Superior Repositioning Research Articles

U-Shaped Osseous Release for Le Fort 1 Osteotomy: Potential Application to Superior Repositioning.

This study was performed to investigate the utility of U-shaped osseous release (USOR) for Le Fort 1 osteotomy as a novel surgical technique for superior repositioning. Thirty-six patients with jaw deformities were divided into 2 groups based on whether or not USOR was adopted (18 in the non-adoption group and 18 in the adoption group). Maxillary surgical time, blood loss, and discrepancy from the planned amount of movement (anterior-posterior and superior-inferior directions) were compared between the 2 groups. Correlations between these items and the planned amount of superior-inferior movement were also examined. There were no significant differences in mean age, preset displacement, surgical time, blood loss, body mass index, or preset displacement error. However, a significant positive correlation was observed between the planned and actual amount of vertical movement only in the adoption group (P=0.0018). In addition, there was a tendency for the error (downward) to increase as the amount of upward movement increased in the non-adoption group, but not the adoption group. These findings suggest that USOR may be a useful technique because it can safely and conveniently remove bony interference and can enable guidance to a more precise position, especially in cases with substantial superior movement.

Influence of the Inferior Turbinate on the Accuracy of Superior Maxillary Repositioning.

Notably, many studies have focused on the bony interference in the maxillary segment when performing maxillary superior repositioning; however, few reports have described the interference with the inferior nasal turbinate. Therefore, the authors aimed to retrospectively analyze the soft tissue or bone tissue volume of the inferior nasal turbinate and the accuracy of maxillary superior repositioning in Le Fort I osteotomy (LF1). The authors included 83 patients with facial deformities who underwent conventional LF1 (maxillary molar elevation between 4.0 and 6.0mm) with/without bilateral sagittal split ramus osteotomy. The ratio of the soft tissue of the inferior turbinate to that of the inferior nasal cavity was used to divide the participants into 2 subgroups (large and small ratio). Similarly, the bony tissue volume of the inferior turbinate was used to divide the participants into 2 subgroups (large and small bony tissues), and the planned or actual amount of superior repositioning was compared 3 dimensionally. In the soft tissue group, the subgroups showed no significant differences (P=0.934). However, the actual maxillary superior repositioning was significantly lower in the large bone group than in the planned maxillary elevation group (P<0.01). In cases where the maxillary molar needs to be elevated by >4mm and the bone tissue of the inferior nasal turbinate is well developed, an adjunctive technique such as horseshoe osteotomy or partial inferior turbinate resection should be considered in addition to LF1 to avoid interference between the inferior nasal turbinate and the maxillary bone fragments.

Comparison of skeletal stability with rigid and wire fixation in patients who have undergone Le Fort I and Anterior Segmental Maxillary Osteotomy

ABSTRACT Background: Maxillary superior repositioning is widely regarded as the most stable procedure in orthognathic surgery, requiring minimal instruments for stabilization. Rigid fixation is considered the ideal method for long-term stability, leading to improved anatomic structures, enhanced recovery of bite forces, and better bite function. Objective: To compare the skeletal stability following Le Fort I and anterior maxillary osteotomy with wire osteosynthesis and rigid fixation. Materials and Methods: A total of 16 patients, including one male and 15 females, underwent Le Fort I and anterior segmental maxillary osteotomy along with fixation using either wire osteosynthesis or rigid fixation for correction of vertical and anteroposterior maxillary excess. Patients were assessed at preoperative, 1-week postoperative, and 6-month postoperative stages using a lateral cephalogram to evaluate skeletal stability. Results: The wire osteosynthesis group showed significant differences in posterior maxillary vertical measurements compared to the rigid fixation group. However, there was no significant difference in anterior vertical and anteroposterior skeletal measurements between the two groups. Conclusion: Wire osteosynthesis is a stable form of fixation for superior repositioning with segmentation of the maxilla for correction of vertical and antero-posterior excess.

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 >4.0mm 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 ≥4.0mm, because the possibility of postoperative obstruction of the inferior nasal passages exist, which may lead to deterioration of nasal ventilation.

