RESUMO

Introduction: The anatomical configuration classified as Vertucci's type III is described as the second most prevalent in mandibular incisors. Methods: Thirty-six Vertucci's type III mandibular incisors were evaluated by micro-computed tomography (micro-CT) and divided into 3 groups (n = 12) according to the root canal preparation protocol (HyFlex CM [HCM], HyFlex EDM [HEDM], and Sequence Rotary File [SRF]). The teeth were scanned before and after performing 0.25 mm and 0.40 mm apical diameter preparations. The canal volume, dentin thickness, percentage of accumulated debris and untouched canal areas, transportation, and centering ability were measured. The data were statistically analyzed by ANOVA, Tukey, Kruskal-Wallis, and Dunn tests (P < 0.05). Results: The volume increase was more evident in the apical third. After 0.40 mm preparation, the SRF system provided a higher reduction (P < 0.05) in dentin thickness on the buccal surface 1 mm from the apex. There was higher canal transportation in the bucco-lingual direction. The 0.40 mm apical preparation reduced the percentage of untouched canal areas. The apical third had the highest percentage of untouched canal areas. The cervical third had the lowest volume of accumulated debris. Conclusions: Increasing the apical preparation to a diameter of 0.40 mm with the HCM, HEDM, and SRF systems in Vertucci's type III root canals of mandibular incisors proved to be safe and effective, reducing untouched canal areas. Clinical relevance: Root flattening can be intense to the point of generating a root canal bifurcation. Despite the decrease in the root canal diameter, a greater enlargement of the apical region is necessary and safe.

RESUMO

Objective: To evaluate the degree of perception among lay people of different age groups about black spaces between lower incisors. Methodology: digital changes were performed in a frontal photograph of a smiling 30 year-old patient, simulating different dimensions of black spaces. The images were printed on photographic paper and applied with a questionnaire in order to evaluate the attractiveness using as tool a visual analogue scale (VAS). The participants were divided into 6 groups, considering race (Caucasian and Negroid) and age (15-19 years, 35-44 years and 65-74 years old). The differences between the examiners were checked by the Mann-Whitney test and the significance level was 5% (α = 0.05) for all analyzes. Results: The photographs that did not have black spaces were better graded and the ones that had larger black spaces scored worse. The older age group and the Negroid race group graded better the photograph with the largest black spaces, compared to the younger age groups and the group of Caucasians. Conclusion: black spaces between lower incisors are esthetically unattractive and their perception decreases with aging, besides being less relevant to older and Negroid people.

Assuntos

RESUMO

OBJECTIVE: This retrospective case series aimed to assess the stability of the papilla around four single crowns supported by narrow-diameter implants replacing all maxillary incisors. Secondary objectives included assessment of marginal bone level stability, incidence of technical and biological complications, and patient satisfaction. MATERIALS AND METHODS: Individuals with four adjacent implants in maxillary incisor sites, placed with a 3 mm inter-implant distance and rehabilitated with single crowns were included. Retrospective data were obtained from photographs and radiographs taken at the delivery of the prosthesis (baseline-T0). Patients were then recalled (≥2 years after T0) for clinical and radiographic examination (follow-up-T1). Photographs were obtained and patient satisfaction was assessed using a visual analogue scale. Papilla height and marginal bone level were compared over time. RESULTS: Data from 10 patients with medium-low smile lines and rehabilitated with 40 implants, in function for 5.4 ± 1.9 years, were analyzed. The papilla height between implants (T0: 2.3 ± 0.9 mm; T1: 2.6 ± 0.7 mm; p = .011) and between tooth and implant (T0: 3.4 ± 0.9 mm; T1: 3.8 ± 0.8 mm; p = .025) increased significantly over the years. The marginal bone level remained stable over time (T0: 0.88 ± 0.57 mm; T1: 0.71 ± 0.67 mm; p = .007). Patients were highly satisfied (97.7 ± 0.3%) with the treatment outcome. CONCLUSION: Within its limitations, this study demonstrated that four single implant-supported crowns placed at maxillary incisor sites may exhibit soft tissue and marginal bone stability over a long period of time. This treatment approach, however, should be restricted to few patients as it requires a proper case selection and skillful execution of all surgical and prosthetic steps.

