Immediate effects of rapid maxillary expansion on the naso-maxillary facial soft tissue using 3D stereophotogrammetry

Influence of facial width on the perception of lip protrusion and its differences between profile and 3-dimensional video clip

INTRODUCTION

This study evaluated the influence of facial width on the perception of lip protrusion and investigated the concordance between 2-dimensional (2D) profile images and 3-dimensional (3D) video clips in assessing lip protrusion.

METHODS

An Asian female standard head model was created using 3D modeling software. Eight head models were constructed by modifying the standard head model in terms of facial width (broad, neutral, and slim) and lip protrusion (retrusive, straight, and protrusive). Overall, 97 Asian raters rated the lip protrusion from the 2D profiles and 3D rotation video clips of the 9 models.

RESULTS

No significant differences were found in the perception of lip protrusion in terms of sex, age, or occupation. Compared with the 2D profiles, the 3D video clips were rated as more protrusive in 8 of the 9 head models, with the retrusive broad, retrusive neutral, straight broad, and straight slim faces showing statistical significance (P <0.01). The rating is significantly higher in slim faces than in broad faces across the 3 groups of 2D profiles (P <0.01). For 3D video clips, the rating was higher in slim faces than in broad faces in all 3 groups, whereas differences were significant in the straight and protrusive groups only (P <0.01).

CONCLUSIONS

In this study, 3D video clips were more sensitive to the perception of lip protrusion than were 2D profiles to some extent. The lips were rated relatively more protrusive in a slim face than in a broad face. Therefore, the relationship between facial width and lip protrusion should be considered in orthodontic treatment goals and treatment plans.

Does Differential Maxillary Expansion Prior to Alveolar Cleft Bone Grafting Affect Nasal Width?

OBJECTIVE

Determine the effects of differential maxillary expansion on nasal width in patients with unilateral cleft lip and alveolus with or without cleft of the secondary palate (UCLA ± P).

DESIGN

Retrospective radiographic study.

SETTING

Institutional.

PARTICIPANTS

Forty patients with UCLA ± P who had alveolar bone grafting (ABG) between 2015 and 2020 and available preexpansion and postexpansion cone beam computed tomography (CBCT) scans. Twenty patients with UCLA ± P who underwent ABG without expansion were included as controls.

MAIN OUTCOME MEASURE

Percent change in width at the nasal pyriform, inferior turbinates, and alar base on cleft and noncleft sides.

RESULTS

The study included 40 patients (24 males, mean age 9.6 years) and 20 controls (10 males, mean age 10.1 years). After maxillary expansion, there was an increase in width on the cleft and noncleft sides compared to nonexpanded controls at nasal pyriform (10.9% cleft side, P ≤ 0.001 and 4.3% noncleft side, P ≤ .001), inferior turbinate (8.7%, P ≤ .001 and 4.5%, P = .01), and alar base (6.7%, P = <.001 and 0.8% P = .54). The increase in width was greater on the cleft side than the noncleft side at the nasal pyriform (7.1%, P ≤ .001), inferior turbinate (4.3%, P ≤ .001), and alar base (7.0%, P ≤ 0.001) in the expansion group. There was good to excellent intra-rater and inter-rater agreement for measurements.

CONCLUSION

Patients with UCLA ± P who undergo differential maxillary expansion before ABG exhibit greater nasal widening on the cleft side.

The Facial Characteristics of Individuals with Posterior Crossbite: A Cross-Sectional Study

Facial morphology is known to be influenced by genetic and environmental factors. Scientific evidence regarding facial parameters in patients with posterior crossbite is lacking. This study aimed to investigate the association between posterior crossbite and facial parameters. This cross-sectional study included 34 adolescents with and 34 adolescents without posterior crossbite in the age range from 13 to 15 years. Facial surface scans were acquired with a 3dMD imaging system, and landmark-based analysis was performed. Data were analyzed using the Mann-Whitney U test and Spearman's correlations. Individuals in the control group had lower face heights (females: p = 0.003, r = 0.45; males: p = 0.005, r = 0.57). The control group females presented with smaller intercanthal width (p = 0.04; r = 0.31) and anatomical nose width (p = 0.004; r = 0.43) compared with the crossbite group females. The males in the control group had wider nostrils. In the control group, significant correlations among different facial parameters were more common, including the correlations between eye width and other transversal face measurements. On the contrary, the facial width was correlated with nasal protrusion (r = 0.657; p < 0.01) and the morphological width of the nose (r = 0.505; p < 0.05) in the crossbite group alone. In both groups, the philtrum width was linked with the anatomical and morphological widths of the nose. Conclusions: Patients with posterior crossbites have increased face height and different patterns of facial proportions compared with individuals without crossbites.