Comparative evaluation of use of reciprocating saw and bur in Le fort I osteotomy for superior repositioning of maxilla: A cross-sectional study

BackgroundTraditionally bur has been used to carry out osteotomy. In a developing country like India, the cost of surgical treatment is the important factor in determining treatment plan. Although the use of bur is cost-effective and efficient, with the advent of newer technology, it is getting replaced with a saw. AimTo evaluate and compare the use of reciprocating saw and bur in Le Fort I Osteotomy for superior repositioning of the maxilla. Materials and MethodsPatients referred from the Department of Orthodontics for the surgical correction of vertical maxillary excess (VME). They were divided into two groups. In group I, osteotomy was performed with Synthes Reciprocating Saw and in group II, bur was used. The parameters recorded in both the groups were time required for the completion of down-fracture, precision of the osteotomy cut (margins of the cut), and ease of superior repositioning. Data was collected from both the groups for comparison. ResultsA total of 14 patients with VME were included in the study. They were divided into two groups. Seven study participants were allotted to each group. In group I, Synthes Reciprocating Saw was used while in group II, a bur was used to carry out the osteotomy cut. In group I, the average time required to complete the down-fracture of the maxilla was 3.5–4 min while in group II it was more than 8 min. The margins of the osteotomy cut were smooth and regular and there was bone-to-bone contact during superior repositioning in Group I. ConclusionThe combination of the use of a saw for inferior osteotomy and a bur for the superior cut would be more beneficial in the superior repositioning of the maxilla.

Comparison of regional soft tissue changes after bimaxillary rotational surgery between class III deformity with overbite and open bite: A 3D imaging analysis

BackgroundThis prospective study aimed to compare regional soft tissue changes between patients with class III overbite and open bite deformities treated with bimaxillary surgery involving clockwise and counter-clockwise mandibular setback, respectively. Material and methodsClass III deformity adults receiving Le Fort I and bilateral sagittal split osteotomies were grouped according to the incisal occlusion: overbite (n = 30) and open bite (n = 30). Combined cone-beam CT scans and 3D facial photographs preoperative and at least 1-year postoperative were taken to assess the soft tissue changes. ResultsPostoperative changes for the overbite and open bite groups included anterior repositioning of nose (−0.8 ± 1.2 mm and −1.1 ± 1.1 mm, respectively) and cheek (−1.9 ± 1.3 mm and −1.7 ± 2.6 mm, respectively), posterior repositioning of chin (5.2 ± 4.0 mm and 4.9 ± 3.2 mm, respectively), and medial (−1.7 ± 2.0 mm and −1.9 ± 2.1 mm, respectively) and posterior (2.7 ± 1.4 mm and 2.8 ± 2.3 mm, respectively) repositioning of bilateral angles. Posterior (1.2 ± 2.0 mm and 5.1 ± 3.3 mm) and inferior (−1.4 ± 2.2 mm and −2.4 ± 2.7 mm) repositioning of upper lip and lower lip occurred in overbite group. Inferior (−2.3 ± 2.4 mm) and superior (3.7 ± 3.4 mm) repositioning of chin occurred in the overbite and open bite groups, respectively. ConclusionsTreatment of class III overbite and open bite deformities with bimaxillary rotational surgery resulted in comparable regional soft tissue changes, except for upper lip, lower lip and chin.

Craniofacial Manifestation and Orthosurgical Management of a Patient with Achondroplasia

Achondroplasia is a bone growth disorder results due to failure in endochondral ossification, conversion of cartilages into mature bones. It is the most common metaphyseal dysplastic condition of long bones. The incidence of achondroplasia is 1:25000–30,000 of live births. Our patient was a diagnosed case of achondroplasia, characterized by short stature, disproportionately short arms and legs, and short fingers. Craniofacial features include prominent forehead (frontal bossing), short cranial base, short nose, depressed nasal bridge, short upper lip leading to increased incisal show along with gingival visibility and hyperactive mentalis. Intraoral examination revealed constricted maxillary arch, multiple missing teeth, increased overjet of 12 mm, nonspecific molar, and canine relation bilaterally. Therapeutic intervention included orthosurgical management, i.e., Stage I (presurgical orthodontics)-leveling and alignment followed by closure of extraction spaces; Stage II (surgical management)–le fort-1 osteotomy and maxillary superior repositioning of 6 mm followed by 5 mm bilateral sagittal split ramus osteotomy with anticlockwise rotation of body of the mandible; and Stage III–settling of occlusion and fixed retention in maxillary and mandibular arch. Present case highlights the craniofacial manifestations of achondroplasia its effective management and the potential complications associated. Treating orthodontist should be aware of these features and their consequences in managing the patient to achieve a successful outcome.

Does maxillomandibular fixation affect skeletal stability following mandibular advancement? A single-blind clinical trial.

