Establishment of a three-dimensional coordinate system for measuring the recurrence rate after orthognathic surgery and evaluation and analysis of the degree of recurrence / 口腔疾病防治

Objective@# To establish a three-dimensional coordinate system that can accurately measure the recurrence rate after orthognathic surgery, and evaluate and analyze the degree of recurrence.@*Methods @#Data from patients who underwent orthognathic surgery in a hospital were selected to reconstruct three-dimensional images with spiral CT. The two researchers used the multiplane assisted positioning method to fix the points three times and screened them using intra-andintreclass correlation coefficients (ICC). Reproducible and accurate landmark points were drawn to establish different coordinate systems and calculate the facial asymmetry index (AI) to determine the coordinate system with the best mid-sagittal plane symmetry. This coordinate system and lateral radiographs were used to separately measure the recurrence rate, and evaluate and analyze the three-dimensional recurrence degree of orthognathic surgery.@*Results @#Ten landmark points that may be repeatedly fixed were obtained, including N (nasion), K (K point), ANS(anterior nasal spine), PNS (posterior nasal spine), Ptm(pterygomaxillary fissure), Gn (gnathion), IZ(IZ point), MZ (MZ point), Ms (mastoideale), Cor (coronion) and and Go (gonion). Three coordinate systems were established, and the most suitable coordinate system was the upper edge point of the left infraorbital foramen. The inner upper edge of the right infraorbital foramen and both sides of the midpoint of the ear points constituted the horizontal plane (HP), which passed through the outermost point of the left zygomatic frontal suture and the outermost point of the right zygomatic frontal suture and was perpendicular to the horizontal plane to constitute the coronal plane (CP). It was perpendicular to the two planes to form a sagittal plane (SP). Two-dimensional and three-dimensional measurements of recurrence were performed on 112 patients, and new three-dimensional recurrence evaluation results were obtained. Less than 40% had low recurrence, 40% to 61% had moderate recurrence, and greater than 61% had high recurrence.@*Conclusion@#This study established a three-dimensional coordinate system suitable for measuring the recurrence rate after orthognathic surgery, obtained a new three-dimensional recurrence evaluation result, and provided a clinical experimental basis for evaluating the effect of orthognathic surgery and improving stability.

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.

Bony Stability and Soft Tissue Changes after Orthognathic Surgery on Patients with Cleft

PURPOSE: The objective of this retrospective study was to assess the skeletal stability after orthognathic surgery for patients with cleft lip and palate. The soft tissue changes in relation to the skeletal movement were also evaluated. METHODS: Thirty one patients with cleft received orthognathic surgery by one surgeon at the Craniofacial Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Osseous and soft tissue landmarks were localized on lateral cephalograms taken at preoperative (T0), postoperative (T1), and after completion of orthodontic treatment (T2) stages. Surgical movement (T0-T1) and relapse (T1-T2) were measured and compared. RESULTS: Mean anteroposterior horizontal advancement of maxilla at point A was 5.5 mm, and the mean horizontal relapse was 0.5 mm (9.1%). The degree of horizontal relapse was found to be correlated to the extent of maxillary advancement. Mean vertical lengthening of maxilla at point A was 3.2 mm, and the mean vertical relapse was 0.6 mm (18.8%). All cases had maxillary clockwise rotation with a mean of 4.4 degrees. The ratio for horizontal advancement of nasal tip/anterior nasal spine was 0.54/1, and the ratio of A' point/A point was 0.68/1 and 0.69/1 for the upper vermilion/upper incisor tip. CONCLUSION: Satisfactory skeletal stability with an acceptable relapse rate was obtained from this study. High soft tissue to skeletal tissue ratios were obtained. Two-jaw surgery, clockwise rotation, rigid fixation, and alar cinch suture appeared to be the contributing factors for favorable results.

Bony Stability and Soft Tissue Changes after Orthognathic Surgery on Patients with Cleft

PURPOSE: The objective of this retrospective study was to assess the skeletal stability after orthognathic surgery for patients with cleft lip and palate. The soft tissue changes in relation to the skeletal movement were also evaluated. METHODS: Thirty one patients with cleft received orthognathic surgery by one surgeon at the Craniofacial Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Osseous and soft tissue landmarks were localized on lateral cephalograms taken at preoperative (T0), postoperative (T1), and after completion of orthodontic treatment (T2) stages. Surgical movement (T0-T1) and relapse (T1-T2) were measured and compared. RESULTS: Mean anteroposterior horizontal advancement of maxilla at point A was 5.5 mm, and the mean horizontal relapse was 0.5 mm (9.1%). The degree of horizontal relapse was found to be correlated to the extent of maxillary advancement. Mean vertical lengthening of maxilla at point A was 3.2 mm, and the mean vertical relapse was 0.6 mm (18.8%). All cases had maxillary clockwise rotation with a mean of 4.4 degrees. The ratio for horizontal advancement of nasal tip/anterior nasal spine was 0.54/1, and the ratio of A' point/A point was 0.68/1 and 0.69/1 for the upper vermilion/upper incisor tip. CONCLUSION: Satisfactory skeletal stability with an acceptable relapse rate was obtained from this study. High soft tissue to skeletal tissue ratios were obtained. Two-jaw surgery, clockwise rotation, rigid fixation, and alar cinch suture appeared to be the contributing factors for favorable results.