Assuntos

RESUMO

Resumo O tratamento ortodôntico com extrações atípicas, quando bem planejado e conduzido, é uma excelente abordagem terapêutica. Esse estudo objetivou apresentar um caso clínico de retratamento ortodôntico em paciente adulto com aparatologia fixa em ambos os arcos e extração do dente 31, e discutir os limites de aceitação do organismo às movimentações ortodônticas. Paciente de 23 anos, vindo de um tratamento ortodôntico anterior, compareceu à clínica da Escola de Especialização Profissional da ABO/MA com relato de dor na região dos incisivos inferiores e queixa estética. Identificou-se a presença de problema periodontal por excesso de vestibularização dos incisivos inferiores. O tratamento ortodôntico adotado corrigiu a vestibularização excessiva dos incisivos inferiores, eliminando as queixas do paciente, e restabelecendo o overjet e overbite ideais, além de manter as relações oclusais de Classe I bilateral. Concluiu-se, neste caso, que a extração de um incisivo foi uma alternativa eficaz para correção da vestibularização excessiva dos incisivos inferiores.(AU)

Abstract Orthodontic treatment with atypical extractions, when well planned and conducted, is an excellent therapeutic approach. This study aimed to present a clinical case of orthodontic retreatment in an adult patient with fixed appliance in both arches and extraction of tooth 31, and discuss the limits of the body's acceptance to orthodontic movements. A 23-year-old patient, coming from a previous orthodontic treatment, attended the clinic of the Professional Specialization School of ABO/MA with a report of pain in the region of the mandibular incisors and aesthetic complaint. The presence of periodontal problem due to excessive buccalization of the mandibular incisors was identified. The orthodontic treatment adopted corrected the excessive buccalization of the mandibular incisors, eliminating the patient's complaints, and restoring the ideal overjet and overbite, in addition to maintaining bilateral Class I occlusal relationships. It was concluded that, in this case, the extraction of an incisor was an effective alternative for the correction of excessive buccalization of the mandibular incisors.(AU)

Assuntos

RESUMO

ABSTRACT Objective: To measure enamel thickness at the proximal surfaces of the mandibular incisors, using micro-computed tomography (micro-CT) scans. Material and Methods: Forty-one single-rooted mandibular incisors were selected and analyzed according to anatomical characteristics, to form three groups: Group 1 - central incisors (n = 18); Group 2 - right lateral incisors (n = 10); and Group 3 - left lateral incisors (n = 13). First, enamel thickness at the proximal contact areas of the mandibular incisors was measured. Second, the mesial and distal surfaces of the lateral incisors were compared. Finally, the relationship between the tooth width and the mean enamel thickness was determined. Each tooth was scanned with a micro-CT scanner, and the image was processed with SCANCO micro-CT onboard analysis software. Results: There were no statistically significant differences in mean enamel thickness between the mesial and distal surfaces for each lateral incisor, or between contralateral lateral incisors. In all surfaces analyzed, the upper zones had statistically significantly thinner enamel (0.52 ± 0.10 mm) when compared to the middle and lower zones (0.60 ± 0.08 mm and 0.59 ± 0.08 mm, respectively). There was no correlation (r =0.07) between enamel thickness of the mandibular incisor and the tooth width. Conclusions: The enamel thickness of the mandibular incisors is similar on the mesial and distal surfaces, with the thinnest layer located at the upper zone.

RESUMO Objetivo: Medir a espessura do esmalte nas superfícies proximais dos incisivos inferiores, usando imagens de microtomografia computadorizada (micro-CT). Material e Métodos: Quarenta e um incisivos inferiores com raiz única foram selecionados e analisados de acordo com as características anatômicas, formando três grupos: Grupo 1 - incisivos centrais (n = 18); Grupo 2 - incisivos laterais direitos (n = 10); e Grupo 3 - incisivos laterais esquerdos (n = 13). Primeiro, foi medida a espessura do esmalte nas áreas de contato proximal dos incisivos inferiores. Em segundo lugar, as faces mesial e distal dos incisivos laterais foram comparadas. Por fim, foi determinada a relação entre a largura do dente e a espessura média do esmalte. Cada dente foi escaneado com um scanner micro-CT, e a imagem foi processada com o software de análise SCANCO micro-CT. Resultados: Não houve diferenças estatisticamente significativas na espessura média do esmalte entre as superfícies mesial e distal de cada incisivo lateral, ou entre os incisivos laterais contralaterais. Em todas as superfícies analisadas, as zonas superiores apresentaram esmalte significativamente mais fino (0,52 ± 0,10 mm) quando comparadas às zonas média e inferior (0,60 ± 0,08 mm e 0,59 ± 0,08 mm, respectivamente). Não houve correlação (r = 0,07) entre a espessura do esmalte do incisivo inferior e a largura do dente. Conclusões: A espessura do esmalte dos incisivos inferiores é semelhante nas faces mesial e distal, com a camada mais fina localizada na zona superior.

RESUMO

SUMMARY: In recent years, aesthetic dentistry has become a major focus for the public. Facial attractiveness plays a key role on modern society and the creation of harmonious smile is an aim for every dentist. The objective of this study was to define certain values of the inter-incisive index in Bulgarians, the sexual dimorphism and bilateral asymmetry and to verify differences of this index between Bulgarians and other Balkan populations. The present study included 121 males and 111 females of Bulgarian origin aged 20- 40 years. Mesiodistal dimensions of maxillary central and lateral incisors were measured by Dentistry Sliding Vernier Caliper. We used the technique of direct anthropometry, modified by Prof. Y. Yordanov. We calculated the inter-incisive index as ratio of the mesiodistal dimension of maxillary lateral incisor to the mesiodistal dimension of the maxillary central incisor. The measurements were analyzed with SPSS 23. The level of statistical significance was set at P< 0.05. The inter-incisive index showed no statistically significant differences between left and right side of the dental arch in both sexes. We did not find statistically significant differences between males and females as well. On the other hand, we found statistically significant differences in MD values of incisors between Bulgarians and other Balkan nations. Inter-incisive index shows no sexual dimorphism and bilateral asymmetry in Bulgarians. This can be helpful in aesthetic dentistry, in prosthodontics and in orthodontic treatment planning.