BackgroundThe stability of the results remains a significant concern in orthognathic surgeries. This study aimed to assess the amount of relapse following mandibular advancement with/without maxillomandibular fixation (MMF).Materials and methodsA single-blind clinical trial was conducted on patients with mandibular retrognathism who underwent BSSO for mandibular advancement and Lefort I maxillary superior repositioning. Patients were randomly divided into two groups of treatment (MMF) and control (no MMF). In the treatment group, MMF was performed for 2 weeks; meanwhile, MMF was not performed in the control group, and only guiding elastics were applied postoperatively. Lateral cephalograms were obtained preoperatively (T1), immediately after surgery (T2), and at 1 year postoperatively (T3). The distance from points A and B to the X and Y plane were measured to identify the amount of vertical and horizontal relapse in 1 year as a primary outcome. An independent t-test was applied in order to find differences in outcomes between the control and treatment groups.ResultsFifty-eight patients were evaluated in two groups (28 patients in the MMF group and 30 in the no-MMF group). The magnitude of mandibular advancement following BSSO was 7.68±1.39 mm and 7.53±1.28, respectively, without significant difference among the groups (p= 0.68). The mean sagittal and vertical changes (relapse) at point B were significantly different between the two groups at 1-year follow-up after the osteotomy (p=0.001 and p=0.05, respectively).ConclusionAccording to the results of this study, patients with short-term MMF following BSSO for mandibular advancement benefit from significantly greater skeletal stability in the sagittal and vertical dimensions.

Management of unilateral temporomandibular joint ankylosis with facial asymmetry

Long-standing temporomandibular joint (TMJ) ankylosis may compromise facial form and function. Treatment planning needs to address both the ankylosis and the facial deformity. A 21-year-old male patient with unilateral TMJ ankylosis of the right side with gross facial asymmetry was planned for a two-stage surgical procedure. First-stage surgery was done to release fibrous ankylosis, create a new functional joint and achieve adequate mouth opening. A vertical ramus osteotomy with superior repositioning of the proximal ramal segment and interpositional temporalis myofascial flap was done to achieve a functional joint and correct the facial height discrepancy. As the mouth opening was &lt;35 mm, ipsilateral coronoidectomy was done and the resected coronoid process was used a graft in the mandibular angle region. 35 mm of mouth opening was achieved intraoperatively.

Autorotation of the Mandible as Sequelae to Maxillary Intrusion: A Systematic Review.

Background:Autorotation of the mandible is a normally anticipated phenomenon following a surgical superior repositioning of the maxilla in clinical situations where patients have an excessive gummy smile. Prediction of the surgical treatment outcome following a presurgical orthodontic treatment is a critical element in the surgical treatment planning.Materials and Methods:The relevant articles were selected by hand search and electronic media (Google Scholar, PubMed, Science Direct, Medline, Embase, and Cochrane) from 1982 to 2020. All the relevant articles were properly screened, and findings were extracted from the articles.Results:It was observed that, following maxillary intrusion, mandible would eventually autorotate to take a new occlusion. Mandibular autorotation as a result of maxillary intrusion would lead to minimal shortening of the lower lip in the vertical plane. It was observed that the amount of mandibular autorotation correlates with the extent of maxillary impaction. Studies have shown that there is a passive soft-tissue response which may be attributed to the fact that no muscular detachment had been affected in the lower lip and soft-tissue chin region during the maxillary surgery.Conclusion:It is observed that there is a definite influence on the mandibular and chin positions as a result of maxillary intrusion and autorotation of the mandible. Every 1 mm of maxillary superior impaction, the chin moved 0.6 mm vertically and 0.2 mm horizontally. There is an appreciable shortening of the lower lip length.

Impact of orthognathic surgery on the treatment of gummy smile: an integrative review.

The gingival smile is considered unpleasant and can be treated in different ways according to its etiological factor. When caused by maxillary vertical growth excess, orthognathic surgery may be indicated to correct the vertical excess. The aim of this integrative review was to evaluate the impact of orthognathic surgery on the treatment of gingival smile. An electronic search was performed of the PubMed/Medline, Cochrane Library, Scopus, and Google Scholar databases. The selection of studies was performed by two blinded reviewers. Firstly, studies were selected by reading the titles and the abstracts of articles. The references from each study selected were then searched to find articles that were not found in the electronic search. After reading the full-text articles, studies that met the inclusion criteria were selected. A total of 667 studies were identified, but only 19 were selected for the integrative review after applying the inclusion and exclusion criteria. The selected articles reported maxillary impaction from 2 to 10 mm, but this amount of superior repositioning of maxilla does not appear to be related to the initial gingival exposure described. Orthognathic surgery is not the first choice of treatment for gingival smile, but it appears to be a suitable therapy for other conditions in the same patient for improving a gummy smile by correction of gingival exposure.

