Three-Dimensional Analysis of Midfacial Soft Tissue Changes According to Maxillary Superior Movement After Horizontal Osteotomy of the Maxilla

Can the Upper Vermilion and the Nasolabial Fold Be Changed With Orthognathic Surgery?

BACKGROUND

Retrusive profiles show an appearance of aging with an under-projected vermilion and pronounced nasolabial folds due to deficient bone support.

PURPOSE

A study was made of the association between orthognathic surgery and changes in the nasolabial and vermilion areas in patients with retrusive profiles.

STUDY DESIGN, SETTING, SAMPLE

A retrospective cohort study evaluated patients subjected to bimaxillary surgery according to the Barcelona Line (BL) protocol during 2021 at Teknon Medical Center (Barcelona, Spain). Subjects with craniofacial syndromes, facial esthetic procedures, and dental rehabilitations involving lip changes, were excluded.

PREDICTOR VARIABLE

The predictor variable was the timing of cephalometric measures, reported as T0 (preoperatively), T1 (1 month after surgery), and T2 (after 1 year of follow-up).

MAIN OUTCOME VARIABLE

The outcome variable corresponded to the soft tissue changes of the nasolabial and vermilion area, reported as the nasolabial fold length and angle, nasolabial angle, upper lip concavity, vermilion length, and upper lip sagittal distance from BL.

COVARIATES

The covariates comprised patient demographic data, the surgical-orthodontic protocol, and the magnitude and direction of the skeletal movements.

ANALYSES

Descriptive and inferential analyses were performed based on analysis of variance, the Bonferroni test, Pearson's linear coefficient, the nonparametric Mann-Whitney U-test, Kruskal-Wallis test, and multiple linear regression models. Statistical significance was considered for P < .05.

RESULTS

The sample comprised 27 subjects with a mean age of 32.5 ± 11.2 years. A mean decrease in nasolabial angle of 5.5 ± 6° was recorded (P < .001), with a shortening of the nasolabial fold length of 4.4 ± 7.6 mm (P = .019). An increase in upper lip concavity angle of 14.4 ± 12° was recorded (P < .001), along with a vermilion lengthening of 1.6 ± 1.3 mm (P < .001) and an increase in upper lip sagittal distance to BL of 5.7 ± 7.3 mm (P = .001), indicating a more projected and everted upper vermilion.

CONCLUSIONS AND RELEVANCE

When adequate dentoskeletal support is provided by specific positional changes of the jaws planned through orthognathic surgery, the length of the nasolabial fold decreases, and the upper vermilion lengthens and becomes slightly everted.

Soft tissue changes with skeletal anchorage in comparison to conventional anchorage protocols in the treatment of bimaxillary proclination patients treated with premolar extraction : A systematic review

PURPOSE

This review systematically evaluates the evidence related to comparisons between skeletal and conventional anchorage protocols in the treatment of bimaxillary proclination patients who underwent premolars extraction with respect to soft tissue profile changes, treatment duration and three-dimensional (3D) soft tissue changes.

METHODS

Electronic database search and hand search with no language limitations were conducted in the Cochrane Library, PubMed, Ovid, Web of Science, Scopus and ClinicalTrials.gov. The selection criteria were set to include studies with patients aged 13 years and above requiring extractions of upper and lower first premolars to treat bimaxillary proclination with high anchorage demand. Risk of bias assessment was undertaken with Cochrane's Risk Of Bias tool 2.0 (ROB 2.0) for randomised controlled trials (RCTs) and ROBINS‑I tool for nonrandomised prospective studies. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used for quality assessment. Results were summarised qualitatively; no meta-analysis was conducted.

RESULTS

Two RCTs and two nonrandomised prospective studies were included. According to the GRADE approach, there is low to very low quality of evidence that treatment using mini-implant anchorage may significantly change nasolabial angle, upper and lower lip procumbence, and facial convexity angle compared to treatment with conventional anchorage. Similarly, very low quality evidence exists showing no differences in treatment duration between treatments with skeletal or conventional anchorage.

CONCLUSIONS

The overall existing evidence regarding the effect of anchorage protocols on soft tissue changes in patients with bimaxillary protrusion and premolar extraction treatment plans is of low quality.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42020216684.

Comparison of Effects between Total Maxillary Setback Osteotomy and Anterior Maxillary Segmental Osteotomy on Nasolabial Morphology

BACKGROUND

The authors aimed to compare the effects of total maxillary setback osteotomy (TMSO) and anterior maxillary segmental osteotomy (AMSO) on nasolabial morphology.

