A comparative analysis of maxillary tooth movement produced by cervical headgear and pend-x appliance.

The purpose of this study was to compare the effects of cervical headgear and pend-x on the maxillary first molar, second molar, first premolar, and upper incisors. Cephalometric radiographs were obtained at the start of treatment (T1) and after molar distalization was completed (T2) for 13 patients in a pend-x group and 13 patients in a cervical headgear group. The changes of the maxillary teeth were measured on maxillary superimpositions. Nonparametric Mann-Whitney U-test was used to compare the mean differences between the two groups. The mean amount of distalization for the headgear group was 3.15 +/- 1.94 mm and that for the pend-x group was 3.81 +/- 2.25 mm. The second molar teeth were also distalized to a mean amount of 2.27 +/- 1.33 mm in the headgear group and 2.04 +/- 2.15 mm in the pend-x group. The mean treatment time for distalization was 11.38 +/- 3.18 months for the headgear group and 7.31 +/- 4.09 months for the pend-x group. During distalization, the maxillary molars tipped distally in both groups, but intergroup differences were not significant. The anterior inclinations of the first premolar and upper incisor increased significantly in the pend-x group (P < .01). Maxillary molars showed no vertical movement in the pend-x group but extruded in the headgear group (P < .01). The anchorage loss of the pend-x appliance as well as the necessary patient compliance and greater treatment time with the cervical headgear should be taken into consideration.