Assessment of Mesial Canals Morphology of Mandibular First Molars Using CBCT: An In-vitro Study / Avaliação da morfologia dos canais mesiais dos primeiros molares inferiores usando TCCB: um estudo in vitro

Objective: The current study aimed to investigate the relationship between canal configuration, distance between mesiobuccal (MB) and mesiolingual (ML) orifices and the degree of canals curvature in the mesial root of permanent mandibular first molars in a sample of Sudanese population using cone-beam computed tomography (CBCT). Material and Methods: A total of 143 extracted mandibular first molars were processed and scanned with CBCT to determine the configuration of the mesial root canals according to the Vertucci classification. The interorificial distance and the degree of canal curvature in clinical (CV) and proximal (PV) views using Schneider technique were assessed. Results: The commonest canal configuration was type IV (53.1%). The interorificial distance was significantly shorter in type VI compared to other types (P < 0.05). Significant association was found for type IV between the MB and ML canal in the primary curvature regarding CV and PV, and for type II regarding PV in primary and secondary curvature (P < 0.05). In type IV the degree of secondary curvature of MB canal regarding PV, and in the ML canal in CV was significantly lower compared to other types (P < 0.05). Significant correlation was seen in PV of primary curvature in the MB for type VI (P < 0.05). Conclusion: The interorificial distance and secondary curvatures in CV for MB canal were found to be key factors for predicting root canal patterns in PV (AU)

Objetivo: O presente estudo teve como objetivo investigar a relação entre a configuração do canal, a distância entre os orifícios de entrada dos canais mesiovestibular (MB) e mesiolingual (ML) e o grau de curvatura dos canais na raiz mesial dos primeiros molares inferiores permanentes em uma amostra da população sudanesa usando tomografia computadorizada cone-beam(TCCB). Material and Methods: Um total de 143 primeiros molares inferiores extraídos foram processados e escaneados com TCCB para determinar a configuração dos canais radiculares mesiais de acordo com a classificação de Vertucci. A distância inter orificios e o grau de curvatura do canal nas vistas clínica (CV) (acredito que a tradução seja essa mesma, seria como uma foto intra oral clínica/perguntei a um endodontista, mas não soube me responder) e proximal (PV) usando a técnica de Schneider foram avaliados. Resultado: A configuração mais comum do canal foi do tipo IV (53,1%). A distância inter-orificios foi significativamente menor no tipo VI em comparação com outros tipos (P <0,05). Correlação significativa foi observada na PV da curvatura primária no MB para o tipo VI (P <0,05). Conclusão: A distância inter orifícios e as curvaturas secundárias na CV para o canal MB foram consideradas fatores-chave na predição dos padrões do canal radicular na PV (AU)

Сross-sectional anatomic study of direct positional relationships between mandibular canal and roots of posterior teeth using cone beam computed tomography

Objectives: to establish the frequency of the various types of direct contacts of the root apices with the wall of the mandibular canal and to determine gender differences in number of such contacts in a selected belarusian population using cone beam computed tomography. methodology: one hundred and two cone beam computed tomography scans were analyzed to classify the types of contact and three-dimensional relationship between the mandibular teeth and the mandibular canal. results: the direct contact between the teeth and the mandibular canal was observed in 63.7 percent of patients. overall 300 roots of 189 teeth were in direct contact with the mandibular canal: 9.3 percent were second premolars, 14.7 percent were first molars, 33.8 percent were second molars and 50.0 percent were third molars. there were no statistically significant differences in the number of teeth with direct contact with the mandibular canal between males and females. conclusion: the direct contact of the root apices with the mandibular canal was most often found in the second and third molars. the root apices of the third molars had the greatest variability of location relatively to the mandibular canal.

Research progress on the middle mesial root canal in the mandibular molar / 口腔疾病防治

@#Of the various root canal morphologies in mandibular molars, the middle mesial root canal is located between the mesiobuccal root canal and the mesiolingual root canal. The middle mesial root canal is a partial or completely independent extra root canal. Because of its fine structure, concealment and even calcification of the root canal orifice, it is difficult to completely clean and fill this root canal and it is easily omitted by dentists. The current study reviewed recent progress in terms of the incidence rate, classification, influencing factors, and exploration and preparation techniques of the middle mesial root canal of the human mandibular molar to provide a reference for clinical diagnoses and treatment.

