External Distraction Osteogenesis Research Articles

Long-term patient-reported outcomes after anterior distraction osteogenesis of the maxilla in patients with cleft

Maxillary growth inhibition in patients with cleft lip and palate (CLP) is an undesired effect that may occur in the teens despite proper primary care. Dental malocclusion and distortion of facial appearance can be treated with external distraction osteogenesis (DO) of the maxilla. This entails a Le Fort I osteotomy, fastening a semi-circular distractor to the skull, distraction for three weeks, and fixation for three months before removal of the device. The aim of this descriptive long-term follow-up study was to evaluate DO of the maxilla from the patient-reported long-term perspective. Fourteen patients underwent a long-term follow-up including a questionnaire regarding their experience of DO. Sex, CLP diagnosis, age at DO and follow-up, and time required for active distraction and fixation were noted. Furthermore, documentation on rhinoplasty, lip plasty and velopharyngeal plasty after DO was registered. Objective results were assessed by a positive dental overjet in the front. Ten patients considered the distractor an everyday constraint, but all thought the procedure was worthwhile and would recommend it to others. Thirteen patients experienced improved bite and chewing, whereas one considered function unchanged. All were satisfied with their dental alignment. Three patients underwent a velopharyngeal plasty after DO. Moreover, six rhinoplasties and two lip plasties were performed. Despite a long and challenging treatment, teenagers and young adults with CLP and maxillary hypoplasia tolerate DO of the maxilla very well. Secondary measures to improve speech and appearance are often indicated.

An Unoperated Crouzon Family Treated with Monobloc Distraction: Challenges and Lessons.

Background:Crouzon syndrome (CS) is a rare form of craniosynostosis characterized by bicoronal craniosynostosis and facial features including severe midface hypoplasia, exophthalmos, and hypertelorism. Most patients are diagnosed and treated in early childhood; however, there are a few reports of Crouzon patients treated as adults with monobloc facial advancement. To our knowledge, this is the first report of a family affected by CS treated sequentially with monobloc facial advancement using combined internal and external distraction osteogenesis (rigid external distraction).Methods:We present a family from Jamaica (mother 47 years old, older daughter 17, and younger daughter 9) who were brought to our craniofacial clinic with stigmata of CS and no previous surgical intervention. Patients had bicoronal craniosynostosis and exorbitism, with varying severity, sequelae, and comorbidities. Here, we delineate our technique of monobloc distraction osteogenesis with advancement osteotomies using dual “push–pull” method, elevation of a split anteriorly based tunneled pericranial flap to seal off nasal cavity, and internal and external distraction.Results:Our patients had favorable outcomes after reconstruction to reduce ocular symptoms and improve midface hypoplasia and aesthetic appearance. No intracranial injury, hardware/soft-tissue infection, hardware failure, or (new) loss of vision were encountered in 10 months follow-up.Conclusions:Dual “push–pull” monobloc distraction is safe and effective for a range of ages in CS; it allows good vector control, accommodates patient compliance, and allows early rigid external distraction device removal with sufficient time for consolidation. This surgery can be performed with highly satisfactory results.

Does the Rigid External Distraction Device Alter Maxillary Pitch in Cleft Maxillary Distraction?

