The effect of Andresen, Harvold, and Begg treatment on overbite and molar eruption.

A retrospective cephalometric study was carried out to compare the vertical dental changes between patients treated with the Andresen (30), Harvold (19), or Begg (30) appliances, and an untreated control group (24). It was found that all three appliances successfully reduced the overbite although the reduction tended to be more stable with the functional appliances. Overbite was reduced by a combination of factors which varied according to the appliance used, but included lower incisor intrusion or restraint, molar eruption, vertical growth of the face and lower incisor proclination in the functional groups. Relapse appeared to be primarily due to continued lower incisor eruption, retroclination of these teeth, and forward rotation of the mandible with continued growth.