Integration accuracy of craniofacial cone-beam computed tomography images with three-dimensional facial scans according to different registration areas

OBJECTIVES

To evaluate the integration accuracy of cone-beam computed tomography (CBCT) images with three-dimensional (3D) facial scans according to different registration areas.

MATERIALS AND METHODS

Twenty-five patients (14 males and 11 females), with a mean age of 19.0 ± 11.3 years, were included in this study. Each patient underwent CBCT and facial scans on the same day in an upright position. The facial scans were integrated with the corresponding soft-tissue images of CBCT scans. Three methods were used to integrate the two imaging modalities based on the facial regions scanned: R1, only the forehead and nasal bridge area were included; R2, the right and left malar area were included; and R3, the forehead, nasal bridge, and malar areas were included. The integration accuracy between the facial scans and CBCT images was evaluated by color-mapping methods and average surface distances, calculated by measuring the 3D distances between the surface points on the two superimposed images.

RESULTS

The average surface differences between facial scans and CBCT images were less than 1.0 mm in all three methods. The R3 method showed fewer differences between the facial scans and CBCT images than the other methods did.

CONCLUSIONS

Facial scans obtained using a low-cost facial scanner showed clinically acceptable performance. The integration accuracy of facial and CBCT scans can be increased by including the forehead, nasal bridge, and malar areas as registration areas.

Does unilateral surgically assisted rapid maxillary expansion (SARME) lead to perinasal asymmetry?

OBJECTIVE

True unilateral posterior crossbite (TUPC) requires unilateral expansion to prevent nonocclusion at the noncrossbite (NC) side. The recommended osteotomies for TUPC after sutural closure are anterior, lateral, and posterior osteotomies only on the crossbite (C) side and median osteotomy of the midpalatal suture, i.e., unilateral surgically assisted rapid maxillary expansion (SARME). The goal was to assess airway and perinasal soft tissue outcomes after SARME.

METHODS

Data from 16 patients (8 males, 8 females; mean age 18.38 ± 1.45 years) were retrospectively assessed after unilateral SARME. The expansion (twice daily: 0.5 mm/day) and retention periods comprised 3 weeks and 6 months, respectively. Stereophotogrammetric images were used for soft tissue assessment; cone beam computed tomography (CBCT) was used to evaluate the anterior nasal airway. Statistical analyses were performed.

RESULTS

Using linear measurements, soft tissue distances of the alar base and alare to midsagittal plane (MSP) were significantly increased on the C side. A significant decrease was observed for the distance from the lower nostril point to the MSP on the NC side compared to a significant increase on the C side. Comparing the C and NC sides, the changes were significantly higher on the C side for all parameters except the upper nostril point to the MSP distance. Cheek volume was significantly higher on the C side. Volume changes of the anterior nasal airway (ANA) were significantly increased on the C side, but volume changes between NC and C were not significantly different.

CONCLUSIONS

Unilateral SARME led to significant expansion of ANA on the C side, but did not lead to asymmetry in the nasal region or have adverse effects on the airway or perinasal soft tissues. Thus, this novel treatment method may be useful in the treatment of patients with TUPC.

Anthropometric Comparison of 3-Dimensional Facial Scan Taken With a Low-Cost Facial Scanner With Cone-Beam Computed Tomography Scan

OBJECTIVE

The aim of this study was to evaluate the accuracy of 3-dimensional (3D) facial scans taken with a low-cost facial scanner compared with cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Twenty-five patients had their CBCT scan and 3D facial scan taken on the same day. Facial scans were taken with a low-cost facial scanner (Bellus3D, ARC-1 scanner) in an upright position. The facial scans were imported into Invivo5 software and were integrated with the corresponding CBCT scans. Then, 16 soft tissue landmarks were identified on the CBCT scans and the 3D-integrated facial scans. The 6 vertical, 7 horizontal, 10 oblique linear, and 11 angular anthropometric measurements were obtained and compared between the CBCT scans and 3D-integrated facial scans using paired t test and Bland-Altman plots.

