Severity of Mandibular Dysmorphology in Treacher Collins Syndrome for Stratification of Perioperative Airway Risk.

BACKGROUND: Patients with Treacher Collins syndrome (TCS) and attendant airway dysmorphology may be predisposed to airway complications in the perioperative period. However, limited data correlates severity of mandibular hypoplasia and airway status. This study aims to improve risk stratification for perioperative airway insufficiency in TCS by using a previously proposed mandibular severity index. METHODS: Patient demographics, perioperative airway status, difficulty of intubation, and Cormack Lehane grade were collected and compared using a TCS mandibular hypoplasia severity grading scale in patients with TCS treated between 2000 and 2022. RESULTS: Twenty-six patients underwent 222 procedures with institutional mandibular severity gradings as follows: 23% Grade I, 31% Grade II, 39% Grade III, 8% Grade IV. Our severity index was associated with intubation difficulty ( P <0.001) and difficult airway status ( P <0.001), with 72% of difficult airways found in grade III and grade IV patients. Mandibular retrusion and ramal hypoplasia subscores were positively correlated with measures of airway severity ( P <0.001), whereas the gonial angle was negatively correlated ( P <0.001). Age was negatively correlated with difficult visualization for endotracheal intubation ( P =0.02) but had no association with difficult airway status ( P =0.2). CONCLUSIONS: This study found a positive correlation between severity of maxillomandibular dysmorphology and perioperative airway difficulty in TCS patients. Our findings suggest that severely affected patients require heightened vigilance throughout life, as difficult airways may not completely resolve with aging. Given the risk of morbidity and mortality associated with airway complications, proper identification and preparation for challenging airways is critical for TCS patients.

Comprehensive Serial Treatment of Treacher Collins Syndrome.

OBJECTIVE: To discuss and summarize the comprehensive serial surgical treatment of Treacher Collins syndrome. MATERIALS AND METHODS: From September 2012 to January 2020, 12 patients with Treacher Collins syndrome were treated by autologous fat graft, mandibular distraction osteogenesis, orbitozygomatic reconstruction with calvarial external lamina, orthognathic surgery combined with postoperative orthodontics, transplantation of upper eyelid orbicularis myocutaneous flap, lateral canthal ligament reduction, and other methods. The authors evaluated the postoperative improvement, summarized experiences, and reviewed literatures about the comprehensive serial treatment of Treacher Collins syndrome. RESULTS: All patients showed significant improvement in appearance and function, and no complications were found during the follow-up period of 5 months to 3 years. CONCLUSIONS: The deformities of Treacher Collins syndrome involves multiple craniofacial region, and only by formulating comprehensive serial treatment strategies according to the malformation characteristics of different patients can the best effect be achieved.

Characterization of Phenotypes and Treatment Modalities in Patients With Treacher-Collins Syndrome.

ABSTRACT: The purpose of this study was to investigate the phenotypes and treatment modalities (Tx-Mod) in patients with Treacher-Collins syndrome (TCS) using a TCS severity index (TSI). The sample consisted of 14 Korean TCS patients treated at the Department of Orthodontics, Seoul National University Dental Hospital during 1998 to 2019. The TSI was calculated by adding the scores from the number of deformity-involved midface structures (eye, ear, zygoma) and the degree of mandibular hypoplasia (Pruzansky-Kaban type, gonial angle, Sella-Nasion-B point angle). The deformity-involved midface structure, degree of mandibular hypoplasia, oral manifestations, dental phenotypes, and Tx-Mod types were investigated using descriptive statistics. The TSI classified the subjects into 2 mild, 6 moderate, and 6 severe cases. The severity of ear and zygoma deformities, degree of condylar hypoplasia (Pruzansky-Kaban type), clockwise-rotated morphology (gonial angle) and retrusive position (Sella-Nasion-B point angle) of the mandible, and frequency of oral/craniofacial cleft, openbite, congenitally missing tooth and impacted tooth showed a tendency of increase from mild to severe TCS cases. After growth observation (78.6%), diverse combinations of Tx-Mods were applied except for functional appliance therapy. Surgical procedures for eye, ear, and zygoma reconstruction were performed on all patients (100%), whereas fixed orthodontic treatment, mandibular distraction osteogenesis, and orthognathic surgery were performed on 50% of patients. Surgical procedure for hearing improvement was the most frequent Tx-Mod (78.6%). The main desires of TCS patients were to obtain the facial esthetics in the midface and to improve hearing function. The TSI might provide a primary data for individualized diagnosis and treatment planning.

