Three-dimensional soft tissue changes after simulated protrusion of upper and lower incisors in young adults: an experimental study.

A comparison of postoperative, three-dimensional soft tissue changes in patients with skeletal class III malocclusions treated via orthodontics-first and surgery-first approaches

To investigate the application of three-dimensional hard and soft tissue virtual surgical planning in orthognathic surgery using a novel digital workflow, we prospectively included twenty-one consecutively treated patients from two private oral surgery practices. Soft tissue facial scans were acquired using the Artec Space Spider, and intra-oral scans were obtained at one month before (T0), and at two (T1) and six months (T2) post-surgery. Cone-beam computed tomography (CBCT) scans were collected at T0 and T1. Serial three-dimensional soft and hard tissue changes were assessed by superimposing the scans in Geomagic Control X. Achieved hard tissue changes were compared to pre-surgical predictions. Differences in soft and hard tissue changes between patients treated with fixed appliances versus Invisalign® were also analyzed. The Artec Space Spider proved to be a reliable component of a novel digital workflow for virtual surgical planning, demonstrating repeatability and reproducibility. Clinically significant soft tissue relapse was observed in both the maxillary and mandibular regions between T1 and T2. Predicted surgical movements for hard tissue landmarks showed high accuracy, and soft-to-hard tissue change ratios at T1 aligned with two-dimensional data reported in the literature. No significant differences in soft or hard tissue changes were found between fixed appliances and Invisalign®. These findings provide valuable insights for enhancing surgical planning and improving clinical outcomes for both clinicians and patients.

To evaluate whether mandibular setback surgery (MSS) for Class III patients would produce gradients of three-dimensional (3D) soft tissue changes in the vertical and transverse aspects. The samples consisted of 26 Class III patients treated with MSS using bilateral sagittal split ramus osteotomy. Lateral cephalograms and 3D facial scan images were taken before and 6 months after MSS, and changes in landmarks and variables were measured using a Rapidform 2006. Paired and independent t-tests were performed for statistical analysis. Landmarks in the upper lip and mouth corner (cheilion, Ch) moved backward and downward (respectively, cupid bow point, 1.0 mm and 0.3 mm, P < .001 and P < .01; alar curvature-Ch midpoint, 0.6 mm and 0.3 mm, both P < .001; Ch, 3.4 mm and 0.8 mm, both P < .001). However, landmarks in stomion (Stm), lower lip, and chin moved backward (Stm, 1.6 mm; labrale inferius [Li], 6.9 mm; LLBP, 6.9 mm; B', 6.7 mm; Pog', 6.7 mm; Me', 6.6 mm; P < .001, respectively). Width and height of upper and lower lip were not altered significantly except for a decrease of lower vermilion height (Stm-Li, 1.7 mm, P < .001). Chin height (B'-Me') was decreased because of backward and upward movement of Me' (3.1 mm, P < .001). Although upper lip projection angle and Stm-transverse projection angle became acute (Ch(Rt)-Ls-Ch(Lt), 5.7 degrees; Ch(Rt)-Stm-Ch(Lt), 6.4 degrees, both P < .001) because of the greater backward movement of Ch than Stm, lower lip projection angle and Stm-vertical projection angle became obtuse (Ch(Rt)-Li-Ch(Lt), 10.8 degrees ; Ls-Stm-Li, 23.5 degrees , both P < .001) because of the larger backward movement of Li than labrale superius (Ls). Three-dimensional soft tissue changes in Class III patients after MSS exhibited increased gradients from upper lip and lower lip to chin as well as from Stm to Ch.

To evaluate the three-dimensional (3D) perioral soft tissue changes after orthodontic treatment in patients with dentoalveolar protrusion using structured light-based scanners. Forty-four Korean adults (19 men and 25 women, 21.4 ± 3.4 years) with dentoalveolar protrusion treated by extraction of all four first premolars and then en masse retraction with maximum anchorage were evaluated. Lateral cephalograms and 3D facial scans were obtained before treatment (T1) and immediately after debonding (T2). Superimposition was performed, and 27 perioral landmarks were identified. The 3D changes in the landmarks and ratio of movement of the soft tissue relative to the horizontal incisal tip were evaluated. A paired t-test and one-way analysis of variance were performed. The upper incisors were retracted 5.76 mm and the lower incisors were retracted 4.62 mm (P < .001). The upper lip moved inferoposteriorly, and the lower lip moved superoposteriorly. In the lower lip, upward movement was greater than backward movement (P < .001). The most prominent changes appeared at the greatest bulge area. The relative ratios were 42%-53% in the upper lip area and 22%-82% in the lower lip area. The lip corners moved superoposteriorly (P < .001). Subnasale moved downward (P < .05) and posteriorly (P < .001), while the landmarks under the nostrils moved upward and posteriorly (P < .001). Facial scans from white structured light scanners efficiently evaluated 3D perioral soft tissue in dentoalveolar protrusion patients. Backward movement and significant vertical movement of the lip were observed. The nasal and lip angle areas showed considerable changes.

