Superior Repositioning Research Articles

The Evaluation of Limit of Superior Repositioning of Maxilla in Le Fort I Osteotomy: A 3D Study Part I

The Evaluation of Limit of Superior Repositioning of Maxilla in Le Fort I Osteotomy: A 3D Study Part I

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

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. 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. 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. 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. 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.

Correction of gummy smile by superior repositioning of maxilla in Bangladeshi people

Vertical maxillary excess is associated with gummy smile, incompetent lip, bimaxillary proclination, Angle’s class-I or class-II malocclusion with or without retogenia. After proper evaluation preoperative orthodontic treatment was performed in every cases and superior repositioning of the maxilla by Le Fort-I osteotomy is presented. Three 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 7.0 mm superiorly at point A. The mandible autorotated anterosuperiorly to achieve sound occlusion. Point B moved 1.0–3.0 mm anteriorly and 5.0–8.0 mm superiorly. The pogonion moved 4.0 mm anteriorly in a case done without genioplasty and the pogonion moved maximum 8.0mm in case done in combination with genioplasty. All patients obtained sound occlusion and a good profile after the operation. Almost no skeletal relapse was observed during 3 years of postoperative follow-up. Amount of gingiva showing during smile was ranges from 5.0mm –7.0mm which was 0-2.0mm after superior repositioning of the maxilla.
 Ban J Orthod & Dentofac Orthop, April 2016; Vol-6 (1-2), P.1-5

Outfracture of the inferior turbinates during superior repositioning Le Fort I osteotomy with cone-beam computed tomographic analysis of the volume of the nasal cavity

We have investigated the volumes of the nasal cavities of 35 patients treated with superior repositioning Le Fort I osteotomy by analysing cone-beam computed tomography (CT) data with a 3-dimensional reconstruction program to correlate changes in the volume of the nasal cavity that were associated with the maxillary superior repositioning and the role of outfracture of the inferior turbinates. The patients were treated at the Pusan National Dental Hospital during the 14-month period January 2011-March 2012.. The patients were divided into two groups, the first of which consisted of 20 patients who had superior repositioning of 4mm or more with a mean superior movement of 5.2mm and outfracture of the inferior turbinates (outfracture group). The second group consisted of 15 patients who also had more than 4mm impaction with a mean superior movement of 5.0mm and for whom outfracture was not done (no outfracture group). Nasal symptoms were investigated preoperatively and 6 months postoperatively using the Nasal Obstruction Symptom Evaluation (NOSE) scale, and 3-dimensional volumetric analysis was made using cone-beam CT data to assess changes in nasal volume. There were significant differences between the groups in volumetric changes (V1-V2) (p=0.001) but no significant differences between the sexes. The volume of the nasal cavity in the outfracture group decreased by 20% after superior repositioning, but that in the no outfracture group decreased by 33%. Among the 20 patients in the outfracture group not one complained of nasal symptoms postoperatively. We conclude that outfracture of the inferior turbinates should be considered when the amount of superior movement of maxilla is more than 4mm.

VERTICAL AND HORIZONTAL STABILITY FOLLOWING LE FORT I OSTEOTOMY WITHOUT BONE GRAFT

objectives: the study aimed to evaluate the vertical and horizontal stability following Le Fort I osteotomy without using any bone graft in patients with maxillary advancement up to 6 mm alone or combined with vertical repositioning. Patients and methods: patients referred for one piece Le Fort I osteotomy with or without other orthognathic procedures were included in this study. In all surgeries, the maxilla was fixed using titanium plates and no bone graft was used in any of the patients. Suspension wires were fixed to be used for IMF with elastics postoperatively. Lateral cephalometric X-rays were taken 1 week after the surgery (T1), and 1 year after the surgery (T2), these X-rays were used to evaluate the postoperative stability using the SNA angle, maxillary depth angle, palatal plane angle, and maxillary height angle to evaluate changes in the horizontal and vertical direction. results: The lateral cephalometric analysis for relapse in the anteroposterior direction showed that only 6 patients out of 18 (33.3%) encountered a relapse of more than 2° in SNA angle and 5 (27.7%) in the maxillary depth angle measurements. Yet in between those patients there was only one (5.5%) out of 18 patients had only maxillary advancement without vertical repositioning. The results of the maxillary height and palatal plane angles showed that all the changes of more than 2° in the vertical direction were in the elongation group (3 patients out of four) (75%) using the palatal plane angle while it was only 1 patient (25%) using the maxillary height angle evaluation. Conclusion: within the limitation of the present study (small sample number especially in the patients with vertical repositioning) ; the study suggests that the use of bone graft can be avoided in maxillary advancement movement up to 6 mm anterior repositioning even this was combined with superior repositioning. Moreover the study recommends the use of bone graft in cases of anterior maxillary advancement with inferior repositioning of the maxilla.

