Mean Horizontal Advancement Research Articles

Skeletal Stability of Two-Jaw Surgery Without Bone Grafting in Patients With Cleft Lip and Palate.

The purpose of this study was to evaluate the postoperative skeletal stability of orthognathic surgery performed without a bone graft in cleft lip and palate patients. Nineteen cleft lip and palate patients that underwent orthognathic surgery from July 2008 to August 2019 at the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital were selected. None of these patients underwent bone grafting during orthognathic surgery. Lateral cephalograms were taken 1 month before surgery (T0), immediately after surgery (T1), and 6 months after surgery (T2). Lateral cephalograms were analyzed using the V-Ceph program. The analysis was performed using SPSS for Windows version 26.0. The analysis was conducted by repeated-measures analysis of variance. A total of 19 patients were included in this retrospective study (9 males/10 females of overall mean age 22 ± 4.89 years). Mean maxillary depth values at the 3-time points were 85.37° ± 2.62° (T0), 90.13° ± 2.77° (T1), and 89.29° ± 2.91° (T2). Mean McNamara-N Perpend values were -5.52 ± 3.19 mm (T0), 0.09 ± 3.10 mm (T1), and -0.83 ± 3.14 mm (T2). Mean sella nasion point A (SNA) values were 75.42° ± 2.98° (T0), 79.19° ± 2.94° (T1), and 78.45° ± 2.84° (T2). Mean relapse rates were maxillary depth 20.15%, McNamara-N Perpend 17.95%, and SNA 18.74%. Mean horizontal advancement was 5.61 ± 2.32 mm based on McNamara vertical to A point, mean horizontal relapse was -0.92 ± 0.56 mm, and the mean horizontal relapse rate was 17.95%. Favorable skeletal stability can be obtained without bone graft when the amount of maxillary advancement is less than 6 mm in cleft patients.

Nasopharyngoscopic Analyses through Anterior Maxillary Distraction Osteogenesis for Adolescent Patients With Cleft Palate

Anterior maxillary distraction osteogenesis (AMDO) is a novel technique for correcting hypoplastic maxilla by sagittal expansion of the maxilla. Recent reports suggest that AMDO does not have an effect on fragile velopharyngeal function in patients with cleft palate. Furthermore, no studies have evaluated the impact of AMDO on velopharyngeal function.We adopted AMDO to correct severe hypoplastic maxilla in adolescent patients with cleft palate and evaluated its impact on velopharyngeal space and function in 8 patients aged 12 to 21 years who underwent AMDO from 2006 to 2014. All the patients had received treatment for cleft palate; however, they still exhibited marginal velopharyngeal insufficiency. The mean activation of the distractor was 10.9 ± 0.9 mm.We determined changes in velopharyngeal closure ratio and closure pattern via nasopharyngoscopy. Additionally, skeletal changes were evaluated using lateral cephalograms.The mean horizontal advancement in the cephalogram obtained 1 year after the distraction was +6.4 mm. Nasopharyngoscopic examination revealed that no deterioration of velopharyngeal gap had occurred after AMDO in all 8 patients. The velopharyngeal closure pattern changed from coronal to circular in 1 patient.Our results indicate that AMDO achieved correction of hypoplastic maxilla without deterioration in velopharyngeal gap and function. Therefore, AMDO is an effective and optimal approach for correcting hypoplastic maxilla especially in patients with fragile velopharyngeal function, such as those with cleft palate.

Bone and Soft Tissue Changes after Two-Jaw Surgery in Cleft Patients.

BackgroundOrthognathic surgery is required in 25% to 35% of patients with a cleft lip and palate, for whom functional recovery and aesthetic improvement after surgery are important. The aim of this study was to examine maxillary and mandibular changes, along with concomitant soft tissue changes, in cleft patients who underwent LeFort I osteotomy and sagittal split ramus osteotomy (two-jaw surgery).MethodsTwenty-eight cleft patients who underwent two-jaw surgery between August 2008 and November 2013 were included. Cephalometric analysis was conducted before and after surgery. Preoperative and postoperative measurements of the bone and soft tissue were compared.ResultsThe mean horizontal advancement of the maxilla (point A) was 6.12 mm, while that of the mandible (point B) was -5.19 mm. The mean point A-nasion-point B angle was -4.1° before surgery, and increased to 2.5° after surgery. The mean nasolabial angle was 72.7° before surgery, and increased to 88.7° after surgery. The mean minimal distance between Rickett's E-line and the upper lip was 6.52 mm before surgery and 1.81 mm after surgery. The ratio of soft tissue change to bone change was 0.55 between point A and point A' and 0.93 between point B and point B'.ConclusionsPatients with cleft lip and palate who underwent two-jaw surgery showed optimal soft tissue changes. The position of the soft tissue (point A') was shifted by a distance equal to 55% of the change in the maxillary bone. Therefore, bone surgery without soft tissue correction can achieve good aesthetic results.

Is It Safe and Effective to Lengthen a Chin With Interpositional Allogenic (Iliac) Graft?