Using a structured light scanner to evaluate 3-dimensional soft-tissue changes after extracting 4 premolars in young adult female patients

Authors' response.

Evaluation of the three-dimensional soft tissue changes after anterior segmental maxillary osteotomy

Aim: The presented article deals with changes in soft tissues due to orthodontic treatment, and seeks to answer the question whether there are differences between patients who underwent non-extraction orthodontic therapy and those who were treated with the extraction of four premolars or two premolars in the maxilla. Material and method: Cephalograms made prior to and following the orthodontic treatment were analyzed. The sample included 200 patients of the Department of Orthodontics, Institute of Dentistry and Oral Sciences and University Hospital Olomouc. We assessed changes in soft tissues of face profile in patients with non-extraction orthodontic therapy and patients with extraction of four or two premolars in the maxila. The analysis was performed with software Kefalo, version 6.19. Results: The results proved statistically significant changes in soft tissues caused by orthodontic therapy and statistically significant differences in comparison of various kinds of therapyɸ– non-extraction and extraction of four or two premolars in the maxilla. We proved statistically significant correlations between the change in hard and soft tissues in non-extraction and two extraction groups. There were several moderately strong correlations, and most weak correlations. The correlations were not strong enough to formulate the rule for prediction of responses of soft tissues to changes in hard tissues. We did not prove that the extraction therapy, either with four or two premolars in the maxilla, results in distinctively negative changes in face profile. Conclusion: The results suggest that soft tissues and their changes depend on aɸnumber of other factors, not only on the change in the position and inclination of upper and lower incisors.

Key Clinical MessageConsideration of growth pattern and occlusal plane is critical in orthodontic treatment planning to achieve optimal dentofacial esthetics and long‐term stability in adolescent patients, which is illustrated by success in orthodontic treatment of an adolescent Class II division 1 malocclusion with nonextraction.

Three-dimensional soft tissue changes after reduction malarplasty in female patients

Residents' journal review

To evaluate the possible soft tissue changes after debonding of labial brackets using three-dimensional (3D) images acquired by a laser scanner. On the same day, 3D facial scans were taken immediately before debonding (T1) and immediately after debonding (T2) from 53 patients, and follow-up scans were taken 3 months after debonding (T3) from 31 patients. To compare the scans, superimpositions were performed and shell-to-shell deviations were used for quantitative analysis. Shell-to-shell deviation map showing warm colors in lip and perioral tissue represented the retrusion of soft tissue after bracket removal. Soft tissue retrusion was significant for all landmarks immediately after debonding (T1-T2) and 3 months after debonding (T1-T3). Gender, bracket type, and the lip thickness variables did not show a clinically significant influence on the amount of soft tissue retrusion at the T1-T3 period. Lip corners and vermilion borders were significantly retruded at the T1-T3 period more than other perioral areas. A negative linear relationship was found in the amount of soft tissue retrusion immediately after debonding (T1-T2) and from debonding to 3 months after debonding (T2-T3). Three-dimensional imaging showed significant changes in lip and perioral soft tissue after debonding of labial brackets. Clinically significant changes, approximately 2 mm of retrusion, occurred in the mouth corners bilaterally. Vermilion border landmarks also demonstrated significant changes in more than 1 mm. However, it was not possible to predict the soft tissue changes. A wide range of individual variability in the response to treatment and soft tissue adaptation was noted.

Correlation Between Soft and Hard Tissue Changes in the Zygomaticomaxillary Region After Bone Contouring Surgery for Fibrous Dysplasia—A Preliminary Study

Soft Tissue Changes Measured With Three-Dimensional Software Provides New Insights for Surgical Predictions

Residents’ journal review