RESULTS

The differences between CBCT scans and 3D-integrated facial scans showed no statistical significance except for 2 vertical measurements. Bland-Altman plots showed that all anthropometric measurements were within the limit of agreement. The differences between CBCT scans and 3D-integrated facial scans were <1.5 mm or 1.5 degrees except for 2 vertical measurements.

CONCLUSIONS

Three-dimensional facial scans taken with facial scanner showed a clinical acceptance when compared with CBCT scans.

An evaluation of three-dimensional facial changes after surgically assisted rapid maxillary expansion (SARME): an observational study

BACKGROUND

The abnormal facial features in maxillary transverse deficiency (MTD) are minimal and limited to a deficiency of the middle facial third, narrow nares and nasal base, and deepened nasolabial folds. The surgical expansion of the narrow maxilla has most obvious effects on widening of the maxillary dental arch and expansion of the maxillary and palatal structures in the transverse plane, however sagittal changes also occurs. The purpose of this observational study was to evaluate the three-dimensional (3D) facial soft tissue changes following surgically assisted rapid maxillary expansion (SARME).

METHODS

In 15 skeletally mature patients with severe maxillary transverse deficiency, the planned maxillary expansion (on average 8.8 mm ± 2.3 mm) was achieved with a bone-borne palatal distractor. The 3D optical scans of the facial surface were obtained before and six months after SARME. In the first part, we defined different anatomical landmarks on both scans and compared cephalometric measurements. In the second part, we registered both 3D scans in the same workplace using the regional best-fit method (forehead, supraorbital and nasal root regions were selected for the superimposition) and conducted surface analysis.

RESULTS

The largest differences between the pre- and post-operation scans were observed in the paranasal and cheek area (1.4 ± 1.0 mm). Significant differences occurred for an increased nasal width, a decreased upper-face height with an unchanged lower height, an increased vertical philtrum height and an increased nasolabial angle. A significant increase in the facial profile angle was also observed, resulting in an increased facial convexity and anterior displacement of the upper-lip area.

CONCLUSIONS

The widening of the nose and increased projection in the cheek and paranasal area in the lateral direction after maxillary expansion were confirmed; moreover, facial convexity increases, reflecting the underlying advancement of the maxilla.

Rapid maxillary expansion treatment increases mid-facial depth in early mixed dentition

OBJECTIVE

To evaluate the effects of rapid maxillary expansion (RME) on mid-facial depth in early mixed dentition and to investigate the relationship between change in mid-facial depth and maxillary sinus and nasal cavity.

METHODS

A total of 35 patients with mixed dentition treated with a Haas expander were included in this retrospective study. All patients underwent a cone-beam computed tomography scan before and after rapid maxillary expansion. The Wilcoxon signed-rank test was performed to evaluate the changes in maxillary width, facial depth, maxillary sinus, and nasal cavity volume before and after expansion. Multiple linear regression analysis was applied to evaluate the correlations among them.

RESULTS

The hard and soft tissue facial depth in the middle third increased significantly (P < 0.001). The gain on the outer sagittal plane (1.04-1.52 mm) was slightly bigger than that on the inner sagittal plane (0.91-1.30 mm). Maxillary width and nasal cavity width increased 3.42 ± 0.93 mm (P < 0.001) and 2.25 ± 0.77 mm (P < 0.001), respectively, after treatment. A gain was also achieved in both nasal cavity volume (2,236.15 mm³, P < 0.001) and maxillary sinus volume (1,227.33 mm³, P < 0.001). Multiple linear regression analysis showed that with the increase in maxillary sinus volume, the facial depth increased as well (B = 0.455-0.683, P < 0.05). Also, statistically significant correlations were found between nasal width and nasal cavity volume (B = 0.384, P < 0.05).