METHODS

This retrospective clinical trial enrolled 130 patients undergoing maxillary surgery using TMSO or AMSO. Ten nasolabial-related parameters and nasal airway volume were measured preoperatively and postoperatively. The soft-tissue digital model was reconstructed using Geomagic Studio and Dolphin image 11.0. Statistical analysis was performed using IBM SPSS Version 27.0.

RESULTS

A total of 75 patients underwent TMSO, and 55 underwent AMSO. Both techniques achieved optimal repositioning of the maxilla. Except for the dorsal nasal length, the dorsal nasal height, the length of the nasal columella, and the upper lip thickness, the remaining parameters were significantly different in the TMSO group. In the AMSO group, only the nasolabial angle, the alar base width, and the greatest alar width showed significant differences. There was a significant difference in the nasal airway volume for the TMSO group. The results of matching maps are consistent with the statistical results.

CONCLUSIONS

TMSO has a more significant impact on both nose and upper lip soft tissues, whereas AMSO has a more significant impact on the upper lip and less on the nasal soft tissue. There is a significant decrease in nasal airway volume after TMSO, whereas AMSO showed less decrease. This retrospective study is helpful for clinicians and patients to understand the different changes in nasolabial morphology caused by the two interventions, which is essential for effective intervention and physician-patient communication.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Three-Dimensional Digital Image Analysis of Skeletal and Soft Tissue Points A and B after Orthodontic Treatment with Premolar Extraction in Bimaxillary Protrusive Patients

Aim. To investigate the effect of changes in incisor tip, apex movement, and inclination on skeletal points A and B and characterize changes in skeletal points A and B to the soft tissue points A and B after incisor retraction in Angle Class I bimaxillary dentoalveolar protrusion. Methods. Twenty-two patients with Angle Class I bimaxillary dentoalveolar protrusion treated with four first premolar extractions were included in this study. The displacement of skeletal and soft tissue points A and B was measured using cone-beam computed tomography (CBCT) using a three-dimensional coordinate system. The movement of the upper and lower incisors was also measured using CBCT-synthesized lateral cephalograms. Results. Changes in the incisal tip, apex, and inclination after retraction did not significantly affect the position of points A and B in any direction (x, y, z). Linear regression analysis showed a statistically significant relationship between skeletal point A and soft tissue point A on the anteroposterior axis (z). Skeletal point A moved forward by 0.07 mm, and soft tissue point A moved forward by 0.38 mm, establishing a ratio of 0.18: 1 (r = 0.554, p < 0.01). Conclusion. The positional complexion of the skeletal points A and B was not directly influenced by changes in the incisor tip, apex, and inclination. Although the results suggest that soft tissue point A follows the anteroposterior position of skeletal point A, its clinical significance is suspected. Thus, hard and soft tissue analysis should be considered in treatment planning.

Three-dimensional analysis of soft tissue changes in full-face view after surgical correction of skeletal class III malocclusion

OBJECTIVE

The objective of this study was to evaluate changes in soft tissue in full-face view because of surgical correction of skeletal Class III malocclusion, using 3-dimensional (3D) laser scanning.

METHODS

Twenty-seven subjects with skeletal Class III malocclusion [11 males; mean age (SD), 24.0 (5.7) years] underwent bilateral sagittal split ramus osteotomy for mandibular setback combined with Lefort I osteotomy with/without maxillary advancement. Twelve patients (group 1) had mandibular setback surgery, and the other 15 (group 2) had combination surgery. Lateral cephalograms and 3D facial scan images were assessed preoperatively and postoperatively. The facial widths upon superimposition of 3D facial images were measured in the same coordinates using a Rapidform 2006 system. Paired and independent t tests were done for statistical analysis.

RESULTS

The midface soft tissue broadened significantly above the cheilion plane postoperatively (P < 0.05). A larger change was observed nearer to subnasale plane, and a similar trend was seen among the horizontal planes in 1- or 2-jaw surgery groups. The widths from the exocanthion plane to the subnasale plane increased more in group 2 [mean (SD), 4.45 (2.45) mm, 8.71 (2.92) mm, and 7.62 (3.13) mm] than those in group 1 [mean (SD), 1.26 (0.97) mm, 1.84 (1.06) mm, and 1.35 (0.65) mm], and this difference was significant (P < 0.05). There was a decrease below the cheilion plane with mandibular setback between groups, but this difference was not significant.

CONCLUSIONS

The measurement method used here for the shape outline of the lateral parts of the face could provide quantitative data for the clinical evaluation and objective analysis of the human face in full-face view. The midface soft tissue in subjects with skeletal Class III malocclusion exhibited a greater increase in width after bimaxillary surgery procedures than mandibular setback-only surgery.

