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

Masticatory function and three-dimensional facial morphology of soft tissues: One year after orthognathic surgery

OBJECTIVE

Dentofacial deformities (DFD) require orthodontic treatment, orthognathic surgery, and speech therapy for aesthetic and functional problems. This longitudinal study analyzed changes in masticatory function and three-dimensional (3D) facial soft tissue in patients with Class II and Class III DFD after orthognathic surgery. In addition, the study investigated the relationship between facial measurements, maximum bite force (MBF), and orofacial myofunctional status (OMS).

DESIGN

The sample consisted of 46 participants, including 10 patients with Class II DFD, and 11 patients with Class III DFD. These groups were assessed before (T0) and 6 months (T1) after surgery. Twelve patients who completed the treatment protocol were evaluated 12 months post-surgery (T2). The patient groups were compared with each other and with a control group (CG) of 25 healthy subjects. The participants underwent MBF and clinical evaluation of OMS, including masticatory behavior, using a validated protocol. The 3D facial soft tissue was assessed using laser scanning.

RESULTS

Compared to the CG, DFD patients showed reduced MBF, masticatory behavior, and OMS scores at T0. At T2, there was an improvement in MBF, masticatory, and OMS scores, but differences were observed compared to the CG. Changes in facial soft tissue followed the underlying hard tissue movement resulting from surgery, and reduction of vertical measurements contributed to improvements in masticatory function.

CONCLUSION

These findings indicated that combined surgery, orthodontic treatment, and speech therapy can lead to a significant improvement in masticatory function and facial soft tissue in DFD patients, although not completely 12 months post-surgery.

Changes in three-dimensional nasal morphology according to the direction of maxillary movement during Le Fort I osteotomy

BACKGROUND

Le Fort I (LFI) osteotomy is commonly performed by orthognathic surgeons; however, postoperative changes in nasolabial morphology are of concern. Several factors influence such changes, but it is difficult to accurately predict the postoperative results. This study evaluated the three-dimensional (3D) morphological changes in the nasal region according to the different directions of maxillary movement during LFI osteotomy.

MATERIALS AND METHODS

Forty-one patients who underwent LFI osteotomies were included. All patients were divided into maxilla-up (Group U: 20 patients) and maxilla-forward (Group F: 21 patients) groups. Soft tissue morphologies were determined preoperatively and 3 or 6 months postoperatively using an optical 3D scanner. All datasets were evaluated in terms of volume changes in nine subregions and changes in linear measurements around the nasal area.

RESULTS

Both groups exhibited increased nasal volumes after surgery in the order of the three upper, three central, and three lower subregions. The change in volume of the central nasal region tended to be greater in Group U than that in Group F.

CONCLUSION

We evaluated 3D morphological changes in the nasal region according to the direction of maxillary movement during LFI osteotomy. Group U exhibited a large change in the volume of the central nasal region.

Effects of Maxillary Movements on Lips Following Orthognathic Surgery: A Retrospective Non-Randomized Clinical Trial

Introduction  Lips play a fundamental role in facial attractiveness and in decisions pertaining to orthognathic surgery. Objective  To assess the upper lip changes following Le Fort I osteotomy for maxillary advancement and/or impaction. Methods  In the present retrospective non-randomized clinical trial, we evaluated 3 groups of patients who underwent Le Fort I osteotomy of the maxilla. Group 1 (n = 35) underwent maxillary advancement, group 2 (n = 14), maxillary impaction, and group 3 (n = 11) was submitted to both maxillary advancement and impaction. The lip thickness of all patients was measured preoperatively, and the participants in each group were categorized into two subgroups: thin (< 12 mm) and thick (> 12 mm) lip. The primary (before orthognathic surgery) and final (after orthodontic bracket removal) lateral cephalograms of the patients were analyzed using the Dolphin software. Comparisons were made using the paired t -test and linear regression in the IBM SPSS Statistics for Windows software. Results  The length of the upper lip increased by 1 mm ( p  = 0.012) on average following maxillary advancement, and it decreased by 0.43 mm ( p  = 0.24) on average following maxillary impaction. In the maxillary advancement group, the change in angulation of the incisors predicted the incisal display ( p  = 0.03). In the maxillary impaction group, skeletal changes in the vertical dimension predicted changes in upper lip length ( p  = 0.033). Conclusions  Le Fort I osteotomy for maxillary advancement significantly increases the length of the upper lip. The assessment of lip thickness prior to surgery can help predict the postoperative results. Changing the angulation of the incisors can predict the incisal display. In maxillary impaction, skeletal changes in the vertical dimension can predict the changes in the length of the upper lip.

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.

