Facial Morphology Changes After Total Maxillary Setback Osteotomy

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.

Analysis of external nasal morphology and the direction of maxillary repositioning following Le Fort I osteotomy

This study investigated the relationship between the direction of maxillary repositioning after Le Fort I osteotomy and changes in external nasal morphology using lateral cephalograms and frontal facial photographs. The results indicated greater changes in external nasal morphology, such as a more forward position of the nasal tip and an increased alar base width, with anterosuperior repositioning than with posterosuperior repositioning. In conclusion, this study demonstrated that the external nasal morphology changes after Le Fort I osteotomy, and that the changes vary depending on the direction of maxilla repositioning.

Recent Trends in Orthognathic Surgery in Asia

Anatomy and standards of beauty are different between Asians and Westerners. Unlike Westerners, Asians have a wide and prominent jaw shape but prefer a slim and soft face shape. To achieve this goal, maxillary setback and/or posterior impaction surgeries are popular among upper jaw surgery, and various adjuvant surgeries are performed simultaneously on the mandible to obtain the so-called oval shape or V-line face. In addition, according to the development of virtual surgery software and orthodontic treatment techniques, the surgery-first approach is now accepted as a reliable option for orthognathic surgery if it is indicated.

Study of soft tissue changes in the upper lip and nose after backward movement of the maxilla in orthognathic surgery

Objectives

This study evaluates soft tissue changes of the upper lip and nose after maxillary setback with orthognathic surgery such as Le Fort I or anterior segmental osteotomy.

Materials and Methods

All 50 patients with bimaxillary protrusion and skeletal Class II malocclusion underwent Le Fort I or anterior segmental osteotomy with backward movement. Soft and hard tissue changes were analyzed using cephalograms collected preoperatively and 6 months postoperatively.

Results

Cluster analysis on the ratios shows that 2 lines intersected at 4 mm point. Based on this point, we divided the subjects into 2 groups Group A (less than 4 mm, 27 subjects) and Group B (more than 4 mm, 23 subjects). Also, each group was divided according to changes of upper incisor angle (≥4°=A1, B1 or <4°=A2, B2). The correlation between A and B groups for Aʼ/ANS and Ls/Is (P<0.001) was significant; Aʼ/A (P=0.002), PRN/A (P=0.043), PRN/ANS (P=0.032), and St/Is (P=0.010). Variation of nasolabial angle between the two groups was not significant. There was no significant correlation of vertical movement and angle variation.

Conclusion

The ratio of soft tissue to hard tissue movement depends on the amount of posterior movement in the maxilla, showing approximately two times higher rates in most of the midface when posterior movement was greater than 4 mm. The soft tissue changes caused by posterior movement of the maxilla were little affected by angular changes of upper incisors. Interestingly, nasolabial angle showed a different tendency between A and B groups and was more affected by incisal angular changes when horizontal posterior movement was less than 4 mm.

Comparison of maxillary setback by maxillary tuberosity removal or intentional pterygoid plate fracture in Le Fort I osteotomy: a long-term evaluation

The purpose of the study was to investigate the clinical application and long-term stability of maxillary setback in Le Fort I osteotomy using maxillary tuberosity removal or intentional pterygoid plate fracture (IPPF). Eighty adult class II patients who underwent Le Fort I osteotomy with bilateral sagittal split ramus osteotomy by the same surgeon between January 2013 and January 2019 were included in this retrospective study. Traditional maxillary tuberosity removal was performed in 40 patients (group I), and the other 40 patients (group II) underwent IPPF to set back the maxilla according to surgeon preference. An obvious change in profile was observed for all of the patients, with no significant relapse at 1year postoperative. The operation time and intraoperative blood loss were significantly higher in group I than in group II (P= 0.037 and P= 0.021, respectively). In group II, the most superior point of the fracture line was at a mean distance of 12.25 ± 2.04 mm above the most inferior point of the pterygoid plate. More bone fragments were noted when the fracture level was low than when it was high. In conclusion, both maxillary tuberosity removal and IPPF resulted in sufficient and stable maxillary setback, with IPPF showing less blood loss and a shorter operative time.