CONCLUSION

The depth of the middle third face increased significantly. The facial depth increase was related to the enlargement of maxillary sinus volume, while the nasal cavity volume gain was related to the nasal width increase. This indicated that RME might enhance the fullness of the mid-face and facilitate the patency of nose breathing.

The Efficacy of Lingual Laser Frenectomy in Pediatric OSAS: A Randomized Double-Blinded and Controlled Clinical Study

This randomized, double-blind and controlled clinical trial investigates how a diode laser lingual frenectomy can improve obstructive sleep apnea syndrome (OSAS) in pediatric patients. Background: Several authors have shown that a short lingual frenulum causes a reduction in incoming air flow and the relationship between OSAS and a short lingual frenulum. Methods: Thirty-two pediatric patients were equally randomly divided into a Study Group (SG) and a Control Group (CG). On each SG patient a polysomnography 1 (PSG1) and a lingual frenectomy were performed using a diode laser via Doctor Smile Wiser technology, power 7 W. After three months, a new polysomnography (PSG2) was performed to evaluate the lingual frenectomy efficacy in pediatric patients. The pain was assessed by a numerical rating scale (NRS) before and after surgery. The CG followed the same protocol without a lingual frenectomy but myofunctional and speech therapy were conducted to qualitatively and quantitatively improve the lingual functionality. In the SG, eight subjects (50%) had severe OSAS and eight had moderate (50%) while in the CG, three subjects had severe OSAS (18.8%) and thirteen had moderate (81.2%). Results: In the SG, 93.8% were classified as mild OSAS and 6.2% as moderate. In contrast, in the CG, 18.75% were classified as mild OSAS, 62.5% as moderate and 18.75% as severe. Conclusion: The study demonstrates how a lingual laser frenectomy can improve OSAS in pediatric patients.

Evaluation of the Soft Tissue Changes after Rapid Maxillary Expansion Using a Handheld Three-Dimensional Scanner: A Prospective Study

Facial soft tissue esthetics is a priority in orthodontic treatment, and emerging of the digital technologies can offer new methods to help the orthodontist toward an esthetic outcome. This prospective study aimed to assess the soft tissue changes of the face after six months of retention following Rapid Maxillary Expansion (RME). The sample consisted of 25 patients (13 females, 12 males, mean age: 11.6 years) who presented with unilateral or bilateral posterior crossbite requiring RME, which was performed with a Hyrax expander. 3D facial images were obtained before treatment (T₀) and at the end of a six-month retention period after the treatment (T₁) using a structured-light 3D handheld scanner. Linear and angular measurements were performed and 3D deviation analyses were done for six morphological regions of the face. Significant changes in various areas of the nasal and the upper lip regions were observed. Based on the results of the study and within the limitations of the study, RME with a Hyrax expander results in significant morphological changes of the face after a six-month retention period.

Three-dimensional stereophotogrammetric analysis of nasolabial soft tissue effects of rapid maxillary expansion: a systematic review of clinical trials

The aim of this systematic review is to analyse the quality and clinical evidence in the literature analysing, through 3D stereophotogrammetry, the nasolabial soft tissue modifications that may occur after rapid maxillary expansion (RME). This systematic literature review was based on the PRISMA-P statement and was registered in the PROSPERO database with the following protocol ID: CRD42017079875. Pubmed, Cochrane, EBSCO, Scopus, Web of Science databases were searched with no restriction of year or publication status. Selection criteria were: randomised clinical trials, controlled clinical trials, cohort studies, cross-sectional studies, case-control studies on patients with unilateral/bilateral crossbite, transverse maxillary deficiency and crowding, treated with RME and monitored by 3D stereophotogrammetry. 652 articles were retrieved in the initial search. After the review process, 11 full-text articles met inclusion criteria. After the evaluation process, 4 publications were included for the present literature review. Due to the heterogeneous methodology meta-analysis was not possible; consequently, a systematic assessment of the studies and summary of the findings from the available evidence were used to answer the research question. The maximum widening of the alar cartilage is 1.41 ± 0.95 mm, whose clinical significance is open to question. The effect of RME on the mouth width remains controversial. In Altindis et al., the difference between pre-treatment and post-treatment mouth width (1.80 mm increment in the banded RME group) was statistically significant, while in Baysal 1.86 mm was considered a non-significant value. Inconsistencies and limitations in the study population and measurement protocols were detected between studies. These data underline the necessity for updated guidelines that allow to standardise, for this type of study, sample selection, measurement methods and collection of results.

