Dual midfacial distraction osteogenesis: Le Fort III minus I and Le Fort I for syndromic craniosynostosis

Midfacial hypoplasia has been corrected by Le Fort III or monobloc forward advancement in one stage in syndromic craniosynostosis, but recently developed distraction osteogenesis has been in use. Whereas the amount of forward mobilization in Le Fort III conventional osteotomy is determined by the preplanned fabricated interdental splint, that in Le Fort III distraction is determined by the positions of the inferior orbital rim, malar complex, and nose. Therefore, the forward mobilization of the upper part of the midface may sometimes be insufficient when one focuses on the final occlusion, and the occlusion might not be satisfied when the forward mobilization is sufficient. Correction of the midfacial hypoplasia should be considered differently in the upper and lower portions of the midface. The upper portion contains the inferior orbit and nose, and the lower portion contains the occlusal structure of the maxillary dentoalveolar portion with the mandible. Separating the midface into two portions and conducting the distraction osteogenesis in both portions separately in different amounts and vectors of distraction is described in this article. Although distraction of the upper portion of the midface can be conducted in one direction with an internal device, distraction of the lower portion of the midface is preferred for conduction by a controllable device because of the need to obtain the preferred occlusion. To obtain better functional and aesthetic results in midfacial distraction in adults and adolescents with syndromic craniosynostosis, dual Le Fort III minus I and Le Fort I midfacial distraction osteogenesis was performed in four cases (in two patients with Crouzon syndrome and in two patients with Apert syndrome). Two females and two males are described (age range, 13 to 26 years). An internal device was used for the upper portion of the midface and an external device was used for the lower portion. The amount of distraction ranged from 14 to 21 mm in the upper portion of the midface and from 11 to 18 mm in the lower portion. No particular complications were noticed over a follow-up period of 10 to 38 months (average follow-up, 19.8 months).     

Distraction osteogenesis of the craniofacial skeleton

In summary, distraction osteogenesis is a safe and effective means of achieving bone lengthening. These techniques were originally applied to the long bones of the extremities; over the past 10 years they have been effectively applied to the bones of the craniofacial skeleton. The new bone regenerate that is observed after distraction osteogenesis is stable, and relapse rates after skeletal advancement are believed to be lower than with conventional osteotomy and bone graft techniques. There is considerable variability in distraction protocols employed in clinical practice, including differences in the types of devices used and in the rate, rhythm, latency, and period of consolidation for distraction osteogenesis. The greatest application for distraction osteogenesis in the craniofacial skeleton has been with mandible lengthening, for which there is presently a 10-year clinical experience. Midfacial advancement is a newer application of distraction osteogenesis, for which clinical experience has been accrued over the past 5 years. This latter experience indicates that distraction osteogenesis is a viable treatment option for lengthening of the hypoplastic mandible and midface. These techniques have advantages over conventional means of bone graft and rigid fixation because of the quality of the bone regenerate, the decrease in the long-term relapse rate of the advanced bone segments in both the mandible and the midface, and the simultaneous soft-tissue elongation that accompanies the distraction process. Distraction osteogenesis is particularly applicable to the correction of severe deformities of the mandible and midface in children with developmental hypoplasia and syndromic craniosynostosis. However, growth is an added variable in this patient population. The amount of overcorrection in lengthening of the hypoplastic bone required to compensate for continued growth discrepancy of the adjacent facial bones is difficult to predict. Therefore, the families of these patients should be informed that many children will require repeated operations at a later age as they reach skeletal maturity.     

Long-term skeletal stability after maxillary advancement with distraction osteogenesis using a rigid external distraction device in cleft maxillary deformities

Rigid external distraction is a highly effective technique for correction of maxillary hypoplasia in patients with orofacial clefts. The clinical results after correction of sagittal maxillary deformities in both the adult and pediatric age groups have been stable. The purpose of this retrospective longitudinal cephalometric study was to review the long-term stability of the repositioned maxilla in cleft patients who underwent maxillary advancement with rigid external distraction. Between April 1, 1995, and April 1, 1999, 17 consecutive patients with cleft maxillary hypoplasia underwent maxillary advancement using rigid external distraction. There were 13 male patients and four female patients, with ages ranging from 5.2 to 23.6 years (mean, 12.6 years). After a modified complete high Le Fort I osteotomy and a latency period of 3 to 5 days, patients underwent maxillary advancement with rigid external distraction until proper facial convexity and dental overjet and overbite were obtained. After active distraction, a 3- to 4-week period of rigid retention was undertaken; this was followed by removable elastic retention for 6 to 8 weeks using, during sleep time, an orthodontic protraction face mask. Cephalometric radiographs were obtained preoperatively, after distraction, at 1 year after distraction, and 2 or more years after distraction. The mean follow-up was 3.3 years (minimum, 2.1 years; maximum, 5.3 years). The following measurements were obtained in each cephalogram: three linear horizontal and two linear vertical maxillary measurements, two angular craniomaxillary measurements, and one craniomandibular measurement. Differences between the preoperative and postoperative cephalometric values were analyzed by paired t tests (p < 0.05). The cephalometric analysis demonstrated postoperatively significant advancement of the maxilla. In addition, the mandibular plane angle opened 1.2 degrees after surgery. After the 1- to 3-year follow-up period, the maxilla was stable in the sagittal plane. Minimal anteroposterior growth was observed in the maxilla compared with that exhibited in the anterior cranial base. However, there was significant vertical maxillary growth over the 3-year observation period. The mandibular plane angle tended to decrease during the follow-up period. The cephalometric data from this study support the clinical impression of maxillary stability after maxillary advancement with rigid external distraction in cleft patients. This effective and stable technique is now considered for all pediatric patients with severe cleft maxillary hypoplasia and for adolescent and adult patients with moderate to severe deformities.     

