title: Survey of Anatomy and Root Canal Morphology of Maxillary First Molars Regarding Age and Gender in an Iranian Population Using Cone-Beam Computed Tomography.
abstract: BACKGROUND
  The purpose of this study was to investigate the root and canal morphology of maxillary first molars with regards to patients' age and gender with cone-beam computed tomography (CBCT).
  
  
  METHODS
  A total of 149 CBCT scans from 92 (67.1%) female and 57 (31.3%) male patients with mean age of 40.5 years were evaluated. Tooth length, presence of root fusion, number of the roots and canals, canal types based on Vertucci's classification, deviation of root and apical foramen in coronal and sagittal planes and the correlation of all items with gender and age were recorded. The Mann Whitney U, Kruskal Wallis and Fisher's exact tests were used to analyze these items.
  
  
  RESULTS
  The rate of root fusion was 1.3%. Multiple canals were present in the following frequencies: four canals 78.5%, five canals 11.4% and three canals 10.1%. Additional canal was detected in 86.6% of mesiobuccal roots in which Vertucci's typeVIconfiguration was the most prevalent followed by typeIIandI. TypeIwas the most common one in distobuccal and palatal roots. There was no statistically significant difference in the canal configurations in relation to gender and age as well as the incidence root or canal numbers (P>0.05). The mean tooth length was 19.3 and 20.3 mm in female and male patients, respectively which was statistically significant (P<0.05). Evaluation of root deviation showed that most commonly, a general pattern of straight-distal in the mesiobuccal and straight-straight for distobuccal and palatal roots occurred. In mesiobuccal roots, straight and distal deviations were more dominant in male and female, respectively (P<0.05). The prevalence of apical foramen deviation in mesiobuccal and palatal roots statistically differed with gender.
  
  
  CONCLUSIONS
  The root and canal configuration of Iranian population showed different features from those of other populations.
authors: Department of Endodontics, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Mandana
authors: M
authors: Naseri
authors: Oral and Maxillofacial Radiology Department, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Yaser
authors: Y
authors: Safi
authors: Proteomics Research Center, Department of Basic Sciences, Rehabilitation School, , Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Alireza
authors: A
authors: Akbarzadeh Baghban
authors: Division of Endodontics, Department of Oral Biological and Medical Sciences, Dental School, University of British Columbia, Canada.
authors: Akbar
authors: A
authors: Khayat
authors: Students Research Office, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Leila
authors: L
authors: Eftekhar
keywords: Age; Cone-Beam Computed Tomography; Gender; Maxillary Molar; Root Canal Morphology; Tooth Anatomy