Three-dimensional digital evaluation of tooth symmetry and volume in patients with missing and peg-shaped maxillary lateral incisors.

INTRODUCTION: This study aimed to evaluate the 3-dimensional tooth crown symmetry and the crown volumes of maxillary and mandibular teeth in patients with unilateral or bilateral missing or peg-shaped maxillary lateral incisors. METHODS: Six groups were established for the possible clinical variations in patients with unilateral missing or peg-shaped maxillary lateral incisors, bilateral presence of these tooth anomalies, and a control group (CG) with normal lateral incisors. The study was conducted on digital dental models of 132 patients. The morphologic symmetry of the antimere teeth was investigated using 3-dimensional deviation analysis. Volumes of contralateral teeth were compared within and among groups for the maxilla and mandible. Furthermore, volumes of teeth were compared in missing and peg-shaped quadrants and quadrants of CG. Intergroup differences were tested using one-way analysis of variance and Kruskal-Wallis tests, whereas paired t and Wilcoxon tests were used for parametric and nonparametric variables, respectively, for intragroup comparisons. RESULTS: Significant deviations in symmetry of antimere teeth were not detected (P >0.05). The volumes of mandibular central and lateral incisors in missing or peg-shaped lateral incisor groups were smaller than in the CG (P <0.05). Per quadrant analysis, volumes of the maxillary central incisor and mandibular central incisors, canines, and first molars in quadrants with missing or peg-shaped lateral incisors were smaller than in the control quadrants (P <0.05). CONCLUSIONS: Neither unilateral nor bilateral presence of missing or peg-shaped maxillary lateral incisors affected the morphologic symmetry of antimere teeth but did affect tooth volume, especially in the mandibular arch.

The human EDAR 370V/A polymorphism affects tooth root morphology potentially through the modification of a reaction-diffusion system.

Morphological variations in human teeth have long been recognized and, in particular, the spatial and temporal distribution of two patterns of dental features in Asia, i.e., Sinodonty and Sundadonty, have contributed to our understanding of the human migration history. However, the molecular mechanisms underlying such dental variations have not yet been completely elucidated. Recent studies have clarified that a nonsynonymous variant in the ectodysplasin A receptor gene (EDAR 370V/A; rs3827760) contributes to crown traits related to Sinodonty. In this study, we examined the association between the EDAR polymorphism and tooth root traits by using computed tomography images and identified that the effects of the EDAR variant on the number and shape of roots differed depending on the tooth type. In addition, to better understand tooth root morphogenesis, a computational analysis for patterns of tooth roots was performed, assuming a reaction-diffusion system. The computational study suggested that the complicated effects of the EDAR polymorphism could be explained when it is considered that EDAR modifies the syntheses of multiple related molecules working in the reaction-diffusion dynamics. In this study, we shed light on the molecular mechanisms of tooth root morphogenesis, which are less understood in comparison to those of tooth crown morphogenesis.

The functional role of the Carabelli trait in early and late hominins.

The Carabelli trait is a dental feature that forms along the lingual margin of the protocone of deciduous and permanent maxillary molars. It is variably expressed, ranging from a small pit or furrow to a large cusp, and its development seems to be associated with crown size and molar cusp spatial configuration. The degree of expression of the Carabelli trait differs systematically between hominin taxa, and for this reason, it has been used extensively in the reconstruction of their phylogeny. However, the functional implications of having a large Carabelli trait remain unclear. In this study, we analyze the macrowear pattern of maxillary molars of early and late hominins using the occlusal fingerprint analysis method, an approach based on digital models of teeth that helps in reconstructing occlusal dynamics occurring during mastication. Tooth crowns with a small Carabelli cusp generally exhibit larger wear contact areas that extended cervically, while two additional new occlusal contact areas are common in teeth characterized by a large Carabelli cusp. These wear areas are created at the beginning of the chewing cycle, when occluding with the slopes of the lingual groove of the lower molars, between the metaconid and entoconid cusps. Advancing tooth wear leads to a slight enlargement of Carabelli occlusal contacts increasing their functional area. A steep inclination could be mechanically important in food reduction and in balancing the functional load distribution during mastication contacts. Steep wear areas are particularly developed in primates that process foods characterized by tough and fibrous textural properties. Future biomechanical and microwear texture analyses could provide additional information on the mechanical adaptation of this dental trait.