Rotation advancement of the midface by distraction osteogenesis

A wide variety of disease processes produce alteration of midfacial skeletal growth, resulting in moderate-to-severe midface deficiency presenting as retrusion associated with Angle's class III malocclusion. Le Fort III osteotomies with advancement can provide an excellent tool for correction of this deformity. Recently, the corrective procedure of choice for advancement of midfacial segments has been distraction osteogenesis after osteotomy. Straight linear advancement is the most common choice for corrective movement of the midfacial segment, whether accomplished through acute surgical advancement or through the progressive distraction technique. Unfortunately, linear advancement can produce abnormal configurations, both at the nasal root and lateral orbits, regardless of the technique used. Enophthalmos, caused by orbital enlargement, may limit the advancement necessary to achieve class I occlusion.The authors have extended the utility of the Le Fort III procedure and have improved the final outcome by creating a controlled rotation advancement of the midfacial segment using distraction. The application of an existing internal distraction device is modified to control the movement of the midfacial segment in a rotation advancement path. Included in the series were 10 patients with severe midface retrusion secondary to multiple congenital syndromes, along with cleft lip and palate. The ages of the patients ranged from 6 to 14 years. An internal distraction system was used in all cases. Application of the distractor was substantially modified to simplify both fixation and removal and to produce controlled rotation advancement. The team orthodontist determined the final occlusal relationship. Percutaneous distractor drive rods were removed 4 to 6 weeks after active distraction to increase patient comfort. The distractors and all associated hardware were removed after 12 to 16 weeks of consolidation; follow-up periods ranged from 1 to 3 years.By using the modified distractor application to produce rotation advancement, the contour abnormalities at the nasal root and lateral orbit and the enophthalmos produced by linear advancement were eliminated. Significant improvement in facial contour and class I occlusion was obtained in all cases. Complications consisted of near exposure of the device in one patient. Stability has been excellent, with no relapse reported by the orthodontist.Rotational advancement of facial segments by distraction allows successful early intervention in patients with significant midface retrusion. The abnormal nasal root and lateral orbital configurations produced by direct linear advancement are avoided, and a stable and normalized facial configuration is produced.     

Immediate versus delayed midface distraction in a primate model using a new intraoral internal device

The theoretic advantage of distraction osteogenesis of the craniofacial skeleton, especially in cases of severe midface retrusion and in the presence of maxillary scarring, is prevention of relapse following significant advancements. The purpose of this study is to demonstrate the utility of a new low-profile, intraoral, internal device for midface distraction at the conventional or high Le Fort I level. In addition, the present study compares the efficacy of immediate versus delayed distraction on subsequent maxillary relapse. Four adult rhesus Macaca mulatta monkeys were divided into two groups. Group 1 underwent immediate midface distraction; group 2 underwent delayed distraction. All four monkeys underwent a modified Le Fort I osteotomy through an upper buccal sulcus incision and bilateral application of the intraoral midface distraction devices. No other osteotomies or incisions were necessary. Immediate distraction, performed in group 1, entailed intraoperative activation of the devices and distraction of 10 mm followed by a 5-day lag period before postoperative activation and distraction of an additional 10 mm at the rate of 1 mm/day. Delayed distraction, performed in group 2, entailed a 5-day postoperative lag period before device activation and distraction of 20 mm at the rate of 1 mm/day. Both groups thus underwent 20 mm of midface distraction. All devices were removed 6 weeks after completion of distraction. All monkeys tolerated the devices and daily distraction uneventfully. On the basis of serial cephalograms and dental models obtained throughout the experimental period, there was no evidence of relapse in either the immediate or delayed groups 6 months after distraction. In addition, on the basis of histologic, ultrastructural, and dry skull analysis, no significant differences were observed in the quality of regenerate bone obtained when comparing the immediate and delayed distraction groups. Significant midface advancement is thus feasible using this new internal, intraoral distraction device, which presents several advantages over other internal devices that require coronal incisions and additional osteotomies to achieve midface advancement. In addition, immediate distraction may abbreviate the distraction period without adverse sequelae.     