RESUMEN: En los últimos años, la odontología estética se ha convertido en un foco importante para el público. El atractivo facial juega un papel clave en la sociedad moderna y la creación de una sonrisa armoniosa es importante para todos los dentistas. El objetivo de este estudio fue definir ciertos valores del índice interincisivo en búlgaros, el dimorfismo sexual y la asimetría bilateral y verificar diferencias de este índice entre búlgaros y otras poblaciones balcánicas. El presente estudio incluyó a 121 hombres y 111 mujeres de origen búlgaro entre 20 y 40 años de edad. Las dimensiones mesiodistales de los incisivos superiores centrales y laterales se midieron con un calibrador Vernier deslizante de odontología. Utilizamos la técnica de antropometría directa, modificada por el Prof. Y. Yordanov y se calculó el índice interincisivo como la relación entre la dimensión mesiodistal del incisivo lateral superior y la dimensión mesiodistal del incisivo central superior. Las medidas se analizaron con SPSS 23. El nivel de significancia estadística se fijó en P<0,05. El índice interincisivo no mostró diferencias estadísticamente significativas entre los lados izquierdo y derecho de la arcada dentaria en ambos sexos. Tampoco encontramos diferencias estadísticamente significativas entre hombres y mujeres. Por otro lado, encontramos diferencias estadísticamente significativas en los valores de DM de los incisivos entre búlgaros y otras naciones balcánicas. El índice interincisivo no muestra dimorfismo sexual ni asimetría bilateral en los búlgaros. Esto puede ser útil en odontología estética, en prostodoncia y en la planificación de tratamientos de ortodoncia.

Assuntos

RESUMO

Resumo Objetivos: Avaliar a prevalência de traumatismo dentário em incisivos superiores de pacientes submetidos a tratamento na Clínica de Ortodontia da UFRJ (Universidade Federal do Rio de Janeiro) e correlacionar oito fatores predisponentes dentofaciais desses indivíduos ao tipo de trauma sofrido. Materiais e Métodos: 765 prontuários de pacientes da Clínica de Ortodontia da UFRJ foram analisados em busca de trauma nos incisivos superiores. 40 prontuários de pacientes traumatizados e com documentação inicial completa foram selecionados. Radiografias cefalométricas laterais foram extraídas dos exames volumétricos, modelos, fotografias e prontuários foram analisados. Resultados: A incompetência labial, o acentuado grau de overjet e a acentuada protrusão e projeção dos incisivos superiores, presentes nos pacientes Classe II esqueléticos, atuam como principais fatores predisponentes para a ocorrência de traumatismo dentário. Conclusões: O tratamento ortodôntico em duas fases, deve ser foco de futuros estudos visando avaliar sua atuação como uma medida preventiva na redução dos índices de trauma dental nesses pacientes.(AU)

Abstract Objective: To evaluate the prevalence of dental trauma in upper incisors of patients submitted to treatment in the orthodontic clinic of UFRJ (Federal University of Rio de Janeiro) and to correlate eight predisposing dentofacial factors of these individuals with the type of trauma suffered. Materials and Methods: 765 medical records of patients of UFRJ Orthodontics Clinic were analyzed for upper incisor trauma. 40 medical records of trauma patients with complete initial documentation were selected. Lateral cephalometric radiographs were extracted from the volumetric exams, models, photographs, and medical records were analyzed. Results: Labial incompetence, marked degree of overjet and protrusion and projection of the upper incisors, present in Class II skeletal patients, act as the main predisposing factors for the occurrence of dental traumatism. Conclusions: two-phase orthodontic treatment should be the focus of future studies aiming to evaluate its performance as a preventive measure in reducing dental trauma rates in these patients.(AU)

Assuntos

RESUMO

ABSTRACT Introduction: There are different possibilities of orthodontic planning for cases with congenital absence of maxillary lateral incisors. This subject divides the opinion of orthodontists and oral rehabilitation clinicians, due to the advantages and disadvantages of each treatment option, which may involve opening spaces for future implants and/or prosthetic restorations, or closing the spaces by positioning the maxillary canines in the place of lateral incisors. The correct diagnosis and careful evaluation of each patient allow to determine the best therapeutic approach. This paper discusses the main topics to be considered when planning these cases. Objectives: To evaluate the main aspects related to orthodontic treatment planning in cases of congenital absence of maxillary lateral incisors, to aid the decision-making, with clinical and scientific basis.