Statement of problemCorrection of cleft maxillary hypoplasia remains a controversial topic. Surgical correction can be accomplished through Le Fort I orthognathic correction, internal distraction osteogenesis, or external distraction osteogenesis.1 Proponents of rigid external distraction (RED) osteogenesis describe the ability of multi-vector directional distraction control as opposed to univector internal distraction. There are currently limited data on the ability of the RED system to alter the maxillary occlusal pitch.The purpose of this study is to address the following clinical question: “Among cleft patients presenting with severe maxillary hypoplasia and treated with rigid external distraction, does the rigid external distraction system result in alteration of the maxillary pitch?”The study hypothesis is: among cleft patients presenting with maxillary hypoplasia treated with RED, the investigators hypothesize that there is no change in maxillary pitch with distraction.The study's specific aims are to design a retrospective cohort study and enroll a sample composed of cleft patients with maxillary hypoplasia treated with RED: 1) identify a cohort of patients with cleft maxillary hypoplasia, 2) quantify the degree of pre-operative maxillary hyperplasia, 3) measure changes in maxillary position achieved through RED. Materials and methodsTo address the research objectives, the investigators designed a retrospective cohort study. The study sample was derived from the population of patients with cleft maxillary hypoplasia who underwent RED by the Department of Oral and Maxillofacial Surgery at the University of Alabama - Birmingham from June 2007 to August 2019. Subjects eligible for study inclusion had cleft maxillary hypoplasia and underwent RED. Subjects were excluded if there were incomplete data collection or their records were not available for review.Demographic and radiographic variables were recorded. Demographics included gender, age at date of surgery, and history of ULCP vs. BLCP. Radiographic variables included standard cephalometric data recorded prior to distraction (T1) and after completion of distraction (T2). Methods of data analysisDescriptive statistics were computed for all study variables. Due to the potential for both positive and negative occlusal pitch change, a paired 2-tailed T-test was used to compare T1 and T2. The level of statistical significance was set at P < .05. ResultsThe study sample was composed of 45 subjects with a mean age at surgery of 12.2+3.4 years. Twenty-two (49%) were BCLP and 27 (60.0%) were male. At T1, mean SNA was 76.35+/-6.4 degrees, and the maxillary occlusal plane to Frankfort horizontal plane was 8.18+/-6.9 degrees. The mean anterior-posterior distraction distance was 11.4+/-5.7 mm. At T2, the mean SNA was 86.0+/-7.5 degrees, and the occlusal plane to FH was 3.78+/-7.3 degrees. The average maxillary occlusal pitch change was -4.4+/-5.8 degrees (P = .005). ConclusionFor cleft lip and palate patients with maxillary hypoplasia, surgical advancement with RED results in counterclockwise rotation of the maxillary occlusal plane.

Surgical Planning for Cleft Lip and/or Palate-Induced Moderate-to-Severe Midfacial Hypoplasia.

Distraction osteogenesis and conventional bimaxillary orthognathic surgery have been performed for the treatment of midfacial hypoplasia for a long time. However, the effect of these 2 techniques on the maxilla, mandible, and whole-facial profile is significantly different. In this study, we aimed to measure the pre- to post-treatment changes in maxillary prominence, mandible size, and facial length and compare them between these 2 techniques to inform selection of the best technique. This single-center, retrospective study included 35 patients with a cleft lip and/or palate-induced midfacial hypoplasia; 25 were treated using rigid external distraction osteogenesis and 10 using bimaxillary orthognathic surgery. Three-dimensional measures of changes in facial structure were obtained from reconstructed computed tomography images and used to compare the effects of the 2 techniques. Satisfactory appearance and occlusion were achieved in all patients. Three-dimensional reconstruction of the craniofacial skeleton revealed significant maxillary advancement (P < 0.001), mandibular (clockwise) rotation (P < 0.001), and increased facial length (P < 0.001) after rigid external distraction osteogenesis and obvious shortening of the mandibular body (P < 0.001) after bimaxillary orthognathic surgery. Distraction osteogenesis can be selected as the first choice of treatment for cleft lip and/or palate-induced midfacial hypoplasia. A mandibular setback procedure can be performed as a second-stage surgery when severe temporomandibular joint complications develop with distraction osteogenesis. Bimaxillary orthognathic surgery results in an obvious shortening of the mandibular body, which is not a natural change in facial morphology. Therapeutic III.

Consolidation Time and Relapse: A Systematic Review of Outcomes in Internal versus External Midface Distraction for Syndromic Craniosynostosis.

The choice between internal and external distraction osteogenesis for midface advancement in patients with syndromic craniosynostosis is based primarily on surgeon preference and expertise. However, differences in outcomes between the two techniques have been sparingly compared. In this work, the authors performed a systematic review to compare outcomes between internal versus external midface distraction. A systematic review was performed of studies published between 1998 and 2018 (61 studies included; n = 689 patients). Operative characteristics, early reoperations, complications, and relapse rates were extracted. Bias evaluation was performed using the Newcastle-Ottawa instrument. Statistical analyses were performed with independent samples t tests and linear regression analyses (p < 0.05 considered significant). The authors found that external distraction was associated with more Le Fort III osteotomies and hardware adjustments (p = 0.023), whereas internal distraction was associated with more monobloc osteotomies and longer consolidation times (p = 0.008). No significant differences in the distance of midface advancement, reoperations, complications, or relapse rates were noted between internal versus external distraction, although external distraction trended toward a slightly higher relapse rate. Regardless of distraction protocol, consolidation time was found to be a strong negative predictor for relapse (beta = -0.792; p = 0.02). No significant differences were demonstrated in advancement distance, reoperative rates, complication rates, or relapse rates for internal versus external distraction for midface advancement. Regardless of distraction type, consolidation time was strongly inversely associated with relapse rates. The trend toward higher relapse in external distraction is potentially explained by the significantly lower consolidation times.