Medidas de piezas dentarias para el posicionamiento correcto de brackets en una población latina (Argentina) / Measures for positioning teeth correct brackets in a Latin population (Argentina)

Introducción: El posicionamiento preciso de los brackets de ortodoncia en las diferentes situaciones clínicas es esencial. Para ello, se utiliza la tabla de McLaughlin-Bennett, realizada sobre una población anglosajona. Dada la gran variabilidad que puede existir en los diferentes grupos poblacionales, para estandarizar las medidas en la colocación de los brackets, sería necesario emprender un análisis de la población local y determinar cuáles serán las alturas de las coronas clínicas de todas las piezas dentarias para nuestra población. Materiales y método: Se estudiaron 200 modelos de estudio de individuos argentinos, caucásicos, de ambos sexos, con dentición permanente completa hasta el segundo molar inclusive, entre 13 y 25 años, que no recibieron tratamiento ortodóncico previo. Resultados: Las diferencias estadísticas existentes, con respecto a lo propuesto por McLaughlin y Bennett, en el maxilar superior fueron: altamente significativas (p = 0,0001) en el incisivo central, incisivo lateral y segundo molar; significativas en el canino (p = 0,0128) y en el primer molar (p = 0,018) y no significativas en el primer premolar (p = 0,239) y segundo premolar (p = 0,1741). En el maxilar inferior: altamente significativas (p = 0,0001) en el segundo molar y no significativas en el resto de las piezas dentarias. Conclusión: Los valores que se obtuvieron con el estudio, dada la variabilidad regional de la muestra, no coinciden con los valores que arroja la tabla de McLaughlin-Bennett, de origen anglosajón. Se sugiere la creación de una tabla acorde con las medidas de los pacientes locales(AU)

Accurate positioning of dental braces in different clinical situations is essential. To that end, it is used the chart developed by McLaughlin and Bennett, which was made in the Anglo-Saxon population. Due to the considerable variability among different population groups, an analysis of the local population would be necessary to be carried out in order to standardize the measurements for the positioning of braces and to determine the clinical crown height of teeth in our population. Two hundred Caucasian, Argentine male and female study models, aged between 13 and 25 with full permanent dentition, fully erupted second molars with no previous orthodontic treatment were studied. Existing statistical differences with regard to the guidelines proposed by McLaughlin and Bennett in the maxilla were: highly significant (p = 0.0001) for second molars, central and lateral incisors; significant for canines (p = 0.0128) and first molars (p = 0.018); and non-significant for first premolars (p = 0.239) and second premolars (p = 0.1741). In the mandible the differences were: highly significant (p = 0.0001) for second molars and non-significant for the other teeth. The values that were obtained in the study, given the regional variability of the sample, do not correspond to the values that are shown in the chart by McLaughlin and Bennett, of Anglo Saxon origin. It is suggested the creation of a new chart in line with the measurements of local patients(AU)

Sex Identification Based on Tooth Crown Trait Analysis Among the Mongoloid Race

Abstract Objective: To determine whether anterior and posterior tooth crown traits exhibit sexual dimorphism and identify traits characteristic to the Mongoloid race, especially among the Indonesian population. Material and Methods: This study cross-sectional study analyzed 108 dental casts from 36 males and 72 females. The traits analyzed included winging, shoveling, double shoveling, canine mesial ridge, canine distal accessory ridge, hypocone, metaconule, Carabelli's cusp, protostylid, metaconulid, enteconulid, and hypoconulid. All tooth crown traits were scored based on the ASUDAS scoring system. Descriptive statistics were used to calculate the absolute and relative frequencies. The Chi-square tests was used to determine significant differences in anterior and posterior tooth crown traits between males and females. Level of significance was set at 5%. Results: None of the traits showed sexual dimorphism. Moreover, the most common traits among the Mongoloid race were hypocone (94.4%) and shoveling (86.1%). Conclusion: Although none of the traits exhibited sexual dimorphism, most of them had a higher incidence among females than males. Nonetheless, further research including adequate samples and a similar number of females and males, is needed, especially for population studies.

Rapid Pliocene adaptive radiation of modern kangaroos.

Differentiating between ancient and younger, more rapidly evolved clades is important for determining paleoenvironmental drivers of diversification. Australia possesses many aridity-adapted lineages, the origins of which have been closely linked to late Miocene continental aridification. Using dental macrowear and molar crown height measurements, spanning the past 25 million years, we show that the most iconic Australian terrestrial mammals, "true" kangaroos (Macropodini), adaptively radiated in response to mid-Pliocene grassland expansion rather than Miocene aridity. In contrast, low-crowned, short-faced kangaroos radiated into predominantly browsing niches as the late Cenozoic became more arid, contradicting the view that this was an interval of global browser decline. Our results implicate warm-to-cool climatic oscillations as a trigger for adaptive radiation and refute arguments attributing Pleistocene megafaunal extinction to aridity-forced dietary change.

Perception of attractiveness of missing maxillary lateral incisors replaced by canines

ABSTRACT Objective: The aim of this study was to evaluate the degree of perception of attractiveness of the smile among dentists, dental students, and lay persons in cases of agenesis of the maxillary lateral incisors replaced by canines for space closure. Methods: A smiling front view extraoral photograph of a 20-year-old woman was digitally altered simulating agenesis and its treatment, by means of: repositioning, reshaping or bleaching the canine, and gingival contour. A questionnaire was distributed to individuals of the three groups (n= 150), with a view to evaluating their degree of esthetic perception. An attractiveness scale was also used, with '0' representing unattractive and '10', very attractive. Results: In the comparative evaluation among all the photographs, the original image obtained the highest level of acceptance. Photograph 'i' (agenesis of both lateral incisors treated with reposition and reshaping of the canines) was ranked as the least attractive by the dentists, whereas the student and lay persons ranked photograph 'f' (agenesis of both lateral incisors treated with reposition of the canines, gingival contour, bleaching and reshaping) as the worst. Conclusion: The methods of treatment most accepted among the dentists and students were those that involved changes in the gingival contour, whereas among lay persons, they were those that involved only reshaping.