RESUMO Introdução: Existem diferentes possibilidades de planejamento ortodôntico para os casos que apresentam ausência congênita de incisivos laterais superiores. Esse é um assunto que divide a opinião de ortodontistas e reabilitadores orais, devido às vantagens e desvantagens de cada uma das opções de tratamento, as quais podem envolver a abertura de espaços para futuros implantes e/ou restaurações protéticas ou o fechamento dos espaços, com posicionamento dos caninos superiores no lugar dos incisivos laterais. O correto diagnóstico e uma criteriosa avaliação de cada paciente permitem determinar a melhor abordagem terapêutica. Nesse artigo, serão discutidos os principais tópicos a serem considerados no planejamento desses casos. Objetivos: Avaliar os principais aspectos relacionados ao planejamento do tratamento ortodôntico nos casos de ausência congênita de incisivos laterais superiores, de maneira a auxiliar nas tomadas de decisão, com embasamento clínico e científico.

RESUMO

RESUMEN: La agenesia de incisivos laterales superiores corresponde a un desafío clínico, en cuanto a planificación de tratamiento, así como también para la obtención de resultados estéticos y funcionales adecuados. Con el fin de conseguirlo, el clínico debería informarse sobre las diferentes opciones terapéuticas disponibles en la actualidad, considerando que la indicación depende de cada caso clínico individual, es decir, del paciente en su contexto integral sumado a su condición intra-oral. Además, es importante evaluar los resultados a largo plazo de las diferentes alternativas, para lograr la resolución clínica más adecuada y estable en el tiempo. El éxito en estos pacientes, requiere de un enfoque multidisciplinario, considerando especialistas en ortodoncia, rehabilitación oral, periodoncia y cirugía oral de ser necesario. El objetivo de esta revisión es describir y comparar las alternativas terapéuticas para la agenesia de incisivos laterales maxilares.

ABSTRACT: The agenesis of upper lateral incisors represents a clinical challenge regarding treatment planning and appropriate aesthetic and functional results. In order to obtain the best results, the clinician should be informed about the different therapeutic options currently available, considering that the indication depends on each individual clinical case, that is, on the patient in his/her comprehensive context in addition to his/her oral condition. It is also important to evaluate long term results from each treatment available, in order to achieve the better outcome and most importantly, a stable clinical resolution over time. The treatment success in this kind of patients requires a multidisciplinary approach, including specialists in orthodontics, oral rehabilitation, periodontics, and oral surgery if necessary. The objective of this review is to describe and compare the therapeutic alternatives for maxillary lateral incisor agenesis.

Assuntos

RESUMO

The aim of this study was to analyze the dimensions of the clinical crown of upper central incisors and the prevalence of tooth shapes by two different protocols. Assessment was performed on each of the 111 dental stone type V maxillae models of students of dentistry from Buenos Aires University [93 females and 18 males, mean age 23.70 (± 2.26) years] The mesial and distal-vestibular angles were defined on each right upper incisor, and the following segments were defined: AB (zenith - incisal edge), CD, EF, GH (apical, middle, and incisal thirds - vestibule - mesial and vestibule-distal angles) and their lengths were determined with a precision caliper. Then, the CD/AB, EF/AB and mean CD-EF/AB ratios were calculated. Shapes were assessed by four independent observers, three of whom evaluated digital images of the models, while the fourth had no access to the images, and determined the shapes using an algorithm developed from the dimensions of the studied segments. Rates and confidence intervals were determined, and Fleiss' Kappa was calculated to assess the agreement among the evaluators who worked with the images and among all of them. Average incisor length was 10 mm, and widths at CD and EF were 7.35 mm (0.65) and 8.27 mm (0.58), respectively. Regarding shapes, 51.58% (47.90-55.20) of the incisors were identified as square, 18.02% (14.50-21.90) as ovoid and 30.41% (30.00-30.90) as triangular. Fleiss' Kappa agreement was 0.71 (0.62-0.80). The application of the proposed algorithm provided a considerable level of agreement among the observers. Regarding tooth size, both the average segment length and the proportions were similar to those reported by various authors.