Klinik und Genetik syndromaler und nichtsyndromaler Kraniosynostosen

With an incidence of 1:2000–1:3000 births, craniosynostoses are among the most common craniofacial anomalies. Growth inhibition caused by premature fusion of one or more cranial sutures can lead to severe deformities of the skull and facial skeleton. Besides the severe aesthetic problems for the patient, it also has important clinical consequences. These may include raised intracranial pressure, optic nerve atrophy, respiratory, and developmental disorders. Despite major efforts, causative genes (e.g., FGFR1-3, TWIST1) have been detected for only a portion of the autosomal dominantly inherited craniosynostosis syndromes. The etiology of non-syndromic craniosynostosis still remains unclear. The application of next generation sequencing technologies will probably lead to the identification of additional causative genes underlying at the least syndromic forms of craniosynostosis in upcoming years. Due to their clinical complexity, particularly the syndromic forms of craniosynostosis require interdisciplinary care. The only treatment option currently available is craniofacial surgery, which in the long term often fails to remedy the genetically determined pathological growth pattern of complex syndromic craniosynostoses.     

Craniofacial distraction with a modular internal distraction system: evolution of design and surgical techniques.

The present report summarizes the evolution of design for a modular internal distraction system that is applicable throughout the craniofacial region. Eleven patients (5 boys, 6 girls), whose ages ranged from 4 months to 10 years at the time of distraction, constitute the basis for this study. The clinical indications for distraction were exorbitism with corneal exposure (n = 1), obstructive sleep apnea (n = 4), tracheostomy decannulation (n = 1), severe maxillary hypoplasia with class III malocclusion (n = 3), severe vertical and sagittal maxillary deficiency with anophthalmia (n = 1), and relapse following frontoorbital advancement in a case of rare craniofacial clefting (n = 1). Twenty-two distraction devices were used in these 11 patients. Two initial prototypes were tested (prototype 1 = 8 devices; prototype 2 = 2 devices) until the modular internal distraction system (MIDS, Howmedica-Leibinger, Inc.) was developed (n = 12 devices). The craniofacial osteotomies used were Le Fort III (n = 4), monobloc (n = 3), mandibular (n = 3), Le Fort I (n = 2), and cranial (n = 1). The distraction distances ranged from 11 to 28 mm. One patient undergoing mandibular distraction developed transient swelling in the left mandibular region, which responded to antibiotics. There were no other complications. Depending on the age of the patient and the length of distraction, the distraction gap was allowed to consolidate from 6 weeks to 3 months. The devices were then removed on either an outpatient or a 23-hour-stay basis. The modular internal distraction system permits widespread application of easily customizable, buried distraction devices throughout the craniofacial region.     

Further evidence of association between mutations in FGFR2 and syndromic craniosynostosis with sacrococcygeal eversion

BACKGROUND: Pfeiffer syndrome (PS; OMIM #101600) is an autosomal dominant disorder characterized by craniosynostosis, midface hypoplasia, broad thumbs, brachydactyly, broad great toes, and variable syndactyly. CASE: We report a case of PS (type 3) with tracheal and visceral involvement and sacrococcygeal eversion. The patient shows facial dysmorphism with macrocephaly, dolichocephaly, and trigonocephaly, and an asymmetric skull, bilateral and severe exophthalmia with shallow orbits and ocular hypertelorism, downslanting palpebral fissures, constant strabismus, short anterior cranial base, and midface hypoplasia. CONCLUSIONS: Molecular analysis of the FGFR2 gene in this patient revealed a point mutation (c.890G>C NM_000141). This mutation leads to the substitution of the residue tryptophan at position 290 to cysteine in the protein (p.Try290Cys). These data reinforce the hypothesis that the p.Trp290Cys mutation is more often associated with a severe and poor prognosis of PS. Furthermore they suggest that the presence of sacrococcygeal defects is not associated with any specific FGFR2 mutation.     

Midface fractures: advantages of immediate extended open reduction and bone grafting

Experience with 240 midface (Le Fort and zygoma) fractures in multiple trauma patients has emphasized that superior aesthetic results are obtained by immediate extended open reduction with primary bone grafting. Internal fixation of 110 zygomatic and 130 Le Fort fractures was performed in the lower midface (zygomaticomaxillary and nasomaxillary buttresses). Open reduction of the condyle was employed in five concomitant Le Fort and subcondylar fractures with a loss of ramus height to prevent superior and posterior displacement of the middle and lower face. Bone grafts were utilized in 74 patients. They were most frequently employed in the orbit and less frequently in the lower midface. Bone graft survival paralleled that observed under elective conditions, and a slightly higher infection rate was observed. Extended open reduction and immediate bone grafting adds a new dimension to the aesthetic results obtained from facial fracture treatment. Structural bony integrity and pre-injury facial architecture may be restored in the absence of soft-tissue contracture. Restoration of the pre-injury facial architecture (the essence of facial fracture treatment) is more accurately accomplished when these techniques are utilized.     

