Postoperative skeletal stability and accuracy of a new combined Le Fort I and horseshoe osteotomy for superior repositioning of the maxilla

Horseshoe osteotomy maintains the nasal cavity and function after superior repositioning

The aim of this prospective cohort study was to compare changes in nasal cavity and function between Le Fort I with and without horseshoe osteotomy after superior repositioning of the maxilla. The patients were divided into 2 groups, a Le Fort I alone (LF alone) group and a combination Le Fort I and horseshoe osteotomy (HS) group. The nasal cavity volume was measured using 3-dimensional computed tomographic images, and nasal resistance was assessed by anterior active mask rhinomanometry. The HS group consisted of 17 patients, and the LF alone group consisted of 15 patients. The magnitude of change in nasal cavity volume was significantly smaller in the HS group than in the LF alone group (p < 0.001), even though the mean amount of superior maxillary movement was considerably larger in the HS group than in the LF alone group (p < 0.001). Mean nasal resistance was significantly smaller postoperatively than preoperatively in the HS group (p < 0.05). Furthermore, the change in nasal resistance was smaller in the HS group than in the LF alone group (p < 0.001). Within the limitations of this study, it seems that horseshoe osteotomy is useful for maintaining the nasal cavity and function after superior repositioning of the maxilla.

Study of Anatomical Changes of the Inferior Nasal Passage After Le Fort I Osteotomy With Superior Repositioning

The relationship between postoperative morphological changes in the inferior nasal cavity and inferior turbinate after Le Fort I osteotomy remains unclear. This study aimed to investigate how the bone volume of the inferior turbinate affects contact with the inferior nasal cavity of patients who underwent superior repositioning. We evaluated the 3-dimensional relationship between the anatomical changes in the inferior nasal passage before and after surgery in 51 patients who underwent Le Fort I osteotomy with an elevation of >4.0 mm in the first molar. The soft tissue and bone volumes of the inferior turbinate and airway volume of the inferior nasal passage were calculated using Proplan CMF 3.0 and compared according to the size of the bone volume of the inferior turbinate. In addition, we reclassified the maxillary movements in the pitch direction and compared the results. The contact rates of the postoperative inferior nasal airway and the inferior turbinate in the large-bone group was 72.3% and that in the small-bone group was 40.0% in the χ2 test. The reduction in the inferior nasal passage volume was significantly greater in the large-bone group (pitch+) than in the small-bone group (pitch+). For patients with well-developed bony tissue of the inferior turbinate, caution is advised if the maxillary elevation is ≥4.0 mm, because the possibility of postoperative obstruction of the inferior nasal passages exist, which may lead to deterioration of nasal ventilation.

Long-term vertical stability of horseshoe osteotomy for the correction of large vertical excess of the maxilla, a retrospective assessment in 15 patients

INTRODUCTION

Vertical stability after a Le Fort I (LF1) osteotomy with substantial upward movement can be compromised by the position and the volume of the inferior turbinate. A horseshoe (HS) osteotomy represents then an alternative as it preserves the hard palate and the intranasal volume. The aim of this study was to assess the vertical stability of the maxilla after HS osteotomy.

MATERIALS AND METHODS

Patients who underwent a HS osteotomy for the correction of long-face syndrome were retrospectively analyzed. The vertical stability was assessed on lateral cephalograms performed preoperatively (T0), immediately postoperatively (T1), and at the last follow-up (T2) by studying points C (the distal cusp of the first maxillary molar), point P (the prosthion, the lowest edge of the maxillary alveolus of the central incisor), and point I (the upper central incisor edge) in a coordinate system. Postoperative complications and aesthetics of the smile were also investigated.

RESULTS

Fifteen patients were included (7 females, 8 males, mean age 25.5 ± 9.8 yeras). The mean impaction ranged from 5 mm on point P to 6.1 mm on point C, with a maximal movement of 9.5 mm. A non-significant relapse of 0.8 ± 1.7, 0.6 ± 0.8, and 0.5 ± 1.8 mm was observed after a mean 20.7 months on point C, P, and I respectively. Smile parameters were significantly improved by the procedure, mainly regarding the correction of the gum smile.

CONCLUSION

HS osteotomy represents a good alternative to total LF1 osteotomy for substantial maxillary upward movement in long face syndrome deformities.

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.

Melolabial interpolated island flap for reconstruction of an anterior oronasal fistula after horseshoe Le Fort I osteotomy with iliac bone grafts interposition - A case report

INTRODUCTION

Horseshoe Le Fort I osteotomy (HLFO) in combination with iliac bone grafts interposition is an established and very effective procedure for reconstructing the severely atrophic maxilla. However potential complications connected to this method, such as oronasal fistula (ONF), have not been described in the literature to date.

CASE PRESENTATION

We report the case of a female patient with severe atrophy of the edentulous maxillary alveolar ridge with type 2 diabetes (T2D). Initially, a sinus floor augmentation was performed, followed by a failed placement of dental implants. Afterwards, HLFO with simultaneous interposition of iliac bone grafts was conducted. Subsequently, an oronasal communication occurred in the antral maxilla. As several local flaps had not achieved sufficient results, a melolabial interpolated island flap was carried out, yielding satisfactory results.

DISCUSSION

Failed implant treatment or bone augmentation procedures in combination with T2D may have resulted in significant tissue irritation and subsequent wound healing complications in the antral maxilla, leading to an ONF.

CONCLUSION

In this case, an ONF occurring after HLFO was described for the first time. The melolabial interpolated island flap proved to be an outstanding long-term solution for the management of an anterior ONF occurring after HLFO over a period of 10 years. Less invasive treatment options including zygomatic implants should be taken into consideration for the treatment of such patients.