El objetivo de este trabajo fue analizar las dimensiones de las coronas clínicas de incisivos centrales superiores, y la prevalencia de cada una de las formas dentarias según diferentes formas de determinación. Se utilizaron modelos de yeso tipo V de 111 estudiantes (93 mujeres y 18 varones) con una media de edad de 23,70 (± 2,26) años. Se definieron los ángulos vestíbulo - mesial y distal para los incisivos centrales superiores derechos (1.1), se definieron los siguientes segmentos: AB (cenit - borde incisal), CD, EF, GH (tercios apical, medio e incisal - ángulos vestíbulo - mesial y vestíbulo- distal) y se determinaron sus longitudes con un calibre de precisión. Se calcularon las proporciones CD/AB, EF/AB y media CDEF/ AB. Las formas de las piezas dentarias fueron identificadas por cuatro observadores independientes, tres lo hicieron mediante la evaluación de imágenes digitales de los modelos confeccionados. El cuarto observador, sin acceso a las imágenes, asignó a cada pieza una de las formas determinadas mediante la aplicación de un algoritmo elaborado ad-hoc. Se obtuvieron tasas e intervalos de confianza y se calculó Kappa de Fleiss para valorar la concordancia entre evaluadores. La longitud promedio fue de 10 mm y el ancho en los segmentos CD y EF fueron de 7.35 mm (0.65) y 8.27 mm (0.58) respectivamente. En cuanto a formas el 51,58% (47.90-55.20) de los incisivos estudiados fueron identificados como cuadrados, el 18.02% (14.50-21.90) como ovoides y el 30,41% (30.00-30.90) triangulares. La concordancia de Kappa de Fleiss fue de 0.71 (0.62-0.80). La aplicación del algoritmo propuesto alcanzó un nivel de concordancia considerable entre los evaluadores. En cuanto al tamaño dentario, tanto la longitud promedio de los segmentos estudiados como las proporciones halladas son similares a las reportadas por diversos autores.

Assuntos

RESUMO

ABSTRACT The aim of this study was to analyze the dimensions of the clinical crown of upper central incisors and the prevalence of tooth shapes by two different protocols. Assessment was performed on each of the 111 dental stone type V maxillae models of students of dentistry from Buenos Aires University [93 females and 18 males, mean age 23.70 (± 2.26) years] The mesial and distal-vestibular angles were defined on each right upper incisor, and the following segments were defined: AB (zenith - incisal edge), CD, EF, GH (apical, middle, and incisal thirds - vestibule - mesial and vestibule-distal angles) and their lengths were determined with a precision caliper. Then, the CD/AB, EF/AB and mean CD-EF/AB ratios were calculated. Shapes were assessed by four independent observers, three of whom evaluated digital images of the models, while the fourth had no access to the images, and determined the shapes using an algorithm developed from the dimensions of the studied segments. Rates and confidence intervals were determined, and Fleiss' Kappa was calculated to assess the agreement among the evaluators who worked with the images and among all of them. Average incisor length was 10 mm, and widths at CD and EF were 7.35 mm (0.65) and 8.27 mm (0.58), respectively. Regarding shapes, 51.58% (47.90-55.20) of the incisors were identified as square, 18.02% (14.50-21.90) as ovoid and 30.41% (30.00-30.90) as triangular. Fleiss' Kappa agreement was 0.71 (0.62-0.80). The application of the proposed algorithm provided a considerable level of agreement among the observers. Regarding tooth size, both the average segment length and the proportions were similar to those reported by various authors.

RESUMEN El objetivo de este trabajo fue analizar las dimensiones de las coronas clínicas de incisivos centrales superiores, y la prevalencia de cada una de las formas dentarias según diferentes formas de determinación. Se utilizaron modelos de yeso tipo V de 111 estudiantes (93 mujeres y 18 varones) con una media de edad de 23,70 (± 2,26) años. Se definieron los ángulos vestíbulo - mesial y distal para los incisivos centrales superiores derechos (1.1), se definieron los siguientes segmentos: AB (cenit - borde incisal), CD, EF, GH (tercios apical, medio e incisal - ángulos vestíbulo - mesial y vestíbulo- distal) y se determinaron sus longitudes con un calibre de precisión. Se calcularon las proporciones CD/AB, EF/AB y media CDEF/ AB. Las formas de las piezas dentarias fueron identificadas por cuatro observadores independientes, tres lo hicieron mediante la evaluación de imágenes digitales de los modelos confeccionados. El cuarto observador, sin acceso a las imágenes, asignó a cada pieza una de las formas determinadas mediante la aplicación de un algoritmo elaborado ad-hoc. Se obtuvieron tasas e intervalos de confianza y se calculó Kappa de Fleiss para valorar la concordancia entre evaluadores. La longitud promedio fue de 10 mm y el ancho en los segmentos CD y EF fueron de 7.35 mm (0.65) y 8.27 mm (0.58) respectivamente. En cuanto a formas el 51,58% (47.90-55.20) de los incisivos estudiados fueron identificados como cuadrados, el 18.02% (14.50-21.90) como ovoides y el 30,41% (30.00-30.90) triangulares. La concordancia de Kappa de Fleiss fue de 0.71 (0.62-0.80). La aplicación del algoritmo propuesto alcanzó un nivel de concordancia considerable entre los evaluadores. En cuanto al tamaño dentario, tanto la longitud promedio de los segmentos estudiados como las proporciones halladas son similares a las reportadas por diversos autores.

