RAPID MAXILLARY EXPANSION - A STUDY OF THE LONG-TERM EFFECTS

A study was made to determine whether skeletal alterations usually pro duced by rapid maxillary expansion may be compensated for in time by g rowth and/or comprehensive orthodontic treatment. In 30 patients, orth odontic treatment was started with rapid maxillary expansion, followed by fixed appliances, not combined with any other form of orthopedic d evice. Mean treatment time was 3.1 years. Nine measurements from the R icketts analysis were studied, based on lateral cephalometric radiogra phs. Records were taken before orthodontic treatment and after complet ion of active therapy. A statistical analysis was made of the nine var iables used, reflecting the vertical and anteroposterior skeletal prop ortions of the face, contrasting the changes before and after treatmen t. Of all the variables studied, the four that change with age accordi ng to the Ricketts analysis (mandibular plane angle, maxillary height, facial depth and facial convexity), yielded statistically significant differences after treatment, indicative of normal growth. The five re maining variables that remain constant with age according to the Ricke tts analysis (facial axis, lower facial height, total facial height, p alatal plane inclination and maxillary depth) showed no significant ch anges after treatment, also indicative of normal growth.