Three Dimensional Evaluation of Palatal Expansion in Growing and Adult Patients

Abstract

The aim of this study was to evaluate the effects of palatal expansion in growing and adult patients three dimensionally. CBCT images were used to evaluate the difference in the pattern of expansion between growing patients and adult patients undergoing palatal expansion without surgical assistance. A sample of 20 subjects that required palatal expansion was selected from the outpatient clinic of the Orthodontic Department in the Faculty of Dentistry, Ain Shams University. The patients were divided into 2 groups according to age; a group of growing patients, which were 14 years old or younger, and a group of adult patients, which were 18 years old or more. 3 patients were lost in the first group and 2 patients were lost in the second group. The final sample included 7 patients in group I and 8 patients in group II. After taking the standard orthodontic records, each patient was treated using a tooth tissue borne expander (Haas expander). The patients were instructed to activate the expander once per day. If a patient complained from pain or ulceration, after a one week rest period, the rate of activation was reduced to once every other day. The end point of the expansion was when overcorrection was achieved in either of the first permanent molars. Each patient received a cone beam computed tomography (CBCT) using iCAT CBCT scanner before the beginning of treatment, and after the end of the expansion procedures. DICOM images were imported in the inVivo anatomage software. TM A statistically significant increase was found in nearly all the transverse measurements. Comparing between the transverse measurements in both groups showed no statistically significant difference. An exception was the inter-jugale width which showed a higher increase in the growing patients. For the growing patients, the skeletal contribution of expansion was 23%, while the alveolar and dental contributions were 44% and 33% respectively. As for the adult patients the percentages were 8%, 61% and 31% for the skeletal, alveolar and dental contribution to total expansion. Tipping of both the alveolar processes and the teeth was found, though the teeth tipped more that the alveolar processes. No statistically significant change was found in the palatal depth. A significant reduction in the alveolar bone height was found in both groups, with no significant difference between the groups. While for adult patients a statistically significant reduction in the tooth length was found indicating apical root resorption, though it was considered clinically insignificant. The expansion procedure had no significant antero-posterior effect on the maxilla.