Assessment of Alar Flare and Efficacy of Alar Cinch Suture in the Management of Alar Flare Following Le Fort 1 Superior Repositioning: A Comparative Study.

To prospectively analyze the amount of alar flare, factors contributing to alar flare and efficacy of cinch suture as an adjunctive procedure for alar flare reduction. Thirty adult patients with vertical maxillary excess, who underwent Le Fort 1 impaction, were divided into 2 groups of 15 each. Alar cinch was performed as an adjunct procedure in group 2 patients and results were compared to group 1 which was the control group. Measurements were made on the patients and on 1:1 standardized photographs. Group 2 showed a near pre-operative alar position compared to group 1. The alar flare resulting from every millimeter of impaction was significantly less in group 2 compared to group 1. Alar cinch suture restores the normal alar width by preventing the lateral drift of the naso-labial muscle and thereby reducing the postoperative nasal flare significantly.

U-shaped Osteotomy Around the Descending Palatine Artery to Prevent Posterior Osseous Interference for Superior/Posterior Repositioning of the Maxilla in Le Fort I Osteotomy.

In maxillary orthognathic surgery, superior repositioning of the maxilla is sometimes difficult, and removal of bony interference, especially around the descending palatine artery (DPA), is very time-consuming in cases of severe maxillary impaction. Posterior repositioning of the maxilla for removal of bony interference between the posterior maxilla and the pterygoid process is also technically difficult. Because the most common site of hemorrhage in Le Fort I osteotomy is the posterior maxilla, this bone removal is a source of frustration for surgeons in DPA injury. When the DPA is injured during bone removal and ligation is performed, aseptic necrosis of the maxilla may occur. Therefore, a simple and safe method for maxillary superior/posterior repositioning is required to remove osseous interference around the DPA. The authors describe here U-shaped osteotomy around the DPA to prevent posterior osseous interference for superior/posterior repositioning of the maxilla in Le Fort I osteotomy.

Spatial changes of the chin in the vertical and sagittal planes after superior repositioning of the maxilla.

The mandible autorotates after maxillary superior repositioning. The aim of this study was to address the changes in chin position in the vertical and sagittal planes after maxillary superior repositioning. This cross-sectional study assessed participants who had class I occlusion with vertical maxillary excess and underwent maxillary superior repositioning. Two lateral cephalograms were taken in central occlusion and natural head position. The amount of maxillary superior repositioning was documented for every participant according to lateral cephalometric indices. The distance between the most prominent point of the chin and a perpendicular line from N to the Frankfort line was used to determine the sagittal changes of the chin before and after surgery. The distance from the N point to Me was used to assess the vertical changes of the chin before and after operation. The Pearson correlation test was used to determine the correlation between the amount of maxillary superior repositioning and the vertical and horizontal changes of the chin. The linear regression model was applied to predict the changes of the chin (dependent factor) according to the vertical change of the maxilla (predictive factor). The occlusal plane angle change, mandibular length, and mandibular plane angle were considered as variable factors. Twenty participants were studied. Analysis of the data demonstrated a significant correlation between the maxillary superior repositioning (predictive factor) and the horizontal and vertical changes of the chin. For every 1 mm of vertical change in the maxilla, the chin could be expected to move 0.21 mm horizontally. For a standard deviation increase of 1 in the maxillary position, the chin advanced by 0.753 of the standard deviation (β = 0.753). For every 1-mm change of the maxilla vertically, it could be estimated that the chin moved 0.71 mm vertically when the amount of maxillary impaction was 8 mm or less. For an increase in standard deviation of 1 in the position of the maxilla, the chin moved superiorly by 0.711 of a standard deviation (β = 0.711). In maxillary superior repositioning greater than 8 mm, for every 1 mm of superior repositioning, the chin moved 0.44 mm superiorly. There was a positive correlation between the occlusal plane change, mandibular length, mandibular plane angle as well as the vertical and horizontal changes of the pogonion (P = 0.001). The chin position after maxillary superior repositioning can be predicted according to the amount of maxillary vertical changes. The vertical change of the chin is more predictable than the horizontal change.

