Cephalometric evaluation of changes in vertical dimension and molar position in adult non-extraction treatment with clear aligners and traditional fixed appliances

ABSTRACT Introduction: Orthodontists have been using clear aligners to treat malocclusions, and one potential effect of treatment with orthodontic is the intrusion and/or resists extrusion posterior teeth. This “bite-block effect” primarily anecdotal due frequent occurrence open bites in patients after aligner therapy. Objective: The purpose this study was compare changes promoted by traditional fixed appliances cephalometric measurements vertical dimension molar position adult Class I malocclusion treated non-extraction. Methods: Pre- post-treatment lateral radiographs either (n=44) or (n=22) were selected for retrospective analysis. Eight interval nominal measurement evaluated: anterior overbite (OB), mandibular plane angle related cranial base (SN_MP) Frankfort (FMA), lower height (L6H) upper (U6H), palatal (PP_MP), facial (LFH), total (TFH), bite (Posterior_OB). A single evaluator traced all cephalographs, select measures compared within between groups. Results: OB decreased (1.15 mm) L6H increased (0.63 appliance group. Mandibular angles (related Frankfort) (0.43° 0.53°, respectively) group, but just FMA showed significant difference groups (difference 0.53°). LFH TFH (ranging from 0.52 mm 0.80 both groups, no differences modality. Presence visible significantly over course treatment. OB, exhibited an interaction stage (pre- post-treatment) modality (clear therapy appliances), among these three variables found. Conclusions: evidence does not support theory that produces better control than appliances. Traditional slightly extruded molar, produced a backward rotation.