Treacher Collins syndrome: Orthodontic treatment with mandibular distraction osteogenesis and orthognathic surgery.

Interdisciplinary treatment for patients with Treacher Collins syndrome is challenging because of the rarity of the condition and the wide variety of phenotypic expression. A 23-year-old male was diagnosed with Treacher Collins syndrome with a history of severe obstructive sleep apnea. He presented with a Pruzansky-Kaban classification grade I mandible, skeletal type II pattern with a hyperdivergent mandibular plane, severe convex profile, and Class II malocclusion with a missing mandibular incisor. Improvement of facial esthetics was achieved by a combination of orthodontics, mandibular distraction osteogenesis, and 2-jaw maxillomandibular advancement surgery. Presurgical orthodontic treatment involved permanent tooth extraction to relieve severe crowding, and Class III mechanics were employed to increase overjet. Correction of mandibular hypoplasia by increasing ramal height and the mandibular length was done by intraoral mandibular distraction osteogenesis. Counterclockwise rotation of the mandibular plane angle and a Class III occlusion with negative overjet were achieved after mandibular distraction osteogenesis. A postdistraction posterior open bite was maintained with a biteplane during the consolidation period. Subsequently, 2-jaw orthognathic surgery was performed. LeFort I osteotomy was done for maxillary advancement to correct an anterior crossbite, eliminate canting, and reestablish occlusal contact at the mandibular occlusal plane. Bilateral sagittal split ramus osteotomy was done to correct the residual mandibular deviation. A genioplasty was also performed to improve chin projection. Postoperatively, the oropharyngeal airway was enlarged. The patient's facial profile and obstructive sleep apnea problem were improved as a result of advancement and counterclockwise rotation of the maxillomandibular complex.

Assessment of Bioabsorbable Hydroxyapatite for Cranial Defect in Children.

PURPOSE: To evaluate the utility and efficacy of bioabsorbable hydroxyapatite and collagen complex (HA/Col) for cranioplasty repair of cranial bone defects in children. METHODS: Two patients (a 6-year-old male and 11-year-old female) with Treacher Collins syndrome received zygoma and orbital floor reconstruction using a full thickness of parietal bone. The bone grafts were taken from each patient's parietal cranium. The right parietal cranial defect was repaired with autologous bone dust, and the left side was repaired with HA/Col in each patient. Computed tomography scans were taken immediately after and at 12 months following surgery. The osteosynthesis areas and thicknesses were measured using computer-aided engineering. RESULTS: Both patients experienced no complications, including infection. In the 6- and 11-year-old patients, the extent of osteosynthesis for HA/Col was 92.2% and 89.4%, respectively; and for the autologous bone dust was 78.5% and 53.2%, respectively. Because of the small sample size, a significant difference could not be calculated; however, the percentage of osteosynthesis for HA/Col was higher than for the autologous bone dust. CONCLUSION: This study showed that HA/Col can be effectively used in cranial defects and can be considered an alternative graft material for cranial reconstruction.

Treacher Collins Syndrome and Tracheostomy: Decannulation Using Mandibular Distraction Osteogenesis.

