Cone beam computed tomography-based evaluation of the relationship between the inferior alveolar canal and the cortical plates and the mandibular molar roots in the saudi subpopulation / Evaluación basada en tomografía computarizada de haz cónico de la relación entre el canal alveolar inferior y las placas corticales y las raíces de los molares mandibulares en la subpoblación saudita

Aim: To assess the distance between the inferior alveolar canal and the roots of the mandibular second molar and the mandibula and cortex in a Saudi Arabian subpopulation through existing CBCT images. Materials and Methods: This retrospective study was performed based on 120 patients CBCT images in five age groups.The distances (D1 and D2) between the buccal cortex (BC), lingual cortex (LC), and mandibular molars and the distances (D3) between the root apices and inferior alveolar nerve canal (IANC) were measured for each dental root on the right and left of the mandible with the help of Vision iCAT software. A radiology specialist with a gap of 15 days twice carried out the measurements. Statistical analysis was carried out with the help of SPSS 24. to analyse variability Chi-square analysis was done, and the p value was fixed at > 0.05. To check inter-person variability, Cohen's variability was fixed at 0.8. Results: The distance between the outer surface of the buccal cortical plate and the buccal root surface ranged between 3.8 and 5.7 mm, whereas the distance between the root apices of the mandibular molars and the IANC ranged between 4.8 and 3.5 mm. The distance from the outer surface of the lingual cortical plate to the lingual root surface varied between 1.2 and 2.8 mm. The mean distance between the root apices and IANC increased with age, more so in males than females. Conclusions: Even though this study was conducted on a small sample size, it will help the dental practitioners in planning endodontic procedures, surgical extractions, and implant placements, and it should be repeated with a higher number of images.

Objetivo: Evaluar la distancia entre el canal alveolar inferior y las raíces del segundo molar mandibular, y la mandíbula y la corteza en una subpoblación de Arabia Saudita a través de imágenes CBCT existentes.Materiales y Métodos: Este estudio retrospectivo se realizó con base en imágenes CBCT de 120 pacientes en cinco grupos de edad. Las distancias (D1 y D2) entre la corteza bucal (BC), la corteza lingual (LC) y los molares mandibulares y las distancias (D3) entre los Se midieron los ápices radiculares y el canal del nervio alveolar inferior (IANC) para cada raíz dental a la derecha e izquierda de la mandíbula con la ayuda del software Vision iCAT. Un especialista en radiología, con un intervalo de 15 días, realizó dos veces las mediciones. El análisis estadístico se realizó con la ayuda del SPSS 24. Para analizar la variabilidad se realizó un análisis de Chi-cuadrado y el valor p se fijó en > 0,05. Para comprobar la variabilidad entre personas, la variabilidad de Cohen se fijó en 0,8. Resultados: La distancia entre la superficie exterior de la placa cortical bucal y la superficie de la raíz bucal osciló entre 3,8 y 5,7 mm, mientras que la distancia entre los ápices radiculares de los molares mandibulares y el IANC osciló entre 4,8 y 3,5 mm. La distancia desde la superficie exterior de la placa cortical lingual hasta la superficie de la raíz lingual varió entre 1,2 y 2,8 mm. La distancia media entre los ápices de las raíces y la IANC aumentó con la edad, más en hombres que en mujeres. Conclusión: Aunque este estudio se realizó con un tamaño de muestra pequeño, ayudará a los odontólogos a planificar procedimientos de endodoncia, extracciones quirúrgicas y colocación de implantes, y debe realizarse con más números.

Vestibular Alveolar bone height measurement: Accuracy and Correlation between direct and indirect techniques / Medición de la altura del hueso alveolar vestibular: precisión y correlación entre técnicas directa e indirecta

ABSTRACT Cone Beam Computed Tomography (CBCT) has modified the perspective of dentistry images, providing manipulable threedimensional images with a 1:1 patient:image ratio. Treatments and diagnosis are modified or corroborated by CBCT; however, its accuracy in thin structures such as cortical bone has been subjected to critical review. The aim of this study is to correlate the measurement of vestibular alveolar bone height using direct measurements and measurements performed with conebeam tomographic images with standard (SD) voxel resolution. Thirty incisor and premolar teeth of patients undergoing open curettage were measured with a highprecision caliper and with Cone Beam Computed Tomography (CBCT) at an SD resolution of 0.16 mm voxels in a 3D Orthophos XG Sirona scanner. Intraobserver evaluation was performed using the intraclass correlation coefficient (ICC). Direct measurements and CBCT measurements were correlated using Pearson correlation (PCC). The mean difference between indirect and direct measurements was 3.15 mm. Paired t test and Pearson Correlation coefficient determined that all measurements differed statistically from each other with p<0.05. With the CT scanner and protocol used in this study, CBCT images do not enable accurate evaluation of vestibular alveolar bone height.

RESUMEN La tomografía de haz cónico (CBCT) ha modificado la perspectiva de la imagenología en odontología que brinda una imagen tridimensional manipulable con una relación 1:1, paciente: imagen. Los tratamientos y diagnósticos se ven modificados o corroborados por el CBCT; sin embargo, la exactitud que presenta en estructuras delgadas como las corticales óseas ha sido sometida a críticas. El objetivo fue correlacionar la medición de la altura del hueso alveolar vestibular mediante mediciones directas y las realizadas con imágenes tomográficas de haz cónico con resolución de vóxel estándar (SD). Treinta dientes incisivos y premolares de pacientes sometidos a un curetaje abierto se midieron con un calibrador de alta precisión y una tomografía computarizada de haz cónico (CBCT) a una resolución SD de 0,16 mm de vóxeles en un escáner 3D Orthophos XG Sirona. La evaluación intraobservador se realizó utilizando el coeficiente de correlación intraclase (ICC), y las mediciones directas y las mediciones CBCT se correlacionaron utilizando la correlación de Pearson (PCC). La diferencia media entre las mediciones indirectas y directas fue de 3,15 mm. La prueba t pareada y el Coeficiente de Correlación de Pearson determinaron que todas las mediciones fueron estadísticamente diferentes entre sí con una p <0.05. Con el escáner de TC y el protocolo utilizado en este estudio, las imágenes CBCT no permiten una evaluación precisa de la altura del hueso alveolar vestibular.

