A Comparison of the Nance Holding Arch and Kloehn Headgear in Maxilliary Molar Anchorage
A sample of thirty first bicuspid extraction patients, ages 9 through adult, were evaluated for maxillary molar anchorage loss during cuspid retraction. The Nance Holding Arch and Kloehn cervical headgear were compared as anchorage devices. A control group received no anchorage mechanics during cuspid retraction. All cuspids were retracted with Hilger's loop retractors. Anchorage loss was measured cephalometrically by comparing the difference in the 6 to PTV measurement on the initial and post cuspid retraction lateral head films. Anchorage loss, as the dependent variable, was compared to the study groups, Angle class, facial type, treatment length, palatal angle and distance of cuspid retraction as independent variables. Eighteen patients were treated with the Nance Holding Arch, six with Kloehn cervical headgear and six with no anchorage mechanics during cuspid retraction. Results show no significant difference in mean anchorage loss in the three groups (Nance = 1.288 mm loss; Headgear = 0.833 mm loss; Control = 1.583 mm loss). Initial molar Angle classification had no significant effect on maxillary molar anchorage. This study showed the least anchorage loss in the Class II end-on sample and the greatest loss in the Class I sample. Dolichofacial patients demonstrated greater anchorage loss than Brachyfacial patients but the difference was not significant. (1.76 mm and 1.26 mm respectively.) Although not significant statistically, steeper, high vaulted palates tend to provide greater molar anchorage when the Nance Holding Arch is used. No correlation was demonstrated between anchorage loss and length of treatment (T1 radiograph to cuspids retracted radiograph). The study showed that the upper molar position can be reliably traced and evaluated for anchorage loss.
Orthodontics and Orthodontology, Molar; Orthodontic Appliances; Dental Arch; Orthodontics, Corrective
Networked Digital Library of Theses and Dissertations