Orthognathic Surgery for Management of Gummy Smile

Excessive gingival show is mainly caused by hypermobility of the upper lip, altered passive eruption, gingival hyperplasia, and bony maxillary vertical excess. Orthognathic surgery is the optimal treatment option for patients with moderate and severe vertical maxillary excess. Surrounding anatomic structures and soft tissue changes such as alternation in the nasal morphology confine the amount of impaction. Therefore, Le Fort 1 may be performed in conjunction with horseshoe osteotomy or partial turbinectomy. The possible necessity of further mandibular orthognathic surgeries and chin repositioning has to be considered. No common major complication and long-term relapse have been reported for maxillary impaction.

Complications on maxilar impaction: A systematic review and meta-analysis

OBJECTIVES

Maxillary impactions are seen as an orthognathic surgical movement that increases the number of complications. The aim of this paper is to research literature on this topic, with special attention to avoiding of complications.

METHODS

A systematic review was carried out according to the PRISMA guidelines. The PROSPERO registration has been performed. A risk of bias assessment was carried out with RevMan and graphics were created. A total of 20 articles were included in this systematic review.

RESULTS

Some interesting and conclusive facts about maxillary impactions. Relapses are not common due to the higher bone contact. Bleeding is a common complication due to the location of palatal artery. Aesthetic and functional complications can arise, especially in the nasal region. Bimaxillary orthognathic surgeries has a higher incidence of complications.

CONCLUSIONS

Today it is not possible to confirm that maxillary impactions alone are responsible for a higher incidence of complications due to the complexity of the three-dimensional movements. Some surgical steps could be safer and cause fewer complications.

Analysis of Gull in Flight Appearance and Related Parameters Following Le Fort I Osteotomy

ABSTRACT

The present study aimed to investigate how "Gull in Flight" appearance and alar-columellar relationship change following maxillary surgery. Thirty-three patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in this retrospective study. Measurements which were angle of columella triangle, alar-rim angle, columella lobular angle, and distance of points forming "Gull in Flight" appearance were evaluated on pre and postoperative frontal and lateral photos of patients. Data was submitted to statistical analysis and significance level was determined as 0.05. Following Le Fort I surgery, distance of points forming "Gull in Flight" appearance with respect to canthus was decreased significantly (P < 0.05). Positions of these points to each other were not changed (P > 0.05). Every 1 mm maxillary impaction led to 0.58 mm reduction in y3 (the distance from the point that illustrates Gull's body) (P = 0.032). There was a decrease in angle of columella triangle, alar-rim angle and increase in columella lobular angle. However, these changes were not found significant (P > 0.05). Angle of columella triangle was increased 2.51 degree for every 1 mm maxillary advancement (P = 0.028). In conclusion, maxillary surgery had an impact on nasal region from frontal view. However, "Gull in Flight" appearance which is one of the aesthetic parameters in nose was not changed following maxillary surgery.

Impact of the Different Types of Le Fort I Maxillary Surgical Movement on Nasal Width Changes: A Photogrammetric Analysis

BACKGROUND

Le Fort I maxillary movements affect nasal width, but nasal width changes with specific movement types have not been formally addressed to date.

OBJECTIVES

The purpose of this study was to analyze and compare the changes in nasal width with different maxillary movements.

METHODS

A retrospective study was performed among consecutive patients who underwent bimaxillary orthognathic surgery (n = 138) and who were grouped based on the type of maxillary movement (ie, maxillary advancement with intrusion [MAI], maxillary advancement with extrusion [MAE], and maxillary setback with intrusion [MSI]). Preoperative and 12-month postoperative nasal widths were analyzed photogrammetrically by 2 blinded evaluators.

RESULTS

Maxillary advancement with intrusion and MAE presented a significantly (P < 0.05) higher alar base widening than MSI did, with no significant (P > 0.05) differences between MAI and MAE. Maxillary advancement movements (MAI and MAE) showed significantly (P < 0.05) higher alar base widening than maxillary setback movement (MSI). However, no significant (P > 0.05) difference was observed between maxillary intrusion (MAI and MSI) and maxillary extrusion (MAE) movements.

CONCLUSIONS

This study shows that the nasal width varies distinctly depending on the type of Le Fort I maxillary surgical movement.

Facial profile changes due to bone cement graft to manage the hyperactive muscles of the gingival smile

Objective:

To evaluate facial profile changes promoted by polymethyl methacrylate (PMMA) cement graft to reduce excessive gingival display due to hyperactivity of the elevator muscles of the upper lip during smiling.