RESUMO

PURPOSE: To evaluate the perception of parents and children and the impact of molar and incisor hypomineralization (MIH) on the oral health-related quality of life (OHRQoL). METHODS: A cross-sectional study was conducted with a group of 253 children aged 6-12 years presenting MIH and their parents or guardians who initially answered an interview containing socioeconomic and demographic questions as well as the Parental-Caregiver's Perceptions Questionnaire (P-CPQ). The children answered the Child Perceptions Questionnaire (CPQ8-10) and Child Perceptions Questionnaire (CPQ11-14) and the clinical evaluation of MIH was performed. Poisson regression with robust variance was used in the data analysis. RESULTS: The parent's perception showed that the impact felt by the children regarding caries leads to a higher oral symptom impact, functional limitation, emotional well-being and total PCPQ score domains, as well. For children with severe MIH, a higher prevalence of impact was felt regarding the functional limitation and emotional well-being. For CPQ8-10, the oral symptoms domain presented the highest mean score, while CPQ11-14 showed the functional limitations domain and P-CPQ the emotional well-being domain. CONCLUSION: Considering the perception of parents or guardians, it was concluded that MIH promotes a negative impact on the OHRQoL. MIH had no significant impact on OHRQoL according to children's perceptions.

Assuntos

RESUMO

INTRODUCTION: This cone-beam computed tomographic (CBCT)-based study evaluated the root canal configurations of mandibular anterior teeth in a large Brazilian population, along with the influence of sex and the frequency of symmetry between the contralateral teeth. METHODS: Overall, 2543 CBCT scans, including those of 4773 lower central incisors (LCIs), 4835 lower lateral incisors (LLIs), and 4805 lower canines (LCs), were analyzed. The scans were obtained from a private radiologic clinic using the PreXion 3D device (Yoshida Dental Mfg Co, Ltd, Tokyo, Japan) with a 0.14-mm voxel size; exposure parameters of 90 kV, 4 mA, and 19 seconds; and a field of view of 80 × 80 mm. Root canal anatomy was analyzed according to the Vertucci classification. Sex influence on the canal distribution and symmetry between the contralateral teeth were analyzed. The data were analyzed statistically and were considered significant when P < .05. RESULTS: All LCIs and LLIs had 1 root, whereas 2.4% of LCs had 2 roots. Two root canals were observed in approximately 20% of LCIs and LLIs and in approximately 11% of LCs. The most common configuration was type I followed by type III. Bilateral symmetry occurred in a majority of the individuals (ie, 91% in LCIs, 87% in LLIs, and 87% in LCs). No sex influence was noted with LLIs and LCs (P > .05). However, LCIs showed a higher prevalence of 2 canals in men (P < .05). CONCLUSIONS: The prevalence of 2 root canals in the mandibular anterior teeth in Brazilians was approximately 20% for central and lateral incisors and 10% for canines.

Assuntos

RESUMO

This study evaluated the internal morphology of lower incisors using computerized microtomography (micro-CT) images. Eighty-nine lower incisors were scanned by micro-CT and reconstructed with NRecon software. 2D parameters (perimeter, root length, circularity and canal diameter) and 3D parameters (volume, surface area and structure model index) were evaluated with CTAn and CTVol software. The results are presented descriptively. It was found that 89.9% of the canals had a single main root canal (type I), followed by type II (6.7%) and III (3.4%), while 5.6% of the specimens presented lateral canals and 1.1% had an apical delta. Mean volume and surface area were 31.80mm³ and 90.58mm², respectively. The most prevalent shape of the root canal at CEJ level was circular (41.6%) and 1mm from the apex, 73% of the samples were classified as oval. Lower incisors with internal anatomical variations may offer a high degree of technical complexity and may result in treatment failure.

Este estudo avaliou a morfologia interna dos dentes incisivos inferiores utilizando imagens de microtomografia computadorizada (micro-TC). 89 incisivos inferiores foram escaneados or micro-CT e reconstruídos com o programa NRecon. Parâmetros 2D - perímetro, comprimento da raiz, circularidade e diâmetro do canal - e parâmetros 3D - volume, área superficial e índice de modelo de estrutura - foram avaliados com os softwares CTAn e CTVol. Os resultados foram apresentados de forma descritiva. 89,9% dos canais apresentaram um único canal radicular principal (tipo I), seguido pelo tipo II (6,7%) e III (3,4%). 5,6% dos espécimes apresentavam canais laterais e 1,1% delta apical. O volume médio e a área de superfície foram 31,80mm³ e 90,58mm², respectivamente. A forma mais prevalente do canal radicular no nível da CEJ foi circular (41,6%) e a 1 mm do ápice, 73% das amostras foram classificadas como ovais. Incisivos inferiores com variações anatômicas internas podem oferecer um alto grau de complexidade técnica e resultar em falha do tratamento.