Comparison of morphological quantitative characteristics of the newly formed alveolar bone after the application of demineralized bone matrix and cortical bone allografts / Comparación de las características morfológicas cuantitativas del hueso alveolar recién formado después de la aplicación de matriz ósea desmineralizada y aloinjertos de hueso cortical

The allografts were used to obtain sufficient alveolar bone tissue for proper dental implant placement. The objective of the present study was to evaluate the morphological and quantitative characteristics (cellular and collagen densities) of the newly formed alveolar bone with the application of cortical bone (CB) and demineralized bone matrix (DBM) allografts. Six samples of alveolar bone tissue from 5 patients (50 ± 6.3 years) were obtained after 6 months of application of the allografts and immediately before the placement of the dental implants. The samples were fixed (buffered formaldehyde, pH7.2), decalcified (EDTA 10 %) and histologically processed (HE and Picro-Sirius) for histologic analysis. Morphological analysis revealed presence of osteocytes and trabeculae in neoformed bone tissue near the allografts and absence of inflammatory and allergic cells; the remnants of CB were located mainly in the periphery of the bone tissue and the remnants of DBM were more incorporated into the tissue. Osteogenitor cells were observed around the remaining material. The cell density was not modified in newly formed bone tissue with the application of both allografts as compared to mature bone tissue. The density of the type I and III collagens present in the osteoids interspersed with the remainder of the materials showed a tendency to increase in the samples treated with DBM. It was concluded that by the histological characteristics observed both grafts were biocompatible, however the bone treated with DBM presented better incorporation and a tendency of increase of the collagen content in the remnant region of the allografts.

Los aloinjertos son utilizados para obtener tejido óseo alveolar apropiado para la colocación correcta del implante dental. El objetivo de este trabajo fue evaluar las características morfológicas y cuantitativas (densidades celulares y de colágeno) del hueso alveolar recién formado con la aplicación de aloinjertos de hueso cortical (CB) y matriz desmineralizada de hueso (DBM). Seis muestras de tejido óseo alveolar fueron obtenidas de 5 pacientes (50 ± 6,3 años) después de 6 meses de aplicación de los aloinjertos e inmediatamente antes de la colocación de los implantes dentales. Las muestras fueron fijadas (formaldehído tamponado, pH 7,2), descalcificadas (EDTA al 10%) y procesadas histológicamente (HE y Picro-Sirius) para el análisis histológico. El análisis morfológico reveló la presencia de osteocitos y trabéculas en el tejido óseo neoformado cerca de los aloinjertos y la ausencia de células inflamatorias y alérgicas; los remanentes de CB se ubicaron principalmente en la periferia del tejido óseo y los remanentes de DBM se incorporaron más en el tejido. Se observaron células osteogenitoras alrededor del material restante. La densidad celular no se modificó en el tejido óseo recién formado con la aplicación de ambos aloinjertos en comparación con el tejido óseo maduro. La densidad de los colágenos de tipo I y III presentes en los osteoides intercalados con el resto de los materiales mostró una tendencia a aumentar en las muestras tratadas con DBM. Se concluyó que, debido a las características histológicas observadas, ambos injertos fueron biocompatibles, sin embargo, el hueso tratado con DBM presentó una mejor incorporación y una tendencia al aumento del contenido de colágeno en la región remanente de los aloinjertos.

Morphometric predictors of lingual undercut depth in the posterior mandible and their relevance to immediate dental implant insertion: recommendations for CBCT / Predictores morfométricos de la profundidad de la «undecurt¼ lingual en la parte posterior de la mandíbula y su relevancia para la inserción inmediata de implantes dentales: recomendaciones para la CBCT

Deep lingual undercut (LU) is commonly encountered in the posterior mandible, and is considered a risk factor in dental implants. In this study we investigated the value of data extracted from OPGs in predicting LU depth. Such predictors might be valuable in reducing the chance of lingual plate perforation (LPP) by recommending CBCTs prior to dental implant insertion when deep LU is anticipated We aimed at assessing the following variables as potential predictors of LU depth: 1) alveolar process height (measured on OPGs), 2) alveolar process width (measured on CBCTs), and 3) the distance from apical region of dental alveoli to superior margin of IAN canal (measured on OPGs). 128 CBCTs and corresponding OPGs of posterior mandibles of 128 patients (70 females, 58 males; age range=18-87 years, mean age=45.8 years, SD=17.0 years) were used. Only dentate sites of lower first (LM1) and second molars (LM2) were considered. Four predictors of LU depth were found, the strongest was the ratio between alveolar process width (which could be assessed clinically) and alveolar process height as measured on OPGs (r=.454 at LM1 site, r=.592 at LM2 site). Predictors derived from OPG measurements might be valuable in anticipating LU depth and might be more valuable when combined with alveolar process width (which might be assessed clinically). We recommend considering the suggested predictors in assessing the need of CBCT prior to immediate dental implant insertion in posterior mandible.

El socavado lingual profundo (SLU) se encuentra comúnmente en la porción posterior de la mandíbula y es considerado un factor de riesgo en los implantes dentales. En este estudio, investigamos el valor de los datos extraídos de los OPG para predecir la profundidad del SLU. Dichos predictores podrían ser valiosos para reducir la posibilidad de perforación de la placa lingual (PPL) recomendando CBCT antes de la inserción del implante dental cuando se anticipa un SLU. El objetivo consistió en evaluar las siguientes variables como posibles predictores de profundidad de SLU: 1) altura del proceso alveolar (medida en OPG), 2) ancho del proceso alveolar (medido en CBCT) y 3) la distancia desde la región apical de los alvéolos dentales al margen superior del canal IAN (medido en OPG). Se utilizaron 128 CBCT y las OPG correspondientes de mandíbulas de 128 pacientes (70 mujeres, 58 hombres; rango de edad = 18-87 años, edad media = 45,8 años, SD = 17,0 años). Sólo se consideraron los sitios dentados de los primeros molares inferiores (LM1) y los segundos molares inferiores (LM2). Se encontraron cuatro predictores de profundidad de SLU, el más fuerte fue la relación entre el ancho del proceso alveolar (que podría evaluarse clínicamente) y la altura del proceso alveolar medida en OPG (r = 0,454 en el sitio LM1, r = 0,592 en el sitio LM2). Los predictores derivados de las mediciones de OPG podrían ser valiosos para anticipar la profundidad de SLU y podrían ser más valiosos cuando se combinan con el ancho del proceso alveolar (que podría evaluarse clínicamente). Recomendamos considerar los factores predictivos sugeridos para evaluar la necesidad de CBCT antes de la inserción inmediata del implante dental en la porción posterior de la mandíbula.