INTRODUCTION: Treacher Collins syndrome (TC) and Pierre Robin sequence (RS) are associated with hypoplastic mandible, glossoptosis, and consequent airway obstruction. Although TC and RS are often grouped together, airway outcomes of bilateral mandibular distraction osteogenesis (MDO) have not been specifically studied in TC. The purpose of this study is to report on the clinical outcomes of MDO in the TC patient population. MATERIALS AND METHODS: A twenty-year single-institution retrospective review of all patients with TC who underwent bilateral MDO was performed. Twenty-four patients were identified after exclusion due to different diagnoses or insufficient medical records. Data on comorbidities, airway status, MDO operations, and complications were collected. Data were compared with published clinical outcomes in RS and data for 13 RS patients from our institution. RESULTS: Surgical success, defined as prevention of imminent tracheostomy or successful decannulation within 1 year after primary distraction, was observed in 21% of TC patients and 65% of RS patients (P = 0.01). Repeat distraction was necessary for 11 TC patients (46%) and 1 RS patient. Complications were divided into minor, moderate, and major based on need for invasive management. Overall, 67% of TC patients had complications, 20% of which were major. CONCLUSIONS: Clinical outcomes to airway function after MDO are significantly inferior in patients with TC compared with patients with RS. Repeat MDO and longer course to decannulation are more prevalent in patients affected by TC.

Decannulation and Airway Outcomes With Maxillomandibular Distraction in Treacher Collins and Nager Syndrome.

BACKGROUND: Treacher Collins syndrome is a rare disorder (1/50,000 live births) with features that include hypoplastic orbitozygomatic complex with downward slanting eyes, and maxillary/mandibular retrusion. Obstructive sleep apnea and tracheostomy-dependence are common. This study presents the outcomes of skeletal distraction on avoidance of tracheostomy and decannulation in this patient population. METHODS: The authors reviewed charts of all patients with Treacher Collins syndrome who underwent craniofacial reconstruction from 2003 to 2016. Primary outcome measures included decannulation of tracheostomy dependent patients and avoidance of tracheostomy. Secondary outcome measures included cephalometric parameters, polysomnography scores, and airway exposure scores on direct laryngoscopy. RESULTS: Twenty-five patients underwent mandibular and maxillary advancement to resolve upper airway obstruction. Mandibular distraction was performed in 24 of 25 patients, and maxillary distraction in 14 of 25 patients. Maxillary distraction was combined with mandibular distraction in 13 of 17 to accomplish greater advancement and counter-clockwise rotation of the entire maxillary-mandibular complex. Six of 7 patients, 85.7%, avoided a tracheostomy and 39% (7 of 18) were decannulated. Cephalometric changes in sella-nasion-A point, sella-nasion-B , occlusal plane angle, and posterior airway space were equivalent between the groups who were able to clear their obstruction and those who were not. CONCLUSIONS: Treacher Collins is a very challenging disease in which to resolve airway obstruction. Thus, thorough evaluation of the entire airway for all levels of obstruction is critical to successful outcomes. Future collaborative efforts between multiple institutions can help to increase our understanding and effective management of this rare disease.

Modified Lefort Distraction Osteogenesis for the Treatment of Nager Syndrome-Associated Midface Hypoplasia: Technique and Review.

The surgical management of midface hypoplasia in the setting of Nager syndrome remains a significant challenge for craniofacial surgeons. This study describes a novel technique using distraction osteogenesis and modified osteotomies for the treatment of midface bony defects in an 11-year-old child with Nager syndrome.Presurgical 3-dimensional planning was performed to design the osteotomies and placement of distractors. The surgical approach required upper buccal sulcus and extended transconjunctival incisions only. Osteotomies were performed from the pyriform aperture through the orbit to include the lateral orbital wall, with bilateral osteotomy of the zygomas through the anterior arch via the transconjunctival incision. Distraction of the en bloc midface segment was successfully performed using external distractors. Bone grafting was not required. There were no complications.External distraction was well tolerated and there were no intraoperative or postoperative complications. The distractors were removed uneventfully after consolidation. The midface was successfully advanced without the need for bone grafting or bicoronal incision. The occlusal plane was leveled and the aesthetic appearance of the child was improved.Symmetrical midface hypoplasia in the context of Nager syndrome can be successfully corrected with en bloc distraction osteogenesis of the maxilla and bilateral zygomas through modified osteotomies that exclude the upper nasal pyramid. The approach is simplified and the need for bicoronal incision and bone grafting is mitigated in this technique, which the authors have named Lefort 2.5.

