| dc.description.abstract | Purpose
To compare treatment and posttreatment differences in areas of contact and near contact (ACNC) between traditional braces and Invisalign® in adults with Class I malocclusion using transilluminated bite registrations.
Materials and Methods
The sample consisted of 80 Class I patients, randomized into one of two treatment groups: traditional braces (40 patients) and Invisalign® (40 patients). The patients were treated by two standardized, ABO-certified orthodontists and were retained with upper wraparound Hawleys and bonded mandibular retainers (spanning lower canine to canine). Blu-Mousse® bite registrations and orthodontic study models were obtained at four timepoints: pre-treatment (T1), debond (T2), one-month retention (T3), and six-months retention (T4). Transillumination of the bite registrations allowed calculation of the areas of contact and near contact (ACNC, 0-350 microns) using a custom software, Halcon Contactos.
Results
ACNC decreased significantly during treatment (T1-T2, 68.8-72.8%), increased significantly during the first-month posttreatment (T2-T3, 14.4-19.6%), and further increased significantly between one- to six- months posttreatment (T3-T4, 11.9-16.6%). There were no statistically significant between-group differences at any of the timepoints. There also were no statistically significant between-group differences in the changes that occurred between timepoints. Trends were similar for areas of contact, areas of near contact, and total ACNC. Significant amounts of posttreatment settling were observed for both groups, with total ACNC values increasing 31.0% for traditional braces and 31.5% for Invisalign®. Total ACNC values obtained after six-months of posttreatment (T4) settling did not attain pre-treatment (T1) values. Traditional braces showed a 41.8% deficit and Invisalign showed a 37.3% deficit from pre-treatment values (T1-T4).
Conclusions
Areas of contact, near contact, and total ACNC decrease significantly during orthodontic treatment, and no significant differences were observed between traditional braces and Invisalign® for the decreases in ACNC. Statistically significant settling occurs posttreatment, with ACNC increasing approximately 31% during the first six months. Significantly more settling was seen at one-month posttreatment than the following five months posttreatment (14.4-19.6% increase after one month vs. 2.4-3.3% increase per month, respectively). Posttreatment ACNC values did not reach pre-treatment values, and a net deficit of approximately 40% was observed for both the traditional braces and Invisalign® groups. Neither treatment modality, when retained with wraparound Hawley retainers, results in a superior ACNC outcome. | en |
