A Cone-beam Computed Tomogrphy Study Of Mesiobuccal Root Canal Morphology Of Maxillary Second Permanent Molars

Pulp diseases and periapical diseases are the most common disease instomatological clinical. They have high incidence rate and outpatient rate.Pulp and periapical disease is the main cause of oral pain, which couldcause intense pain during the acute inflammation period. It brings greatsuffering to patient’s physical and mental. Root canal therapy is the bestprocess for pulp diseases and periapical disease. The focus of root canaltherapy is thorough canal debridement and effective filling of the entireroot canal system. The complex root canal system is composed of rootcanal、 intercanal anastomoses、 lateral branch of root canal、 apicalramification、apical furcation and accessory root canal. Owning an intimateknowledge of morphology of the root canals is the key to the success ofroot canal therapy.Root canal system exist in the dentine，complicated and influenced byrace, region, individuals, and many other factors. We have explored it formany years, but failed to fully grasp on it so far. There are varied methods, but each has advantages and disadvantages.Cone beam computed tomography (CBCT) is a new technologydeveloped in the last century. Compared with traditional CT, it has a lowerdose, shorter scanning time, higher image quality, etc. And it offersexcellent imaging capabilities with the bone of maxillofacial region. Inrecent years, we accumulated a large number of maxillofacial CBCTimaging data. At the same time, we accumulated a large number of CBCTimaging data of dentition. CBCT could analyze in quantity and positioning.It has become a new popular method in canal morphology research.ObjectiveTo evaluate the root canal morphology of mesiobuccal root canal ofmaxillary second permanent molars by using cone beam computedtomography.Methods551cases of CBCT data were collected, the gender、age、tooth positionof the sample, and the number and morphology including the curvatureposition, curvature direction and curvature angle of the mesiobuccal rootcanals were recorded. The Vertucci’s classification was used to record theroot canal configurations of mesiobuccal root canal.Results1The incidence rate of second mesiobuccal canal（MB2）of themaxillary second permanent molars is25.41%in the551cases. The incidence rate of male is30.68%; the incidence rate of female is20.56%.The rate is higher in men than in women. The incidence rate of theleft side is27.94%; the incidence rate of the right side is22.94%.There isno statistical differences between the incidence rate of MB2and the age.The incidence rate of MB2is not associated with age. When the MB2waspresent, the main configurations of mesiobuccal root was type Ⅱ(2-1) andtype Ⅳ (2-2).2The mesiobuccal root canal in the maxillary second molar mostlycurved to distal and palatal. And the curved root canal accounted for87.54%, moderate curved canal accounted for39.00%, severe curved canalaccounted for19.28%,and57.57%of curvatures were occurred in themiddle1/3root region.ConclusionThe incidence rate of MB2in the maxillary second molar is high. Thenumber of the moderate and severe curved root canal is large. It is difficultto complete the root canal therapy. The morphology of the root canal couldbe shown by CBCT in all levels. It is an advanced method in oral clinicalradiological examination, and it is also a good tool to analyze themorphology of root canal.