RESUMO Objetivo: o objetivo do presente estudo foi avaliar o grau de percepção da atratividade do sorriso por dentistas, estudantes de Odontologia e leigos, em casos de agenesia dos incisivos laterais superiores substituídos por caninos, para fechamento do espaço. Métodos: uma fotografia extrabucal frontal do sorriso de uma mulher com 20 anos de idade foi alterada simulando agenesia e seu tratamento por meio de: reposicionamento do canino, remodelação, clareamento ou contorno gengival. Um questionário foi distribuído aos indivíduos dos três grupos (n= 150), com o objetivo de avaliar o grau de percepção estética. Uma escala de atratividade também foi usada, com '0' representando pouco atraente e '10', muito atraente. Resultados: na avaliação comparativa entre as fotografias, a imagem original obteve o maior nível de aceitação. A fotografia "i" (agenesia de ambos os incisivos laterais tratada com reposição e remodelação dos caninos) foi classificada como a menos atraente pelos dentistas, enquanto os estudantes e os leigos classificaram a "f" (agenesia de ambos os incisivos laterais tratada com reposição dos caninos, contorno gengival, clareamento e remodelação) como a pior. Conclusão: os métodos de tratamento mais aceitos entre dentistas e estudantes foram aqueles que envolviam mudanças no contorno gengival, enquanto entre os leigos foram aqueles que envolviam apenas remodelação.

[Dental morphological and metric characteristics in contemporary and historical population of Târgu Mureș]. / Fogak morfológiai és metrikus jellegzetességeinek vizsgálata marosvásárhelyi középkori leleteken és a jelenkori helyi populáció körében.

INTRODUCTION: Teeth, as an integral part of human organism, are not exceptions from the physical anthropology changes caused by biological evolution and the way of living. Different stress factors and the natural selection are contributing to the emphasis of certain morphological characteristics. AIM: Comparison of dental metric characteristics and the presence of accessory tooth cusps between human remains from the Middle Ages and dental study models of today's patients. MATERIAL AND METHOD: Morphological characteristics of 132 teeth from 19 skulls and 694 teeth on dental models of 30 patients were examined. The mesiodistal, incisivocervical and buccolingual diameters of crowns were measured by a validated 2D image analysis method. Carabelli and talon cusps were also examined using a magnifying glass. RESULTS: Statistically significant differences between the size of the 14th-century and the present-day teeth were found in some of the teeth groups. In medieval artifacts, lateral teeth had smaller crown width than teeth measured in the contemporary population. The Carabelli cusps found in the archeological human remains belonged to grades 1 and 3 on Dahlberg scale (23.07%), while the Carabelli cusps observed in the contemporary group belonged to grades 3, 4, 5, 6 and 7 (50.90%). Talon cusp occurred only once in the contemporary group. CONCLUSION: In case of the contemporary teeth, the Carabelli cusps appeared in a more pronounced morphological form and with a higher frequency, which emphasizes the European origin of today's population. Orv Hetil. 2018; 159(30): 1235-1240.

Aplicación de toxina botulínica tipo A para el manejo de la sonrisa gingival / Application of type-A botulinic toxin for the management of gummy smile

La toxina botulínica tipo A puede ser utilizada en diversas situaciones de interés odontológico, entre ellas, los trastornos temporo-mandibulares, hábitos parafuncionales, hipertrofia del músculo masetero, parálisis facial, asimetría de labios y, más recientemente, en los casos de hipermiotonía labial y sonrisa gingival. El objetivo de este trabajo es reportar el caso de un paciente con queja estética de sonrisa gingival. La aplicación de la toxina botulínica promovió la dehiscencia uniforme del labio superior y minimizó la molestia causada por la sonrisa gingival de forma rápida y poco invasiva, mostrando que esta puede convertirse en una alternativa terapéutica eficaz para el tratamiento de la sonrisa gingival, favoreciendo la estética facial y la autoestima del paciente.

Botulinum toxin type A could be used in various situations of dental interest including temporomandibular disorders, parafunctional habits, masseter muscle hypertrophy, facial paralysis, lip asymmetry and more recently in the cases of hyper myotonic lips and gummy smile. The aim of this paper is to report the case of a patient with complaint of gingival aesthetic smile. The application of botulinum toxin promoted the uniform dehiscence of the upper lip and minimized the discomfort caused by the gummy smile in a fast and little invasive way, showing that botulinum toxin can become an effective therapeutic alternative for the treatment of gummy smile, favoring facial aesthetics and patient self-esteem.