Influence of maxillary advancement surgery on skeletal and soft-tissue changes in the nose - a retrospective cone-beam computed tomography study

Objectives

Surgical correction of skeletal maxillary retroposition is often associated with changes in the morphology of the nose. Unwanted alar flaring of the nose is observed in many cases. The aim of the present study was therefore to investigate the influence of surgical advancement of the maxilla on changes in the soft-tissue morphology of the nose. Having a coefficient that allows prediction of change in the nasal width in Caucasian patients after surgery would be helpful for treatment planning.

Materials and methods

All 33 patients included in this retrospective study were of Caucasian descent and had skeletal Class III with maxillary retrognathia. They were all treated with maxillary advancement using a combination of orthodontic and maxillofacial surgery methods. Two cone-beam computed tomography (CBCT) datasets were available for all of the study's participants (16 female, 17 male; age 24.3 ± 10.4 years): the first CBCT imaging was obtained before the planned procedure (T0) and the second 14.1 ± 6.4 months postoperatively (T1). Morphological changes were recorded three-dimensionally using computer-aided methods (Mimics (Materialise NV, Leuven/Belgium), Geomagic (Geomagics, Morrisville/USA)). Statistical analysis was carried out using SPSS 21 for Mac.

Results

The mean sagittal advancement of the maxilla was 5.58 mm. The width of the nose at the alar base (Alb) changed by a mean of + 2.59 mm (±1.26 mm) and at the ala (Al) by a mean of + 3.17 mm (±1.32 mm). Both of these changes were statistically highly significant (P = 0.000). The increase in the width of the nose corresponded to approximately half of the maxillary advancement distance in over 80 % of the patients. The nasolabial angle declined by an average of −6.65° (±7.71°).

Conclusions

Maxillary advancement correlates with a distinct morphological change in nasal width. This should be taken into account in the treatment approach and in the information provided to patients.

Three-dimensional assessment of upper lip positional changes according to simulated maxillary anterior tooth movements by white light scanning

Objective

Esthetic improvements during orthodontic treatment are achieved by changes in positions of the lips and surrounding soft tissues. Facial soft-tissue movement has already been two-dimensionally evaluated by cephalometry. In this study, we aimed to three-dimensionally assess positional changes of the adult upper lip according to simulated maxillary anterior tooth movements by white light scanning.

Methods

We measured changes in three-dimensional coordinates of labial landmarks in relation to maxillary incisor movements of normal adults simulated with films of varying thickness by using a white light scanner.

Results

With increasing protraction, the upper lip moved forward and significantly upward. Labial movement was limited by the surrounding soft tissues. The extent of movement above the vermilion border was slightly less than half that of the teeth, showing strong correlation. Most changes were concentrated in the depression above the upper vermilion border. Labial movement toward the nose was reduced significantly.

Conclusions

After adequately controlling several variables and using white light scanning with high reproducibility and accuracy, the coefficient of determination showed moderate values (0.40-0.77) and significant changes could be determined. This method would be useful to predict soft-tissue positional changes according to tooth movements.

Three-dimensional soft-tissue and hard-tissue changes in the treatment of bimaxillary protrusion

INTRODUCTION

Facial convexity related to bimaxillary protrusion is prevalent in many populations. Underlying skeletal protrusion combined with increased dentoalveolar protrusion contributes to facial muscle imbalance and lip incompetence, which is undesirable for many patients. In this study, we evaluated the relationship between soft-tissue and hard-tissue changes in an orthodontically treated Asian population.

METHODS

Twenty-four consecutive adult Asian patients (mean age, 24 years), diagnosed with severe bimaxillary dentoalveolar protrusion, were evaluated using pretreatment and posttreatment cone-beam computed tomography. The patients were treated with 4 first premolar extractions followed by anterior retraction with either skeletal or intraoral anchorage. Serial cone-beam computed tomography radiographs were registered on the entire cranial base and fossa. Soft-tissue and hard-tissue changes were determined through landmark displacement and color mapping.

RESULTS

Upper lip retraction was concentrated between the nasolabial folds and commissures. Lower lip retraction was accompanied by significant redistribution of soft tissues at pogonion. Soft-tissue changes correlated well with regional facial muscle activity. Significant retractions (2-4 mm) of the soft tissues occurred beyond the midsagittal region. Use of skeletal anchorage resulted in 1.5 mm greater lower lip retraction than intraoral anchorage, with greater retraction of the maxillary and mandibular incisor root apices.

CONCLUSIONS

Profound soft-tissue changes accompanied retraction of the anterior dentition with both treatment modalities.

