaterial utilizado, y la calidad ósea resultante en cada procedimiento en particular sin perder de vista la variabilidad que puede presentarse dependiendo de cada caso clínico.

Molars extraction for bone graft study in rabbits / Extração de molares para estudos de enxertos ósseos em coelhos

PURPOSE: The aim of this study was to describe an experimental surgical technique to be used in the evaluation of bone grafts in rabbits. METHODS: The operative technique was performed in jaws, with external approach from the labial commissure to the last molar tooth. An incision about 1cm extended forward to the alveolar ridge, followed by a exposing the cervical region of the alveolar bone and dental elements was done. Thus, after extraction of first molar with forceps, the tooth socket left was filled with hydroxyapatite. The bone gain was analyzed by histopathological studies. RESULTS: The histological analyses indicated formed bone surrounding the biomaterial. CONCLUSION: The experimental model using the tooth socket of the rabbit molar is a feasible procedure for studies of bone grafts.

OBJETIVO: Descrever uma técnica cirúrgica em coelhos para avaliação de enxertos ósseos. MÉTODOS: A técnica operatória consiste numa incisão na topografia da comissura labial até o ultimo molar. Uma incisão de 1cm no rebordo para expor o osso alveolar e a região cervical dos molares. Realizou-se a exodontia com fórceps e o alvéolo é preenchido com hidroxiapatita. Após o tempo de cicatrização é realizada a avaliação histológica. RESULTADOS: A análise histológica mostrou o novo osso formado rodeando biomaterial. CONCLUSÃO: O modelo cirúrgico para avaliação de enxertos ósseos utilizando molares de coelhos se mostrou factível.

Morphometric analysis of the sockets for the upper temporary molar teeth in human foetuses / Análisis morfométrico de los alvéolos de molares temporales superiores en fetos humanos

Foetal therapy has made foetal anatomy a promising field. Maxilla had been the core research attraction of many scientists. Alveolar arches, specially the maxillary one had been consistently the focus of attention for research workers due to its importance in dentistry. Twenty nine human foetuses were grouped into I (< 24 weeks of IUL), II (25-30 weeks of IUL) and III (> 30 weeks of IUL). Maxillae were dissected out and sockets were carefully cleaned. Sockets for the temporary molars, which also hold permanent premolars were measured with the help of Vernier callipers. Three parameters, i.e. maximum mesiodistal diameter,maximum transverse diameter and maximum depth were considered. Readings were analysed statistically by using Student's 't' test. Growth was maximum in group II for the mesiodistal diameter of the socket for 1st temporary molar but significant bilateral variation or sexual dimorphism was not found. A very high rate of growth (+63 percent) was noticed in group II foetuses. Contrary to mesiodistal values, transverse diameter showed significant higher values on left side in group II foetuses. Similarly in late foetuses of group III, values were significantly more in males than those in females. It might be reflecting the higher measurements in general in male adult skeleton compared to females. The increase in the depth was significantly higher in the last two groups but the rate was again more in group II (57 percent) than in group III (29 percent). Although no bilateral variations were noticed, the value was found to be higher in male than female in last foetal group. The values increased with great rate in both group II and III foetuses for the mesiodistal diameter of the socket for 2nd temporary molar. An unexpected increase in the mesiodistal readings of female socket was observed in group II. The values of transverse diameter showed a consistent increase i.e. a significant increase in group II and III foetuses, a pattern...