Proporciones del ancho/longitud de las coronas clínicas de los dientes anteriores del maxilar en una población Latino-Americana / Width/length ratios of clinical crowns of maxillary anterior teeth in a Latin-American cohort

Objetivo: Analizar las dimensiones de las coronas clínicas de los dientes anteriores del maxilar con respecto al ancho, longitud y proporción del ancho/longitud; y determinar si existe una correlación entre estos parámetros, así como con la altura facial en una población Latino-Americana. Material y métodos: Este estudio fue observacional de tipo transversal, se seleccionó una muestra de 94 estudiantes de ambos sexos entre 17 y 28 años de edad. Se evaluó en modelos confeccionadosde yeso el ancho, la longitud y la proporción entre ancho/longitud delincisivo central (IC), lateral (IL) y canino (CA) superior derecho, asícomo también se determinó clínicamente la altura facial utilizando un Vernier digital. Resultados: La longitud promedio de las coronas clínicas (en mm) de varones versus mujeres fue del IC: 10.36 versus 9.45; IL: 8.90 versus 8.24 y CA: 10.37 versus 9.43; mientras queel ancho promedio fue del IC: 8.44 versus 8.16; del IL: 7.00 versus 6.78 y del CA: 8.26 versus 8.00. La proporción promedio del ancho/longitud de las coronas clínicas de los varones versus mujeres fue del IC: 0.81 versus 0.86; IL: 0.78 versus 0.82 y CA: 0.80 versus 0.85. Se obtuvieron diferencias signifi cativas del ancho, longitud y la proporción del ancho/longitud de estas coronas por género (p < 0.05). Ademásse encontró una correlación positiva entre las dimensiones de estos dientes, mientras que se obtuvo una correlación relativa con la altura facial. Conclusión: Los resultados indican que en varones y mujeres la proporción del ancho / longitud promedio de las coronas clínicas de los dientes anterosuperiores es 0.82; además del ancho, la longitud de éstos es mayor en los varones y existe una correlación positiva entre las dimensiones dentarias, todo ello nos puede servir como pautas para el plan de tratamiento, procedimientos clínicos estéticos en odontología restauradora para nuestra población.

Objective: To analyze the dimensions of clinical crowns of maxillary anterior teeth in terms of width, length, and width/length ratio, and todetermine whether there is a correlation between these parameters and facial height in a Latin American cohort. Material and methods: Anobservational cross-sectional study was conducted, in which a sampleof 94 students of both sexes, aged between 17 and 28 years old, wasselected. Plaster models were used to measure the width, length, andwidth/length ratio of the central incisor (CI), lateral incisor (LI) andupper-right canine (CA); facial height was also measured using a digital Vernier caliper. Results: The average length of the clinical crowns(in mm) for males versus females was CI: 10.36 versus 9.45; LI: 8.90versus 8.24 and CA: 10.37 versus 9.43; the average width was CI: 8.44versus 8.16; LI: 7.00 versus 6.78 and CA: 8.26 versus 8.00. The averagewidth/length ratio of the clinical crowns of males versus females wasCI: 0.81 versus 0.86; LI: 0.78 versus 0.82 and CA: 0.80 versus 0.85.Signifi cant diff erences in the width, length, and width/length ratio ofthese crowns were found between the sexes (p < 0.05). Furthermore, apositive correlation was found between the dimensions of these teeth,and a relative correlation with facial height. Conclusion: The resultssuggest that, in both men and women, the average width/length ratioof the clinical crowns of upper anterior teeth is 0.82; Furthermore, thewidth and length of these teeth is greater in males and there is a positivecorrelation between the dental dimensions. Together these fi ndingscan serve as guidelines in planning the treatment and clinical aesthetic procedures used in restorative dentistry for our cohort.

Crown-to-root ratios in terms of length, surface area and volume: a pilot study of premolars / Relaciones de la corona y raíz dentaria en términos de longitud superficie y volumen: un estudio piloto de dientes premolares

The objective of this study was to construct three-dimensional (3D) images of premolars to measure the length, surface area and volume of crown and root and to analyze the mathematical relation among crown-to-root ratios in terms of length, surface area and volume. Twenty-five premolars were scanned using micro-computed tomography (micro CT) in vitro to build 3D models. The long axis and enamelo-cemental junction of each tooth were determined with the help of Geomagic Studio software, and the length, surface and volume of crown and root were measured. The crown-to-root ratios in terms of length, surface and volume were calculated and the relationship among length, surface area and volume of crown and root as well their ratios were analyzed using SPSS software. The interrelationship among crown length (x), surface area (y) and volume (z) could be expressed as z= -808.2 0+ 124.80x +3.35y -5.59x2-0.14xy+3.47y 2*10-4 (R2 = 0.99) and that of root length (x1), surface area (y1) and volume (z1), as z1= -207.50 +13.87x1+1.75y1 + 5.03x12*10-2-8.05x 1y1 *10-2+ 2.58*10-3y12 (R2 = 0.93) . The correlation among crown-to-root ratio in length(x2), crown-to-root ratio in surface area (y2) and crown-to-root ratio in volume (z2) could be expressed in z2= -4.48*10-2 -1.25x2*10-2+1.20y2 + 3.29x22-5.05x2y2 + 2.00y22 (R2 = 0.96). The length, surface area and volume of crown and root of premolars share a close relationship, while, a definite mathematical relation could be observed amongst their ratios. Crown to root ratio in terms of length, surface and volume, may provide a novel multi-criterion method for evaluating tooth function.