Methods:

Eleven patients (all females, age range: 20 to 43 years) presenting gingival smile that were treated with PMMA cement grafts in a private clinic were selected for this retrospective study. Three angular and ten linear cephalometric facial profile measurements were performed preoperatively (baseline, T₁) and at least 6 months postoperatively (T₂). Differences between T₁ and T₂ were verified by Wilcoxon test, and the correlation between the thickness of the graft and facial profile changes was statistically evaluated by Spearman’s Coefficient test. The significance level was set at p< 0.05.

Results:

The nasolabial angle (p= 0.03) and the labial component of the nasolabial angle showed statistically significant differences (p= 0.04), with higher values in T₂. No correlations were found between the graft thickness and the statistically significant facial profile changes (p> 0.05).

Conclusions:

The PMMA bone cement graft projected the upper lip forward, thereby increasing the nasolabial angle without affecting the nasal component. No correlations between the graft thickness and the facial profile changes were detected.

Nasolabial Changes Following Double Jaw Surgery

BACKGROUND

This study aimed to analyze 3-dimensional nasolabial soft tissue changes following double jaw surgery with Le Fort I maxillary advancement and relate them to underlying surgical movements.

METHODS

Pre- and post-surgical cone-beam computed tomography images of 37 maxillomandibular surgery patients with ≥2 mm of advancement at A-point were analyzed. Lateral cephalograms were constructed to determine horizontal and vertical surgical movements and 3-dimensional facial images were created from the CBCTs to calculate linear and angular changes.

RESULTS

Alar base width increased 1.9 mm, nasal tip protrusion decreased 0.74 mm, the upper lip flattened 7.71 degree and increased 0.9 mm in length, nasal tip was displaced 2.47 mm superiorly causing an increased concavity of 5.52 degree for the overall dorsal surface and 3.99 degree at the supratip break angle (SBA), nasal tip angle decreased 2.16 degree and nasolabial angle decreased 7.37 degree. Correlations were found between underlying surgical movements and nasal tip protrusion, SBA, nasolabial angle (NLA), and nasal tip elevation (NTE). Multiple linear regression equations were calculated to predict changes in SBA from horizontal change at A-point, NLA from horizontal change at B-point, and NTE from the change at A-point horizontally and U1-tip vertically.

CONCLUSION

Double jaw surgery with maxillary advancement has significant effects on nasolabial anatomy.

Stability of Vertical, Horizontal and Angular Parameters Following Superior Repositioning of Maxilla by Le Fort I Osteotomy: A Cephalometric Study

INTRODUCTION

The restoration of normal jaw function, optimal facial aesthetics and long term stability are the goals of any orthognathic surgical procedures. During the last two decades, several cephalometric investigations have been reported on the skeletal changes following maxillary surgical procedures. The stability following LeFort I osteotomy and maxillary superior repositioning of the maxilla has not been studied extensively.

AIM

This study was aimed at determining the surgical changes brought about by superior repositioning of the maxilla by Le Fort I osteotomy and evaluate the stability of the surgical procedure one year following surgery.

MATERIALS AND METHODS

Presurgical and postsurgical and one year post surgical lateral cephalograms of 10 adult patients (age group - 17 to 40 years, with a mean age of 22.2 years) who had been treated successfully by maxillary Le-Fort I osteotomy and impaction were obtained. The lateral cephalograms were grouped into three categories: T1- Presurgical, T2- Postsurgical, T3- One year postsurgical. Comparisons were made between T1-T2 and T2-T3 to assess the changes following surgery and to evaluate the stability, one year following the surgery using 5 horizontal, 5 vertical linear and 2 angular measurement. Statistical analysis was done with SPSS (Version 17). Results were expressed as mean±standard deviation. A paired t-test was used to analyze the paired observations.

RESULTS

The difference between T1 and T2 values of vertical changes showed that they were statistically highly significant whereas from T2 to T3 they were insignificant. The difference between T1 and T2 values of all the horizontal changes showed that they were statistically significant whereas True Vertical Line (TVL) to point Anterior Nasal Spine (ANS) was not statistically significant. The horizontal changes from T2 to T3 were statistically not significant whereas TVL to point Incisal edge of upper incisor (Is) was statistically significant. The angular changes from T1 to T2, T2 to T3 were statistically not significant.

CONCLUSION

There was a significant reduction in the facial height and significant anterior movement of maxilla after surgery. Even after one year of surgery, negligible amount of relapse was recorded except at the incisors.