This is a retrospective review of a consecutive series of patients undergoing chin lengthening at the time of orthognathic surgery over a 3-year timeframe. The genioplasty procedures studied included lengthening to the extent that an interpositional graft was deemed necessary (n = 19). Allogenic (iliac) corticocancellous bone was used in all cases. Each patient underwent lateral cephalometric radiography within 2 months before and 5 weeks after surgery. From the radiographs, quantitative measurements (millimeters) were made to document the vertical lengthening and horizontal advancement achieved. Chin region wound healing parameters were reviewed to document evidence of infection, sequestra, need for reoperation, and evidence of fibrous union. Inpatient hospital and outpatient office records were reviewed for any evidence of sepsis or viral transmission. The patients' mean age at operation was 35 years (range, 15 to 58 yr). Analysis of preoperative and 5-week postoperative radiographs documented a mean vertical lengthening of 7 mm (range, 4 to 10 mm). The mean horizontal advancement at the pogonion was confirmed to be 2 mm (range, 1 to 3 mm). None of the study patients sustained chin region infection graft sequestra, fibrous union, or need for reoperation. There were no cases of postoperative sepsis or viral illness to indicate systemic infectious sequelae. The study confirms the safety of allogenic (iliac) corticocancellous grafting to fill interpositional defects associated with a transverse symphyseal lengthening osteotomy.

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.

Apples and Oranges—Midface Hypoplasia and the Le Fort I Osteotomy in Cleft Lip and Palate Patients: A Classification Scheme and Treatment Protocol

To present a classification and treatment protocol for cleft lip and palate patients with midface hypoplasia. Retrospective case series. Craniofacial center. The study included 133 patients with cleft lip and palate and maxillary hypoplasia treated with Le Fort I osteotomy between January 2000 and July 2006. Modified Le Fort I osteotomy. Patients were divided into three groups based on the number of free-standing bony maxillary segments, and treatment was tailored to their deformity. Complications and long-term relapse rates. The 133 patients underwent 142 operations with mean follow-up of 27 months. Mean horizontal advancement was 7.1 +/- 1.9 mm, 6.5 +/- 1.3 mm, 6.4 +/- 1.6 mm, and 6.5 +/- 1.3 mm for groups I, II, IIIA, and IIIB, respectively. Complications consisted of nine bony relapses, three hematomas, and two transitory neurosensory losses. Analysis of variance using number of maxillary pieces as the independent variable and millimeters of advancement as the dependent variable demonstrated no difference in the amounts that the groups were advanced (p = .23). Relapse rates for groups I, II, IIIA, and IIIB were 2/62 (3.2%), 5/53 (9.4%), 2/14 (14.3%), and 0/4 (0.0%), respectively. Analysis of variance did not demonstrate a statistical difference in relapse rates based on number of maxillary pieces. Cleft lip and palate patients can be classified into three groups based on the number of maxillary segments. Our classification system defines the differences among this diverse group of patients and also facilitates unique treatment of each group.

Skeletal stability of Le Fort I osteotomy in patients with isolated cleft palate and bilateral cleft lip and palate

Abstract.The skeletal stability of Le Fort I osteotomy was evaluated retrospectively in 14 patients with isolated cleft palate (CP, mean age 27.2 years) and 11 patients with bilateral cleft lip and palate (BCLP, mean age 23.7 years). The osteotomy was fixed with titanium plates and the osteotomy gap was grafted with autologous bone. Neither intermaxillary fixation nor occlusal splints were used postoperatively. Skeletal stability was analysed both horizontally and vertically by cephalograms taken shortly before operation, immediately afterwards, and at six months and at one year postoperatively.In the CP group the mean maxillary horizontal advancement (point A) was 4.7mm (range 0.3–7.8) and the mean vertical lengthening 3.6mm (range 0.7–6.1). One year postoperatively the mean relapse was 8.5% (0.4mm) horizontally and 16.7% (0.6mm) vertically. In the BCLP group the mean horizontal advancement was 5.3mm (range 0.2–10.7) and the mean vertical lengthening 7.3mm (range 0.6–11.8). The mean postoperative relapse was 9.4% (0.5mm) horizontally and 17.8% (1.3mm) vertically. The skeletal stability and relapse were similar in both cleft types although BCLP patients had more residual cleft problems and their mean surgical advancement was greater. There was great individual variation.

The stability of facial osteotomies. Part 5. Maxillary advancement with miniplate and screw fixation

Surgical repositioning of the dento-skeletal components of the middle-third of the face, combined with appropriate orthodontic treatment, can be used to improve function and aesthetics. However, the attainment of three-dimensional stability following corrective jaw surgery continues to be a major problem in the postsurgical period. This paper examines the short-term (six weeks postoperative) and long-term (12 months postoperative) horizontal skeletal stability of Le Fort I maxillary advancement in 15 patients. The mean horizontal advancement of the maxilla was 8.76 +/- 0.99 mm. Six weeks later, a mean relapse of 0.22 +/- 0.19 mm was identified. The mean relapse at long-term follow-up was 0.61 +/- 0.26 mm (6.96%). These results indicate that rigid miniplate and screw fixation of Le Fort I osteotomy undertaken to correct horizontal mid-dentofacial deficiency is both statistically and surgically predictable and stable when reviewed up to twelve months after surgery.

