Journal of Oral Implantology June 2012 - (Page 203)

RESEARCH Relationships Between the Gonial Angle and Mandibular Ramus Morphology in Dentate Subjects: A Panoramic Radiophotometric Study Takahiro Ogawa, DDS, PhD1 Shigeo Osato, DDS, PhD1* Yuichi Shishido, DDS2 Michio Okada, DDS1 Kimiharu Misaki, DDS2 Analysis of dental panoramic radiographs (DPRs) is an indispensable diagnostic tool for dental implants both pre and post operation. Many studies on linear and angular morphometry of the mandibular body have been conducted, but those on the mandibular ramus have not yet been reported. The purpose of this study was to investigate the differences in the morphometric parameters of the mandibular ramus between high and low gonial angles (GAs) on DPRs as well as between genders, and to determine the relationships between GA and variables of the mandibular ramus morphometry. The DPRs of 156 dentate subjects (78 for each gender) with more than 15 teeth present, a mean age of 49.54 years, and a mean number of teeth of 26.20 were examined. The films were divided into the following 2 groups of GA: less than 1208 (low gonial angle, LGA) and more than 1258 (high gonial angle, HGA) in both the right and left sides. The parameters for Ar 0 -Go, MaF-Go, RW, and RD in the LGA group were significantly larger than those in the HGA group in both men and women, but that for the ramus angle (RA) was significantly smaller in the LGA group than in the HGA group. Significant gender differences in the 2 GA groups were recognized with respect to the Ar 0 -Go, MaF-Go, RW, and RD parameters. Significant negative low and moderate correlations were found between GA and the Ar 0 -Go, MaF-Go, RW, and RD variables, whereas significant positive low correlation was found between GA and the RA variable. Within the limits of this study, the analysis of the mandibular ramus morphometry on DPRs in terms of GA size and gender was found to be useful for devising a highly predictive and strategic plan for implant-supported oral rehabilitation. Key Words: gonial angle, mandibular ramus morphometry, ramus cortical index (RCI), ramus notch depth, ascending ramus 1 2 Department of Histology, The Nippon Dental University School of Life Dentistry at Tokyo, Japan. Tokyo Implant Research Group, Japan. * Corresponding author, e-mail: osato-s@giga.ocn.ne.jp DOI: 10.1563/AAID-JOI-D-09-00143 Journal of Oral Implantology 203

Table of Contents for the Digital Edition of Journal of Oral Implantology June 2012

Editorial
Relationships Between the Gonial Angle and Mandibular Ramus Morphology in Dentate Subjects: A Panoramic Radiophotometric Study
A Comparison of Peripheral Marginal Bone Loss at Dental Implants Measured With Conventional Intraoral Film and Digitized Radiographs
Microstrains Around Standard and Mini Implants Supporting Different Bridge Designs
Surface and Biomechanical Study of Titanium Implants Modified by Laser With and Without Hydroxyapatite Coating, in Rabbits
Survival and Success Rates of Immediately and Early Loaded Implants: 12-Month Results From a Multicentric Randomized Clinical Study
Posttreatment Quantification of Patient Experiences With Full-Arch Implant Treatment Using a Modification of the OHIP-14 Questionnaire
Correlation Between Occlusal Forces and Marginal Bone Levels Around Implant- Retained Restorations: A Clinico-Radiological Study
The Influence of Maximum Bite Force on Patient Satisfaction and Quality of Life of Patients Wearing Mandibular Implant Overdentures
Guided Flapless Surgery With Immediate Loading for the High Narrow Ridge Without Grafting
Estimation of the Safe Distance Between the Implant and an Adjacent Tilted Implant Using Trigonometry
Chair-Side Fabrication of a Fixed Implant-Supported Prosthesis in an Edentulous Mandible From A Diagnostic Wax-Up: A Clinical Report
A Comparison Between Screw- and Cement-Retained Implant Prostheses. A Literature Review

Journal of Oral Implantology June 2012