El objetivo de este estudio fue construir imágenes tridimensionales (3D) de los dientes premolares para medir la longitud, superficie y volumen de la corona y raíz, junto con analizar la relación matemática entre las proporciones de la corona a la raíz en términos de longitud, superficie y volumen. Veinticinco premolares fueron escaneados mediante microtomografía computadorizada (microTC) in vitro para construir modelos en 3D. Con el software Geomagic se determinaron el eje y la unión amelo-cementaria de cada diente, y se midieron la longitud, superficie y volumen de la corona y la raíz de los dientes premolares. Con el programa SPSS se calcularon y analizaron las proporciones de la corona a la raíz en términos de longitud, superficie y volumen y la relación entre la longitud, superficie y volumen de la corona y de la raíz. La interrelación entre la longitud de la corona (x), superficie (y) y el volumen (z) puede ser expresado como z= -808,2 0+ 124,80x + 3,35y -5,59x2-0,14xy + 3.47y2*10-4 (R2= 0,99) y la de longitud de la raíz (x1), área de superficie (y1) y el volumen (z1), como z1= -207,50 + 13.87x1 + 1.75y1 + 5.03x12 * 10-2-8.05x1y1 * 10-2 + 2,58 * 10-3y12 (R2= 0,93). La correlación entre la relación de corona a raíz en longitud (x2), la relación corona a raíz en superficie (y2) y la relación corona a raíz en volumen (Z2) podría expresarse en z2 = -4,48 * 10-2 * 10-2 -1.25x2 + 1.20y2 3.29x22-5.05x2y2 + 2.00y22 (R2= 0,96). La longitud, superficie y volumen de la corona y la raíz de los dientes premolares comparten una estrecha relación, mientras que, una relación matemática definida se pudo observar entre sus proporciones. La relación entre la corona y raíz en términos de longitud, superficie y volumen, puede proporcionar un nuevo método multi-criterio para evaluar la función de los dientes.

Lobodontia: Genetic entity with specific pattern of dental dysmorphology.

A characteristic pattern of dental anomalies including cone-shaped premolars, multitubercular molar crowns, pyramidal molar roots with single root canals, shovel-shaped incisors with palatal invaginations and hypodontia usually described as lobodontia was recognised as a separate entity. Only a few family reports on this condition have been published until now. The prevalence of the condition is estimated to be less than 1:1000,000. In the present paper we tried to delineate and clarify some additional aspects of this rare genetic entity in three families with 17 affected members. This represents the largest number of cases recorded since now. The analyses of dental morphology, crown-size profile patterns, pedigree analyses, and analyses of digitopalmar dermatoglyphics were performed in 7 examined patients. Crown-size profile pattern was calculated for seven patients and compared with standards for the Croatian population. The most striking features of the condition are conical premolars, tritubercular canines, single pyramidal molar roots, multitubercular molar crowns and invaginated upper incisors. A considerable reduction of crown-size was observed for all premolars, particularly in mandible. The alveolar process in the premolar region was hypoplastic and thin in all patients studied. Gender ratio of affected individuals was approximately M1:F1. Our data suggest that the prevalence of this condition is less than 1:300,000 in the Croatian population, which is considerably higher than previously reported in the literature. The analysis of the anomaly in all the families showed a slight variability in the clinical picture and autosomal dominant (AD) mode of inheritance. It could be concluded that this rare condition described as lobodontia represents a true genetic entity which follows AD mode of inheritance and displays variability in its expression.

An Update on Crown Lengthening. Part 2: Increasing Clinical Crown Height to Facilitate Predictable Restorations.

This is the second paper in this two-part series. Paper one provided an overview of managing gingival tissue excess and paper two will focus on increasing clinical crown height to facilitate restorative treatment. Crown lengthening is a surgical procedure aimed at the removal of gingival tissue with or without adjunctive bone removal. The different types of procedure undertaken will be discussed over the two papers. In order to provide predictable restorations, care must be taken to ensure the integrity of the margins. If this is not taken into account it can lead to an impingement on the biologic width, which may in turn lead to chronic inflammation resulting in recession or the development of periodontal problems which can be hard to manage. Clinical Relevance: This paper aims to reinforce the need for thorough diagnosis and treatment planning and provides an overview of the various procedures that can be undertaken.

