Pendulum appliances with 2 anchorage designs: conventional anchorage vs bone anchorage.Am J Orthod Dentofacial Orthop. 2008 Mar; 133(3):339.e9-339.e17.AJ
The aim of this retrospective study was to compare the dentoalveolar and skeletal effects obtained with 2 types of pendulum appliance with different anchorage designs: bone-anchored pendulum appliance (BAPA) and conventional pendulum appliance (CPA).
The sample consisted of 39 patients (25 girls, 14 boys) with Angle Class II molar relationships. Correction of the molar relationship was achieved with the BAPA with palatal intermaxillary fixation screws for anchorage in the first group (n = 22) and with the CPA in the second group (n = 17). Lateral cephalograms before treatment and at the end of distalization were measured, and changes in the groups and the differences between the groups were analyzed statistically.
The average distalization times were 6.8 months for the BAPA group and 5.1 months for the CPA group. The maxillary first molars were tipped 9.1 degrees in the BAPA group and 5.3 degrees in the CPA group; the molars moved distally 4.8 mm in the BAPA group and 2.7 mm in the CPA group. Despite mesialization of the premolars and proclination of the incisors with the CPA, both premolars were spontaneously distalized, and the incisors were retruded with the BAPA.
The amount of distal molar movement was similar between the BAPA and the CPA. No anchorage loss or spontaneous distal premolar and incisor movement, which might decrease total treatment time, was seen with the BAPA.