Orthodontic and surgical management of a patient with severe skeletal Class II deformity and facial asymmetry: A case report with a 5-year follow-up

In this case report, we present the orthodontic and surgical management of an 18-year-old girl who had a severe craniofacial deformity, including maxillary prognathism, vertical maxillary excess (gummy smile), mandibular retrognathism, receding chin, and facial asymmetry caused by unilateral temporomandibular joint ankylosis. For correction of the facial asymmetry, the patient's right mandibular ramus and body were lengthened via distraction osteogenesis after 5 months of preoperative orthodontic therapy. Subsequently, extraction of 4 first premolars, bimaxillary anterior segmental osteotomy, and genioplasty were simultaneously performed in the second-stage operation to correct the skeletal deformities in the sagittal and vertical planes. Postoperative orthodontic treatment completed the final occlusal adjustment. The total active treatment period lasted approximately 30 months. The clinical results show that the patient's facial esthetics were significantly improved with minimal surgical invasion and distress, and a desirable occlusion was achieved. These pleasing results were maintained during the 5-year follow-up.

Displacement Patterns of the Maxilla During Parallel and Rotational Setback Movements: A Finite Element Analysis

BACKGROUND The purpose of this analysis was to evaluate the displacement patterns of the maxilla under parallel and rotational setbacks using the finite element method (FEM). MATERIAL AND METHODS A three-dimensional (3D) finite element model of a hemimaxilla was constructed. Through a conventional Le Fort I osteotomy, 2 and 3 mm of posterior movement in a parallel and rotational manner were simulated and the displacement pattern of the maxilla in each movement type was evaluated. RESULTS Both parallel and rotational setbacks resulted in lateral and inferior displacement of the maxillary segment. The largest inferior displacement was 3.0 mm and the largest lateral displacement was 1.84 mm. All lateral displacements in the anterior region were found to be more than 1 mm. CONCLUSIONS The results of this study may provide insight into how the maxilla tends to move during total maxillary setback surgery.

Le Fort II Setback Osteotomy to Correct Naso-Ethmoido-Maxillary Protrusion

BACKGROUND

Marked class II dentofacial deformity associated with centrofacial protrusion may be difficult to treat successfully. The purpose of this article was to report on Le Fort II setback osteotomy (LIISBO) to correct Naso-Ethmoido-Maxillary Protrusion (NEMP), to describe its indications and surgical techniques, and to analyze aesthetic and occlusal changes.

MATERIALS AND METHODS

From November 2011 to November 2014, patients with NEMP, treated with LIISBO, were included in the study. Cephalometric analysis of Delaire was performed before and 1 year after surgery. Skeletal and soft tissues movements were measured between preoperative and postoperative lateral cephalographs.

RESULTS

Fourteen patients were treated in our department by LIISBO. Ten patients were analyzed and presented a stable class I occlusion with reliable aesthetic results. The mean maxillary setback was -2.8 mm at nasopalatal point (Np), -3.1 mm at A point, and -3.7 mm at Pti (inferior pterygomaxilar point). The mean maxillary impaction was -2.4 mm at Np, -3 mm at A point, and -0.6 mm at Pti. The B, mental, and pogonion points showed an advancement with an average of +7.4, +7.9, and +7.7 mm, respectively. Measured soft tissues variations showed a backward movement of the nasal tip, the subnasal point, and the upper lip of -1.5, -1.6, and -0.7 mm, respectively. The lower lip, sublabial point, and the skin pogonion were advanced by +3.2, +5.4, and +6.2 mm, respectively.

CONCLUSIONS

Le Fort II setback osteotomy may be regarded as the ideal treatment for adult patient presenting a NEMP syndrome.

Maxillary single-jaw surgery combining Le Fort I and modified horseshoe osteotomies for the correction of maxillary excess

A modified technique of horseshoe osteotomy combined with Le Fort I osteotomy for superior and posterior repositioning of the maxilla is presented. Eight patients with maxillary excess associated with retrogenia or microgenia were treated with this technique in combination with genioplasty. The maxillary segment was repositioned a maximum of 5.0mm posteriorly and 7.0mm superiorly at point A. The mandible autorotated anterosuperiorly to achieve sound occlusion. Point B moved 2.0-10.0mm anteriorly and 5.0-10.0mm superiorly. The pogonion moved 7.0-17.0mm anteriorly in combination with genioplasty. All patients obtained sound occlusion and a good profile after the operation. Almost no skeletal relapse was observed during 1 year of postoperative follow-up. Patients with long faces with maxillary excess and retrogenia often have small, unstable condyles. In these cases, because surgical intervention to the ramus can result in postoperative progressive condylar resorption, maxillary single-jaw surgery with a horseshoe osteotomy, thereby avoiding ramus intervention, is a less invasive option.