Surgical procedures for correcting vertical maxillary excess: A review

INTRODUCTION

Vertical maxillary excess, a common orthodontic problem that leads to long faces and open bites, can be repositioned with a Le Fort I osteotomy. However, the Le Fort I osteotomy poses the risk of a variety of complications including descending palatine artery (DPA) injury. Although several Le Fort I osteotomy modifications were reported to avoid complications associated with this osteotomy, only a few of such studies were conducted in Japan, and details remain scarce.

PATIENTS AND METHODS

We performed a literature review regarding modifications of Le Fort I osteotomies, including Le Fort I with a horseshoe osteotomy, modified horseshoe osteotomy, unilateral horseshoe osteotomy, pyramidal osteotomy, and U-shaped osteotomy. We identified eight relevant studies conducted in Japan; one study did not provide the number of patients examined. The 77 patients (seven studies) with vertical maxillary excess who underwent orthognathic surgery were ≥17 years old.

DISCUSSION

There were no severe complications after the modified Le Fort I osteotomies. The postoperative maxillary changes obtained by the conventional horseshoe, modified horseshoe, unilateral type of horseshoe, pyramidal, and U-shaped osteotomies were nearly repositioned to the planned position and remained stable for ≥12 months post-surgery.

CONCLUSION

Our review indicates that preserving the DPA can lower the incidence of intra- and post-operative complications. Each modification of the Le Fort I osteotomy (i.e., conventional horseshoe, modified horseshoe, unilateral horseshoe, pyramidal, and U-shaped osteotomy) has its respective advantages and indications.

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.

Influence of the anatomical form of the posterior maxilla on the reliability of superior maxillary repositioning by Le Fort I osteotomy

Certain patients with facial deformities require superior repositioning of the maxilla via Le Fort I osteotomy; however, the magnitude of superior repositioning of the maxilla is often less than expected. In this study, the correlation between the accuracy of superior repositioning of the maxilla and the anatomical form of the maxillary posterior region was examined. Seventy-five patients who underwent Le Fort I osteotomy without forward movement of the maxilla but with superior repositioning of the maxilla were included in this study. The bone volume around the descending palatine artery (DPA), the angle of the junction between the pterygoid process and the tuberosity, and the distance between the upper second molar and the pterygoid process were measured via three-dimensional analysis. A significant negative correlation (r=-0.566) was found between the bone volume around the DPA and the ratio of repositioning (actual movement divided by expected movement). It is possible that the superior repositioning of the maxilla expected prior to surgery was not sufficiently attained because of the large volume of bone around the DPA. The results of this study show that in some patients, superior repositioning was not achieved at the expected level because of bone interference attributable to the anatomical form of the maxillary posterior region.

CAD/CAM splint based on soft tissue 3D simulation for treatment of facial asymmetry

BACKGROUND

Most cases of facial asymmetry involve yaw deformity, and determination of the yaw correction level is very difficult.

METHODS

We use three-dimensional soft tissue simulation to determine the yaw correction level. This three-dimensional simulation is based on the addition of cephalometric prediction to gradual yaw correction. Optimal yaw correction is determined visually, and an intermediate splint is fabricated with computer-aided design and computer-aided manufacturing. Application of positioning devices and the performance of horseshoe osteotomy are advisable.

RESULTS

With this procedure, accurate repositioning of jaws was confirmed and patients obtained fairly good facial contour.

CONCLUSIONS

This procedure is a promising method for a widespread, predictable treatment of facial asymmetry.

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.

[Horseshoe Le Fort I osteotomy]

INTRODUCTION

Performing Le Fort I impaction osteotomy can be compromised or impossible. The intranasal volume of the lower turbinates prevents an important maxillary impaction. In this case, horseshoe osteotomy is an alternative.

SURGICAL TECHNIQUE

The first step is to lower the inferior edge of the pyriform aperture and the anterior floor of the nasal fossae with a bur. The palatine alveolar wall is cut through resection of the maxillary sinus anterior and lateral walls. The maxillary dental arch may be impacted without freeing the vomer or cutting through lateral walls of the nasal fossa, after having dissected the palatine fibrous mucosa and disjoined the pterygomaxillary suture.

DISCUSSION

This technique has mainly been used in pre-implantation surgery to lower the maxillary crest in edentulate patients, and to increase the crestal height after bone grafting without modifying the position of the hard palate. It is a good alternative to the usual Le Fort I osteotomy for important impactions when the alveolar bone height is sufficient.

A novel design of a computer-generated splint for vertical repositioning of the maxilla after Le Fort I osteotomy

OBJECTIVE

The objective of this study was to evaluate the efficacy of a novel tooth/bony-supported virtual splint design to control the maxillary vertical, rotational, and anteroposterior intraoperative movements.

STUDY DESIGN

A tooth/bone-borne splint was designed to position the osteotomized maxilla intraoperatively. Lateral cephalometric radiographs were obtained 1 week before the operation and 1 week after to compare the planned and actual movements of the maxilla.

RESULTS

The paired t test showed no significant difference between the planned and actual movements in both the vertical and horizontal measurements (P ≤ .05). The difference between the planned and actual horizontal movements in 4 (66.7%) of the 6 patients was 1 mm or less. For the vertical movements, 5 (83.3%) of the 6 patients showed a difference equal to or less than 1 mm.

CONCLUSIONS

The 2-piece surgical stent showed accurate control on the osteotomized maxilla and succeeded its repositioning to the preplanned positions.