Does maxillary superior repositioning affect nasal airway function?

This study aimed to assess nasal airflow, nasal resistance, and the cross-sectional area of the nasal cavity in patients who have had maxillary superior repositioning (MSR). This is a cross-sectional study, and nasal airflow, nasal resistance, and the cross-sectional area of the nasal cavity were evaluated by rhinometry and acoustic rhinometry techniques in patients who had had MSR. Thirty-two patients were studied, and the mean (SD) MSR was 5.03 (1.61) (range 3-8) mm. There was a significant correlation between the mean MSR and the mean change in nasal airflow and nasal resistance (p=0.001 and p=0.005, respectively). There was also a correlation between MSR and the change in the cross-sectional area of the inferior concha (p=0.001), but there was no correlation between the mean MSR and the change in cross-sectional area of the isthmus (p=0.07). Nasal airflow increases when the mean MSR is less than 6.5mm, and when maxillary impaction is 6.5mm or more, nasal airflow decreases. It seems, therefore, that MSR of less than 6.5mm was associated with an improvement in nasal airflow. When maxillary impaction was more than 6.5mm, nasal airflow and the cross-sectional area of the nasal cavity decreased, and nasal resistance increased.

Lefort I osteotomy in combination with modified Wassmund technique: A new combination for surgery- first orthognathic approach

Objective: The aim of this technical note is to present a unique combination of orthognathic surgery which incorporates Wassmund technique and Lefort I osteotomy a part of surgery- first orthognathic approach (SFOA) in prognathic maxilla.Methods: Usually, the SFOA indications are minimally involved skeletal discrepancy and most often procedure is bilateral sagittal split ramus osteotomy (BSSRO) for setback or Lefort I osteotomy with superior repositioning. The current report illustrated SFOA in case of gummy smiling with maxillary anteroposterior excess. We have used Lefort I osteotomy in conjunction with Wassmund procedure (incorporating our own modification) for setback of premaxilla in SFOA.Results: The gummy smile was reduced from 9 mm to 3 mm with excellent occlusion in one surgery with improved psychological benefit to the patient.Conclusion: In contrast to the limited skeletal abnormality as an indication of SFOA, the current report presentation reveals a unique technique for dealing with a large skeletal discrepancy with the combination of Lefort I osteotomy and Wassmund technique. A growing acceptance in surgical and orthodontic communities toward SFOA lead an increasing demand in the patients with wide range of skeletal deformity correction in a short period of time. The surgeons should not restrict his horizon to BSSRO or Lefort I osteotomy in SFOA. The comprehensive knowledge of different surgical technique can widened the extent of SFOA.

Quantitative Prediction of Change in Chin Position in Le Fort I Impaction.

Vertical maxillary excess, a dentofacial deformity present in a large proportion of population impute an increased lower facial height due to increased maxillary height. This results in a clockwise rotation in the mandible, and the chin advances posteriorly and inferiorly. Le Fort I superior repositioning of the maxilla begets movement of pogonion point anteriorly and cranially. Cephalometric analysis helps to access change in position of chin following Le Fort I impaction. In our study, from this analysis a formula was defined to perceive the exact amount of this change in chin position along the vertical and sagittal plane as a result of autorotation. This experimental study assessed 45 patients with vertical maxillary excess over a period of 2years and 6months (January 2016-May 2018) in Government Medical College Hospital, Kottayam, Kerala, India. The planned procedure was Le Fort I superior impaction for correction of vertical maxillary excess. Pre-operative cephalograph was taken initially. Post-operative cephalograph after 3months was then compared with initial pre-operative cephalograph to assess the change in position of the pogonion and menton. Forty-five participants were studied. The multiple regression model was applied to predict the changes in the chin (dependent factor) according to the vertical change in the maxilla (predictive factor). For every 1mm change in the maxilla vertically, the chin was estimated to move 0.59 vertically. For a standard deviation increase of 1 in the position of the maxilla, the chin moved superiorly by 0.744 of the standard deviation. For every 1mm of vertical change in the maxilla, the chin could be expected to move 0.22mm horizontally. For a standard deviation increase of 1 in the maxillary position, the chin advanced by 0.273 of the standard deviation. This study draws to a conclusive finding that the movement of maxilla in the superior direction has an effect on the repositioning of the chin in the anterior and cranial directions. This has led to a formulation that 1mm of superior impaction of maxilla results in 0.6mm of vertical and 0.2mm of sagittal movement of chin. This might help to have a glance of future chin position and aid in deciding the need for mandibular surgery.