Periodontal and dental effects of surgically assisted rapid maxillary expansion, assessed by using digital study models

OBJECTIVE: The present study assessed the maxillary dental arch changes produced by surgically assisted rapid maxillary expansion (SARME). METHODS: Dental casts from 18 patients (mean age of 23.3 years) were obtained at treatment onset (T1), three months after SARME (T2) and 6 months after expansion (T3). The casts were scanned in a 3D scanner (D-250, 3Shape, Copenhagen, Denmark). Maxillary dental arch width, dental crown tipping and height were measured and assessed by ANOVA and Tukey's test. RESULTS: Increased transversal widths from T1 and T2 and the maintenance of these values from T2 and T3 were observed. Buccal teeth tipping also showed statistically significant differences, with an increase in all teeth from T1 to T2 and a decrease from T2 to T3. No statistically significant difference was found for dental crown height, except for left first and second molars, although clinically irrelevant. CONCLUSION: SARME proved to be an effective and stable procedure, with minimum periodontal hazards. .

OBJETIVOS: o presente estudo teve o objetivo de avaliar as alterações dentárias e periodontais decorrentes da Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC). MÉTODOS: foram obtidos os modelos de gesso de 18 pacientes (média de idade de 23,3 anos), ao início (T1), 3 meses após a ERMAC (T2) e 6 meses após a expansão (T3). Os modelos foram digitalizados (Scanner 3D 3Shape D-250) e mensuraram-se as distâncias transversais, bem como a inclinação e a altura da coroa clínica dos dentes posteriores. Para análise dos resultados, aplicou-se a análise de Variância e o teste de Tukey. RESULTADOS: nas distâncias transversais, observou-se um aumento de T1 para T2 e uma manutenção de T2 para T3. As inclinações dentárias demonstraram diferenças estatisticamente significativas em alguns dentes; porém, numericamente tenderam a um aumento de T1 para T2 e a uma diminuição de T2 para T3. Não se observou diferença estatisticamente significativa na altura da coroa clínica, exceto nos primeiros e segundos molares do lado esquerdo, porém, clinicamente irrelevante. CONCLUSÕES: a ERMAC demonstrou ser um procedimento efetivo e estável, com mínima repercussão periodontal. .

Changes of Root Length and Root-to-Crown Ratio after Apical Surgery: An Analysis by Using Cone-beam Computed Tomography.

INTRODUCTION: Apical surgery is an important treatment option for teeth with post-treatment periodontitis. Although apical surgery involves root-end resection, no morphometric data are yet available about root-end resection and its impact on the root-to-crown ratio (RCR). The present study assessed the length of apicectomy and calculated the loss of root length and changes of RCR after apical surgery. METHODS: In a prospective clinical study, cone-beam computed tomography scans were taken preoperatively and postoperatively. From these images, the crown and root lengths of 61 roots (54 teeth in 47 patients) were measured before and after apical surgery. Data were collected relative to the cementoenamel junction (CEJ) as well as to the crestal bone level (CBL). One observer took all measurements twice (to calculate the intraobserver variability), and the means were used for further analysis. The following parameters were assessed for all treated teeth as well as for specific tooth groups: length of root-end resection and percentage change of root length, preoperative and postoperative RCRs, and percentage change of RCR after apical surgery. RESULTS: The mean length of root-end resection was 3.58 ± 1.43 mm (relative to the CBL). This amounted to a loss of 33.2% of clinical and 26% of anatomic root length. There was an overall significant difference between the tooth groups (P < .05). There was also a statistically significant difference comparing mandibular and maxillary teeth (P < .05), but not for incisors/canines versus premolars/molars (P = .125). The mean preoperative and postoperative RCRs (relative to CEJ) were 1.83 and 1.35, respectively (P < .001). With regard to the CBL reference, the mean preoperative and postoperative RCRs were 1.08 and 0.71 (CBL), respectively (P < .001). The calculated changes of RCR after apical surgery were 24.8% relative to CEJ and 33.3% relative to CBL (P < .001). Across the different tooth groups, the mean RCR was not significantly different (P = .244 for CEJ and 0.114 for CBL). CONCLUSIONS: This CBCT-based study demonstrated that the RCR is significantly changed after root-end resection in apical surgery irrespective of the clinical (CBL) or anatomic (CEJ) reference levels. The lowest, and thus clinically most critical, postoperative RCR was observed in maxillary incisors. Future clinical studies need to show the impact of resection length and RCR changes on the outcome of apical surgery.