Vital staining of palatal soft tissue in horseshoe Le Fort I osteotomy for superior repositioning of the maxilla.

In maxillary orthognathic surgery, superior repositioning of the maxilla is sometimes difficult, and removal of the bony interference, especially around the descending palatine artery, is very time-consuming in cases of severe maxillary impaction. A useful method introduced for superior repositioning of the maxilla is horseshoe-shaped osteotomy combined with Le Fort I osteotomy (horseshoe Le Fort I osteotomy). However, injury to the palatal soft tissue during horseshoe-shaped osteotomy may cause aseptic complications of the maxilla. Therefore, a safe method is required to prevent such injury to reduce the risk for aseptic necrosis. We describe here vital staining of palatal soft tissue in horseshoe Le Fort I osteotomy for safer superior repositioning of the maxilla.

A comparative assessment of maxillary perfusion between two different Le Fort I osteotomy techniques

Compromised maxillary perfusion following Le Fort I osteotomy is a potentially serious complication resulting in hard and/or soft tissue loss. The aim of this study was to compare the change in perfusion between two techniques of posterior maxillary disjunction by intraoperative measurement of maxillary gingival blood flow (GBF). Further, we sought to correlate the association of the movement of the maxilla and estimated blood loss as factors. The study population comprised 38 individuals, divided equally into two groups: a pterygoid disjunction group and a third molar socket disjunction group. GBF was measured using Doppler flowmetry. A P-value of <0.05 was considered significant. There was a significant drop in GBF in both groups. However, there was no significant difference between the groups based on magnitude of blood flow drop. Superior repositioning of the osteotomized maxilla caused the greatest drop in GBF, which was statistically significant. There was significantly less blood loss in the pterygoid disjunction group. In conclusion, Le Fort I osteotomy causes a significant decrease in GBF. The technique used for posterior maxillary disjunction does not influence the magnitude of drop in perfusion. There is a significant correlation of other factors such as the effect of superior repositioning of the maxilla and blood loss with the osteotomy techniques.

Role of Le Fort I Osteotomy in Orthosurgical Management of Maxillary Deformities in North Indian Population

Background : Le Fort I osteotomy is one of the most commonly performed procedure, either alone or in conjunction with other orthognathic procedures for maxillary deformities. Objective: The present prospective study pertains to definite diagnosis, orthosurgical planning with cephalometric predictions of dento-osseus deformities of maxilla and their correction by LeFort I osteotomy. Material and Methods: Fourteen patients with skeletal deformity along with malocclusion which was too severe to be corrected orthodontically alone were selected. Parameters were selected on the basis of clinical findings, cephalometrically hard and soft tissue landmarks [COGS (Burstone and Legan) and Steiners analysis]. Parameters were observed and compared preoperatively prediction values, postoperatively and on follow-up. Results: There were obvious improvement in various linear and angular readings of hard and soft tissues.In linear measurements,NANS ⊥ HP decreased from 57.62 ± 3.3 to 52.4 ± 2.9; ANS-Gn ⊥ HP decreased from 75.8 ± 8.1 to 69.3 ± 6.1; NA || HP reduced by approximately 5mm; N-Pg || HP decreased from -12.07 ± 9.6 to -3.78 ± 8.8 and PNS-N ⊥ HP decreased from 55.28 ± 5.08 to 58.07 ± 4.4. On analysis of angular hard tissue measurements, N-A-Pg angle decreased from 5.14 ± 5.75 to 4.17 ± 2.73 (superior repositioning of maxilla) and increased from 3.0 ± 1.4 to 4.5 ± 0.7 (inferior repositioning of maxilla);MP-HP angle, Ar-Go-Gn angle decreased following superior repositioning and increased following inferior repositioning of maxilla and SNA angle decreased from mean 80.8 to 79.5. Conclusion: LeFort I osteotomy is really a workhouse of orthognathic surgery in which maxilla can be mobilized in vertical and saggital planes to correct various dento-osseous deformities.