Determinación del área en diferentes sitios utilizados para colocación de mini implantes en la cresta infracigomática / Determination of the area in different sites used for the placement of mini-implants in the infrazygomatic crest

RESUMEN Introducción: estudios recientes indican que la cresta infracigomática es un sitio favorable para la colocación de mini implantes, sin embargo es importante conocer sus dimensiones anatómicas para colocarlos en una posición segura y lograr buena estabilidad. Objetivo: determinar el área, en diferentes zonas de la cresta infracigomática, que son utilizadas para la colocación de miniimplantes. Materiales y métodos: estudio descriptivo, observacional y transversal de 60 casos, con previo tratamiento de Ortodoncia y que reunieron los criterios de inclusión. Se utilizaron archivos radiográficos y de tomografías con tecnología cone-beam. Se realizó la estadística descriptiva y pruebas ANOVA, t de Student y método de comparación de Tukey para relacionar las variables. Resultados: la zona de mayor área de hueso se encontró a nivel de la cúspide mesiovestibular del segundo molar (30.2+12.1mm2). La clase esqueletal II presentó mayor área (33.6+11.2mm2). Se encontraron diferencias estadísticamente significativas al relacionar las variables área y zona, así como área y clase esqueletal, pero no hubo significancia estadística al relacionar el área con el sexo. Conclusiones. a nivel de la segunda molar superior es la referencia ideal para la colocación de mini implantes, en la cresta infracigomática, ya que esta tiene mayor área. Los casos Clase II presentan también un área mayor. El sexo no fue determinante (AU).

ABSTRACT Introduction: recent studies indicate that the infrazygomatic crest is a favorable site for the placement of miniscrew (mini implante), however it is important to know its anatomical dimensions to place them in a secure position and to obtain good stability. Objective: to determine the area in different sites of the infrazygomatic crest that is used for the placement of mini-implants. Materials and methods: descriptive, observational and cross-sectional study of 60 cases, with previous orthodontic treatment, that fulfilled the inclusion criteria. Radiographic and tomographic files with cone-beam technology were used. Descriptive statistics, ANOVA and t-Student tests, and Tukey's comparison method were used to relate the variables. Results: The zone with the largest area was found at the level of the second molar in the mesiovestibular cusp (30.2 + 12.1 mm2). Skeletal class II showed the largest area (33.6 + 11.2mm2). Statistically significant differences were found when relating the area and site variables as well as area and skeletal class, but there was no statistical significance in relating the area to sex. Conclusions: the level of the upper second molar is the ideal reference for the placement of mini-implants in the infrazygomatic crest since it has a larger area. Class II cases also have a larger area. Sex was not determinant (AU).

Relationship between mandibular symphysis dimensions and mandibular anterior alveolar bone thickness as assessed with cone-beam computed tomography

ABSTRACT Objective: To determine the relationship between symphysis dimensions and alveolar bone thickness (ABT) of the mandibular anterior teeth. Methods: Cone-beam computed tomography images of 51 patients were collected and measured. The buccal and lingual ABT of the mandibular anterior teeth was measured at 3 and 6 mm apical to the cemento-enamel junction (CEJ) and at the root apices. The symphysis height and width were measured. The symphysis ratio was the ratio of symphysis height to symphysis width. Kendall's tau correlation coefficient was used to determine the relationships between the variables at a 0.05 significance level. Results: The mandibular anterior teeth lingual and apical ABT positively correlated with symphysis width (p<0.05). Moreover, these thicknesses negatively correlated with the symphysis ratio (p<0.05). Symphysis widths and ratios showed higher correlation coefficients with total and buccal apical ABT, compared with lingual ABT. Buccal ABT at 3 and 6 mm apical to the CEJ was not significantly correlated with most symphysis dimensions. The mean thickness of the buccal alveolar bone at the upper root half was only 0.2-0.6 mm, which was very thin, when compared with other regions. Conclusion: For mandibular anterior teeth, the apical alveolar bone and lingual alveolar bone tended to be thicker in patients with a wide and short symphysis, compared to those with a narrow and long symphysis. Buccal alveolar bone was, in general, very thin and did not show a significant relationship with most symphysis dimensions.

RESUMO Objetivo: o objetivo desse artigo foi avaliar a correlação entre as dimensões da sínfise e a espessura do osso alveolar (EOA) na região anterior da mandíbula. Métodos: imagens de tomografia computadorizada de feixe cônico (TCFC) de 51 pacientes foram selecionadas e medidas. As EOAs vestibular e lingual dos dentes anteroinferiores foram medidas a 3 mm e a 6 mm para apical da junção cemento-esmalte (JCE) e nos ápices radiculares. A altura e a largura da sínfise foram medidas, e calculou-se a proporção entre ambas, chamada de proporção da sínfise. O coeficiente de correlação tau de Kendall foi utilizado para determinar a correlação entre as variáveis, com nível de significância de 0,05. Resultados: as EOAs vestibular e lingual dos dentes anteroinferiores apresentaram correlação positiva com a largura da sínfise (p< 0,05). Porém, essas EOAs apresentaram correlação negativa com a proporção da sínfise (p <0,05). A largura e a proporção da sínfise apresentaram maiores coeficientes de correlação com a EOA total e vestibular apical e, em comparação com a EOA lingual. A EOA vestibular a 3 mm e a 6 mm para apical da JCE não apresentou correlação significativa com a maioria das dimensões da sínfise. A espessura média do osso alveolar vestibular na metade superior da raiz foi de apenas 0,2 a 0,6 mm - muito delgada quando comparada com outras regiões. Conclusão: nos dentes anteroinferiores, o osso alveolar apical e o osso alveolar lingual tendem a ser mais espessos nos pacientes com sínfise mais larga e curta, em comparação àqueles com sínfise mais estreita e longa. O osso alveolar vestibular foi, em geral, muito fino e não apresentou relação significativa com a maioria das dimensões da sínfise.

Three dimensional evaluation of alveolar bone changes in response to different rapid palatal expansion activation rates

ABSTRACT Introduction: The aim of this multi-center retrospective study was to quantify the changes in alveolar bone height and thickness after using two different rapid palatal expansion (RPE) activation protocols, and to determine whether a more rapid rate of expansion is likely to cause more adverse effects, such as alveolar tipping, dental tipping, fenestration and dehiscence of anchorage teeth. Methods: The sample consisted of pre- and post-expansion records from 40 subjects (age 8-15 years) who underwent RPE using a 4-banded Hyrax appliance as part of their orthodontic treatment to correct posterior buccal crossbites. Subjects were divided into two groups according to their RPE activation rates (0.5 mm/day and 0.8 mm/day; n = 20 each group). Three-dimensional images for all included subjects were evaluated using Dolphin Imaging Software 11.7 Premium. Maxillary base width, buccal and palatal cortical bone thickness, alveolar bone height, and root angulation and length were measured. Significance of the changes in the measurements was evaluated using Wilcoxon signed-rank test and comparisons between groups were done using ANOVA. Significance was defined at p ≤ 0.05. Results: RPE activation rates of 0.5 mm per day (Group 1) and 0.8 mm per day (Group 2) caused significant increase in arch width following treatment; however, Group 2 showed greater increases compared to Group 1 (p < 0.01). Buccal alveolar height and width decreased significantly in both groups. Both treatment protocols resulted in significant increases in buccal-lingual angulation of teeth; however, Group 2 showed greater increases compared to Group 1 (p < 0.01). Conclusion: Both activation rates are associated with significant increase in intra-arch widths. However, 0.8 mm/day resulted in greater increases. The 0.8 mm/day activation rate also resulted in more increased dental tipping and decreased buccal alveolar bone thickness over 0.5 mm/day.