Bilateral Malar Reconstruction Using Patient-Specific Polyether Ether Ketone Implants in Treacher-Collins Syndrome Patients With Absent Zygomas.

The authors performed bilateral malar reconstruction using polyether ether ketone implants in 3 patients with Treacher-Collins syndrome with absent, as opposed to hypoplastic, zygomata. These patient-specific implants were fabricated using computed-aided design software reformatted from three-dimensional bony preoperative computed tomography images. The first time the authors performed this procedure the implant compressed the globe resulting in temporary anisocoria that was quickly recognized intraoperatively. The implant was immediately removed and the patient made a full-recovery with no ocular disturbance. The computer-aided design and manufacturing process was adjusted to include periorbital soft-tissue boundaries to aid in contouring the new implants. The same patient, and 2 further patients, subsequently underwent malar reconstruction using this soft tissue periorbital boundary fabrication process with an additional 2 mm relief removed from the implant's orbital surface. These subsequent procedures were performed without complication and with pleasing aesthetic results. The authors describe their experience and the salutary lessons learnt.

A Morphological Classification Scheme for the Mandibular Hypoplasia in Treacher Collins Syndrome.

BACKGROUND: Mandibular hypoplasia is a hallmark of Treacher Collins syndrome (TCS), and its severity accounts for significant functional morbidity. The purpose of this study is to develop a mandibular classification scheme. METHODS: A classification scheme was designed based on three-dimensional computed tomography (3D-CT) scans to assess 3 characteristic features: degree of condylar hypoplasia, mandibular plane angle (condylion-gonion-menton), and degree of retrognathia (sella-nasion-B point angle). Each category was graded from I to IV and a composite mandible classification was determined by the median value among the 3 component grades. RESULTS: Twenty patients with TCS, aged 1 month to 20 years, with at least one 3D-CT prior to mandibular surgery were studied. Overall, 33 3D-CTs were evaluated and ordered from least to most severe phenotype with 10 (30%) Grade 1 (least severe), 14 (42%) Grade 2, 7 (21%) Grade 3, and 2 (7%) Grade 4 (most severe). Seven patients had at least 2 longitudinal scans encompassing an average 5.7 (range 5-11) years of growth. Despite increasing age, mandibular classification (both components and composite) remained stable in those patients over time (P = 0.2182). CONCLUSION: The authors present a classification scheme for the TCS mandible based on degree of condylar hypoplasia, mandibular plane angle (Co-Go-Me angle), and retrognathia (SNB angle). While there is a natural progression of the mandibular morphology with age, patients followed longitudinally demonstrate consistency in their classification. Further work is needed to determine the classification scheme's validity, generalizability, and overall utility.

A Case Report of Absent Epiglottis in Children With Nager Syndrome: Its Impact on Swallowing.

OBJECTIVE: This clinical report is the first literature report exploring the issues of an absent epiglottis in children diagnosed with Nager syndrome. Absent epiglottis has previously been described in children with Pierre Robin sequence and other syndromes. CONCLUSION: The function of the epiglottis and its contribution to swallowing has always been debated. In this article and from our literature review, we felt that absent epiglottis possibly contributed to the aspiration risk and may partly explain the long-term feeding issues in these children despite corrective surgeries.

The Craniofacial and Upper Limb Management of Nager Syndrome.