Changing the Facial Features of Patients With Treacher Collins Syndrome

Treacher Collins syndrome is a disorder characterized by various congenital soft tissue anomalies involving hypoplasia of the zygoma, maxilla, and mandible. A variety of treatments have been reported to date. These treatments can be classified into 2 major types. The first type involves osteotomy for hard tissue such as the zygoma and mandible. The second type involves plastic surgery using bone grafting in the malar region and soft tissue repair of eyelid deformities. We devised a new treatment to comprehensively correct hard and soft tissue deformities in the upper half of the face of Treacher Collins patients. The aim was to "change facial features and make it difficult to tell that the patients have this disorder." This innovative treatment strategy consists of 3 stages: (1) placement of dermal fat graft from the lower eyelid to the malar subcutaneous area, (2) custom-made synthetic zygomatic bone grafting, and (3) Z-plasty flap transposition from the upper to the lower eyelid and superior repositioning and fixation of the lateral canthal tendon using a Mitek anchor system. This method was used on 4 patients with Treacher Collins syndrome who had moderate to severe hypoplasia of the zygomas and the lower eyelids. Facial features of these patients were markedly improved and very good results were obtained. There were no major complications intraoperatively or postoperatively in any of the patients during the series of treatments. In synthetic bone grafting in the second stage, the implant in some patients was in the way of the infraorbital nerve. Thus, the nerve was detached and then sutured under the microscope. Postoperatively, patients had almost full restoration of sensory nerve torpor within 5 to 6 months. We devised a 3-stage treatment to "change facial features" of patients with hypoplasia of the upper half of the face due to Treacher Collins syndrome. The treatment protocol provided a very effective way to treat deformities of the upper half of the face in patients with Treacher Collins syndrome.

Maxillary Posterior Segmentation Using an Oscillating Saw in Le Fort I Posterior or Superior Movement Without Pterygomaxillary Separation

Any remaining tuberosity or pterygoid plate frequently interferes with posterior or superior movement of the maxilla, if no pterygomaxillary separation is performed in low-level Le Fort I osteotomy. The objective of this report is to describe a technique for maxillary posterior segmentation using an oscillating saw in Le Fort I posterior or superior movement without pterygomaxillary separation and to present the authors' preliminary multicenter experience with this technique. The authors retrospectively evaluated patients who underwent double-jaw surgery at 3 orthognathic surgery centers from May 2010 to December 2012. In all cases, the segmentation procedure was performed using an oscillating saw on a posterior or tuberosity area of the maxilla before downfracture obtained by leverage alone without pterygomaxillary separation, below or near the lower part of the pterygoid plate. In total, 1,231 patients (411 male and 820 female; mean age, 24.9 yr) were enrolled. Mean surgical time for the maxillary procedure was 55.9 minutes. None of the patients received a blood transfusion, and no significant soft or hard tissue complications clinically compromised the healing of the repositioned maxilla. Mean maxillary posterior and superior movements were 3.4 mm (range, 2.1 to 5.6 mm) and 4.0 mm (range, 1.3 to 5.6 mm), respectively. The preliminary results indicate that this maxillary posterior segmentation procedure using an oscillating saw in low-level stepped Le Fort I osteotomy can be completed safely and effectively for posterior or superior repositioning of the maxilla, with no need to disturb the integrity of the pterygoid plate.

Anterior maxillary osteotomy: A technical note for superior repositioning: A bird wing segment.

Aim:The aim of this study is to evaluate the efficacy of a single piece bird wing osteotectomy segment during anterior maxillary osteotomy (AMO) markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method thereby reducing the kinking effect to the palatal pedicle and gives good perfusion to the anterior segment.Materials and Methods:This study was conducted at Karpaga Vinayaga Institute of Dental Sciences composing of 20 patients in which male: female ratio was 8:12, with a mean age of 25-30 years. This bird wing segment technique is performed following presurgical orthodontics under the guidance of clinical assessment of the gummy smile with an incisal show when the lip is at repose (vertical maxillary excess), especially for the calculated amount of superior repositioning. It is calculated by subtracting 2 mm from the total amount of an incisor show when the lip is at repose. The normal incisal show when the lip is at repose is 2 mm. After conventional primary AMO cut was performed, the precise calculated.Results:All our cases were tested positive for pulp vitality, no relapse, and minimal edema and with no changes in the bite or dentoalveolar relation followed until 1 year postoperatively indicating a good perfusion to the anterior segment and all the patients were satisfied esthetically and free of complaints.Conclusion:This simple technique allows the precise amount of calculated bone removal in a single piece from the nasal floor markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method there by reducing the kinking effect to the palatal pedicle and maintains good perfusion.