Skeletal stability after maxillary posterior-superior movement for skeletal Class III deformities: pterygoid process fracture versus removal

PURPOSE

To evaluate maxillary stability after Le Fort I osteotomy using posterosuperior movement after pterygoid process fracture or removal and mandibular setback surgery for skeletal Class III deformities.

MATERIALS AND METHODS

A retrospective cohort study was performed of changes in 28 patients with skeletal Class III deformity using 3-dimensional (3D) measurement point coordinates obtained by cone-beam computed tomographic superimposition. The predictor variable was management of the pterygoid process (fracture vs removal). The outcome variables were changes in measurement points based on 3D coordinates obtained preoperatively, immediately postoperatively, and 6 months after surgery. Linear mixed-effects models were applied to evaluate postoperative stability.

RESULTS

The 3D cephalometric outcome variables for 14 patients who had undergone pterygoid process fracture were compared with those for 14 patients who had undergone pterygoid process removal. The postoperative nasopalatine canal points moved superiorly 0.11 mm and inferiorly 0.06 mm in the fracture and removal groups, respectively. However, most of the postoperative relapse was within 1 mm. There were no differences in postoperative skeletal changes shown by the fracture and removal groups (P < .05).

CONCLUSIONS

The results suggest that surgeons can achieve good skeletal stability in posterosuperior movement from Le Fort I osteotomy, regardless of whether the pterygoid process is fractured or removed.

[Naso-ethmoido-maxillary protrusion (NEMP): a specific dysmorphosis]

Naso-ethmoido-maxillary protrusion (NEMP) is a rare dental and facial dysmorphosis, with excessive growth of basicranium, ethmoid, maxillary, and nasal bones. The clinical presentation includes nasal and upper lip protrusion, telecanthus, a class 2 malocclusion with maxillary protrusion and exoclusion. The craniofacial field is increased in Delaire's analysis. Contrary to isolated maxillary protrusion secondary to membranous ossification dysfunction, NEMP is a constitutional anomaly resulting from an excessive primary growth of the chondrocranium. The therapeutic management of NEMP should take into account these specificities.

Effects of bimax and segmental surgeries for correction of bimaxillary dentoalveolar protrusion class I on soft tissue parameters: upper lip thickness and curvature, nasolabial angle and nasal prominence

AIM

Results of this study can show if bimax surgery for posterior repositioning of maxilla and correction of BPCLI has priority to the currently used segmental orthognathic surgery or not.

MATERIALS AND METHODS

This study was done on 40 white- skinned Iranian patients with bimaxillary dentoalveolar protrusion class I (BPCLI) who sought treatment for their deformity. In the first group, treatment includes segmental surgery for backward replacement of anterior segment of the upper and lower jaw. In the second group, treatment was bimax surgery, in which whole upper and lower jaw moved backward. Twenty patients were included in each group. For this purpose, we measured upper lip thickness (ULT, distance between LS and IA), nose prominence (NP, distance between nasal tip and the perpendicular line from upper lip vermilion on FHP), subsulcus depth (SSD, distance of SLS from this perpendicular line), SN to H line distance and finally, nasolabial angle (NLA) before and after surgery.

RESULTS

In our study, 65% of patients were female and the mean of age was 27 (17-39) years old. The mean of SNA, SNB, ANB and INA in our patients were 81.7 ± 2.9, 78.8 ± 2.8, 4.50 ± 1.4 and 120 ± 8.7, respectively. All variables except SSD were analyzed with t-test to compare the results of two methods of surgery. Differences in the values of NP, NLA, SN to H line distance and ULT before and after segmental and bimax surgeries between before and after surgery were significant. After surgeries, ULT and the SN to H line distance reduced significantly, and NLA became corrected to its normal range (90-110).

CONCLUSION

The results of this study showed that bimax and segmental surgeries can effectively correct BPCLI. Because of possible dental and periodontal complications of segmental surgery, we highly recommend bimax surgery for treatment of BPCLI.