INTRODUCTION: Nager syndrome is a rare condition characterized by craniofacial and upper limb abnormalities. It is commonly mistaken for Treacher Collins syndrome, with which it shares the same craniofacial phenotype. However, patients with Treacher Collins do not exhibit hand anomalies, which are seen in patients with Nager syndrome. This paper reviews the multidisciplinary management of patients with Nager syndrome who were treated at the Australian Craniofacial Unit, Adelaide and the Erasmus Medical Centre, Rotterdam. METHODS: The database of both units was scrutinized and the case-notes of the patients with Nager syndrome were reviewed. Data was collected on patient demographics, surgical management, complications, and outcome. RESULTS: Nine patients (6 M:3 F) were identified with Nager syndrome, with a mean age at presentation of 3.7 years (range 8 days to 11.8 years). The mean follow-up time was 2.2 years (2 months to 19 years). SF3B4 mutation was noted in 2 patients and 1 patient had an X:9 translocation. Seven (77.8%) had obstructive sleep apnoea, with 5 patients diagnosed as severe obstructive sleep apnoea. Four patients had pollicization of their index, 2 patients had excision of extra radial digits and 1 patient underwent thumb duplication correction. Craniofacial surgery included mandibular advancement in 5 patients, temporo-mandibular joint reconstruction in 2 patients, and a genioplasty in 1 patient. CONCLUSION: Nager syndrome is a rare acrofacial dysostosis syndrome that is best managed within the realms of a multidisciplinary team. The authors would advocate early pollicization in patients with thumb anomalies to prevent any impairment in manual dexterity.

Long-Term Surgical and Speech Outcomes Following Palatoplasty in Patients With Treacher-Collins Syndrome.

BACKGROUND: Cleft palate is present in one-third of patients with Treacher-Collins syndrome. The authors present long-term speech and surgical outcomes of palatoplasty in this challenging patient population. METHODS: A retrospective review of all patients with Treacher-Collins syndrome and cleft palate was conducted over a 35-year period at a single institution. Demographics, palatal, mandibular, airway, and surgical outcomes were recorded. Speech outcomes were assessed by the same craniofacial speech pathologist. RESULTS: Fifty-eight patients with Treacher-Collins syndrome were identified: 43% (25) had a cleft palate and 16% (9) underwent palatoplasty at our institution. Cleft palate types included 1 Veau I, 5 Veau II, 1 Veau III, and 2 Veau IV. Mean age at the time of palatoplasty was 2.0 years (range, 1.0-6.7 years). Three patients had fistulas (33%) and underwent repairs. Pruzansky classifications included 1 type IIA, 6 type IIB, and 2 type III. Seven patients completed long-term speech evaluations. Mean age at follow-up was 13.9 years (range 2.2-24.3 years). Six patients had articulatory velopharyngeal dysfunction related to Treacher-Collins syndrome. Two patients had structural velopharyngeal dysfunction and required further palatal/pharyngeal surgery. CONCLUSIONS: Cleft palate repair in patients with Treacher-Collins syndrome has a high incidence of velopharyngeal dysfunction. However, the majority of patients are articulatory-based in whom further surgery would not provide benefit. Patients with Treacher-Collins syndrome and cleft palate require close evaluation by a speech pathologist as the incidence of articulatory dysfunction is high.

Perioperative management of 19 infants undergoing glossopexy (tongue-lip adhesion) procedure: a retrospective study.

BACKGROUND: Glossopexy (tongue-lip adhesion) is a procedure in which the tongue is anchored to the lower lip and mandible to relieve the upper airway obstruction mainly in infants with Pierre Robin sequence. Infants suffering from severe upper airway obstruction and feeding difficulties due to glossoptosis are the candidates for this procedure and are predicted to demonstrate difficult airway and difficult intubation. METHODS: We retrospectively examined the perioperative management of 19 infants undergoing glossopexy procedure at our institution from 1992 to 2010. RESULTS: Out of 19 patients, Pierre Robin sequence was diagnosed in 17, Treacher Collins syndrome in 1, and Stickler syndrome in 1. In all of them, inhalation anesthesia was induced with a nasopharyngeal tube in place. Nine patients underwent fiberoptic intubation. After surgery, 12 patients were extubated in the operating room and 11 of them required a nasopharyngeal tube to keep the airway open. Seven patients left the operating room with the trachea intubated. Two patients received tracheostomy at the age of 2 months. Seventeen patients underwent release of tongue-lip adhesion coincidentally with the palate repair at 7-14 months of age. For this surgery, no one required fiberoptic intubation. CONCLUSIONS: The airway of these patients should be managed carefully not only before but also after the operation. A nasopharyngeal tube was effective in maintaining the upper airway patency during anesthesia induction and before and after operation.