RESUMO Introdução: o objetivo do presente estudo retrospectivo multicêntrico foi quantificar as alterações na altura e na espessura do osso alveolar após o uso de dois diferentes protocolos de ativação na expansão rápida da maxila (ERM), bem como determinar se uma taxa de expansão mais rápida tem maior probabilidade de causar mais efeitos adversos, tais como inclinação dos dentes e do processo alveolar, fenestração e deiscência dos dentes de ancoragem. Métodos: a amostra consistiu de registros pré- e pós-expansão de 40 indivíduos (com idades entre 8 e 15 anos) que se submeteram à expansão rápida da maxila usando o aparelho Hyrax com quatro bandas como parte de seu tratamento ortodôntico para correção da mordida cruzada posterior. Os indivíduos foram divididos em dois grupos, de acordo com a taxa de ativação na expansão rápida da maxila (0,5 mm/dia e 0,8 mm/dia; n = 20 cada grupo). Imagens tridimensionais de todos os indivíduos da amostra foram avaliadas com o uso do software Dolphin Imaging v. 11.7 Premium. Foram analisadas as seguintes medidas: largura da base da maxila, espessura das corticais ósseas vestibular e lingual, altura do osso alveolar, angulação e comprimento das raízes. A significância das alterações nessas medidas foi avaliada com o teste não paramétrico de Wilcoxon e as comparações entre os grupos foram feitas usando a ANOVA. A significância foi definida como p ≤ 0,05. Resultados: as taxas de ativação na ERM de 0,5mm/dia (Grupo 1) e 0,8mm/dia (Grupo 2) causaram aumento significativo na largura da arcada após o tratamento. Porém, o Grupo 2 apresentou maior aumento, se comparado ao Grupo 1 (p < 0,01). A altura e a largura do osso alveolar vestibular diminuíram significativamente em ambos os grupos. Ambos os protocolos de tratamento resultaram em aumento significativo na inclinação vestibulolingual dos dentes. Porém, o Grupo 2 apresentou maior aumento, em comparação ao Grupo 1 (p < 0,01). Conclusão: ambas as taxas de ativação estão associadas a um aumento significativo nas larguras intra-arcada; entretanto, a taxa de 0,8mm/dia resultou em maior aumento. Essa mesma taxa de ativação também resultou em maior inclinação dos dentes e em redução mais acentuada da espessura do osso alveolar vestibular.

Morphological characteristics of the facial bone wall related to the tooth position in the alveolar crest in the maxillary anterior / Características morfológicas de la tabla ósea vestibular en relación a la posición dentaria en la cresta alveolar en la zona anterior del maxilar superior

The purpose of this study was to analyze whether the position of the tooth in the alveolar ridge influences the thickness of the facial bone wall and the distance between the cementoenamel junction (CEJ) and osseous zenith (OZ). Conebeam computed tomography (CBCT) scans from fifty four dentate patients were included in the study (22 male and 32 female, mean age 41.5 years). The measurements taken included: (1).The Facial bone thickness at 7 different equidistant levels measuring levels (ML 17) between OZ and the root apex (A). (2) The CEJ OZ distance. (3) Facial position of the tooth (FPT) relative to a straight line traced from mesial to distal interproximal depressions of the alveolar plate at the level of the CEJ. The Facial bone wall thickness ranged between 0 mm and 3.8 mm, with greater values at more apical levels. Mean values were smaller than 1 mm at every level except ML7. The CEJOZ distance varied between 0.5 mm and 6.9 mm (mean 2.9 mm). The Mean of FPT value was 0.6 mm. No statistically significant correlation was found between FPT and the CEJOZ distance. Weak negative statistically significant correlations were found between FPT and the thickness of the facial bone wall at MP1 and MP3. Within the limits of this study, no clinically relevant correlation between FPT and facial bone thickness ­ CEJOZ distance was found. More studies should be conducted to evaluate a greater number of teeth, especially those that may present misalignment with greater FPT values (AU)

El objetivo del presente estudio fue analizar si la posición de la pieza dentaria en el reborde alveolar influencia el espesor de la tabla ósea vestibular y la distancia entre el limite amelocementario (LAC) y el cenit óseo (CO). Tomografías computadas haz de cono (TC) de 54 pacientes dentados fueron incluidas en el estudio (22 hombres y 32 mujeres, edad promedio 41.5 años). Las medidas registradas fueron: (1) espesor de la tabla ósea vestibular en 7 diferentes niveles de medición (NM 17) entre CO y el ápice radicular (AR). (2) La distancia LACCO. (3) Posición vestibular de la pieza dentaria (PVD) en relación a una línea recta trazada desde la depresión interproximal mesial a la depresión interproximal distal de la tabla ósea a nivel del LAC. El espesor de la tabla ósea vestibular fue 03.8mm, con valores mayores registrados a nivel más apical. El valor promedio fue menor a 1 mm excepto en NM7. La distancia LACCO varió entre 0.5 y 6.9mm (promedio 2.9mm). El promedio de PVD fue de 0.6mm. No se encontró correlación estadísticamente significativa entre la PVD y la distancia LACCO. Se halló una correlación débil negativa estadísticamente significativa entre la PVD y el espesor de la tabla ósea vestibular en NM1 y NM3. Dentro de las limitaciones de este estudio, no se encontró una correlación clínicamente significativa entre PVD y espesor de la tabla ósea vestibular ­ distancia LACCO. Se deben llevar a cabo más estudios para evaluar un mayor número de piezas dentarias, especialmente aquellas que se encuentran desalineadas con valores PVD mayores (AU)

Maxillary dentoalveolar assessment following retraction of maxillary incisors: a preliminary study

