Assessment of Condylar Position in Centric Relation and Maximal Intercuspation in Different Types of Malocclusion Using Cone Beam Computed Tomography

Abstract

Background: This study was conducted for the assessment of condylar position in centric relation and maximal intercuspation in different types of malocclusion using cone beam computed tomography.

Material and methods: Lateral cephalograms were taken for patients attending the Outdoor patient Department and the Department of Orthodontics and Dentofacial Orthopaedics, JCD Dental College, Sirsa. These individuals were screened on the basis of Steiners analysis for skeletal classification and were then divided into three groups as Group 1 - Class I Normal Occlusion, Group 2 - Class II Division1 Malocclusion and Group 3 - Class II Division 2 Malocclusion. The Lateral cephalograms of each group were taken with the subjects in Natural Head Position by the same operator with the film distance to the x-ray tube fixed at 5 feet. Fuji medical dry imaging X-ray film 8” × 10” were exposed at 60 to 90 KVP and tube current at 2 to 15 mA for 0.8 seconds. Lateral cephalograms were obtained from CS 8000C cephalostat machine manufactured by Care-stream Dental. (Fig.5). The radiographs obtained were traced on acetate tracing sheets of 0.003 inch thickness with a sharp 3H pencil on a viewbox. Linear and angular measurements were obtained nearest to 0.5mm and 0.5 degrees by ruler scale and protractor.

Results: Comparison of mean measurements obtained from all the groups in left frontal MI was done and result showed significant difference between group 1- Class I Normal occlusion, group 2- Class II Div.1 and group-3 Class II Div.2 malocclusion. (p=<0.001). The inter-group comparison of mean Left Frontal MI was done. The result showed a significant differencebetweenGroup1-ClassINormal occlusionandGroup3-ClassIIDiv.2malocclusion as compared to Group 2- Class II Div.1 malocclusion.

Conclusion: From the results of the present study, the following conclusions can be drawn from the evaluation of condylar position in Maximal Intercuspation (MI) and Centric Relation (CR) position in both lateral and frontal cuts of right and left TMJs in Class INormal occlusion, Class II Division1 malocclusion and Class II Division 2 malocclusion. ThisstudyfoundsomevariationsincondylepositioninbothCRandMI,even though these variations were statistically insignificant. The study found statistically significant difference in left lateral MI as compared to right lateralMIinGroup1-ClassINormalocclusionandGroup2-ClassIIDiv.1andalso foundstatisticallysignificantdifferencebetweenCRandMIonbothsidesinpatients with Class IIDiv.2.