Three-dimensional evaluation of midfacial asymmetry in patients with nonsyndromic unilateral cleft lip and palate by cone-beam computed tomography

Objective

To compare three-dimensionally the midfacial hard- and soft-tissue asymmetries between the affected and the unaffected sides and determine the relationship between the hard tissue and the overlying soft tissue in patients with nonsyndromic complete unilateral cleft lip and palate (UCLP) by cone-beam computed tomography (CBCT) analysis.

Methods

The maxillofacial regions of 26 adults (18 men, 8 women) with nonsyndromic UCLP were scanned by CBCT and reconstructed by three-dimensional dental imaging. The frontal-view midfacial analysis was based on a 3 × 3 grid of vertical and horizontal lines and their intersecting points. Two additional points were used for assessing the dentoalveolar area. Linear and surface measurements from three reference planes (Basion-perpendicular, midsagittal reference, and Frankfurt horizontal planes) to the intersecting points were used to evaluate the anteroposterior, transverse, and vertical asymmetries as well as convexity or concavity.

Results

Anteroposteriorly, the soft tissue in the nasolabial and dentoalveolar regions was significantly thicker and positioned more anteriorly on the affected side than on the unaffected side (p < 0.05). The hard tissue in the dentoalveolar region was significantly retruded on the affected side compared with the unaffected side (p < 0.05). The other midfacial regions showed no significant differences.

Conclusions

With the exception of the nasolabial and dentoalveolar regions, no distinctive midfacial hard- and soft-tissue asymmetries exist between the affected and the unaffected sides in patients with nonsyndromic UCLP.

Effect of mandibular advancement on the natural position of the head: a preliminary study of 3-dimensional cephalometric analysis

Our aim was to investigate the potential effect of advancement by bilateral sagittal split osteotomy (BSSO) on the natural position of the head by using 3-dimensional cephalomentric analysis. Seven consecutive patients who had had only BSSO advancement, and had had preoperative and 6-week postoperative cone beam computed tomography (CT) scans, were recruited to this retrospective study. Two variables, SNB and SNC2, were used to indicate the craniomandibular alignment and craniocervical inclination, respectively, in the midsagittal plane. Using 3-dimensional cephalometric analysis software, the SNB and the SNC2 were recorded in volume and measured in the midsagittal plane at 3 independent time-points. The reliability was measured and a paired t test used to assess the significance of differences between the means of SNB and SNC2 before and after operation. The 3-dimensional cephalometric measurement showed good reliability. The SNB was increased as planned in all the mandibles that were advanced, the cervical vertebrae were brought forward after BSSO, and the SNC2 was significantly increased in 6 of the 7 patients. Three-dimensional cephalometric analysis may provide an alternative way of assessing cephalometrics. After BSSO advancement, the natural position of the head changed by increasing the craniocervical inclination in an anteroposterior direction.

Bimaxillary surgery in Class III malocclusion: soft and hard tissue changes

The aim of this study was to quantify anteroposterior facial soft tissue changes with respect to underlying skeletal movements after Le Fort I maxillary advancement and mandibular setback surgery with sagittal split osteotomy in Class III skeletal deformity by using lateral cephalograms taken before and after the operation. The material consisted of 31 patient (15 female, 16 male cases, mean age was 26.7 ± 2.5 years) with Class III skeletal deformity. All patients were treated by Le Fort I maxillary advancement and mandibular setback surgery with sagittal split osteotomy. Lateral cephalograms were taken before and 1.4 ± 0.3 years after surgery. Wilcoxon test was used to compare the pre- and post-surgical measurements. Pearson correlation test was used to compare the relationships between the skeletal, dental and facial soft tissue changes. In the maxilla, the APOINTAP (the anteroposterior position of A point) and ITIPAP (the anteroposterior position of upper incisor) showed significant protractions (-3.19 ± 3.63, and -3.19 ± 4.52, p < 0.01). In the mandible, the L1TIPAP (the anteroposterior position of lower incisor, -3.20 ± 5.83, p < 0.01), L1TIPSI (the superoinferior position of lower incisor, -2.43 ± 10.31, p < 0.05), BPOINTSP (the superoinferior position of B point, -2.28 ± 12.51, p < 0.05) and BPOINTAP (the anteroposterior position of B point, -3.19 ± 9.31, p < 0.01) showed significant retractions and upper positions after bimaxillary surgery. The insignificant decrease in soft tissue Pog-Vert distance was correlated the significant upper position of B point and lower incisor (r: 0.851, p < 0.001 and r: 0.842, p < 0.001).