Comparison of Midface Advancement by External and Internal Craniofacial Distraction Osteogenesis.

Background:Distraction osteogenesis (DO) is employed to address the midface abnormalities using either an external DO (EDO) or an internal DO (IDO) device. There are few studies that have reported EDO and IDO outcomes through cephalometric evaluation. The aim of this retrospective, record-based study is to compare the change in position of the midface resulting from distraction of noncomplicated cases of Le Fort III osteotomies with EDO as well as IDO and compare the groups using standard right facing lateral cephalometry. We hypothesized that there would be no difference between EDO and IDO in terms of displacement (of point of reference) as well as complications.Materials and Methods:Retrospective analyses of cases fulfilling inclusion and exclusion criteria were retrieved from archives. Using two sets of right-side cephalometry, preoperative and after consolidation (at the end of the treatment), the changes in Point A and Orbitale (O) as described by Lima et al. were used for the study. Movement in X-axis and Y-axis was noted down and subjected to statistical analysis. Descriptive statistics, the coefficient of variability (expressed as percentage), and the interquartile range (maximum and minimum values) were presented. P ≤ 0.05 was taken as statistically significant.Results:Significant midface advancement was achieved with the procedure. There were five cases of EDO and eight cases of IDO. The age at which patients were operated ranged from 9 to 18 years (mean: 13 years). The mean follow-up time was for 14 ± 8 months. There were eight females (3 – EDO and 5 – IDO) and five males in total. There was no complication in the entire study group. The difference in total bone length gain along the horizontal axis was as follows: 12.19 and 12.84 along the Point A for EDO and IDO and 3.89 and 4.65 along the Point O for EDO and IDO, respectively. The difference was not statistically significant (P = 0.833 and 0.622, respectively). The total movement along the vector at Point A in EDO and IDO was 13.08 and 12.56, respectively, the difference of which was not statistically significant (P = 1); while along the vector at Point O in EDO and IDO, the total movement was 10.98 and 11.48, respectively, the difference of which was not again statistically significant (P = 0.833).Discussion:The significance of the difference in EDO and IDO is discussed using the biomechanical principles and the results deliberated based on the existing literature.Conclusion:The positioning of the devices plays a significant role in deciding the outcome. Both the distractors have their distinct advantages and their applications have to be customized.

Residents' journal review

Residents' journal review

Monobloc Frontofacial or Le Fort III Distraction Osteogenesis in Syndromic Craniosynostosis: Three-Dimensional Evaluation of Treatment Outcome and the Need for Central Distraction.

The objectives of this study were to investigate the treatment effect, morphology, and volumetric outcomes of monobloc frontofacial or Le Fort III distraction osteogenesis in syndromic craniosynostosis by 3-dimensional evaluation. Nine consecutive patients underwent monobloc frontofacial or Le Fort III distraction during 2003 to 2012 were included and evaluated. The patient's evaluation is a minimum of a 4-year follow-up. Pretreatment, post-treatment advancement, and relapse were quantified. The changes in intracranial volume, upper airway volume, globe protrusion, advancement at bilateral malar eminence, and central face were calculated from computerized tomography before and after treatment. After distraction, the intracranial volume was increased by 16.4% in average, and the upper airway volume increased by 64.1%. Orbital protrusion improved by 9.9 mm in the left eye and 10.5 mm in the right eye in comparison to the preoperative status. Bilateral malar eminences advancement was greater than the dorsum advancement by 7.1 mm. The external distraction osteogenesis device caused significant technical difficulties with advancement of the midface in growing bones. The central midface did not advance as hoped for. This finding may suggest a need for modification in the distraction device in order to improve the central facial distraction vector.

