Facial soft-tissue changes after rapid maxillary expansion analyzed with 3-dimensional stereophotogrammetry: A randomized, controlled clinical trial

Abstract

Objective: To evaluate three-dimensional (3-D) soft tissue facial changes following rapid maxillary expansion (RME) and to compare these changes with an untreated control group. Materials and Methods: Patients who need RME as a part of their orthodontic treatment were randomly divided into two groups of 17 patients each. Eligibility criteria included having maxillary transverse deficiency with crossbite, and to be in the normal range according to body mass index. In the first group (mean age = 13.4 ± 1.2 years), expansion was performed. The second group received no treatment initially and served as untreated control (mean age = 12.8 ± 1.3 years). Skeletal and soft tissue changes were evaluated using posteroanterior cephalograms and 3-D facial images. The primary outcome of this study was to assess the soft tissue changes. The secondary outcomes were evaluation hard tissue and soft tissue relations. Randomization was done with preprepared random number tables. Blinding was applicable for outcome assessment only. MANOVA, t-test, and correlation analyses were used (P = .05). Results: In both groups, there was a general trend of increase for the transverse skeletal measurements, but these increases were more limited in the control group. Alar base width was greater in the treatment group (P = .002). Pogonion soft tissue point (P = .022) was located more posteriorly in the expansion group compared with the control group. Conclusions: Soft tissue changes between groups were similar, except for the alar base, which became wider in the treatment group. Weak correlations were found between the skeletal and soft tissue changes.

3D facial soft tissue changes after rapid maxillary expansion on primary teeth: A randomized clinical trial

“…The aim of the present RCT was to evaluate long‐term effects on facial soft tissue produced by RME treatment. Baysal et al recently published an RCT showing nonsignificant differences in soft tissue changes with RME treatment after 6‐month retention in the treated group compared with control, except for alar base width that increased of approximately 1 mm in treated subjects after treatment. In the present study, alar base width increased 1.98 mm in treated group compared with control, but the difference might not be clinically significant in the impact of the whole face, even though a large effect was detected between the groups for this variable.…”

“…Generally, RME was suggested to promote a transitory increase in skeletal vertical dimension of the face due to downward and backward rotation of the mandible . Baysal et al showed significant downward and backward displacement of pogonion, even if bonded acrylic splint expander was employed in order to prevent the bite opening effects. In the present investigation, an expander with bands on the upper primary teeth was employed and no significant differences in the face heights were reported between treated and control group.…”

“…A sample size for this trial was calculated. The variable Alr‐All (interalar width) was indicated as primary outcome variable, and a clinically relevant change of 0.99 mm with a combined standard deviation (SD) of 0.95 mm derived from Baysal et al was established. According to the calculated sample size, at least 15 subjects per group were necessary to retrieve β = .80 with α set at .05.…”

“…Additionally, the direct measurements on the face are necessarily accompanied by a distortion of the soft tissue or by a difficult identification of the landmarks . Due to the inaccuracy of these methods to quantify soft tissue changes, the proposal of alternative techniques has continuously grown as 3D analysis through stereophotogrammetry or cone beam computed tomography (CBCT) …”

Volume Assessment of the Effect of Obturators on Facial Form Following Surgery for Head and Neck Cancer Using Stereophotogrammetry

“…For example, the technique has been used to report on basal facial surface symmetry . Stereophotogrammetry has also been used to assess facial morphology on adults with unilateral cleft lip and palate, and the effects of orthodontic treatment undertaken by rapid maxillary expansion . In relation to the rehabilitation of individuals with hemifacial microsomia, a stereophotogrammetry technique has been used to predict the position and size of an artificial ear on the face …”