Measurement accuracy and reliability of tooth length on conventional and CBCT reconstructed panoramic radiographs

INTRODUCTION: This in vivo study assessed accuracy and reliability of tooth length measurements obtained from conventional panoramic radiographs and CBCT panoramic reconstructions to that of a digital caliper (gold standard). METHODS: The sample consisted of subjects who had CBCT and conventional panoramic radiographic imaging and who required maxillary premolar extraction for routine orthodontic treatment. A total of 48 teeth extracted from 26 subjects were measured directly with digital calipers. Radiographic images were scanned and digitally measured in Dolphin 3D software. Accuracy of tooth length measurements made by CBCT panoramic reconstructions, conventional panoramic radiographs and digital caliper (gold standard) were compared to each other by repeated measures one-way ANOVA with Bonferroni correction and by single measures intraclass correlation coefficient. RESULTS: Repeated root length measures with digital calipers, panoramic radiographs and CBCT constructed panoramic-like images were all individually highly reliable. Compared to the caliper (gold standard), tooth measurements obtained from conventional panoramic radiographs were on average 6.3 mm (SD = 2.0 mm) longer, while tooth measurements from CBCT panoramic reconstructions were an average of 1.7 mm (SD = 1.2 mm) shorter. CONCLUSIONS: In comparison to actual tooth lengths, conventional panoramic radiographs were relatively inaccurate, overestimating the lengths by 29%, while CBCT panoramic reconstructions underestimated the lengths by 4%. .

INTRODUÇÃO: este estudo in vivo avaliou a precisão e a confiabilidade de medições do comprimento dentário realizadas em radiografias panorâmicas convencionais e em reconstruções panorâmicas de tomografias computadorizadas de feixe cônico (TCFC), comparando-as com medições feitas com um paquímetro digital, consideradas o padrão-ouro. MÉTODOS: a amostra incluiu indivíduos que já tivessem realizado tanto exames imaginológicos de TCFC quanto radiografias panorâmicas, e cujo tratamento ortodôntico exigisse a extração de pré-molar superior. No total, 48 dentes extraídos, de 26 pacientes, foram mensurados diretamente com paquímetros digitais. As radiografias foram escaneadas e digitalmente avaliadas com a ajuda do software Dolphin 3D. Por meio da análise de variância simples com correção de Bonferroni e Coeficiente de Correlação Intraclasse simples, comparou-se a precisão das medições de comprimento dentário realizadas em reconstruções panorâmicas de TCFC, em radiografias panorâmicas convencionais e com paquímetro digital. RESULTADOS: medições repetidas de comprimento dentário feitas com o paquímetro digital, radiografias panorâmicas e reconstruções panorâmicas de TCFC foram todas consideradas, individualmente, altamente confiáveis. Em comparação ao paquímetro, as medidas obtidas por meio de radiografias panorâmicas convencionais foram, em média, 6,3 ± 2,0mm mais longas, enquanto as medidas obtidas por meio das reconstruções panorâmicas de TCFC foram, em média, 1,7 ± 1,2mm mais curtas. CONCLUSÕES: em comparação com o real comprimento dentário, as radiografias panorâmicas convencionais foram relativamente ...

Prevalence of altered passive eruption in orthodontically treated and untreated patients.

BACKGROUND: Some authors have reported that after orthodontic treatment (OT), a "gummy smile" might develop. Nevertheless, there are no studies in the literature that investigate whether OT increases the presence of altered passive eruption (APE). The primary aim of this cross-sectional study is to evaluate the prevalence of APE after OT (OT group) and compare it with patients who never received OT (control group). A secondary aim is to identify which variables are related to APE. METHODS: The study population consisted of 190 patients (95 patients each in the control and OT groups), providing 1,140 anterior teeth for the clinical examination. The following clinical parameters were assessed: presence or absence of APE, clinical crown length, and gingival biotype, which was divided into three categories: thin-scalloped, thick-flat, and thick-scalloped. RESULTS: Twenty-eight patients (29.5%) were diagnosed with APE in the control group and 40 (42.1%) in the OT group, although this difference was not statistically significant (P = 0.07). Furthermore, 34 (75.6%) patients with thick-flat biotype were diagnosed with APE, whereas 30 (31.3%) and four (8.2%) with thick-scalloped and thin-scalloped biotypes, respectively, had APE. These differences were statistically significant (P <0.001). CONCLUSIONS: It was concluded that: 1) the prevalence of APE is higher after OT but not to a statistically significant degree and 2) APE is more common in individuals with a thick-flat gingival biotype.

Evaluation of a photographic method to measure dental angulation

Objective: To analyze the reliability and reproducibility of a simplified method for analysis of dental angulation using digital photos of plaster dental casts. Methods: Digital and standardized photographs of plaster casts were performed and posteriorly imported to an angle reading graphic program in order to have measurements obtained. Such procedures were repeated to evaluate the random error and to analyze reproducibility through intraclass correlation. The sample consisted of 12 individuals (six male and six female) with full permanent dentition orthodontically untreated. The analyses were bilaterally carried out, and generated 24 measurements. Results: The random error showed variation of 0.77 to 2.55 degrees for teeth angulation. The statistical analysis revealed that the method presents excellent reproducibility (p < 0.0001) for all teeth, except for the upper premolars. In spite of that, it is still considered statistically significant (p < 0.001). Conclusion: The proposed method presents enough reliability that justifies its use in the development of scientific research as well as in clinical practice. .