0890 INDIVIDUALIZED THERAPY FOR TREATING OBSTRUCTIVE SLEEP APNEA IN PEDIATRIC CROUZON SYNDROME PATIENTS

Pediatric patients with Crouzon syndrome have great possibilities in suffering from obstructive sleep apnea (OSA), which is mainly due to midfacial hypoplasia and facial deformities. For most patients, a multi-disciplinary and sequential treatment plan is necessary to make for Crouzon syndrome often has different phenotypes of different severity in OSA and facial deformities. Typical patients were selected in this study to illustrate the necessity of individualized therapy for treating OSA. In the study, four Crouzon syndrome children of different severity in suffering from OSA and maxillofacial deformities were introduced. Detailed information in individualized treatment options was given including clinical manifestations, radiological findings, polysomnography detectings and treatment combinations. Based on the above findings, different but effective treatment options for these children’s OSA problems were adopted, either by surgeries including distraction osteogenesis and craniomaxillofacial surgeries with or without tonsillectomy, or by noninvasive continuous positive airway pressure (CPAP) therapy. Patient 1 was performed with LeFort IIIosteotomy and external distraction osteogenesis. Patient 2 was given LeFort IIIosteotomy and external distractor fixation and concurrent bilateral mandibular body osteotomy and internal distractor fixation for bimaxillary distraction. Patient 3 received LeFort I osteotomy for maxillary advancement with concurrent bilateral tonsillectomy. Differently, patient 4 with mild OSA disturbance adopted initial continuous positive airway pressure (CPAP) with good adherence and body development. Six years later, he began orthodontic treatment for preparing for orthognathic surgery. Recently bimaxillary surgery was performed on him to enlarge upper airway anatomically as well as improve facial profile. Follow-up studies showed problems of OSA and nocturnal hypoxia of those four patients were all alleviated greatly, as well as maxillofacial deformities. Combined with preoperative and postoperative orthodontics, patient 1 and 4 also got optimal results in better facial profile and dental occlusion. Thus, given Crouzon patients had great possiblilities in suffering from OSA and hypoxia problems, individualized therapy should be made and performed carefully to obtain optimized treatment results based on adequate clinical evaluations and patients’ conditions including age, disease severity and esthetic considerations. This work was supported by the National Natural Science Foundation of China (Grant number: 81470786).

Bilateral mandibular distraction in micrognathism or hypoplasia of mandible, hazrat fatemeh hospital

ObjectiveTo determine the results of Bilateral Distraction Osteogenesis (DO) versus traditional methods in treatment of micrognathia. MethodsDuring 6 years we had 67 patients with micrognathia. In group A, randomly 35 were treated with traditional methods (Saggital osteotomy and/or bone grafts) and group B 32 cases were treated with Bilateral External Distraction Osteogenesis. Follow up was 36+/− 6 months. X-Ray, CT scan and cast modelling were done for all of the patients. SNA, SNB angles were measured in cephalograms. The patients were examined after one, two, three, six, 12 months for any complications and signs of bone resorption and relapse. Bony and soft tissue advancements were measured and compared with each other. ResultsDuring 6 years we had 67 patients with class II malocclusion. Mean SNA angle in group A was 80.8 (80–81.5) and 80.9 (80–82) in group B. Mean SNB angle in group A was 77.6 (76.5–78) and 77.4 (76.5–78.5). After treatment mean SNB in group A was 79.1 and the difference was significant comparing to pre-op measurement (P<0.005). Mean SNB in group B after treatment was 79.2 which was significantly different comparing with SNB angle before surgery. The mean SNA in both group were not statistically and significantly different. The mean SNB after surgery in both group were not statistically and significantly different. Mean Mandibular advancement in group A was 11.9 mm (7.5–18 mm) and group B with DO treatment was12.1 mm (8–19 mm) which was not significantly different. The patient in group A evaluate the surgical results as excellent (60%) and good (28.5%). The patient in group B evaluate the results as excellent (78.1%) and good (15.6%). ConclusionThe Bilateral Distraction Oseogenesis method can bring forwards the retruded mandible effectively and its results has no difference with older methods. It is an effective and reliable procedure for hypoplasia of Mandible and the results are comparable with older methods.