LeFort osteotomy used to enucleate a major dentigerous cyst / Osteotomía LeFort I utilizada para enuclear un gran quiste dentígero

LeFort I Osteotomy is a surgical technique frequently used for dentofacial deformities treatment. A few cases report show this technique for pathology treatment; LeFort I approach show many advantages as good visibility, good surgical control and very little postsurgical complications. In this case report, the authors present a great dentigerous cyst in premaxillae area related to supernumerary tooth. Almost three year treatment with one year of decompression, enucleation with LeFort I approach with modified sequence and one year of post operatory control showing success and predictability of technique.

La osteotomía LeFort I es una técnica quirúrgica frecuentemente utilizada para el tratamiento de deformidades dentofaciales. Pocos casos han mostrado su uso para el tratamiento de patologías; el acceso con osteomotias LeFort I muestra muchas ventajas como la buena visibilidad, buen control de la cirugía y pocas complicaciones postquirúrgicas. En este reporte de caso, los autores presentan un quiste dentígero de grandes proporciones en el área de la premaxila asociada a un diente supranumerario. Casi tres años de tratamiento con un año de descompresión, enucleación con acceso de LeFort I con una secuencia modificada y un año de control postquirúrgico muestran éxito y predictibilidad de la técnica.

Reposición maxilar y reconstrucción con injerto de cresta lliaca: parte 1: indicaciones y técnica quirúrgica / Maxillary repositioning and reconstruction with lliac crest graft: part 1: indications and surgical technique

Las técnicas de implantología actuales, no se limitan a evaluar la instalación de implantes y la rehabilitación protésica, sino que deben abocarse a resolver los problemas integrales de nuestros pacientes. De esta forma, devolver armonía facial perdida debe ser un criterio trascendente en la elección de los tratamientos. Con este principio, la estética se establece como un punto de inicio de nuestras terapias, lo cual lleva obligatoriamente a interrelacionarla con la función del sistema estomatognático. Este artículo tiene como objetivo discutir algunos conceptos asociados a la reconstrucción de maxilares atróficos y establecer su relación con fenómenos de deficiencias dentofaciales. Desarrollamos una revisión de aspectos que consideramos relevantes a la hora de escoger determinados tratamientos y presentamos uno de nuestros casos para ejemplificarlo.

Despite solve the implant installation and prosthesis rehabilitation the actual implant are also used to solve other disorders. This way, restore the facial symmetry lost has to be transcendent criteria when choosing a treatment. With this principle, aesthetic becomes a major point in our therapy, correlating it with the stomatognathic system function. The meaning of the present article is discuss some concepts associated with the reconstruction of the atrophic maxillas and established its relation with dentofacial deformities. It was performed a literature review of some points that we consider relevant when choosing a treatment planning and showing one of ours clinical case to exemplify.

Damage to an Endotracheal Tube during Lefort I Osteotomy: A case report / 대한마취과학회지

In maxillofacial surgery endotracheal tube provides patent airway and prevents patient from aspirating the blood. But serious complications such as tube obstruction or injury have been reported. In this case, endotracheal tube injury by surgical saw during Lefort I osteotomy occurred. We could not exchange the defective tube for a good one using laryngoscope or fiberoptic bronchoscope due to edema and blood in nostril and oral cavity. We didn't have any tube exchanger available too. Therefore, to provide patent and safe airway, we packed gauze around the lacerated part of tube, provided positive end expiratory pressure ventilation and increased oxygen flow. After anesthesia, the damaged tube was safely removed and there were no respiratory complications.