Objetivo: analisar a confiabilidade e reprodutibilidade de um método simplificado para análise da angulação dentária que faz uso de fotografias digitalizadas de modelos de gesso. Métodos: foram realizadas fotografias digitalizadas e padronizadas de modelos de gesso, posteriormente transportadas para um programa gráfico de leitura de ângulos, para a obtenção das medidas. Tais procedimentos foram repetidos para avaliação do erro do método casual e para a análise da reprodutibilidade por meio da Correlação Intraclasse. A amostra constituiu-se de 12 indivíduos com dentição permanente completa e não tratados ortodonticamente, sendo seis do sexo masculino e seis do feminino. As análises foram feitas bilateralmente, gerando 24 medidas. Resultados: o erro casual mostrou uma variação de 0,77 a 2,55º para a angulação dos dentes. A análise estatística revelou que o método apresenta uma excelente reprodutibilidade (r = 0,65 - 0,91; p < 0,0001) para todos os dentes, exceto para os pré-molares superiores, mas ainda assim estatisticamente significativa (p < 0,001). Conclusão: o método proposto apresenta confiabilidade suficiente para justificar seu uso no desenvolvimento de pesquisas científicas, bem como na prática clínica. .

Frequency and variability of dental morphology in deciduous and permanent dentition of a Nasa indigenous group in the municipality of Morales, Cauca, Colombia / Frecuencia y variabilidad de la morfología dental en dentición temporal y permanente de un grupo de indígenas Nasa del municipio de Morales (Cauca, Colombia)

Abstract Objectives: To determine the frequency, variability, sexual dimorphism and bilateral symmetry of fourteen dental crown traits in the deciduous and permanent dentition of 60 dental models (35 women and 25 men) obtained from a native, indigenous group of Nasa school children of the Musse Ukue group in the municipality of Morales, Department of Cauca, Colombia. Methods: This is a quantitative, descriptive, cross-sectional study that characterizes dental morphology by means of the systems for temporary dentition from Dahlberg (winging), and ASUDAS (crowding, reduction of hypocone, metaconule and cusp 6), Hanihara (central and lateral incisors in shovel-shape and cusp 7), Sciulli (double bit, layered fold protostylid, cusp pattern and cusp number) and Grine (Carabelli trait); and in permanent dentition from ASUDAS (Winging, crowding, central and lateral incisors in shovel-shape and double shovel-shape, Carabelli trait, hypocone reduction, metaconule, cusp pattern, cusp number, layered fold protostylid, cusp 6 and cusp 7). Results: The most frequent dental crown features were the shovel-shaped form, grooved and fossa forms of the Carabelli trait, metaconule, cusp pattern Y6, layered fold, protostylid (point P) and cusp 6. Sexual dimorphism was not observed and there was bilateral symmetry in the expression of these features. Conclusions: The sample studied presented a great affinity with ethnic groups belonging to the Mongoloid Dental Complex due to the frequency (expression) and variability (gradation) of the tooth crown traits, upper incisors, the Carabelli trait, the protostylid, cusp 6 and cusp 7. The influence of the Caucasoide Dental Complex associated with ethno-historical processes cannot be ruled out.

Resumen Objetivos: Determinar la frecuencia, la variabilidad, el dimorfismo sexual y la simetría bilateral de 14 Rasgos Morfológicos Dentales Coronales (RMDC) en dentición temporal y permanente de 60 modelos (35 mujeres y 25 hombres) obtenidos de un grupo de indígenas escolares Nasa del cabildo Musse Ukue del municipio de Morales, departamento del Cauca. Métodos: Estudio descriptivo transversal cuantitativo que caracteriza la morfología dental mediante los sistemas en dentición temporal Dahlberg (winging), Asudas (crowding, reducción de hipocono, metacónulo y cúspide 6), Hanihara (incisivos centrales y laterales en pala y cúspide 7), Sciulli (doble pala, protostílido, pliegue acodado, patrón cuspídeo y número de cúspides) y Grine (cúspide de Carabelli); y en dentición permanente Asudas (Winging, crowding, incisivos centrales y laterales en pala, doble pala, cúspide de Carabelli, reducción del hipocono, metacónulo, patrón cuspídeo, número de cúspides, pliegue acodado, protostílido, cúspide 6 y cúspide 7). Resultados: Los RMDC más frecuentes fueron la forma de pala, formas surco y fosa de la cúspide de Carabelli, metacónulo, patrón cuspídeo Y6, pliegue acodado, protostílido (punto P) y cúspide 6. No se observó dimorfismo sexual y hubo simetría bilateral en la expresión de los rasgos. Conclusiones: La muestra estudiada presenta una alta afinidad con grupos étnicos pertenecientes al Complejo Dental Mongoloide debido a la frecuencia (expresión) y variabilidad (gradación) de los RMDC, incisivos en pala, la cúspide Carabelli, el Protostílido, la cúspide 6 y la cúspide 7; sin embargo, no se puede descartar influencia del Complejo Dental Caucasoide asociado con procesos etno-históricos.