The stability of facial osteotomies. 4. Maxillary and mandibular (with or without chin) advancement with rigid internal fixation.

The short-term (6 weeks postoperative) and long-term (12 months postoperative) horizontal skeletal stability of combined maxillary and mandibular advancement was evaluated by cephalometric analysis of 15 patients. The mean horizontal advancement of the maxilla was 5.84 mm. Six weeks later a mean horizontal relapse of 0.03 mm (0.05%) was identified. The mean horizontal relapse at long-term follow-up was 0.59 mm (10.1%). The mean horizontal advancement of the mandible was 12.35 mm at menton and 12.65 mm at pogonion. At 6 weeks, mean horizontal relapse, respectively at the above landmarks, was 0.11 mm and 0.21 mm (1.3%). The mean horizontal relapse at long-term follow-up was 2.19 mm and 1.98 mm (16.6%) respectively for the same landmarks. Subjectively and objectively, improvements were seen in facial aesthetics and dental occlusion. The results indicate that rigid fixation of osteotomies undertaken to correct 'horizontal facial deficiency' is a surgically predictable and relatively stable procedure when reviewed up to 12 months after surgery.

The stability of facial osteotomies. 2. Mandibular advancement with bicortical screw fixation.

Surgical repositioning of the dento-skeletal components of the lower third of face, combined with appropriate orthodontic treatment, can be used to improve function and aesthetics. However, the attainment of three-dimensional stability following corrective jaw surgery continues to be a major problem in the post-surgical period. This paper examines the short-term (6 week post-operative) and long-term (12 months postoperative) horizontal skeletal stability of bilateral sagittal split mandibular advancement in 15 patients. The mean horizontal advancement of the mandible was 6.1 mm. Six weeks later, a mean continued forward movement of 0.16 mm was identified. The mean relapse at long-term follow-up was 0.46 mm (7.5%). Results indicate that rigid bicortical screw fixation of bilateral sagittal split osteotomies undertaken to correct horizontal lower dentofacial deficiency is both statistically and surgically predictable and stable when reviewed up to twelve months after surgery.

The stability of facial advancement surgery (in the management of combined mid and lower dento-facial deficiency)

The short-term (6 weeks postoperative) and long-term (12 months postoperative) skeletal stability of combined maxillary and mandibular advancement was evaluated by cephalometric analysis in 15 patients. The mean horizontal advancement of the maxilla was 5.84 mm. 6 weeks later a mean relapse of 0.03 mm (0.5%) was identified. The mean relapse at long-term follow-up was 0.59 mm (10.1%). The mean horizontal advancement of the mandible was 12.35 mm at menton and 12.65 mm at pogonion. At 6 weeks, mean horizontal relapse, respectively at the above landmarks, was 0.11 mm and 0.21 mm (1.3%). The mean relapse at long-term follow-up was respectively 2.19 mm and 1.98 mm (16.9%). Subjectively and objectively improvements were seen in facial aesthetics and dental occlusion. The results indicated that rigid fixation of osteotomies undertaken to correct 'horizontal facial deficiency' is a surgically predictable and relatively stable procedure when reviewed up to 12 months after surgery.

Skeletal stability following miniplate fixation after bilateral sagittal split osteotomy for mandibular advancement

Skeletal stability after monocortical miniplate fixation of bilateral sagittal split osteotomies to advance the mandible was evaluated in 20 patients. Three angles and four linear measurements were analyzed on lateral cephalometric radiographs before surgery, immediately after surgery, and at least 6 months after surgery. The mean horizontal advancement at pogonion was 5.0 mm; 6 months after surgery the advancement increased 0.3 mm because of occlusal settling. The mean lengthening of the distance gonion to menton was 5.8 mm and a relapse of 0.3 mm (5.2%) was found. The mean increase of anterior facial height measured at long-term follow-up was 3.6 mm. This study shows that fixation of the advanced mandible with intraorally applied monocortical miniplates after the bilateral sagittal split osteotomy is a stable procedure.

Le fort I maxillary osteotomies in cleft palate cases: Surgical changes and stability

Surgical and postsurgical changes in maxillary position following transpalatal osteotomy at the le Fort I level in 30 patients with clefts of lip and palate were evaluated cephalometrically. By superimposing on natural reference structures, a more accurate and detailed evaluation of change in maxillary position was possible than by using conventional cephalometric analyses. The mean horizontal advancement was 9 mm, with a mean vertical change of 3 mm. While it is customary to express postsurgical relapse as a percentage of surgical change (in this case 7% mean horizontal relapse and 23% mean vertical relapse), the most remarkable finding to emerge from this study was the variability in surgical and postsurgical change which would be obscured by concentrating on descriptive statistics. Postsurgical change was related to the amount of surgical change, but the correlation coefficients are quite low, and so other factors must be responsible for a significant proportion of any relapse.