Evaluation of the vertical holding appliance in treatment of high-angle patients

Controlling the vertical dimension of high-angle patients without the benef it of compliance can be a challenging aspect of orthodontic treatment. This retrospective study examines the skeletal and dental effects of a modified transpalatal bar, dubbed the vertical holding appliance (VHA), which was u sed in an attempt to control the vertical dimension of high-angle patients. Two cephalometrically similar groups of high-angle patients (16 patients e ach) were compared to determine advantages from using the VHA, Group I (n = 16, pretreatment age 13.4 +/- 1.6 years) was treated with 4 premolar extra ctions in conjunction with the VHA cemented in place for 17.4 +/- 6.1 month s. Group II (n = 16, pretreatment age 13.4 +/- 1.9 years), which was matche d for age and pretreatment skeletal pattern, was treated with the Tweed tec hnique and 4 premolar extractions. Lateral cephalometric radiographs were t aken before the placement of the VHA, as well as at the end of treatment. T he results showed that although y-axis increased significantly in group II (P < .05), it remained the same in group I. Within group I, the Franfort ma ndibular plane angle and gonion gnathion/sella nasion angle decreased, wher eas both of these values increased in group II. However, these changes were statistically insignificant. Lower anterior face height increased more in group II than in group I (P < .05). The percentage of lower anterior face h eight to total anterior face height decreased in group I, whereas it increa sed in group II. The difference between the 2 groups was determined to be s ignificant (P < .01). Eruption of the maxillary first molar within group I was less than in group II. No significant differences were found between gr oups I and II for changes in overbite.