Stability of maxillary position after lefort i osteotomy using biodegradable plates and screws

INTRODUCTION: In orthognathic surgery, internal fixation has been usually done with titanium plates and screws. Recently, Biodegradable plates and screws have been frequently used but the reports of long term results of postoperative stability are rare, especially after maxillary reposition in orthognathic surgery. OBJECTIVE: In order to clarify the clinical utility of self-reinforced bioresorbable poly-70L / 30DL-Lactide miniplates & screws in maxillary fixation after LeFort I osteotomy, this study examined the postsurgical changes in maxilla and complications of biodegradable plates and screws. STUDY DESIGN: Nineteen patients who had undergone maxillary internal fixation using biodegradable plates and screws were evaluated radiographically and clinically. A comparison study of the changes in maxilla position after surgery in all 19 patients was performed with 1-week, 1-month, 3-months, 6-months and/or 1-year postoperative lateral cephalograms by tracing. Complication of the biodegradable plates and screws was evaluated by follow-up roentgenograms and clinical observation. And one-way ANOVA test was used for statistical analysis. RESULTS: The position of the maxillary bone was stable after surgery and was not changed significantly from 1 week to 1 year after operation. And we could not find any complication of biodegradable plates and screws. CONCLUSIONS: Internal fixation of the maxilla after LeFort I osteotomy using self-reinforced biodegradable plates and screws is a reliable method for maintaining postoperative position of the maxilla after LeFort I osteotomy.

Correction of Vertical Excess of the Lower Face

Since Wilmar first described term "Long face", various methods have been performed to enhance features of the patients with vertical excess of face, but Kawamoto established that the sole method to correct these deformities is to shorten the height of maxilla by LeFort I osteotomy. Features of the lower long facial pattern, conveniently called "Long face syndrome", "Horse face" has following characteristics; 1) Disproportionally elingated lower half of the face. 2) Widely separated lip and visible anterior teeth. 3) Hyperactivity of mentalis muscle. 4) The smile is typically "Gummy" 5)On profile, convex dorsum of nose, and receded double bump appearance of chin. 6) Tendency of class II malocclusion. From May, 1994 to April, 1999 we have treated 6 cases of vertical maxillary excess, "Long face syndrome" patient using maxillary LeFort I osteotomy and ancillary mandibular surgery. Sometimes there were combined bimaxillary prognathi and hemifacial hypertrophies. Age varied from 22 to 31(mean 23) and follow-up period varied from 6 months to 3 years(mean 1 year). Vertical shortening, rotation of the maxilla and combined mandibular adjustment surgery resulted in good facial harmony improvement of characteristics above and satisfaction of the patient with long face syndrome.

A Study On The Postoperative Stability Of Lefort I Osteotomy In The Two-Jaw Surgery Of The Skeletal Class Iii Malocclusion Patients

PURPOSE: The purpose of this study was to evaluate the postoperative stability of LeFort I osteotomy in two-jaw surgery of class III malocclusion and to help the establishment of treatment planning in patients with a skeletal class III malocclusion future. MATERIALS AND METHODS: The lateral cephalograms of 14 patients who had been underwent two-jaw surgery via one-piece osteotomy were traced and the landmarks were identified. Repeated tracings and construction of reference planes were Comparisons were made from the immediate postoperative to late postoperative results of each landmarks on the horizontal and vertical directions. CONCLUSIONS: 1. The horizontal changes of landmark ANS, point A, PNS and Mx6Rt between immediate postoperative to late postoperative were statistically insignificant(p>0.05). 2. The vertical changes of landmark ANS, point A, PNS, Mx6Cr and Mx6Rt between immediate postoperative to late postoperative data were statistically insignificant(p>0.05). 3. The horizontal change of landmark Mx6Cr between immediate postoperative to late postoperative data was statistically significant(p<0.05). 4. Results showed that it was stable that one-piece LeFort I osteotomy in two-jaw surgery of skeletal class III malocclusion.

Application of LeFort I osteotomy in the treatment of old maxillary fracture / 实用口腔医学杂志

Objective:To study the effects of LeFort I osteotomy in the treatment of old maxillary fracture.Methods:30 patients with old maxillary fracture were treated with LeFort I osteotomy,the rehabilitation of occluding relation and masticatory function were observed after operation.Results:28 patients had well-pleasing occluding relation and masticatory function; 2 patients dissatisfied with their masticatory function, because of unbalance of nerve-muscle after their occlusal plane were rebuilt.Conclusion:LeFort I osteotomy can be a method in the treatment of old maxillary fracture.

A case report of hemifacial microsomia / 영남의대학술지

This is a case report and review of literature that deals with hemifacial microsomia corrected by costochondral graft, Lefort I osteotomy and bilateral intraoral sagittal split ramus osteotomy. Patient, 23 years old female, had visited to treat the esthetic problem due to a deviation of jaw. On the basis of clinical and radiographic examinations, she was diagnosed as hemifacial microsomia. First, costochondral graft was performed to bridge the defect between glenoid fossa and body of mandible. After 11 months,. Patient was performed a Lefort I osteotomy and bilateral intraoral sagittal split ramus osteotomy to create a symmetric jaw. Patient was satiesfied with final esthetics and there have been no evidence of infection ill now.