Prevalence of Middle Mesial Canal Based on Clinical and Radiological Evaluation in Permanent Mandibular First Molar: A Clinical and Cone-beam Computed Tomography Analysis

Background: The success of endodontic therapy depends on the complete debridement of the entire root canal system. Manystudies have investigated the morphology of mandibular molar, but the prevalence of the middle mesial canal in the mesialroot of the mandibular first molar is still the subject of controversy. Missed canal and consequently inadequate debridement ofthe root canal system can eventually lead to failure of therapy. Hence, it is imperative to meticulously look for extra canals toensure successful treatment.Materials and Methods: In this in vivo study, 100 patients who reported for root canal treatment were included in the study.Patients’ age and sex were recorded. After access cavity preparation, a standardized technique is performed between themesiobuccal canal and mesiolingual canal to search for a middle mesial canal using a dental operating microscope and confirmedradiologically by taking cone-beam computed tomographic image and results were analyzed.Results: In our study, out of 100 patients included that 50 patients were male and 50 patients were female. Based on gender,the prevalence of middle mesial canal in tooth number 36 and 46 is 18% (9 patients) and 19% (10 patients); for females andmales, it is 20% (10 patients) and 22% (11 patients). Based on age group, the prevalence of middle mesial canal in tooth number36 and 46 between the age of 15 and 30 is 23% (13 patients) and 24% (15 patients), between the age of 31 and 60 is 20%(5 patients) and 22% (6 patients), and age above 60 is 14% (1 patient) and 16% (2 patients), respectively.Conclusion: From this study, we concluded that the prevalence of the middle mesial canal in the permanent mandibular firstmolar can be as high as 24%, with the prevalence being higher in males than females and the age group between 15 and30 years had the highest prevalence.

Detectability of middle mesial canal in mandibular molar after troughing using ultrasonics and magnification: an ex vivo study

Abstract The aim of this study was to evaluate the frequency of the identification of middle mesial (MM) canals in extracted permanent first and second mandibular molars before and after executing a troughing technique with high magnification. Sample consisted of 105 mandibular molars. After gaining access to the pulp chamber and cleaning the chamber floor, root canals were detected in three different stages. The initial location was performed under direct viewing without magnification. In the second stage, a dental operating microscope was employed at 12 magnification. If the MM canal was not observed, a standardized troughing technique was executed with the use of an ultrasonic tip between the mesiobuccal and mesiolingual canals under magnification. Statistical differences in the frequency of MM canals before and after troughing were determined using McNemar's test, with the significance level set at 5%. No significant increase in the identification of the MM canal was found when comparing observations before (9.52%) and after (12.38%) the troughing technique under high magnification. However, viewing under magnification and the execution of troughing significantly increased the location of the MM canal (12.38%) when compared to viewing without magnification (3.81%) (p<0.01). The troughing technique with the aid of a dental operating microscope significantly improved the identification of MM canals compared to viewing without magnification. Troughing is a safe, minimally invasive procedure that benefits the treatment of mandibular molars.

Resumo O objetivo deste estudo foi avaliar a frequência de identificação do canal médio-mesial (MM) antes e após a execução da técnica de troughing sob ampliação microscópica em primeiros e segundos molares inferiores permanentes extraídos. A amostra foi composta por 105 molares inferiores. Após abertura coronária e limpeza do assoalho pulpar, os canais radiculares foram detectados em três etapas diferentes. A localização inicial foi realizada sob visão direta, sem ampliação microscópica. Na segunda visualização, foi empregado um microscópio óptico com um aumento de ´12. Se o canal MM não foi observado, uma técnica padronizada de troughing foi realizada com o uso de pontas ultrassônicas entre os canais mésio-vestibular e mésio-lingual sob ampliação microscópica. Diferenças estatísticas na frequência dos canais MM antes e após o troughing foram determinadas usando o teste de McNemar, com um nível de significância de 5%. Não houve um aumento estatisticamente significativo na identificação do canal MM quando comparadas as visualizações antes (9,52%) e depois (12,38%) da técnica do troughing utilizando o microscópio óptico. Porém, a visualização com microscópio e a execução do troughing aumentaram significativamente a localização do canal MM (12,38%) quando comparada à visão prévia sem aumento (3,81%) (p<0,01). A técnica do troughing com o auxílio do microscópio óptico aumentou significativamente a identificação do canal MM quando comparada à visualização sem magnificação. Troughing é um técnica segura, minimamente invasiva e traz benefícios ao tratamento de molares inferiores.

CBCT detection of the incidence of middle mesial canal and isthmus in the mandibular first molar / 口腔疾病防治

Objective @# To analyze the morphology and incidence of middle mesial canal (MM) and isthmus in the mandibular first permanent molar by cone-beam computed tomography (CBCT).@*Methods@# Statistical analysis was performed on images from patients who underwent CBCT examination in the Department of Radiology at Stomatological Hospital, Southern Medical University. Samples exhibiting root canal treatment, root resorption and calcification were excluded. Data regarding sex, age, the presence or absence of isthmus and MM, and the number of roots and root canals were recorded.@*Results @#Of the 217 mandibular first molar samples, 8 (3.7%) had an MM, and 2 (0.9%) had an independent apical foramen. The overall incidence rate of isthmus was 57.1%; this rate was 50.7% in the cervical third of the root canal, 17.5% in the middle third, and 13.4% in the apical third. The incidence rate of isthmus was 61.8% on the left side, 52.3% on the right side, 58.7% in males, and 55.8% in females. No significant difference was found between the left and right sides or between females and males (P > 0.05). The incidence rate of isthmus in people under 60 was greater than 50% but was significantly lower in people older than 60.@*Conclusion@#Only a very small proportion of MMs have an independent apical foramen in the mandibular first molar. The incidence of isthmus in the mesial root of the mandibular first permanent molar is high, and isthmus usually occurs in the cervical third of the root canal. During root canal treatment or apical surgery, attention should be given to the physical and chemical preparation of the isthmus.

Re-Treatment of A Mandibular First Molar With An Independent Middle Mesial Canal- A Case Report.

With increasing reports of aberrant canal morphology, the clinician needs to be aware of varied anatomy in teeth. The purpose of this article is to report the successful non surgical endodontic re-treatment of one such clinical case of mandibular first molar with three mesial canals in which the middle mesial canal had an independent foramen.

Diagnosis And Treatment of Mandibular First Molar With Three Mesial Root Canals - A Case Report.

The knowledge of the internal anatomy of root canals is very important for the success of endodontic treatment. Variations in dental anatomy are found in all teeth. Lack of knowledge of anatomic variations and their characteristics in different teeth has been one of the main causes of endodontic therapy failure. This case report describes the endodontic treatment of a mandibular first molar with five root canals, its incidence of occurrence and discusses the importance of their identification and treatment.