Is there a Vertical 'Price' for Correction of a Class II Malocclusion?

Abstract

AIM: The amount of growth any individual can be expected to grow may or may not depend on the particular form of treatment (Johnston, 1999). The aim of this study was to investigate vertical skeletal changes during treatment of a Class II malocclusion with various orthodontic devices. SUBJECTS AND METHOD: (1) Fixed appliance group: 18 consecutive subjects treated non-extraction and Class II elastics, and (2) Headgear-functional appliance group: 22 consecutive subjects treated with Headgear-Herbst with step-by-step advancement of the mandible followed by a headgear-activator as a retainer. Lateral cephalograms were obtained at the start of treatment (T0), and after 6 (T6), 12 (T12) and 18 (T18) months. LFH (Me to Sp') and mandibular plane angle (NSL/ML) were estimated. RESULTS: The growth changes over 6 months in millimetres were: LFH +1.8*** and NSL/ML 0.0. For group 1 LFH and NSL/ML changed 3.1***/1.5* at T6; 4.2***/1.3*.at T12, and 5.0***/1.0* at T18. For group 2 the corresponding figures were 2.2**/0.1, 2.7***/–0.6*, and 2.7***/–1.1*, respectively. There was a statistically significant difference for both cephalometric variables between the two treatment groups at all occasions, except for LFH at T6 (P < 0.07). CONCLUSION: With orthodontic treatment of Class II malocclusions the change in the vertical dimension is affected in various ways with different orthodontic device, varying from good control of the vertical dimension to a significant price in lengthening of the face and opening of the mandibular plane angle.