Color changes of maxillary and mandibular incisors following surgical orthodontic treatment: A prospective controlled clinical pilot study

Abstract

Objective: To assess possible color changes of natural teeth after surgical orthodontic treatment.

Methods: This prospective controlled clinical pilot trial included 6 consecutively treated surgical orthodontic patients with class III malocclusion and neutral vertical relation (ST: surgical treatment), 3 of which received double jaw osteotomies (SGI: surgical subgroup I) and 3 received single mandibular sagittal split ramus osteotomies (SGII: surgical subgroup II). Eleven untreated individuals (UC: untreated control) and 9 individuals who received conventional comprehensive orthodontic treatment only (OC: orthodontic control) served as controls. Tooth color measurements were performed using a reflectance spectrophotometer on the upper and lower incisors before the initiation of the surgical orthodontic treatment (T1) and after its completion (T2). Primary endpoint was E* (T1–T2) of summarized CIE-L*a*b* color differences. The null hypothesis of this study was that there is no statistically significant change in total tooth color difference E* CIE-(L*a*b*) in vivo at baseline and following surgical orthodontic treatment.

Results: There was a statistically significant increase in E* (T1–T2) in the ST group compared to the UC and OC groups. Single mandibular surgery had a stronger effect on the lower teeth in comparison to double jaw surgery, while Le Fort I osteotomy, as part SGI, had a stronger effect on the upper teeth. Despite statistical significance, the majority of mean values of these color changes were lower than the threshold value of color alterations considered to be perceivable by the naked eye in a clinical setting (3.7 E units), with the exception of the mandibular incisors in SGII, where this threshold value was slightly exceeded.

Conclusions: Orthognathic surgery showed a measurable effect on tooth color. However, esthetic disturbance or patient discomfort based on these color and lightness alterations are unlikely, due to their small impact and low perceptibility in a clinical setting.