Author(s)

Lo John, Yau Yat Yin, Yeung Wai Chow David, Cheung Lim Kwong

Department of Diagnostic Imaging, Hong Kong Adventist Hospital, Hong Kong, China.
Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, the University of Hong Kong, Hong Kong, China.

Objectives: To 1) explore the planar scintigraphic findings in asymmetry patients caused by unilateral condylar hyperplasia (UCH) or asymmetric mandibular hyperplasia (AMH); 2) develop a local agecondylar activity reference norm; and 3) check the accuracy of the new norm and compare with other analytical methods. Material and Method: Chinese patients with mandibular asymmetry and scintigraphic findings available were recruited. Clinical, radiographic records and scintigraphic condylar activity ratio (CAR) were studied. Regression analysis was performed to quantify the relationship between age and CAR to develop a new norm. The sensitivity of condylar activity assessment using a) traditional norm; b) new norm; and c) percentile difference was compared. In patients with serial data available, longitudinal analysis of the scintigraphic changes were checked. Result: 109 patients were eligible for the study. Significant difference in CAR was noted between UCH and AMH patients. Linear relationship was observed between age and CAR. A new norm of the age-CAR was established, which showed improved sensitivity in condylar activity prediction in UCH and AMH when compared with traditional norm. Relative to percentile difference, the sensitivity of new norm was lower in AMH but not in UCH patients. Serial analysis revealed gradual decline in CAR with minimal change in percentile difference. Conclusion and Clinical Relevance: There is difference in scintigraphic condylar activity between UCH and AMH patients. A norm of age-CAR relationship was established, which showed improved sensitivity in condylar activity prediction in UCH patients. Further study is required to confirm the role of scintigraphy in AMH.

cintigraphy; Bone Scan; Facial Asymmetry; Mandibular Asymmetry; Unilateral Condylar Hyperplasia

John, L. , Yin, Y. , Chow David, Y. and Kwong, C. (2012) Planar scintigraphy in assessment of mandibular asymmetry: Unilateral condylar hyperplasia vs asymmetric mandibular hyperplasia. Journal of Biomedical Science and Engineering, 5, 836-844. doi: 10.4236/jbise.2012.512A106.