ABSTRACT Objective: The aim of this preliminary study was to assess changes in tooth length and alveolar thickness following retraction of maxillary incisors. Methods: A total of 11 patients presenting severe maxillary dentoalveolar protrusion revealed by initial (T1) cone-beam computed tomography (CBCT), and whose treatment plan included extraction of maxillary first premolars and retraction of maxillary incisors, were selected and submitted to CBCT examination one month after the end of incisors retraction (T2). The premaxilla was assessed through seven axial slices by means of Dolphin ImagingTM software. In each of these slices, five measurements of the distance from the buccal cortical bone to the palatal cortical bone were performed. Tooth length of maxillary incisors (n = 44) was also measured in sagittal slices. Measurements were repeated after a two-week interval, and intraclass correlation coefficient (ICC) was used to test examiner calibration. Wilcoxon test was used to detect differences in measurements performed at the two time intervals. Results: The ICC was satisfactory for tooth length (0.890) and for premaxilla alveolar thickness measurements (0.980). Analysis of data showed no statistically significant differences (p > 0.05) in tooth length or alveolar thickness between the two-time intervals assessed. Conclusion: The force used in retraction of maxillary incisors in this research did not promote significant changes in tooth length of maxillary incisors or in premaxilla alveolar thickness.

RESUMO Objetivo: o objetivo deste estudo preliminar foi avaliar as alterações no comprimento dentário e na espessura alveolar durante a retração dos incisivos superiores. Métodos: um total de 11 pacientes apresentando protrusão dentoalveolar severa, de acordo com a tomografia computadorizada de feixe cônico (TCFC) inicial (T1), e que continham no seu plano de tratamento extração dos pré-molares superiores e retração dos incisivos superiores, foram selecionados e submetidos a exames de TCFC um mês após o término da retração dos incisivos (T2). Com o auxílio do software Dolphin Imaging(r), a prémaxila foi dividida em sete cortes axiais. Em cada corte axial, foram realizadas cinco medições da distância da cortical vestibular a lingual. O comprimento dos incisivos superiores (n = 44) foi medido no corte sagital. As medições foram refeitas após o intervalo de duas semanas e o coeficiente de correlação intraclasse (ICC) foi utilizado para avaliar a calibração do examinador. Utilizou-se o teste de Wilcoxon para detectar diferenças nas medições realizadas nos dois intervalos de tempo. Resultados: o ICC mostrou-se satisfatório tanto para o comprimento dentário (0,890) quanto para a espessura alveolar da pré-maxila (0,980). Não foram observadas diferenças estatísticas significativas para comprimento dentário e para as espessuras alveolares (p < 0,05) nos períodos avaliados. Conclusões: as forças atuantes na retração dos incisivos, nessa pesquisa, não provocaram alterações significativas no comprimento dentário dos incisivos superiores, nem mudanças na espessura alveolar da pré-maxila.

Preservación de alvéolos mediante fosfato tricálcico beta, con y sin membrana / Socket preservation using beta-tricalcium phosphate with or without membrane

El presente estudio evalúa los resultados de la utilización del fosfato tricálcico beta en la preservación de alvéolos postextracción al emplearlo solo o en conjunto con membranas no reabsorbibles. Se seleccionaron 18 dientes con indicación de extracción y con condiciones favorables para la preservación del alvéolo y posterior colocación de un implante oseointegrado. En 10 alvéolos se utilizó como relleno fosfato tricálcico beta en conjunto con membrana no reabsorbible, y 8 alvéolos fueron tratados solamente con fosfato tricálcico beta. Previo a la cirugía se evaluó el ancho y alto de cada alvéolo, mediante una tomografía computarizada de alta resolución, evaluación que fue repetida 6 meses después de realizada la intervención quirúrgica. Al momento de efectuar la técnica quirúrgica para la instalación de los implantes se tomaron muestras histológicas del sitio de colocación del implante para estudiar las características histológicas del sitio injertado después de 6 meses de realizada la cirugía de extracción dentaria y preservación de alvéolo. El uso de fosfato tricálcico beta, independiente o no del uso de membrana, mantuvo la altura del alvéolo transcurridos 6 meses desde su colocación, mientras que el ancho del alvéolo se mantuvo solo en el grupo sin membrana. Los resultados histológicos demostraron cantidades variables de regeneración ósea.

The present study evaluated the results of the post-extraction socket preservation technique using Beta-Tricalcium Phosphate with and without the use of a non-resorbable membrane. A total of 18 teeth with indication of extraction and socket preservation were selected, with 10 alveoli being treated with Beta-Tricalcium Phosphate combined with a non-resorbable membrane, and the other 8 with Beta-Tricalcium Phosphate only. The width and height of each socket was evaluated using computed tomography, prior to the extraction, and 6 months after the surgery. At the time of performing the surgical technique for installing the implants, histological specimens were taken from the implant site in order to study the graft site 6 months after the dental extraction surgery and alveoli preservation.The use of Beta-Tricalcium Phosphate, whether a membrane is used or not, maintained the alveolar height 6 months after the extraction, while the width of the alveolus only remained in the group without membrane. Histological results showed varying amounts of bone regeneration.

Alterações dentoalveolares em adultos promovidas pelo uso de arco auxiliar de expansão em TMA avaliadas por meio de tomografias computadorizadas / Dentoalveolar effects of using a TMA auxiliary expansion archwire: analysis of computed tomography

A atresia maxilar é um quadro de desarranjo de desenvolvimento do arco dentário presente em diversos tipos de má oclusão, desde as alterações transversais mais simples e puras até as formas mais graves, contemplando as divergências verticais e sagitais. O diagnóstico desta atresia, muitas vezes, é simplificado na presença ou não de mordida cruzada posterior, sendo ela unilateral ou bilateral. No entanto, faz-se necessário uma avaliação mais criteriosa que compreenda não só a própria alteração de forma do arco dentário, mas também as modificações oclusais subsequentes, como relação sagital de classe II ou III de Angle ou as discrepâncias verticais. Uma das possíveis formas de tratamento ortodôntico está ligada as expansões rápidas da maxila, método de incrementos ósseos por meio de forças ortopédicas, quando o indivíduo ainda apresenta potencial de crescimento craniofacial, ou seja, crianças e adolescentes. Já na vida adulta, esta possibilidade de ganhos ortopédicos não mais está presente e a opção não cirúrgica é o tratamento ortodôntico compensatório, por meio de expansão dentoalveolar do arco maxilar. O objetivo deste trabalho foi descrever os resultados de expansão dentoalveolar, obtidos utilizando-se o arco auxiliar de expansão em TMA (tungstênio, molibdênio e alloy), a partir de medidas lineares e angulares obtidas, bem como a integridade da cortical óssea vestibular desta área. Foi realizado um estudo retrospectivo de análise de tomografias computadorizadas, contidas na documentação ortodôntica de 13 pacientes tratados em uma clínica particular, realizadas antes e após a realização desta mecânica de expansão dentoalveolar. Para esta expansão, estes pacientes foram submetidos à instalação de um sobre-arco utilizado por vestibular como um arco auxiliar, sendo justaposto e unido ao fio de nivelamento principal (0,017x0,025 Termoativado) em cinco pontos, sendo 2 pontos nas entradas do tubo dos primeiros molares, 2 pontos entre os pré-molares e 1 ponto entre os incisivos centrais, por meio de fio de amarrilho 0,010 aço. Os resultados apresentaram ganhos estatisticamente significantes para aumento da distância das cúspides ao plano vertical mediano de todos os dentes medidos, bem como aumento da inclinação vestibular destes. A cortical óssea demonstrou adaptação, tendo deslocamento na mesma direção do movimento dentário, porém em menor quantidade. O aumento transversal das distâncias inter-dentárias também apresentou aumentos significativos e condizentes com a literatura. Desta forma, o arco auxiliar de expansão demonstrou-se eficiente para expansão dentoalveolar no paciente adulto, por meio de aumento da inclinação vestibular, com deslocamento dentário maior que o movimento de crista óssea, apresentado ganhos transversais significantes.(AU)