Dual Midfacial Distraction Osteogenesis for Crouzon Syndrome: Long-Term Follow-Up Study for Relapse and Growth

Rigid external distraction osteogenesis is regarded as a standard treatment for congenital midfacial hypoplasia. However, external distraction for the upper portion of the midface is not as effective and tends to rotate the midfacial segment in a counterclockwise direction. Moreover, patients poorly tolerate it because of the device's bulkiness. To prevent such drawbacks of an external distractor, both external and internal distractors were synchronously applied to patients with Crouzon syndrome. In 6 patients with Crouzon syndrome in whom a dual-distraction technique was applied, distraction of the midfacial region was performed for up to a mean length of 15.3 mm. The external distractor was removed after a 1-month consolidation period, but the internal distractor was maintained for more than 6 months. The degree of advancement of the midface and ossification was measured with lateral cephalometry and 3-dimensional computed tomography imaging, respectively. At long-term follow-up (mean, 4.6 years), the facial contours retained the initial distraction geometry with almost no relapse, showing that the ideal facial contour and occlusion could be obtained. Bone deposition was found to be continually progressing even 6 months postoperatively, and more than 6 months of consolidation was required for complete ossification that mainly occurred in the pterygomaxillary junction and lateral orbital wall. The dual-distraction technique can induce balanced growth without the recurrence of hypoplasia, and it may eventually yield satisfactory outcomes in Crouzon syndrome.

Comparison of internal versus external distraction osteogenesis of premaxilla for management of maxillary retrusion in cleft lip and palate patients

Objective: The premaxillary distraction osteogenesis was used for treatment of maxillary retrusion in cleft lip and palate patients. In this paper, we would like to compare the result of the pre-maxillary distraction osteogenesis with different fixation technique (intraoral, extraoral and hybrid method).

Intracranial Fixation Pin Migration

External distraction osteogenesis has long been used in treatment of congenital midface hypoplasia. Distraction osteogenesis is associated with lower relapse rate and less complications compared with standard Le Fort III osteotomy. General complications in using rigid external distraction include localized infection, loosening of pins, and pin displacement. A 24-year-old female patient with Apert syndrome who underwent Le Fort III distraction osteogenesis is reported. Standard Le Fort III osteotomy was performed, and external distractor was placed. After 7-day latency period, the distractor was activated at the rate of 1 mm/d and finished after 20 days. A mild localized infection was recognized at the eighth week of consolidation period, and debridement was carried out at the left side of pin fixation. Obvious displacement of distractor occurred 1 week later while the patient was sleeping, and emergency operation was performed to remove the distractor and depress the left temporal skull bone fracture after clinical evaluation. The patient was asymptomatic clinically, and the advancement of the midface was stable. Le Fort I osteotomy was performed 3 years later to obtain a normal occlusion, and the patient was satisfied with the final outcome. We concluded that an unwanted trauma might cause severe complications such as skull bone fracture secondary to related local infection, and close follow-up and management are necessary for those cases.

External Distraction Osteogenesis in the Pediatric Mandible

Mandibular distraction osteogenesis is an effective tool with which to correct facial asymmetry, restore proper occlusion and, more importantly, create an appropriate airway in the micrognathic infant. As a component of many syndromes, micrognathia can impair feeding and speech development and can obstruct the neonatal airway. However, bony lengthening secondary to external mandibular distraction osteogenesis can provide added space, preventing oropharyngeal soft tissues from occluding the airway. Although external distraction of the mandible has been applied for more than a decade, this procedure often proves technically challenging. Here, as a supplement to their video presentation, the authors present a practical discussion of their current technique for mandibular distraction osteogenesis using an external device in a child with Treacher Collins syndrome.

Surgical Treatment of Obstructive Sleep Apnea Syndrome Due to Mandibular Deficiency

Background and Objectives: Sleep apnea syndrome affects about 4% of men and 2% of women in middle age. Surgical protocol for obstructive sleep apnea syndrome (OSAS) in patients without maxillomandibular deficiency was well established. However, the optimal surgical treatment of OSAS in patients with facial bony abnormalities needs further studies. Materials and Methods: We demonstrate the effect of surgery in the treatment of OSAS resulted from mandibular deficiency. Nine cases with OSAS due to mandibular deficiency were selected. Patients were examinated and evaluated by cephalometric analysis and polysomnographic data. Three cases were treated by temporomandibular joint (TMJ) reconstruction with costochondral graft. Five cases underwent external distraction osteogenesis (DOG). Mandibular advancement with osteotomy was completed in one case. Results: Though respiratory disturbance index (RDI) improved in some patients, all patients reported improved symptoms and quality of sleep. Conclusion: The surgical procedures of TMJ reconstruction and DOG combined with mandibular advancement are useful to the patients of mandibular deficiency with OSAS.