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

OBJECTIVES

The aim of the present randomized controlled trial (RCT) was therefore the tridimensional evaluation of soft tissue changes after rapid maxillary expansion in growing patients.

SETTING AND SAMPLE POPULATION

Treated group comprised 17 patients (10 males and 7 females) with a mean age of 9.8 ± 1.2 years, and control group comprised 17 patients (13 males and 4 females) with a mean age of 9.1 ± 2.1 years.

MATERIAL & METHODS

All patients of the treated group underwent maxillary expansion with Haas-type expander while patients of the control group underwent no treatment. 3D facial scans were acquired at T1, at the beginning of treatment or observation period, and at T2, 18 months apart. The mean interval between the timepoints was 18.2 ± 0.4 months.

RESULTS

The main differences between groups were reported in the nasal area. Nasal width (Alr-All) significantly increased in the treated group compared with the control. The increase in intereye and mouth width in the study group did not show differences with the control group. No significant differences were reported for lips' protrusion, angular measurements and facial heights between groups. The total nose volume difference was significantly higher in the treated group compared with control, and this result was related mainly to the significant increase in the nasal dorsum volume.

CONCLUSION

Maxillary expansion produced significant increase in the nasal base and nasal volumes, but its clinical relevance is still questionable.

Facial soft tissue changes after nonsurgical rapid maxillary expansion: a systematic review and meta-analysis

Background

The present systematic review and meta-analysis aimed to test the hypothesis that no facial soft tissue changes occur after nonsurgical rapid maxillary expansion (RME), in order to provide a reference for orthodontists.

Methods

PubMed, EMBASE, Cochrane Library, OVID, MEDLINE, CINAHL, Scopus, and ScienceDirect databases were electronically and manually searched up to December 2017, and randomized controlled, clinical controlled trials, cohort studies and retrospective studies where soft tissue changes were measured before and after nonsurgical RME were identified. Study appraisal and synthesis were performed by two reviewers who completed the study selection and quality assessment procedures independently and in duplicate. Data from the involved studies were pooled using Revman 5.3.

Results

A total of 1762 articles were identified after the removal of duplicates. After selection and quality assessment, 15 studies met the inclusion criteria for the systematic review, and 13 articles were ultimately included in the meta-analysis. The quality of the involved studies was relatively moderate. Pre-expansion, postexpansion, and postretention data were pooled. The nasal width, alar base width, and distances from the lower lips to the E line showed significant changes after expansion. Moreover, after retention, the nasal width, mouth width, upper philtrum width, and distance from the lower lip to the E line showed significant increases relative to the baseline values. Limitations of the present study included the moderate quality of the included studies and the fact that the results were based on short-term observations of patients in the growth phase.

Conclusion

Our findings suggest that RME results in a significantly increased nasal width, mouth width, upper philtrum width, and distance from the lower lip to the E line after the retention phase. However, the clinical importance of these findings is questionable.

Electronic supplementary material

The online version of this article (10.1186/s13005-018-0162-8) contains supplementary material, which is available to authorized users.

Soft tissue changes in the orofacial region after rapid maxillary expansion : A cone beam computed tomography study

OBJECTIVE

Rapid maxillary expansion (RME) is usually used for expanding the maxillary bony segments. Many studies have assessed the dental and skeletal effects of the expansion treatment but few studies evaluated soft tissue changes using cone beam computed tomography (CBCT) images. This study aims to compare soft tissue changes after RME in prepubertal and postpubertal subjects using CBCT images. The null hypothesis of this study is there is no difference between prepubertal and postpubertal patients in soft tissue changes after RME treatment.