The Maxillary constriction is a developmental disorder present in various types of malocclusion, from the most simple and pure transverse changes to the most severe forms, causing vertical and sagittal problems. This malocclusion diagnosis is often simplified in the presence or not of posterior crossbite, which can be uni or bilateral. However, a complete evaluation must include not only the dental arch form changes, but also the subsequent occlusal modifications, such as sagittal relationships of Class II or III malocclusions and vertical discrepancies. Maxillary constriction treatment can be performed by rapid maxillary expansion, using orthopedic forces when there is still craniofacial growth. In adults, the possibility of orthopedic changes is no longer present and the non-surgical option is compensatory orthodontic treatment with dentoalveolar expansion, when the disorder magnitude allows. The objective of this study was to evaluate the effects of dentoalveolar expansion, obtained with a TMA (tungsten and molybdenum alloy) auxiliary expansion archwire, by means of linear and angular measurements, and the integrity of the buccal cortical bone in the posterior area. A retrospective analysis of CT scans, of orthodontic records of 13 patients treated at a private clinic, performed immediately before and after the auxiliary expansion archwire, was used. For the expansion, the patients underwent installation of a secondary arch combined with the primary archwire (0.017x0.025-inch heatactivated Ni-Ti), ligated in five points. Two points in the first molar tube entries, 2 points between the premolars and 1 point between the central incisors, with a 0.010- inch steel ligature wire. The results showed statistically significant transverse increase and buccal inclination for all teeth. The cortical bone showed adaptability and displacement in the same direction of tooth movement, but in smaller amounts. Thus, the auxiliary expansion arch wire proved to be effective to correct dentoalveolar constriction in adult patients, by increasing the buccal dental inclination with larger displacements than the bone crest adaptation and with significant transverse gains.(AU)

Location and classification of Canalis sinuosus for cone beam computed tomography: avoiding misdiagnosis

Abstract The aim of this study was to assess the presence, location and, multiplanar distance of the canalis sinuosus (CS) between the incisive foramen and the anterior maxillary alveolar ridge using cone beam computed tomography (CBCT). Therefore, 500 CBCT maxillary images obtained from male and female patients aged 20 to 80 years were selected to assist in the dental treatment. Low-quality tomographic images were discarded. All images were captured with the i-CATTM Classic tomograph and assessed using the XoranCatTM software. The axial sections were analyzed at the incisive foramen in order to verify the CS presence in laterality and location. Furthermore, linear measurements of the nasal cavity floor, buccal cortical bone, and alveolar ridge crest were made. All the collected data were statistically analyzed. Results show a variation of the CS in relation to the classification and distance of anatomical structures, but no significant difference between the right and left sides. It should be highlighted that CBCT is necessary before invasive procedures in order to preserve important anatomical structures. In conclusion, the location of the CS varies in relation to the alveolar ridge crest and buccal cortical bone, assuming that it is going to be located by the upper lateral incisor palatine.

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.

Vertical bone measurements from cone beam computed tomography images using different software packages

This article aimed at comparing the accuracy of linear measurement tools of different commercial software packages. Eight fully edentulous dry mandibles were selected for this study. Incisor, canine, premolar, first molar and second molar regions were selected. Cone beam computed tomography (CBCT) images were obtained with i-CAT Next Generation. Linear bone measurements were performed by one observer on the cross-sectional images using three different software packages: XoranCat®, OnDemand3D® and KDIS3D®, all able to assess DICOM images. In addition, 25% of the sample was reevaluated for the purpose of reproducibility. The mandibles were sectioned to obtain the gold standard for each region. Intraclass coefficients (ICC) were calculated to examine the agreement between the two periods of evaluation; the one-way analysis of variance performed with the post-hoc Dunnett test was used to compare each of the software-derived measurements with the gold standard. The ICC values were excellent for all software packages. The least difference between the software-derived measurements and the gold standard was obtained with the OnDemand3D and KDIS3D (-0.11 and -0.14 mm, respectively), and the greatest, with the XoranCAT (+0.25 mm). However, there was no statistical significant difference between the measurements obtained with the different software packages and the gold standard (p> 0.05). In conclusion, linear bone measurements were not influenced by the software package used to reconstruct the image from CBCT DICOM data.

Transverse effects on the nasomaxillary complex one year after rapid maxillary expansion as the only intervention: A controlled study

The aim of this study was to assess by means of cone-beam computed tomography (CBCT) scans the transverse effects on the nasomaxillary complex in patients submitted to rapid maxillary expansion (RME) using Haas expander in comparison to untreated individuals. This prospective controlled clinical study assessed 30 subjects (18 boys and 12 girls) with mixed dentition and during pubertal growth. The treated group was submitted to RME with Haas expander, retention for six months and a six-month follow-up after removal. The control group matched the treated group in terms of age and sex distribution. CBCT scans were taken at treatment onset and one year after the expander was activated. Maxillary first molars (U6) width, right and left U6 angulation, maxillary alveolar width, maxillary basal width, palatal alveolar width, palatal base width, right and left alveolar angulation, palatal area, nasal base width, nasal cavity width and inferior nasal cavity area on the posterior, middle and anterior coronal slices were measured with Dolphin Imaging Software(r) 11.5, except for the first two variables which were performed only on the posterior slice. All transverse dimensions increased significantly (P < 0.05) in the treated group in comparison to the control, except for alveolar angulation and inferior nasal cavity area (P > 0.05). Results suggest that increase of molar, maxillary, palatal and nasal transverse dimensions was stable in comparison to the control group one year after treatment with RME.