Surgical correction of class II skeletal malocclusion in an adult patient

Correction of skeletal deformities in adult patients with orthodontics is limited. Orthognathic surgery is the best option for cases when camouflage treatment is questionable and growth modulation is not possible. This case report illustrates the benefit of the team approach in correcting vertical maxillary excess along with class II skeletal deformity. A cosmetic correction was achieved by superior repositioning of maxilla with LeFort I osteotomy and augmentation genioplasty, along with orthodontic treatment. The patient's facial appearance was markedly improved along with functional and stable occlusion

Severe gummy smile with class II malocclusion treated with LeFort I osteotomy combined with horseshoe osteotomy and intraoral vertical ramus osteotomy.

In this article, we report the successful surgical treatment of a patient, 34 years of age, who had a severe gummy smile and a class II malocclusion. The patient had an 11-mm gingival exposure during full smile and a convex profile. A LeFort I osteotomy combined with a horseshoe osteotomy was used for the superior repositioning of the maxilla;then, an intraoral vertical ramus osteotomy (IVRO) and genioplasty were performed for mandibular advancement. The maxilla was acceptably impacted 8mm at the first incisor and 5mm at the first molar. Both the occlusion and facial appearance were significantly improved by this surgical-orthodontic treatment. Our results suggest that the combination of a horseshoe osteotomy with a LeFort I osteotomy is a useful technique for reliable superior repositioning of the maxilla.

Efficacy of v-y closure of upper lip after le fort I osteotomy advancement and superior repositioning on facial esthetics in comparison to simple continuous closure: a statistical analysis.

This study aims to evaluate efficacy of V-Y closure of upper lip incision on facial esthetics in comparison to simple continuous closure after Le Fort I advancement and superior repositioning of maxilla. Thirty-four patients were divided in two groups i.e. V-Y closure group (group I=17patients) and simple continuous closure group (group II=17patients). The preoperative and 1year post-operative linear and angular changes of hard and soft tissue points of groups I and II were statistically compared. Labial changes were more favourable in V-Y closure group in comparison to simple continuous closure group in both the Le Fort I maxillary movements. The upturning and forward movement of the nose were seen in both the maxillary movements but these nasal changes did not differ significantly between the groups. It was observed that the technique of V-Y closure of upper lip delivers adequate results contributing to better facial esthetics when compared to simple continuous closure.

Comparison of rigid and semirigid fixation for advancement genioplasty.

To compare the skeletal stability of rigid versus semirigid fixation for advancement genioplasty by the assessment of vertical and horizontal measurements pre-operatively and post-operatively on lateral cephalometric radiographs. The study comprised of patients who underwent standard advancement genioplasty by inferior osteotomy of the chin with broadest musculoperiosteal pedicle with either rigid fixation or wire fixation. The displacements of vertical and horizontal measurements resulting following surgery was derived by calculating the difference between preoperative, immediate post-operative and 1year post-operatively on lateral cephalometric radiographs. Preoperative measurements were marked as T1, immediate post-operative as T2, 1year follow up post-operative as T3. In the semirigid group a mean horizontal advancement of 5.97mm was accompanied by a relapse of 1.623mm during a period of minimum 1year. The mean superior repositioning of menton was 0.7mm. This was accompanied by a relapse of 0.325mm during a period of 1year. In the rigid group a mean horizontal advancement of 4.815mm was accompanied by a relapse of 0.2mm during a period of 1year. The mean superior repositioning of menton was 0.975mm. This was accompanied by a relapse of 0.1mm during a period of 1year. This study confirms the findings of several previous studies that contribute data specific towards the use of rigid fixation in advancement genioplasty. In our study we also observed that, in cases where large advancements are necessary, wire fixation may offer insufficient means of fixation particularly if the movement is complex and asymmetrical, in which case rigid fixation devices are more helpful.

An accurate maxillary superior repositioning technique without intraoperative measurement in bimaxillary orthognathic surgery

This article describes a simple and accurate technique for maxillary superior repositioning without any intraoperative measurement using reference points that can be the source of error in bimaxillary orthognathic surgery. A bilateral straight locking miniplates (SLMs)/screw system secured to the maxilla and mandible maintains the three-dimensional relationship between the mandible and the skull base precisely like the incisor pin of an articulator in model surgery. The maxilla can then be accurately moved into the planned position identical to that in model surgery by the SLMs technique.

Midfacial soft tissue changes after leveling Le Fort I osteotomy with differential reduction

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. 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. 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. 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.