Imaging Study Of Pulp Cavity And Root Canal Morphology Of Mandibular First Mammary Molar

Objective Conical beam computed tomography(CBCT)was used to analyze the priority exposure of the proximal and distal medullary angles,the number and distribution of root canals,the height of the medullary cavity and the thickness of the pulp chamber floor of children’s mandibular first molars.CBCT was used to analyze the anatomical rules of the pulp cavity and root morphology of the mandibular first deciduous molar,providing anatomical basis for clinical treatment and data for the laboratory study of the anatomical morphology of the pulp cavity and root canal system of deciduous molar.Methods Collected in the Inner Mongolia medical university affiliated hospital dental image center,a total of 181 children aged 4 to 8,a total of 362 of mandibular first milk molars of CBCT imaging data,collect the basic information of children,using Invivo5 software for mandibular first molar CBCT images 3 d reconstruction and medullary Angle observation measurement nearly far preferred exposure,root number and distribution of root canal,the height of the medullary cavity and the thickness of the bottom of the pulp chamber,etc.,will collect the raw data into Excel form to establish database,the data integration analysis.SPSS20.0 software was used for data statistics.Chi-square test was used for counting data,and t test was used for measuring data.P < 0.05 was considered to have a significant difference,and the difference was statistically significant.Results 1.A total of 181 children were included in this study,including 113 males and 68 females.There were a total of 362 cases of mandibular first molars,including 181 left and 181 right mandibular first molars.2.Preferential exposure to the proximal and distal middle pulp Angle: Among362 mandibular first molars in this study,199(54.9%)had the proximal middle pulp Angle preferred exposure;The distal medial medullary angles were exposed preferentially in 2(0.5%),and the proximal,proximal and distal medial medullary angles were exposed simultaneously in 161(44.4%).3.Number and distribution of roots and canals: Six root canal shapes were observed in 362 mandibular first molars: 1111(34.2%),1112(15.1%),1122(0.5%),1211(27.9%),1212(19.3%)and 1222(2.7%).Type 1111 was the most common type,accounting for 34.2%,followed by type 1211,accounting for 27.9%.The morphology of mandibular first molars was 34.2% with double canals,43.5% with three canals,and 22.0% with four canals.4.The pulp cavity height and pulp chamber floor thickness of mandibular first molars: In 362 mandibular first molars,the H value of pulp cavity height(?)was1.12±0.44 mm,and the T value of pulp chamber floor thickness(?)was1.72±0.30 mm.In male children(226 mandibular first molars),the height H(?)of the medullary cavity was 1.16±0.47 mm.The H value(?)of the medullary cavity height in female and children(136 mandibular first molars)was 1.05±0.39 mm.5.In this study,a total of 181 children and 362 mandibular first molars had no correlation between the priority exposure of proximal and distal medullary angles,the number and distribution of root canals,the height of the medullary cavity and the thickness of the pulp floor(P > 0.05)and the comparison on the left and right sides(P<0.05).6.A total of 181 children were included in this study,and a total of 362 mandibular first mammary molars had no correlation with gender(P > 0.05)in terms of priority exposure to proximal and distal medullary angles,the number and distribution of root canals,and the thickness of pulp chamber floor.The height of medullary cavity was correlated with gender,and the difference was statistically significant(P < 0.05).Conclusions 1.In children’s first mandibular molars,the proximal mesedullary Angle was more frequently exposed to the distal mesedullary Angle.2.The proximal and middle roots of the mandibular first deciduous molars are all single roots,in which there may be single or double canals,while in the distal roots there may be single,single or double canals.The results of this study suggest that the root canal should be carefully explored and searched in the course of clinical treatment to avoid root canal omissions.3.The pulp chamber floor thickness of the mandibular first molar is greater than the height of the pulp cavity,and the height of the pulp cavity is correlated with gender.