Abstract
Objectives
The purpose of this study was to evaluate the effects of short-term expansion treatment using the quad-helix appliance on dentofacial morphology in orthodontic patients presenting with a hyperdivergent facial pattern.
Methods
The treatment group consisted of 40 patients with a hyperdivergent facial pattern, who were treated for maxillary incisor crowding with a quad-helix appliance during the mixed dentition period. Lateral cephalograms taken at the start (T0) and end (T1) of the treatment were obtained as a course of care. A similar number of patients, who possessed the same type of facial pattern and who remained untreated, were assigned to a control group. Two consecutive lateral cephalograms of each untreated patient were taken at the same time points as T0 and T1. All cephalograms were traced, analysed and compared between the two groups.
Results
The treatment changes as a result of the quad-helix appliance were expressed in an upward rotation of the mandible (2.34°) and distal tipping and impeded mesial movement of the maxillary first molars. Significant differences were evident between the treatment and control groups.
Conclusion
Quad-helix appliance treatment can be appropriate for significantly decreasing the mandibular plane angle in hyperdivergent patients presenting with moderate maxillary incisor crowding and a positive overjet and overbite.