Midfacial soft-tissue changes after mandibular setback surgery with or without paranasal augmentation: cone-beam computed tomography (CBCT) volume superimposition

The aim of this article is to compare the soft-tissue changes in the midfacial areas of patients who had undergone mandibular setback sagittal split ramus osteotomy (SSRO) with that of mandibular setback SSRO with paranasal augmentation. The subjects included 15 patients (group I), SSRO with paranasal augmentation and 20 patients (group II), SSRO alone. To evaluate the difference of the midfacial soft-tissue changes between groups, cone-beam computed tomography superimposition was utilized and the soft-tissue changes were measured both preoperatively and postoperatively by a 10 × 27 grid. In group I, the soft tissues were changed at the areas bounded superiorly by the infraorbital foramen, zygomatic eminence, posteriorly by the masseteric muscle and medially by the lateral aspect of the nose and following the nasolabial fold. In group II, the midfacial soft-tissue measurements were unchanged. This study may help clinicians to predict improvement in the midfacial region from mandibular setback SSRO with or without a paranasal augmentation procedure in class III deformities.

Facial soft tissue changes after maxillary impaction and mandibular advancement in high angle class II cases

The aim of this study was to determine the vertical and anteroposterior alterations in the soft, the dental and the skeletal tissues associated with the facial profile after Le Fort I maxillary impaction in conjunction with sagittal split osteotomy for mandibular advancement performed in patients with a high angle Class II skeletal deformity.The study population consists of 21 patients (11 females and 10 males, mean age 24.5±1.6 years) who underwent Le Fort I maxillary impaction in conjunction with sagittal split osteotomy for mandibular advancement. Lateral cephalograms were obtained prior to the surgery and 1.3±0.2 years postoperatively. Wilcoxon test was performed to compare the pre- and postsurgical cephalometric measurements. Pearson correlation test was carried out to determine the relative changes in skeletal, dental and the facial soft tissues.The insignificant decrease in the nasolabial angle was correlated with the significant decrease in the vertical position of the nose due to the nasal protraction noticed after bimaxillary surgery. The retraction of both the upper lip and the upper incisors was correlated with the insignificant decrease in the columella-lobular angle. The insignificant decrease in both the vertical height of the mandibular B point and the lower incisors was correlated with the insignificant decrease in vertical height of the soft tissue pogonion, attributable to the resulting superior movement of the soft tissues of the chin and the counter clockwise rotation of the mandible after maxillary impaction and bilateral sagittal split osteotomy, respectively.Le Fort I maxillary impaction in conjunction with mandibular sagittal split osteotomy for mandibular advancement significantly affected the vertical and anteroposterior positions of the maxilla and the mandible, respectively. When performed in combination, these surgical techniques may efficiently alter the position of upper incisor and the nasal position in both vertical and anteroposterior directions. Bimaxillary orthognathic surgery seems to be an efficient method for obtaining satisfactory results in the appearance of the soft, the dental and the skeletal tissues associated with the facial profile in patients with high angle Class II skeletal deformity.

Midfacial soft tissue changes after leveling Le Fort I osteotomy with differential reduction. Cone-beam computed tomography volume superimposition

OBJECTIVE

To compare the short- and long-side soft tissue changes in the midfacial areas of patients who have undergone superior repositioning Le Fort I osteotomies for the correction of occlusal cant. The null hypothesis was that there were no significant differences in the midfacial soft tissue changes between the greater- and lesser-reduction sides.

MATERIALS AND METHODS

The subjects included 25 patients who had undergone Le Fort I osteotomy with superior repositioning and mandibular setback sagittal split ramus osteotomy. Using the cone-beam computed tomography volume superimposition method, the soft tissue changes were measured and determined both preoperatively and postoperatively. A 10 × 27 grid at 4.5-mm (vertical) and 5-mm (horizontal) intervals was used for the hard to soft tissue response.

RESULTS

The mean difference in the reduction from leveling Le Fort I osteotomy was 3.2 ± 1.2 mm between the short and long sides (P < .05). The mandibular setback movement averaged 5.4 ± 3.3 mm on the long side and 5.0 ± 3.6 mm on the short side (P > .05). The soft tissue areas below the Frankfort horizontal (FH) plane to 13.5 mm showed different changes after the differential leveling Le Fort I osteotomies.

CONCLUSIONS

The distinctly changed areas, which showed differences between the greater- and lesser-reduction sides beyond the 2.5-mm average for the soft tissue response, were below the FH plane to 13.5 mm and lateral to the midsagittal reference plane to 30 mm. In light of this, oral surgeons and orthodontists should be concerned about the volumetric midfacial difference after leveling the maxillary occlusal plane at the preoperative stage and thus should take appropriate measures to improve it.