OBJETIVO: avaliar, por meio de tomografias computadorizada de feixe cônico (TCFC), as dimensões transversais do complexo nasomaxilar de pacientes submetidos à expansão rápida da maxila (ERM) e sem intervenção. MÉTODOS: este estudo clínico prospectivo e controlado avaliou 30 indivíduos (18 meninos e 12 meninas) durante o período de crescimento puberal e dentição mista. O grupo tratado foi submetido à ERM com expansor de Haas, permanecendo 6 meses em contenção e sendo acompanhados por mais 6 meses após a remoção. O grupo controle foi acompanhado durante o mesmo tempo. Foram realizadas TCFC ao início e um ano após a fase ativa. Com o programa Dolphin Imaging 11.5, a largura entre os primeiros molares superiores (U6), angulação dos U6 direito e esquerdo, largura maxilar alveolar, largura maxilar basal, largura alveolar do palato, largura basal do palato, angulação alveolar direita e esquerda, área palatina, largura da base nasal, largura da cavidade nasal e área da cavidade nasal inferior foram obtidas em cortes coronais posterior, médio e anterior, com exceção das duas primeiras medidas, que foram obtidas apenas no corte coronal posterior. RESULTADOS: todas as medidas foram significativamente (p < 0,05) maiores no grupo da ERM, com exceção da angulação alveolar e da área da cavidade nasal, as quais não foram significativas (p > 0,05) entre os grupos. Os resultados sugerem que, um ano após a ERM, a dimensão transversal na cavidade nasal, maxila, palato e região dos molares são maiores do que em indivíduos não tratados. O protocolo de ERM utilizado foi eficaz na manutenção da dimensão transversal durante período de acompanhamento. .

The influence of mandibular ridge anatomy on treatment outcome with conventional complete dentures

Since prognostic indicators are likely to take on increasingimportance as a diagnostic tool for selection of patients forimplant provision, this study investigated the influence of theshape and resiliency of the mandibular alveolar ridge on theretention and stability of conventional complete dentures. Ninety-three edentulous patients wearing both maxillary andmandibular conventional complete dentures composed the sample.Data were collected regarding shape and resiliencyof themandibular residual ridge. Dentures were assessed for retentionand stability using an objective and reproducible tool.The associationsbetween the clinical characteristics of the mandibularalveolar ridge and denture retention and stability were analyzedusing chi-square and Fisher exact tests (α = 0.05). A significantassociation between ridge shape and denture stability (p < 0.05)was found, while ridge resiliency was significantly associated todenture retention (p < 0.001). Based on the results, mandibularridge shape and resiliency influenced the retention and stabilityof conventional complete dentures...

Reasons for mini-implants failure: choosing installation site should be valued!

Mini-implant loss is often associated with physical and mechanical aspects that result from choosing an inappropriate placement site. It is worth highlighting that: a) Interdental alveolar bone crests are flexible and deformable. For this reason, they may not offer the ideal absolute anchorage. The more cervical the structures, the more delicate they are, thus offering less physical support for mini-implant placement; b) Alveolar bone crests of triangular shape are more deformable, whereas those of rectangular shape are more flexible; c) The bases of the alveolar processes of the maxilla and the mandible are not flexible, for this reason, they are more likely to receive mini-implants; d) The more cervical a mini-implant is placed, the higher the risk of loss; the more apical a mini-implant is placed, the better its prognosis will be; e) 3D evaluations play a major role in planning the use of mini-implants. Based on the aforementioned considerations, the hypotheses about mini-implant loss are as follows: 1) Deflection of maxillary and mandibular alveolar processes when mini-implants are more cervically placed; 2) Mini-implants placed too near the periodontal ligament, with normal intra-alveolar tooth movement; 3) Low bone density, low thickness and low alveolar bone volume; 4) Low alveolar cortical bone thickness; 5) Excessive pressure inducing trabecular bone microfracture; 6) Sites of higher anatomical weakness in the mandible and the maxilla; 7) Thicker gingival tissue not considered when choosing the mini-implant.

As perdas de mini-implantes estão quase sempre relacionadas aos aspectos físicos e mecânicos decorrentes de uma escolha inadequada do local de inserção. Deve se destacar que: a) As cristas ósseas alveolares interdentárias têm flexão e se deformam, e podem não oferecer ancoragem tão absoluta. Quanto mais cervicais, as estruturas são mais delicadas e oferecem menos suporte físico para os mini-implantes; b) as cristas ósseas alveolares triangulares se deformam mais, e as retangulares são menos flexíveis; c) as bases do processo alveolar nos corpos da maxila e mandíbula não têm capacidade flexiva, e seu volume e estruturas são maiores, logo, são mais receptivas para mini-implantes; d) quanto mais próximo da cervical se coloca um mini-implante, maior é o risco de se perdê-lo; quanto mais apical se coloca o mini-implante, melhor é o seu prognóstico; e) avaliar a região tridimensionalmente representa um passo fundamental no planejamento do uso de mini-implantes. Com base nessas considerações, as hipóteses para a perda de mini-implantes são: 1) Deflexão do processo alveolar da maxila e mandíbula, quando fixados em posições mais cervicais; 2) proximidade com o ligamento periodontal e o movimento dentário intra-alveolar normal; 3) densidade óssea menor, pouca espessura e menor volume ósseo alveolar; 4) espessura menor da cortical óssea alveolar; 5) pressão excessiva, induzindo microfraturas ósseas trabeculares; 6) locais de maior fragilidade anatômica mandibular e maxilar; 7) espessura maior do tecido gengival não considerada na escolha do mini-implante.