Soft tissue changes after posterior impaction and setback of the maxilla with Le Fort I osteotomy in skeletal class III patients

The purpose of this retrospective study was to evaluate the changes in the upper lip (UL) by posterior impaction and setback (PI-SB) of the maxilla. The samples consisted of 29 skeletal Class III patients (10 men and 19 women) who received bimaxillary surgery including PI-SB of the maxilla after Le Fort I osteotomy. Lateral cephalograms were taken at 1 week before surgery (T0) and 6 months after surgery (T1). After linear and angular changes of the hard and soft tissue variables were measured, the paired t test, Pearson correlation test, and univariate linear regression analysis were performed for statistical analyses. The changes in the hard tissue landmarks were as follows: ANS, U1E, and U6MBC moved backward (P < 0.001, P < 0.001, and P < 0.05, respectively) and upward (P < 0.001, P < 0.01, and P < 0.001, respectively), whereas A point, U1A, and PNS moved upward only (P < 0.01, P < 0.01, and P < 0.001, respectively). In terms of the soft tissue change, although subnasale (Sn) did not show significant change, pronasale (Pn) moved upward (P < 0.05); UL, backward and downward (all P < 0.001); and Stms (stomodium-superius), backward (P < 0.001). There were significant correlations between the horizontal change of the UL and that of A point and U1E (P < 0.01, P < 0.05). The regression equation of the horizontal change of UL and U1E was [INCREMENT]UL-vertical reference line (VRL) = (0.476 × [INCREMENT]U1E-VRL) - 0.581 (P < 0.05). If U1E moves backward by 3 mm and 5 mm, the UL is predicted to move backward by 0.9 mm and 1.8 mm, respectively. These results might provide a guideline in diagnosis and treatment planning for maxillary surgery with PI-SB.

Comparative Study of Skeletal Stability between Postoperative Skeletal Intermaxillary Fixation and No Skeletal Fixation after Bilateral Sagittal Split Ramus Osteotomy: an 18 Months Retrospective Study

Objectives

The purpose of the present study was to evaluate skeletal stability after mandibular advancement with bilateral sagittal split osteotomy.

Material and Methods

Twenty-six patients underwent single-jaw bilateral sagittal split osteotomy (BSSO) to correct skeletal Class II malocclusion. One group (n = 13) were treated postoperatively with skeletal elastic intermaxillary fixation (IMF) while the other group (n = 13) where threated without skeletal elastic IMF.

Results

The mean advancement at B-point and Pog in the skeletal elastic IMF group was 6.44 mm and 7.22 mm, respectively. Relapse at follow-up at B-point was -0.74 mm and -0.29 mm at Pog. The mean advancement at B-point and Pog in the no skeletal elastic IMF group was 6.30 mm and 6.45 mm, respectively. Relapse at follow-up at B-point was -0.97 mm and -0.86 mm at Pog. There was no statistical significant (P > 0.05) difference between the skeletal IMF group and the no skeletal group regarding advancement nor relapse at B-point or Pog.

Conclusions

Bilateral sagittal split osteotomy is characterized as a stable treatment to correct Class II malocclusion. This study demonstrated no difference of relapse between the skeletal intermaxillary fixation group and the no skeletal intermaxillary fixation group. Because of selection-bias and the reduced number of patients it still remains inconclusive whether to recommend skeletal intermaxillary fixation or not in the prevention of relapse after mandibular advancement.

A Cephalometric Analysis for Evaluation of Changes in Soft Tissues in the Regions of the Upper and Lower Lips and Chin due to Orthognathic Maxillary Advancement Surgery

Introduction There is currently no consensus regarding the best method for predicting the changes in soft tissues due to the modification of hard tissues in orthognathic surgery.

Objective To measure the changes in soft tissues of the upper lip, lower lip, and chin regions due to the modifications of hard tissues caused by orthognathic maxillary advancement surgery using a cephalometric methodology.

Methods The study was conducted on 35 patients with dentoskeletal and facial deformities submitted to orthognathic maxillary advancement surgery. Two teleradiographs were taken: one during the preoperative period and the other 1 year after the surgery, on which the cephalometric tracing was drawn.

Results A strong correlation (r = 0.747) was demonstrated in the horizontal analysis between the hard A (Ah) point (located in the deepest point of the anterior curvature of the maxilla) and the soft A (As) point in the advancement of the maxilla, with a mean variation of 0.859% occurring in As with each 1% variation of the Ah point. A mean variation of 0.698% occurred in the superior soft prostion point (prolongation of the superior hard prostion point to its corresponding point on soft tissue) for each 1% variation in the superior hard prostion point (bone point located at the junction of the alveolar process with the crown of the upper incisors).

Conclusion The cephalometric methodology applied here revealed that the soft tissues of the upper lip accompanied 70 to 80% of the movement of hard tissues in maxillary advancement and that the soft tissues of the lower lip did not change or showed no significant changes.