Assuntos

RESUMO

ABSTRACT This study evaluated the internal morphology of lower incisors using computerized microtomography (microCT) images. Eightynine lower incisors were scanned by microCT and reconstructed with NRecon software. 2D parameters (perimeter, root length, circularity and canal diameter) and 3D parameters (volume, surface area and structure model index) were evaluated with CTAn and CTVol software. The results are presented descriptively. It was found that 89.9% of the canals had a single main root canal (type I), followed by type II (6.7%) and III (3.4%), while 5.6% of the specimens presented lateral canals and 1.1% had an apical delta. Mean volume and surface area were 31.80mm³ and 90.58mm², respectively. The most prevalent shape of the root canal at CEJ level was circular (41.6%) and 1mm from the apex, 73% of the samples were classified as oval. Lower incisors with internal anatomical variations may offer a high degree of technical complexity and may result in treatment failure.

RESUMO Este estudo avaliou a morfologia interna dos dentes incisivos inferiores utilizando imagens de microtomografia computado rizada (microTC). 89 incisivos inferiores foram escaneados por microCT e reconstruídos com o programa NRecon. Parâmetros 2D perímetro, comprimento da raiz, circularidade e diâmetro do canal e parâmetros 3D volume, área superficial e índice de modelo de estrutura foram avaliados com os softwares CTAn e CTVol. Os resultados foram apresentados de forma descritiva. 89,9% dos canais apresentaram um único canal radicular principal (tipo I), seguido pelo tipo II (6,7%) e III (3,4%). 5,6% dos espécimes apresentavam canais laterais e 1,1% delta apical. O volume médio e a área de superfície foram 31,80mm³ e 90,58mm², respectivamente. A forma mais prevalente do canal radicular no nível da CEJ foi circular (41,6%) e a 1 mm do ápice, 73% das amostras foram classificadas como ovais. Incisivos inferiores com variações anatômicas internas podem oferecer um alto grau de complexidade técnica e resultar em falha do tratamento.

Assuntos

RESUMO

This cross-sectional survey was carried out to ascertain the prevalence of fractured incisors in 11-12-year-olds. In addition we explored the relationship with overjet, incompetent lips, incisor inclination and to determine if there was any association with ethnicity and gender. All permanent incisors were examined in 672 children comprising 356 females (53.1%) and 315 males (46.9%). The sample comprised 11-12-year-olds in high schools across Trinidad and Tobago. Statistical analysis was undertaken using Chi-square test, independent t-test, and binary logistic regression. The prevalence of fractured incisors was 18.9%. Boys presented with an increased incidence of fractured incisors than girls. 86.3% of dental trauma was untreated. The average overjet of subjects with fractured incisors was 4.2 mm. 18.62% of subjects with fractured incisors had incompetent lips. The most common malocclusion (18.81%) with fractured incisors was class 2 division 1. The Afro-Trinidadian ethnicity had the highest prevalence of fractured incisors (11.0%) when compared to mixed ethnicities, which was statistically significant. Maxillary central incisors were the most commonly injured teeth. Most patients delayed in seeking dental treatment for fractured incisors in our population. Early orthodontic treatment is recommended to help reduce the risk of dental trauma.

RESUMO

Objective: To evaluate the influence of mandibular third molars on relapse of mandibular anterior crowding in orthodontically treated patients.Material and Methods: Sample included orthodontic records of 108 patients: Group 1: 72 patients (39 female; 33 male) with third molars present in the postretention evaluation stage. Group 2: 36 patients (18 female; 18 male) who did not present the third molars in the postretention evaluation stage. Panoramic radiographs and dental models were evaluated at three different stages: pre-treatment; posttreatment and postretention. Panoramic radiographs showed the presence or absence of third molars in the 3 evaluated stages and on the dental models, overbite and mandibular anterior crowding was measured by the Little Irregularity Index. For intergroup comparisons, t-tests and a multifactorial regression analysis were used.Results: There was no statistically significant difference in the relapse of mandibular anterior crowding among the groups with and without mandibular third molars at the postretention stage.Conclusion: The presence or absence of mandibular third molars did not influence the relapse of mandibular anterior crowding in orthodontically treated patients.

Assuntos

RESUMO

Leveling the curve of Spee is a commonly-used strategy to correct deep bites. Although several techniques have been proposed to intrude mandibular incisors (MI), flaring of these teeth is often observed and in many instances undesired. A three-dimensional (3D) finite element model (FEM) was used to locate the ideal point of force application (PFA) to achieve pure MI intrusion with the three-piece arches' technique. It comprised (1) a 0.021 × 0.025 in. stainless steel (SS) wire that passively filled the slots of the canine and premolar brackets and the first and second molar tubes, bilaterally; (2) a 0.0215 × 0.0275 in. SS intrusion base arch (IBA) inserted into the MI brackets, that presented a step down distal to the lateral incisors brackets and a posterior extension arm; (3) titanium-molybdenum tip-back springs designed to apply the intrusion force, fitted inside the first molar gingival tube. Four PFA on the IBA were simulated (FEM 1, 2, 3, and 4). FEM 3 resulted in pure MI and was considered the ideal PFA. FEM1 and 2 showed intrusion and buccal crown flaring of the MI, whereas FEM4 resulted in intrusion and lingual crown flaring of those teeth. Clinicians may consider three-piece arch mechanics to achieve pure MI intrusion. However, they must be aware that when force was applied anteriorly or posteriorly to the ideal PFA, the incisors would incline labially or lingually, respectively.