Relação entre o movimento ortodôntico vestibular dos incisivos inferiores e características do osso alveolar vestibular e lingual: avaliação por meio da tomografia computadorizada cone-beam / Labial movement of the mandibular incisors and tomographic characteristics of the labial and lingual alveolar bone

O objetivo principal desta pesquisa foi avaliar as características do osso alveolar vestibular e lingual, na região ântero-inferior, em pacientes que realizaram tratamento ortodôntico corretivo não cirúrgico da má oclusão de Classe II. Material e Métodos: A amostra foi constituída de 32 pacientes divididos de acordo com a inclinação vestibular dos incisivos inferiores em dois grupos: Grupo Experimental que protruíram ou inclinaram os incisivos para vestibular em 1,5 mm e/ou 10o ou mais e Grupo Controle que protruíram ou inclinaram os incisivos para vestibular menos de 1,5 mm e/ou 10o. Estes grupos foram compatibilizados de acordo com a idade, sexo e padrão facial. O nível da crista óssea alveolar vestibular e lingual, a espessura da tábua óssea vestibular e lingual na metade e no ápice radicular, assim como a presença ou ausência de deiscências e fenestrações foram avaliados nos cortes parassagitais em imagens de tomografia computadorizada cone-beam, realizadas após um ano da remoção do aparelho fixo, na região dos seis dentes anteriores inferiores. A comparação intergrupos foi realizada por meio do teste t e o teste de Mann-Whitney para as avaliações quantitativas e pelo teste Exato de Fisher para as avaliações qualitativas (p<0,05). Verificou-se a correlação entre as medidas quantitativas e a quantidade de protrusão/inclinação vestibular dos incisivos inferiores por meio dos testes de Pearson e de Spearman. Resultados: O grupo experimental demonstrou espessura da tábua óssea vestibular no nível apical maior para os incisivos centrais, e espessura da tábua óssea lingual no nível apical menor para os incisivos centrais, laterais e caninos, em relação ao grupo controle. Maior número de deiscências na lingual dos incisivos centrais e fenestrações na vestibular dos incisivos laterais foi encontrado para o grupo experimental em comparação ao grupo controle. No nível apical dos incisivos centrais e caninos...

The aim of this study was to assess the morphology of the mandibular incisors labial and lingual alveolar bone in patients who underwent Class II nonsurgical orthodontic treatment. The sample comprised 32 patients who were divided into two groups according to the amount of labial protrusion of the mandibular incisors: the experimental group (EG) - which protruded or labially tipped the incisors 1.5 mm and/or 10o or more; and the control group (CG) - which protruded or labially tipped the incisors less than 1.5 mm and/or 10o. These groups were matched according to age, sex and facial pattern. Measurements of the vertical alveolar bone level and alveolar bone thickness of the labial and lingual plate, as well as the presence and absence of dehiscences and fenestrations were evaluated in cone-beam computed tomography cross-sectional images of the six mandibular anterior teeth, taken one year after appliance removal. Intergroup comparisons were performed using Mann-Whitney and t tests for quantitative assessments and Fisher Exact Test for qualitative assessments. Correlation between quantitative measures and the amount of protrusion/labial inclination of the mandibular incisors was evaluated with Pearson and Spearman tests. The experimental group showed significant greater thickness of the apical buccal bone plate of the central incisors and smaller thickness of the apical lingual bone plate of the central incisors, lateral incisors and canines. Greater number of lingual dehiscences in the central incisors and labial fenestrations in the lateral incisors was found for the experimental group. At the apical level of the central incisors and canines, the greater the amount of labial inclination and protrusion of the mandibular incisors during treatment, the smaller was the lingual bone plate thickness and greater was the thickness of the labial bone plate. The protrusion degree of the mandibular incisors influenced the apical bone plate thickness...

Efeitos periodontais da movimentação dentária de molares inferiores para área de rebordo alveolar atrófico / Periodontal effects of lower molar movement to atrophic areas

Objetivos: Avaliar a espessura da tábua óssea e nível de crista vestibular e lingual de segundos pré-molares e molares após o tratamento ortodôntico em pacientes com perda do primeiro molar inferior. Além de investigar presença de fenestrações e o comportamento dos parâmetros clínicos periodontais. Métodos: A amostra foi composta de 36 hemiarcos os quais foram divididos em 3 grupos: Grupo Abertura (GA - 15 molares verticalizados), Grupo Fechamento (GF - 12 molares mesializados para área de rebordo atrófico) e Grupo Controle (GC 9 hemiarcos sem perdas dentárias). Após a movimentação, os pacientes foram submetidos a exames de tomografia computadorizada de feixe cônico (TCFC) seguindo protocolos de 0,2 mm de voxel a 6 cm de FOV, no aparelho i-CAT Cone-Beam 3-D Dental Imaging System. Todas as medições foram realizadas no Dolphin em cortes parassagitais e avaliadas nas faces vestibular e lingual. Presença de fenestrações, posição do ápice radicular e recobrimento radicular também foram avaliados. Além disso, profundidade de sondagem, índice de sangramento gengival, recessão e índice de placa foram mensurados antes e depois do tratamento. A comparação intergrupos do nível da crista e espessura óssea foi realizado com o ANOVA seguido do teste de Tukey. A comparação intergrupos para a presença de fenestração e a posição do ápice radicular foi avaliada usando o Qui-quadrado enquanto o recobrimento radicular foi comparado pelo teste de Kruskal-wallis e Mann-Whitney. Os parâmetros clínicos periodontais foram comparados por meio do teste t pareado (intragrupos) e ANOVA e Tukey (intergrupos). Resultados: Não houve diferença significante entre os grupos para nenhuma medição realizada no segundo pré-molar. Houve um menor nível da crista óssea vestibular e lingual para o grupo fechamento. Não houve diferença para a espessura da tábua óssea e para a presença de fenestrações entre os grupos. GF apresentou ápices radiculares mais centralizados, enquanto os demais grupos...

Objective: The aim of this study was to evaluate the buccal and lingual bone plate thickness measurements and dehiscences of mandibular second premolars and molars after orthodontic treatment in patients with loss of first permanent molar and to investigate periodontal parameters behavior. Methods: The sample comprised 36 hemiarchs which were divided into 3 groups: GA (15 uprighted molars), GF (12 molars that were moved to atrophic areas) and GC (control grup 9 molars aligned and leveled). Posttreatment CBCT exams of the mandible were taken with voxel dimensions of 0.2 mm using the i-CAT Cone-Beam 3-D Dental Imaging System. Linear measurements were performed using the Dolphin software on cross section slices. Dehiscences and bone plate thickness measurements at middle of root were taken in buccal and lingual surfaces. Fenestrations, root apex position e root coverage were evaluated. Besides, the probing depth, plaque index, recession level and gingival bleeding index were evaluated before and after molar movement. The comparison between groups regarding dehiscence and bone thickness was performed by ANOVA followed by Tukey test. Presence of fenestration and root apex position were investigated by chi-square test. Root coverage measurements were performed by kruskal-wallis and Mann-Whitney. Periodontal parameters investigation were performed by Student t test (intergroup) and ANOVA and Tukey test (intergroup). Results: There were no significant differences for premolars measurements. Other than that, the distance between the CEJ and the alveolar crest was significant higher for molars that were moved to atrophic areas without differences on bone thickness. There was no difference for presence of fenestration between groups. GF showed centralized root apex, while others groups showed a small buccal root displacement. GF showed lower root coverage than GA and GC. Regarding periodontal parameters, there was no differences for intragroup...