Distraction Osteogenesis in the Management of Severe Maxillary Hypoplasia in Cleft Lip and Palate Patients

The aim of this study was to systematically review literature reporting on the use of external distraction osteogenesis (DO) and internal DO in the treatment of severe maxillary hypoplasia in cleft and palate patients. Literature research has been performed using the PubMed database of the National Library of Medicine and National Institutes of Health from 1966 to August 2007. We used cleft lip and palate and distraction osteogenesis as key words. Of the 104 articles found, we only considered the Anglo-Saxon literature, which reported on the correction of the maxillary hypoplasia with DO techniques. A total of 32 studies reported on anteroposterior external DO (27 studies on rigid external device and 5 on face mask), 17 studies reported on anteroposterior internal DO, and 3 studies reported on transverse internal DO have been retained for this review. Despite the heterogeneity and methodological limitations of most of the studies, results showed that external DO with rigid external device and internal DO resulted to be a more reliable and accurate technique than the face mask in the management of severe maxillary hypoplasia in patients with cleft lip and palate. The current review demonstrated that external and internal DO in the treatment of severe maxillary hypoplasia in cleft and palate patients (1) is a reproducible and valuable alternative to standard orthognathic surgery procedures, (2) allows for a global improvement in facial aesthetic, (3) allows a maxillary correction in patients during the period of mixed dentition, and (4) allows either for an unchanged or better velopharyngeal function.

Complications in maxillary distraction using the RED II device: a retrospective analysis of 21 patients

Rigid external distraction osteogenesis (DO) in the treatment of midface hypoplasia has been shown to be effective and safe, but there have been several case reports on complications. Here is presented an overview of the complications in a series of 21 patients with various craniofacial anomalies. All patients were treated using the rigid external distraction II (RED II) device after Le Fort I or III osteotomy. Distraction started 1 week postoperatively and continued until Class I occlusion was achieved; it was then continued to include a 15% overcorrection. All data were collected and categorized retrospectively from the patients’ files. After a mean period of distraction of 34 days, 42 complications were reported in six different categories. Pin loosening (42.9%) and frame migrations (28.6%) were the most common complications. Of the frame migrations 25% were traumatic. Intracranial penetration of one fixation pin occurred during removal of the RED II device in one patient. From these results it can be deduced that application of the RED II device is associated with a substantial number of specific complications that mainly concern the pins of the halo-frame. The stability of the device is discussed as the distraction distance achieved was less than expected.

Longitudinal Cephalometric Analysis After Maxillary Distraction Osteogenesis

The aim of this study was to analyze the long-term dentoskeletal changes in patients who received distraction osteogenesis of the maxilla. Seventeen patients aged 12 to 31 years underwent rigid external distraction osteogenesis for treatment of maxillary hypoplasia. Cephalograms were evaluated retrospectively regarding linear and angular measurements. Follow-up times ranged from 1 to 5 years. In two patients, there was no consolidation of the Le Fort I segment to the midface. After the 0- to 12-month period, the maxilla had a stable position in all patients. Nevertheless, there was further decrease of SNA and ANB and an increase of the facial concavity thereafter. Ongoing growth of the facial skeleton must be considered when distraction osteogenesis is chosen for the advancement of the maxilla in adolescents.

Internal vs. external distraction osteogenesis for advancement of cleft maxillary hypoplasia

Internal vs. external distraction osteogenesis for advancement of cleft maxillary hypoplasia

Rigid External Distraction Osteogenesis for a Patient With Maxillary Hypoplasia and Oligodontia

Abstract Objective: In this report, the orthodontic treatment combined with rigid external distraction osteogenesis in a 5.5-year-old girl with midfacial hypoplasia and oligodontia is described. Patient: The child presented with a reduced maxilla, protruding lower lip, skeletal Class III jaw relationship with a low mandibular plane angle, a short and flattened nose, anterior crossbite, and aplasia of 16 permanent teeth. The patient was treated with rigid external maxillary distraction osteogenesis, maxillary protraction headgear, and Class III elastics. Following treatment, the maxilla was displaced in a forward direction with new bone formation at the tuberosities and the mandible rotated backward in relation to the anterior cranial base. The anterior crossbite was corrected, and the skeletal jaw relationship changed from a Class III to a Class I skeletal pattern. The soft tissue facial profile showed that the nasal projection had been increased, the nasolabial angle increased, and the lower lip protrusi...