Oral and maxillofacial radiologyThree-dimensional quantification of mandibular asymmetry through cone-beam computerized tomography

ObjectiveThe aim of this study was to determine if 3-dimensional (3D) shape analysis precisely diagnoses right and left differences in asymmetry patients.Study designCone-beam computerized tomography (CT) data were acquired before treatment from 20 patients with mandibular asymmetry. 3D shape analysis was used to localize and quantify the extent of virtually simulated asymmetry. Two approaches were used: 1) mirroring on the midsagittal plane determined from landmarks; and 2) mirroring on an arbitrary plane and then registering on the cranial base of the original image. The validation presented in this study used simulated data and was applied to 3 clinical cases.ResultsFor mirroring on the midsagittal plane, there was a >99% probability that the difference between measured and simulated asymmetry was <0.5 mm. For mirroring with cranial base registration, there was a >84% probability of differences <0.5 mm.ConclusionsMandibular asymmetry can be precisely quantified with both mirroring methods. Cranial base registration has the potential to be used for patients with trauma situations or when key landmarks are unreliable or absent.