La terapia fetal ha hecho de la anatomía fetal un campo prometedor. El maxilar ha sido la atracción central de investigación de muchos científicos. Los arcos alveolares, especialmente el maxilar ha sido siempre el foco de atención para los investigadores debido a su importancia en la odontología. Veintinueve fetos humanos se agruparon en grupos I (< 24 semanas de vida intrauterina), II (25-30 semanas de vida intrauterina) y III (> 30 semanas de vida intrauterina). Los maxilares fueron disecados y los alvéolos fueron limpiados cuidadosamente. Los alvéolos de los molares temporales, que también tienen premolares permanentes, fueron medidos con la ayuda de un caliper Vernier. Fueron considerados 3 parámetros, es decir, diámetro mesiodistal máximo, diámetro transverso máximo y profundidad máxima. Las lecturas fueron analizadas estadísticamente mediante el uso de la prueba t de Student. El crecimiento fue máximo en el grupo II para el diámetro mesiodistal del alvéolo del primer molar temporal, pero la variación significativa o bilateral de dimorfismo sexual no fue encontrada. Una tasa muy alta de crecimiento (+63 por ciento) se observó en los fetos del grupo II. Contrariamente a los valores mesiodistal, los diámetros transversos mostraron valores significativamente más altos en el lado izquierdo en el grupo de fetos II. Del mismo modo en los fetos del grupo III, los valores fueron significativamente más altos en varones que en las de mujeres. Esto podría estar reflejando las mediciones más altas en general en el esqueleto del hombre adulto en comparación con las mujeres. El aumento de la profundidad fue significativamente mayor en los dos últimos grupos, pero la tasa fue mayor en el grupo II (57 por ciento) que en el grupo III (29 por ciento). Aunque no se observaron variaciones bilaterales, el valor se encontró que fue mayor en niños que en niñas en el grupo fetal. Los valores se incrementaron con rangos excepcionales tanto en el grupo de...

Uso de barreira exposta ao meio bucal para regeneração óssea guiada após a exodontia / Regeneration of alveolar bone through membrane exposed to the oral environment

A manutenção, ou a recuperação, do rebordo alveolar após a perda do dente tornou-se um dos principais objetivos do cirurgião-dentista quando visa a reabilitação do seu paciente através de implantes osteointegráveis. Ao longo dos últimos anos várias técnicas e materiais foram descritos para a realização da Regeneração Óssea Guiada (RGO), e a maioria tem em comum o fato de exigir o preenchimento do defeito ósseo, com enxertos ou materiais aloplásticos, e também de ser recoberto por um retalho para que haja cicatrização por primeira intenção. Esse tipo de cirurgia, mesmo em áreas pequenas, tem morbidade e o sucesso não ocorre em todos os casos. Por outro lado existem poucos estudos sobre barreiras expostas ao meio bucal e praticamente raros os estudos sobre barreiras expostas ao meio bucal que sejam removidas em poucos dias e que não exijam enxertos para preenchimento do alvéolo ou do defeito ósseo. Este artigo faz uma revisão rápida da literatura sobre o tema e apresenta o relato de um caso clínico em que houve extenso defeito ósseo pós-extração dentária. O defeito foi protegido por uma barreira regenerativa de polipropileno, deixada intencionalmente exposta ao meio bucal, e que foi removida uma semana após a cirurgia. Nenhum tipo de biomaterial foi usado para preencher o defeito a ser reparado, apenas sangue. Este relato mostra uma possibilidade na mudança de paradigma quanto à ROG, particularmente no que se refere à exposição ao meio bucal e à necessidade de enxertos. A viabilidade deste tipo de técnica, aliada à sua reduzida morbidade, abre novas perspectivas nessa área da odontologia.

The maintenance or recovery of the alveolar ridge after tooth loss has become a major goal of the dentist when targeted to the rehabilitation of the patient through osseointegration implants. Over the past years, many techniques and materiais have been described for the realization of Guided Bone Re- generation (GBR), and most have in common that they require the filling of bone defects with grafts or alloplastic materiais, and also to be covered bya surgical flap for first intention healing. This type of sur- gery, even in small áreas, has high morbidity and success does not occur in ali cases. Moreover there are few studies on membranes exposed to the oral environment and practically rare studies on membrane exposed to the oral environment to be removed in a few days and not requiring grafts to fill the alveolus or bone defect. This article is a quick review of the literature on the subject and presents a report of a case in which there was extensive bone defect after tooth extraction. The defect was protected bya polypropylene membrane intentionally exposed to the oral environment, and that was removed one week after surgery. Neither type of biomaterial was used to fill the defect to be repaired, only blood. This report shows a possibility in the paradigm shift on the GBR, particularly with regard to exposure to the oral environment and the need for grafts. The feasibility of this type of technique, coupled with reduced morbidity, opens new perspectives in bone regeneration and dentistry.

The direction and location of mental foramen and incidence of accessory mental foramen in south Indian mandibles.

One hundred and forty two south Indian mandibles of unknown sex were examined for the variations of the location and direction of the mental foramen. Accessory mental foramen were also looked for. The findings have been compared with those of other studies in the literature. Topography of the mental foramen is of practical importance to the dental and maxillo-facial surgeon for purpose of anesthesia and surgical procedures.