Horseshoe Le Fort I osteotomy for gummy smile and facial asymmetry: Two cases

Introduction: In cases with gummy smile or asymmetry of the maxilla, superior repositioning of the maxilla is required. If superior repositioning by a Le Fort I osteotomy alone is difficult, a horseshoe Le Fort I osteotomy can be used. Presentation of cases: Case 1: A 24-year-old Japanese woman patient presented with a gummy smile and an open bite. After we performed a horseshoe Le Fort I osteotomy, the maxillary segment was repositioned superiorly 3.0 mm at upper tooth number 1 (U1) and 5.0 mm at upper tooth number 6 (U6). Case 2: A 21-year-old Japanese man presented with severe facial asymmetry. After we performed a unilateral modified horseshoe Le Fort I osteotomy, the maxillary segment was superiorly repositioned 6.0 mm at the right U6. Discussion: This procedure eliminated the risk of intraoperative bleeding because it was unnecessary to remove bones around the descending palatine artery, and it was possible to maintain the chamber size of the nasal cavities. Conclusion: The horseshoe Le Fort I osteotomy is a reliable technique for cases with severe gummy smile or asymmetry of the maxilla.

Modification of LeFort I osteotomy for severe maxillary vertical excess asymmetry

A superfluous maxillary alveolus exacerbates excess of the vertical maxilla, and leads to a severe form of deformity. This poses a unique surgical challenge. In such conditions, the dimensions of the maxilla cephalad to the anterior nasal spine are normal, which limits superior repositioning of the maxilla when done in a conventional manner. The objective of this paper is to highlight the importance of a modified approach to this deformity using a subnasal maxillary osteotomy. Advantages of subspinal maxillary osteotomy include the reduction of maxillary alveolar excess and increase in the scope for maxillary impaction.

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.

Investigation of two-stage total maxillary alveolar osteotomy for superior repositioning of the maxilla in patients with a gummy smile accompanied by a high palate

Investigation of two-stage total maxillary alveolar osteotomy for superior repositioning of the maxilla in patients with a gummy smile accompanied by a high palate

Evaluation of Three-Dimensional Changes in Pharyngeal Airway Following Isolated Lefort One Osteotomy for the Correction of Vertical Maxillary Excess: A Prospective Study.

Orthognathic surgery involves movement of jaws in all three planes, and this being a part of airway complex, displacement of jaws can influence the dimension of airway at all levels. Lefort one osteotomy surgery with superior repositioning is a common procedure done for patients with vertical maxillary excess. The purpose of this study was to evaluate the three-dimensional volumetric changes in airway after lefort one impaction surgery using three-dimensional cone beam computed tomography (3D-CBCT) in patients with vertical maxillary excess (VME). A prospective analysis of 15 patients who underwent isolated lefort one impaction surgery was done with pre-operative (T0) and 3-months (T1) post-operative 3D-CBCT scans. Airway was divided into three segments, nasopharyngeal, velopharyngeal and oropharyngeal. Volumetric analysis of all these segments was done before and after surgery. Paired 't test' was used to assess the mean difference in airway volume and area between T0 and T1. One-way ANOVA was used to check the mean percentage difference in airway volume and area among the three segments. The mean percentage of nasopharyngeal volume difference was - 0.6299 ± 0.9146%, velopharyngeal volume difference was - 0.5205 ± 1.107%, oropharyngeal volume difference was - 1.492 ± 2.745%. Though volume and area of pharyngeal airway were decreased after maxillary impaction surgery in all three segments of airway studied, they were not statistically significant. Among the three segments of airway studied, oropharyngeal airway volume has shown the highest post-surgical reduction though statistically insignificant. ESS scores were within normal limits. Hence, we are of the opinion that there is lack of evidence to conclude that the patients undergoing lefort one superior repositioning for the treatment of VME might develop significant narrowing of PAS that may predispose the patient to breathing disorders.