Evaluating the potential key factors in assessing the morphology of mesiobuccal canal in maxillary first and second molars.

The purpose of this study was to provide further information on the morphology of the root canals and pulp chambers of 100 maxillary first and 100 maxillary second molars, with particular reference to the anatomical relationship of the root canal patterns and the distance between mesiobuccal (MB) and mesiolingual (ML) orifices. Each transverse section was digitally imaged to measure the interorificial distance using a stereomicroscope. The angles of primary curvatures were determined in both buccolingual (clinic view, CV) and mesiodistal (proximal view, PV) directions and the canal configuration of the MB root was classified according to the Weine classification. The rhomboidal pulp chamber floor morphology predominated in each tooth type. The mean interorificial distance in both maxillary first and second molars was significantly shorter in type II compared with type III (P < 0.05). The interorificial distance was correlated with the primary curvature of MB canal in PV in maxillary first molars (P < 0.05), whereas the primary curvature of ML canal in CV was correlated with the primary curvature of ML canal in PV in maxillary second molars (P < 0.01). The evaluation of interorificial distance in both types of maxillary molars and the curvature of ML canal in CV in maxillary second molar can give valuable information to the clinician.