Recent research has shown that in the majority (80%) of children with high angle morphology, mandibular divergency is compensated for, resulting in a positive overbite. The aim of the present investigation was to determine the possible related variables associated with the compensating mechanism in high angle patients. The study material consisted of pre-treatment lateral cephalometric radiographs of high angle patients with permanent dentitions. Of the 150 patients selected randomly from the archives of orthodontics clinic, 99 patients fulfilled the selection criteria and were included in the study. For the assessment of the compensation amount, the patients were divided into two groups: overbite<0 mm and overbite≥0 mm. Almost half of the subjects exhibited a positive overbite (n=53), while the other half exhibited an openbite relationship (n=46). The investigated variables were vertical skeletal measurement and ratios, dental angle and distances, postural measurements and measurements related to airway and hyoid bone position obtained from the lateral cephalograms. The pronounced skeletal vertical characteristic in patients with vertical skeletal pattern and an openbite was a posterior inclination of maxillary basal structures. These patients also exhibited more protrusive and superiorly positioned upper incisors. The patients with compensation on the other hand presented more superiorly positioned lower incisors. The parameters regarding the position of the hyoid bone, pharyngeal air-way and head posture did not reveal any differences between the overbite and openbite groups in our study.

Keywords: Icreased vertical development, Anterior openbite, Deep bite, Compernsation