MATERIALS AND METHODS

A total of 28 patients (10 males, 18 females) with a bonded type of rapid maxillary expander were included in this study. The patients were divided into two subgroups according to cervical vertebral maturation stage. Prepubertal and postpubertal groups were obtained. Following the selection of CBCT images from the archive, pretreatment (T0) and postretention measurements (T1) were performed. Nine linear and one angular measurement for a total of 10 measurements were evaluated on each CBCT image. The mean differences between T0 and T1 measurements were compared by using the paired-samples t test and significance was set at P < 0.05.

RESULTS

The largest median increase was found in cheek projection of the prepubertal group. Changes in soft tissue nasal base, philtrum width, upper lip length, columella width, columella height, and cheek projection were statistically significant (P < 0.001) in both groups. No significant differences were observed in soft tissue alar base, nostril width, nostril height, and nasolabial angle.

CONCLUSION

Some significant changes in facial soft tissues were observed after RME treatment but there were no significant differences between prepubertal and postpubertal subjects. The null hypothesis is accepted because there were no significant differences between the groups.

The effects of maxillary expansion on the soft tissue facial profile

Purpose

The aims of this retrospective study were to evaluate the possible changes in soft tissue facial profile induced by orthopedic rapid maxillary expansion (RME) and surgically assisted rapid maxillary expansion (SARME), and to correlate them with the underlying hard tissue alterations.

Materials and Methods

16 patients who received bone borne SARME and 25 patients who were subjected to RME using metal cast splint hyrax appliance were analyzed retrospectively. This research was conducted on lateral cephalometric radiographs taken on 2 occasions: before expansion (T1) and at the beginning of any further orthodontic treatment (T2). Investigated lateral cephalometric parameters consisted of Holdaway soft tissue measurements with some supplementary soft tissue, skeletal and dental assessments.

Results

The acquisition of T2 cephalograms which conforms to the initiation of further orthodontic treatment corresponded to 83.25±3.51 days for SARME and 85.68±4.37 days for RME after the expansion was completed. The only significant change in soft tissue profile of the SARME group was a decrease in upper lip thickness (p<0.05), whereas in the RME group, decrease in soft tissue facial profile angle and increase in H angle were found to be statistically significant (p<0.05 for each). For the RME group, the changes in soft tissue facial profile angle and H angle correlated only with the changes in SNB angle (p<0.05).

Conclusion

While bone-borne SARME did not seem to possess the potential to alter soft tissue profile, tooth-borne RME caused a more convex soft tissue profile related to a reduction in SNB.

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

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.

Effects of rapid maxillary expansion on facial soft tissues : Deviation analysis on three-dimensional images

OBJECTIVE

Changes in soft tissue in various morphological regions of the face immediately after rapid maxillary expansion (RME) were examined using three-dimensional (3D) deviation analyses.

PATIENTS AND METHODS

A total of 50 patients were included in the study; 25 patients (11 female and 14 male) presented with a unilateral or bilateral posterior crossbite malocclusion requiring RME. In addition, 25 patients (13 female and 12 male) were included as a control group. The mean ages of the study group and control group were 9.8 years (range 8.1-12.6 years) and 9.6 years (range 8.3-12.2 years), respectively. The 3D stereophotogrammetric images acquired immediately before the appliance was cemented and after expansion had been completed in the treatment group were compared using Rapidform software. The 3D deviation analyses were made for the complete face and in the upper and lower face, upper and lower lips and nose regions. The amount of negative and positive deviations and the mean deviations were examined on the facial meshes for the 95th percentiles.

RESULTS

Immediately after RME, the mean absolute deviation over the complete face was 0.54 ± 0.16 mm. The mean change for the upper face was 0.42 ± 0.17 mm (mean positive deviation: 0.37 ± 0.17 mm; mean negative deviation: -0.48 ± 0.18 mm). The mean absolute deviation was 0.62 ± 0.28 mm in the upper lip and 0.60 ± 0.34 mm in the lower lip. In the nose area, the absolute deviation was 0.41 ± 0.21 mm (mean positive deviation: 0.39 ± 0.16 mm; mean negative deviation: -0.43 ± 0.26 mm).

CONCLUSIONS

Changes in facial soft tissues in the upper face, lower face, nasal soft tissues, and lower and upper lip regions were observed after RME.