Biomechanical analysis of distalization of mandibular molars by placing a mini-plate: A finite element study / 대한치과교정학회지

OBJECTIVE: The objective of this study was to analyze the patterns of tooth movements when distalization of mandibular molars using a mini-plate took place. A finite element analysis was applied to analyze patterns of tooth movements. METHODS: The model of the mandible and teeth were used to build a finite element analysis model, and a mini-plate was inserted in the mandibular ramus. Two different orthodontic forces were established for displacement of mandibular molars. Orthodontic forces were applied at the level of the bracket and at the level of the cemento-enamel junction in the mandibular canine respectively. RESULTS: orthodontic forces at the level of the cemento-enamel junction resulted in a greater biomechanical bodily movement in distalization of the mandibular molars compared to when the orthodontic forces were applied at the level of the bracket. Applying orthodontic forces to the cemento-enamel junction also resulted in unwanted greater extrusive movements in distalization of the mandibular molars compared to the bracket level. CONCLUSIONS: With considering the mode of orthodontic teeth movement, applying different vertical orthodontic forces for distalization of mandibular molars can lead to more effective distalization of teeth.

RADIX ENTOMOLARIS – A Case Series Of Endodontic Management Of A Rare Anatomic Variation In Mandibular Molars.

Radix Entomolarisis the presence of a distolingual supernumerary root found in the first, second, and third mandibular molars .The prevalence of three-rooted mandibular first molars appears to be less than 5% in Eurasian and Asian populations. This case series describes successful endodontic management of a series of seven cases of Radix Entomolaris

An evaluation of canal curvature at the apical one third in type II mesial canals of mandibular molars

OBJECTIVES: The purpose of this study was to evaluate the buccolingual curvature at the apical one third in type II mesial canals of mandibular molars using the radius and angle of curvature. MATERIALS AND METHODS: Total 100 mandibular molars were selected. Following an endodontic access in the teeth, their distal roots were removed. #15 H- or K-files (Dentsply Maillefer) were inserted into the mesiobuccal and mesiolingual canals of the teeth. Radiographs of the teeth were taken for the proximal view. Among them, type II canals were selected and divided into two subgroups, IIa and IIb. In type IIa, two separate canals merged into one canal before reaching the apex and in type IIb, two separate canals merged into one canal within the apical foramen. The radius and angle of curvature of specimens were examined. RESULTS: In type II, mean radius of curvature in mesiolingual and mesiobuccal canals were 2.82 mm and 3.58 mm, respectively. The radius of the curvature of mesiolingual canals were significantly smaller than that of mesiobuccal canals in type II, and especially in type IIa. However, there were no statistically significant differences in radius of curvature between mesiobuccal and mesiolingual canals in type IIb and there were no significant differences in angle of curvature between type IIa and IIb. CONCLUSION: In this study, type II mesial canals of mandibular molars showed severe curvature in the proximal view. Especially, mesiolingual canals of type IIa had more abrupt curvature than mesiobuccal canals at the apical one third.

Avaliação do desgaste da zona de perigo de molares inferiores utilizando o sistema rotatório ProTaper / Evaluation of the flaring in mandibular molars danger zone using ProTaper rotatory system

O objetivo deste estudo foi avaliar in vitro o desgaste da zona de perigo em molares inferiores, após utilização do sistema de instrumentação rotatória ProTaper. Foram utilizadas 60 raízes mesiais de molares inferiores, as quais foram divididas em 4 grupos experimentais. Um grupo foi mantido como controle e os demais foram respectivamente instrumentados com as limas SX; SX e S1; SX, S1 e S2. Os resultados foram submetidos à análise estatística, demonstrando uma diferença significante no nível de 1% entre os grupos experimentais, com um aumento do desgaste da zona de perigo diretamente proporcional ao aumento do diâmetro dos instrumentos ProTaper. Conclui-se que por não ter acontecido nenhum caso de perfuração radicular a segurança desses instrumentos no preparo de molares inferiores foi demonstrada

The aim of this study was to evaluate in vitro the flaring in mandibular molars danger zone, after root canal instrumentation with the ProTaper rotatory instrument system. Sixty extracted mandibular molars with fully formed apices had the mesial roots sectioned. The specimens were divided into four groups and instrumented until Shaping X, Shaping 1 and Shaping 2 files,respectively. One group was kept as control with no instrumentation. The results submitted to statistical analysis, showed a 1% significant difference among experimental groups, with an enlargement of the flaring in danger zone being directly proportional to the diameter of ProTaper instruments. Itis concluded that the use of this instruments on the preparation of mandibular molars is safe because there isnt any report of root perforation.