Early Fat Grafting for Augmentation of Orbitozygomatic Region in Treacher Collins Syndrome.

This report presents our preliminary experience with the effect of early fat grafting (FG) (at ≥ 6 months of age) in timely bone reconstruction of the orbitozygomatic area in patients with Treacher Collins syndrome. FG is performed 2 to 3 consecutive times after the age 6 months. Bone reconstruction is performed ≥ 6 months after the last FG session. This protocol was applied in 3 patients. There was no need for further reconstruction of the lower eyelids in 2 patients. Malar bone reconstructions, using calvarial bone grafts, were performed in all of the patients. Eighteen months after bone reconstruction, there was limited absorption of the bone grafts. Early FG of the orbitozygomatic area improves contour and tissue quality, restores volume, and can possibly minimize bone resorption following zygomatic bone framework reconstruction.

Neonatal mandibular distraction in a patient with Treacher Collins syndrome.

The purpose of this study was to analyze a case of mandibular distraction in a case of Treacher Collins syndrome. Mandibular distraction is an adequate surgical treatment of patients with Pierre Robin sequence and represents an alternative to tracheostomy. In severe hypoplastic cases or when three-dimensional vector control or gonial angle control is necessary, extraoral bidirectional or multidirectional devices have an advantage over intraoral devices. The anchorage obtained with transfixing Kirschner wires fixed in the mandibular distal segment and symphysis is crucial in neonates for the stability of the devices. Moreover, with the use of a second pin for each bone segment, the extraoral devices allow to modify the vector orientation and consequently the shape of the newly formed mandible.

Carotid artery dissection and stroke complicating treatment of postmandibular distraction ankylosis: a case report.

Mandibular distraction osteogenesis is an increasingly accepted treatment option for severe upper airway obstruction in grade 3 Robin sequence. Complications are rarely reported but can include fracture, pin dislodgement, tooth bud damage, and temporomandibular joint ankylosis. Operative correction of these complications can carry inherent risks of their own. We present a patient who incurred carotid artery dissection and stroke after release of postdistraction coronoid-zygomatic ankylosis for the treatment of mandibular micrognathia.

Changing the facial features of patients with Treacher Collins syndrome: protocol for 3-stage treatment of hard and soft tissue hypoplasia in the upper half of the face.

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.

Piezoelectric osteotomy for distraction osteogenesis of the pediatric mandible.

BACKGROUND: Distraction osteogenesis of the mandible requires a complete osteotomy so that the proximal and distal segments may be separated, thereby producing length. One of the main complications of this technique is lingual nerve injury due to trauma induced by either the saw or the osteotome. The purpose of this article was to suggest the use of piezosurgery in performing near-complete osteotomy of either the body or ramus of the mandible. METHODS: Surgical procedure was performed under general anesthesia, and it lasted approximately 90 minutes. After the buccal cortex of the mandible was dissected, a piezosurgical device was used for the planned osteotomy. The gap created by the device allowed visualization of the nerve, thereby permitting completion osteotomy of the lingual cortex. The patient did not show any neurological postoperative complication. CONCLUSIONS: The use of piezoelectric surgery appears to be a safer option in performing distraction osteogenesis of the pediatric mandible. The presumed disadvantage of this technique, notably an increased operating time due to the lower power cut of the piezoelectric device, was not encountered.

Screw implantation in the globe: the risk of delayed hardware migration from craniofacial repair.

Plating system modification has enabled the use of rigid fixation in younger patients having maxillofacial surgery. One of the common reported complications of the use of plates and screws in children is screw migration due to skeletal maturation. Ophthalmic complications due to maxillofacial surgery reported to date include oculomotor and abducens palsies, lacrimal damage and vision loss due to infection, retrobulbar hemorrhage, and compartment syndrome. We describe a complication unique to screw migration resulting in orbital fixation and near-globe rupture in a patient with Treacher Collins syndrome. We hope to alert our colleagues to the potential risk of screw and hardware migration and breakage, particularly in the setting of craniofacial surgery performed on a child before maturation of craniofacial osseous structures.