Experimental panoramic positioning errors for inducing condylar cutoff and superimposition of cervical vertebrae on the mandibular ramus

Kang,  Byung Cheol; Kim,  Min Jong; Park,  Hye Sun; Hwang,  Sel Ae; Yoon,  Suk Ja; Lee,  Jae Seo

J Korean Dent Assoc > Volume 56(3); 2018 > Article

The Journal of The Korean Dental Association 2018;56(3):134-141.
Published online March 31, 2018.

하악과두 잘림과 경추의 하악지 겹침을 야기하는 파노라마방사선촬영 오류

강병철¹, 김민종², 박혜선³, 황슬애⁴, 윤숙자⁵, 이재서⁶

^¹전남대학교 치의학전문대학원 영상치의학교실
^²전남대학교 치의학전문대학원 치의학과
^³전남대학교 치의학전문대학원 치의학과
^⁴전남대학교 치의학전문대학원 치의학과
^⁵전남대학교 치의학전문대학원 영상치의학교실
^⁶전남대학교 치의학전문대학원 영상치의학교실

Experimental panoramic positioning errors for inducing condylar cutoff and superimposition of cervical vertebrae on the mandibular ramus

Byung Cheol Kang¹, Min Jong Kim², Hye Sun Park³, Sel Ae Hwang⁴, Suk Ja Yoon⁵, Jae Seo Lee⁶

¹Department of Oral and Maxillofacial Radiology, School of Dentistry, Chonnam National University
²School of Dentistry, Chonnam National University
³School of Dentistry, Chonnam National University
⁴School of Dentistry, Chonnam National University
⁵Department of Oral and Maxillofacial Radiology, School of Dentistry, Chonnam National University
⁶Department of Oral and Maxillofacial Radiology, School of Dentistry, Chonnam National University

Abstract

Purpose
To measure the head tilting angle creating initial condylar cut-off and to find the head position inducing the superimposition of the cervical vertebrae over the mandibular ramus on panoramic radiograph. Materials and Methods: The panoramic radiographs were taken with Didactic skull on cervical spine model (Scientific GmbH, Hamburg, Germany) using Kodak 8000c Digital Panoramic radiography. For the inherent radiolucency of the plastic skull model, radiopaque 1 mm diameter lead wires were attached along the margin of the mandibular condyle, ramus, mandibular body, cervical vertebrae, and FH plane of the skull model. For measuring the head tilting angle creating the condylar head cutoff, panoramic radiographs were taken by tilting the FH plane downward in 5 degree increments. For finding the distance between transverse process of the third cervical vertebra and gonion inducing superimposition of cervical vertebrae on the mandibular ramus, panoramic radiographs were taken by decreasing the distance in 0.5 cm increments. Result and Conclusion: The condylar cutoff began to appear when the head of skull model was tilted downward by 15o. As the head tilting angle increasing, the condylar cutoff became more prominent. The superimposition of cervical vertebrae over the mandibular ramus began to appear when the distance between the gonion and third cervical vertebra was 1.0 cm. As the distance decreasing, the superimpostion became more prominent.

Key Words: Mandibular Condyle;Panoramic Radiography;Vertebra;