Assessment Of Root Canal Morphology Of The Mandibular First Premolars In Chinese Population Using Cone Beam Computed Tomography(CBCT)

Root canal therapy is the most effective treatment technique for pulp and periapical disease.Successful root canal therapy depends on a thorough understanding of the root morphology and internal anatomy of the root canal system in order to thoroughly clean,prepare and fill the root canal.In the 1990s,CBCT(cone-beam computed tomography)was gradually applied to clinical practice,so that clinicians have a more comprehensive understanding of the root canal morphology.In particular,the mandibular first premolar root and root canal anatomy system is complex and varied,a considerable proportion of which is the C shaped root canal.In this study,CBCT was used to analyze the anatomical structure of mandibular first premolars,with a view to providing some reference for clinical root canal therapy.Objective:The aim of this study was to evaluate the root canal morphology of the mandibular first premolars in Chinese population by use of cone beam computed tomography(CBCT).Materials and Methods:In present study,3953 CBCT images of mandibular first premolars were obtained from 2038 patients.We recorded the data of gender,age,teeth position,and the number of roots and canals.Root canal configuration was also evaluated according to the Vertucci's classification and the Fan's categorization in C-shaped canal configurations.Results:Most mandibular first premolars had a single root and one canal.Overall,Type ?,which indicated one root canal,was the most prevalent(77.92%),and The C-shaped canal configuration was observed in 14.12%of cases followed by Type V(5.06%),Type ?(1.8%),Type ?(0.51%),Type X(0.46%),Type ?(0.08%),Type VII(0.05%)and Type VI(0.03%).There was no significant difference in the number of canals and root canal configurations between left and right side(P>0.05).The incidence of C-shaped canal and Type ? were significantly different between females and males and among different ages(P<0.05),The incidence of type I root canal was higher in females than in males and The incidence of type C root canal was higher in males than in females.The incidence of type I root canal incidence was higher in the 50 years old than in ?20,21-30,31-40 or 41-50 age group,on the contrary,the incidence of type C root canal was lower than that in ?20,21-30 or 41-50 age group,and there was no significant difference between other age groups.Conclusions:The mandibular first premolars showed variable and complex canal morphology in Chinese population.We need to pay attention to the high incidence of C-shaped root canal in mandibular first premolars.