title: Comparison of digital panoramic radiography versus cone beam computerized tomography for measuring alveolar bone.
abstract: BACKGROUND
  Cone beam computerized tomography (CBCT) has been widely used in dental implanting. However, the local hospitals usually don't have access to CBCT due to the cost and medical investment, especially in West of China. The doctors in local hospitals have to make reasonable dental planting using orthopantomography (OPG) to reduce risks. Therefore, it is clinically meaningful to determine the magnification rate of OPG to obtain correct diagnosis. This study investigated the magnification rate of OPG in measuring different maxillofacial loci compared with CBCT.
  
  
  METHODS
  Eighty-six patients demanding dental implanting were scanned by CBCT and OPG. The vertical distance between the alveolar ridge crest of the maxillary first molar and the sinus bottom of the upper jaw, the distance between the alveolar ridge crest of the mandibular first molars and the top of nerviduct in the mandibular alveolar, and the distance between the alveolar ridge crest of the maxillary central incisors and the bottoms of the nasal cavities were measured. The horizontal distance in those loci were also measured. The distances derived from CBCT were used as reference. The distances between the two methods were compared using paired t-test. The magnification rates at these positions were calculated. The relationship between the data acquired from the two methods was analyzed Pearson correlation.
  
  
  RESULTS
  The correlation coefficients (R) between the paired samples obtained from OPG and CBCT were highly related (P < 0.05) with R values varying from 0.840 and 0.959 in vertical distances and R values varying from 0.703 and 0.904 in horizontal distances. Compared with data obtained from CBCT, the mean vertical magnification rates were 11.38% and 12.95% vertically and 8.55% and 9.43% horizontally for the first molars in the right and left maxilla respectively; 7.26% and 6.35% vertically and 5.33% and 4.96% horizontally for the first molars in the right and left mandible respectively; and 5.55% and 4.84% vertically and 6.53% and 7.47% horizontally for the central incisors in the upper right and left jaws respectively.
  
  
  CONCLUSIONS
  The magnification rates of OPG at these teeth are different. The distances measured by OPG were highly correlated with that measured by CBCT.
authors.affiliation: Department of Oral Radiology, Xiangya Stomatological Hospital, Central South University, No. 72 Xiangya Road, Changsha, 410078, China.|School of Stomatology, Central South University, Changsha, China.
authors.forename: Zunan
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Department of Oral Radiology, Xiangya Stomatological Hospital, Central South University, No. 72 Xiangya Road, Changsha, 410078, China.|School of Stomatology, Central South University, Changsha, China.
authors.forename: Xianchu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Oral Radiology, Xiangya Stomatological Hospital, Central South University, No. 72 Xiangya Road, Changsha, 410078, China. chenkejia56@163.com.|School of Stomatology, Central South University, Changsha, China. chenkejia56@163.com.
authors.forename: Kejia
authors.initials: K
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D002681:China; D015331:Cohort Studies; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003757:Dental Implantation / Q000009:adverse effects / Q000379:methods; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery; D008875:Middle Aged; D011862:Radiography, Panoramic / Q000379:methods*; D012044:Regression Analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015921:Dental Implants
keywords: Cone beam computerized tomography; Dental implanting; Digital panoramic radiography; Magnification rate