Severe unilateral scissor bite and bimaxillary protrusion treated by horseshoe Le Fort I osteotomy combined with mid-alveolar osteotomy

This report describes an orthognathic surgical case employing horseshoe Le Fort I osteotomy (HLFO) combined with mid-alveolar osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) for a patient with severe unilateral scissor bite and bimaxillary protrusion. A female patient (aged 26 years, 2 months) presented with a chief complaint of dysmasesis caused by scissor bite on the right side. The clinical examination revealed difficulty in lip closure and a convex profile. Overerupted right maxillary premolars and molars and lingual tipping of the right mandibular premolars and molars were indicated before treatment. After 3 months of presurgical orthodontic treatment, two-jaw surgery involving a combination of HLFO with mid-alveolar osteotomy and BSSRO was performed. A good interdigitation in the right side was established by superior-posterior-medial movement of the dento-alveolar segment of the maxilla. Next, both the maxilla and mandible were moved superiorly and posteriorly to correct the improper lip protrusion, thereby improving the patient's profile. Our results suggest that this new orthognathic surgery technique-achieved by combining HLFO with mid-alveolar osteotomy and BSSRO-is effective for adult patients exhibiting severe unilateral scissor bite and bimaxillary protrusion.

Soft-tissue profile changes associated with anterior maxillary osteotomy for severe maxillary protrusion

OBJECTIVES

The aim of this study was to evaluate the soft-tissue profile changes after correction of severe maxillary protrusion with anterior maxillary osteotomy via a cephalometric analysis.

PATIENTS AND METHODS

Using Wunderer technique, anterior maxillary osteotomies were performed in 14 patients (12 females and 2 males) having severe maxillary protrusion. Standardized lateral digital cephalograms, true size, were taken before the treatment and 12 months after removal of the fixation means. The soft-tissue profile changes resulting from anterior maxillary osteotomy were evaluated by comparing the preoperative and postoperative cephalometric analyses. A statistical analysis was performed using paired t test. The differences were considered significant at P < 0.05.

RESULTS

The labial prominence showed reductions of 31% and 20% for the upper and lower lips, respectively. An increase in the nasolabial angle (16%) was noted subsequent to anterior maxillary osteotomies. Also, the facial convexity angle was increased (7%) postoperatively. The interlabial gap and the upper-lip curvature obviously decreased (56% and 60%, respectively) after surgery. The curvature of the lower lip, labiomental fold, showed a decrease of 17% after surgery, causing flatness to the lower face. The postoperative changes in the soft-tissue cephalometric measurements were statistically significant except for the lower-lip curvature and prominence as well as the lower-face height.

CONCLUSIONS

Anterior maxillary osteotomy is a highly recommended treatment modality for patients with severe maxillary protrusion. The technique is simple with minimal postoperative complications, and the soft-tissue profile changes after surgery are predictable.

Surgical and orthodontic treatment of skeletal Class III featuring severe transversal and sagittal discrepancy

AIMS

Anterior cross-bite is a difficult malocclusion to treat in adult patients, especially if compounded by skeletal discrepancy. The present study describes a dentoskeletal Class III case and aims to provide the clinician with rational guidelines for presurgical orthodontic preparation and postsurgical finishing.

PATIENT AND METHODS

In this case, a 20-year-old male patient, R.M, was treated for severe dental and skeletal Class III malocclusion on both the transversal and anteroposterior planes via combined orthodontics and surgery. Initially, the treatment involved surgically-assisted expansion of the upper jaw (total 1 month), followed by a fixed-orthodontics phase to decompensate for the malocclusion in preparation for movement of the osseous bases with the aim of achieving maximum coordination of the dental arches. After 19 months of orthodontic preparation, the patient underwent combined orthognathic surgery (upper and lower jaws). In the subsequent 4 months, orthodontic stabilization and finishing were performed, and debonding was carried out 24 months after the start of active treatment.

RESULTS

The combined orthodontic and surgical treatment adequately corrected the severe Class III over a period of 2 years, leading to a satisfactory occlusal, functional and aesthetic result.

CONCLUSIONS

Thorough diagnosis and close communication between the orthodontist and maxillofacial surgeon, operating as an interdisciplinary team, ensures good outcomes, even in complex orthodontic and surgical cases.