Morphologic characteristics of open bite patients with and without condylar degeneration utilizing CBCT 3-dimensional analysis

Authors

Armita Fartash, University of the PacificFollow
Isabel Kwon, University of the PacificFollow
Jacqui Payne, University of the PacificFollow
Brad Albertson, University of the PacificFollow
Linda Phi, University of the PacificFollow
Joorok Park, University of the PacificFollow
Heesoo Oh, University of the PacificFollow

Lead Author Affiliation

Department of Orthodontics

Introduction/Context/Diagnosis

Condylar degeneration can result in backward rotation the mandible and opening of the mandibular plane angle, resulting in an anterior open bite. The purpose of the study was to compare the morphologic characteristics of patients with anterior open bites with and without condylar degeneration utilizing CBCT 3D analysis.

Methods/Treatment Plan

40 anterior open bite patients of the orthodontic clinic at UOP were evaluated. The patients were sorted into 2 groups based on their phase of condylar degeneration, including 20 patients with condylar degeneration and 20 patients without condylar degeneration. 3 raters performed 3D analysis for the CBCT images and obtained 24 cephalometric measurements to gather information on certain morphologic characteristics. Independent t test was used to assess the difference in these morphologic characteristics between the 2 groups.

Results/Outcome

The degeneration group showed significantly shorter total mandibular length, shorter ramus height, larger condylar axis angle, smaller condylar height, smaller difference in height between the condyle and coronoid process, shorter distance from Sella Perpendicular-Pog, larger ANB, and larger overjet.

Significance/Conclusions

Patients with condylar degeneration have a greater Class II tendency, as evidenced by the larger ANB, shorter total mandibular length, shorter Sella Perpendicular-Pog, and larger overjet. There was no difference in mandibular body length between the two groups, evidencing that the difference in total mandibular length is due to the shorter ramus height in the degeneration group. The degeneration group had a larger condylar axis angle, though the reason remains unclear. This may be due to adaptation of the condyle to functional forces or reduced medio-lateral development of the mandible. The degeneration group had a shorter condyle height and a smaller difference in height between the condyle and coronoid process. This finding may be useful as a predictor for condylar degeneration and may warrant further investigation of the condyle for degenerative changes with CBCT.

Location

2nd floor clinic and reception waiting areas

Format

Poster