RESUMO

The aim of this study was to evaluate the influence of different anterior load type and restorative procedure on stress distribution of maxillary incisors with different noncarious cervical lesions (NCCLs) morphologies. Three-dimensional models of a maxillary incisor were generated. Beyond the sound model (SO), five NCCLs morphologies were simulated: shallow (SH), notched (NO), concave (CO), wedge-haped (WS) and irregular with dual center (IR' and IR"). Composite resin restoration of all the models was simulated (R). Two different anterior loads were applied: 100N on palatine middle third (ML) and 500 N on palatine incisal third (IL). The data were obtained in MPa using the Maximum Principal Stress and Von Mises criteria and the statistical analysis was performed (paired t-test with 95% confidence level). The IL provided higher compressive stress than ML, mainly on WS (-136.3MPa), IR" (-117.5) and NO (-71.1 MPa). The highest tensile stress found within the restored models was on NOR with IL (19,1 MPa). The Von Mises results showed higher stress concentration on non-restored and IL models (p<0.001). The anterior load type and restorative status were determinant factors on stress distribution pattern changes, whereas NCCLs morphologies had little influence in maxillary incisors.

O objetivo deste estudo foi avaliar a influência de diferentes tipos de contatos anteriores e procedimentos restauradores na distribuição de tensões de incisivos superiores com diferentes morfologias de lesões cervicais não-cariosas (NCCLs). Modelos tridimensionais de um incisivo central superior foram gerados. Além do modelo hígido (SO), foram simuladas cinco morfologias de NCCLs: rasas (SH), entalhadas (NO), côncavas (CO), em forma de cunha (WS) e irregulares com centro duplo (IR' e IR''). Restauração com resina composta em todos os modelos foi simulada (R). Dois contatos anteriores diferentes foram aplicadas: 100N no terço médio palatino (ML) e 500N no terço incisal palatino (IL). Os dados foram obtidos em MPa utilizando os critérios de Tensão Máxima Principal e de Von Mises e a análise estatística foi realizada (teste t pareado com nível de significância de 95%). A IL proporcionou maior estresse compressivo que ML, principalmente em WS (-136,3MPa), IR "(-117,5) e NO (-71,1 MPa). A maior tensão de tração encontrada nos modelos restaurados foi na NOR com IL (19,1 MPa). Os resultados de Von Mises mostraram maior concentração de estresse nos modelos não restaurados e IL (p <0,001). O tipo de contato anterior e a presença de restauração foram fatores determinantes nas alterações do padrão de distribuição de estresse, enquanto as morfologias dos NCCLs tiveram pouca influência nos incisivos superiores.

Assuntos

RESUMO

A melhor maneira de se reproduzir um dente é mostrar as características anatômicas por todos os ângulos de observação. É muito importante saber reproduzir, expressar, fazer e entender a morfologia dental. Não existe um dente igual ao outro (mesmo nas mesmas classes dentais) e é preciso que um dente seja ideal de acordo com a cavidade bucal, com os lábios e a face. Existem várias técnicas e maneiras para se expressar isso. Para se ter essa "técnica" é preciso dedicação. A repetição do fazer aliado ao conhecimento teórico levam à reprodução da morfologia dental natural. Quando tudo isso se harmoniza na cavidade bucal, a reparação estética torna-se equilibrada, coesiva e funcional. Em outras palavras, para reproduzir o formato natural de um dente verdadeiro, é importante ou essencial o conhecimento da anatomia, da função e da integração dessas ao sorriso do paciente. Para que a reprodução chegue à perfeição, são necessários o treinamento assíduo e o estudo orientado. A anatomia dental envolve traçados que precisam ser desmistificados e outros que necessitam ser calculados e o estudo das faces de um dente determina um aprimoramento do conhecimento necessário à construção de trabalhos protéticos.

The best way to reproduce a tooth is to show the anatomical characteristics from all observation angles. It is very important to know how to reproduce, present, make and understand dental morphology. There are no equal teeth (even in the same dental classes) and it is necessary for a tooth to be ideal according to oral cavity, lips and face. There are several techniques and ways to express it. In order to have such "technique" it is necessary a great effort. Constant practice and technical knowledge takes to natural dental morphology reproduction. When all this is coordinated in the oral cavity, aesthetic repair becomes balanced, cohesive and functional. In other words, to reproduce the natural shape of a real tooth, it is important or essential anatomy and function knowledge, and the integration of these to the patient smile. For reproduction to come to perfection, frequent training and guided study are required. Dental anatomy involves tracings that have to be demystified and others that must be calculated and tooth faces study determines necessary knowledge improvement for the construction of prosthetic work

Assuntos