Interceptive Management of Pseudo-Class III Malocclusion in a Growing Patient Using a Sagittal Screw Appliance: A Case Report

Abstract

Functional anterior crossbite is often misdiagnosed as skeletal Class III malocclusion, necessitating careful evaluation and timely intervention. This case report describes the interceptive orthodontic management of a 14-year-old female with anterior crossbite and a forward mandibular shift. Clinical and cephalometric findings confirmed a functional discrepancy without true skeletal Class III features. Treatment involved a sagittal screw appliance with posterior bite blocks to advance the maxillary anterior segment and eliminate occlusal interference. This was followed by fixed mechanotherapy using the MBT 0.018" prescription to align and level both arches. Post-treatment cephalometric analysis showed improvement in ANB angle (from –2° to 0°), increased overjet, and deep bite correction. A stable Class I occlusion with improved facial profile was achieved. Early diagnosis and use of functional appliances in growing patients can successfully correct CR–CO discrepancies, minimize skeletal progression, and reduce the need for surgical intervention.