Craniosynostosis and congenital tracheal anomalies in an infant with Pfeiffer syndrome carrying the W290C FGFR2 mutation

Pfeiffer syndrome (OMIM 101600) is an autosomal dominant disorder characterized by craniosynostosis, midface hypoplasia, ocular proptosis and digital malformations. We report on a type II Pfeiffer female infant with craniosynostosis, hydrocephalus, and characteristic craniofacial and digital abnormalities. The patient had a history of airway difficulty. Bronchoscopy at age four months revealed low tracheal stenosis and fibrous cartilaginous rings. She underwent tracheostomy for the treatment of cyanotic episodes. Molecular analysis revealed a de novo missense mutation c.870 G>T (TGG>TGT) in the FGFR2 gene that predicts a substitution of cysteine for tryptophan at the codon 290, (W290C). There is phenotypic heterogeneity of tracheal anomalies due to FGFR2 mutations. A review of the literature shows that Pfeiffer patients with the similar tracheal abnormalities can be caused by different FGFR2 mutations and, likewise, the patients with the same FGFR2 mutation may manifest different kinds of tracheal anomalies. Tracheal anomalies may occur in Pfeiffer patients and cause morbidity and mortality because of airway obstruction. Recognition and detailed evaluation of tracheal anomalies should be included in the early diagnostic workup for severe Pfeiffer patients.     

The Le Fort III osteotomy: to distract or not to distract?

Treatment of the craniofacial dysostoses (e.g., Crouzon, Apert, Pfeiffer, Saethre-Chotzen syndromes) is critically dependent on the successful advancement of the midface with a Le Fort III procedure. The purpose of this retrospective clinical outcome study was to evaluate a new technique for distracting the Le Fort III procedure and to compare its results in growing children with those of the standard Le Fort III osteotomy. The records of 22 children were reviewed; 10 patients (mean age, 6.5 years) underwent a standard Le Fort III procedure, and 12 patients (mean age, 7.5 years) underwent a Le Fort III distraction procedure. The distraction group included two separate techniques, bilateral buried distraction (n = 2) and halo distraction (n = 10). Preoperative and 2- to 3-month postoperative cephalograms were analyzed. The average horizontal advancement achieved in the standard Le Fort III group was 6 mm, compared with 19 mm of advancement in the distraction group (p 相似文献   

A recurrent pattern syndrome of craniosynostosis associated with arachnodactyly and abdominal hernias

A new syndrome of craniosynostosis is described in two unrelated male children. Associated anomalies include severe exophthalmus; maxillary and mandibular hypoplasia; soft tissue hypertrophy of the palatal shelves; low-set ears with soft, pliable auricles; thoracic anomalies; multiple abdominal hernias; arachnodactyly; and camptodactyly. Functional disorders include infantile hypotonia, developmental delay, mental retardation, and obstructive apnea. Karyotypes were normal. An etiology for this recurrent pattern syndrome has not yet been established in the absence of a family history of similar anomalies in both cases.     

Heterozygous mutations of FREM1 are associated with an increased risk of isolated metopic craniosynostosis in humans and mice

The premature fusion of the paired frontal bones results in metopic craniosynostosis (MC) and gives rise to the clinical phenotype of trigonocephaly. Deletions of chromosome 9p22.3 are well described as a cause of MC with variably penetrant midface hypoplasia. In order to identify the gene responsible for the trigonocephaly component of the 9p22.3 syndrome, a cohort of 109 patients were assessed by high-resolution arrays and MLPA for copy number variations (CNVs) involving 9p22. Five CNVs involving FREM1, all of which were de novo variants, were identified by array-based analyses. The remaining 104 patients with MC were then subjected to targeted FREM1 gene re-sequencing, which identified 3 further mutant alleles, one of which was de novo. Consistent with a pathogenic role, mouse Frem1 mRNA and protein expression was demonstrated in the metopic suture as well as in the pericranium and dura mater. Micro-computed tomography based analyses of the mouse posterior frontal (PF) suture, the human metopic suture equivalent, revealed advanced fusion in all mice homozygous for either of two different Frem1 mutant alleles, while heterozygotes exhibited variably penetrant PF suture anomalies. Gene dosage-related penetrance of midfacial hypoplasia was also evident in the Frem1 mutants. These data suggest that CNVs and mutations involving FREM1 can be identified in a significant percentage of people with MC with or without midface hypoplasia. Furthermore, we present Frem1 mutant mice as the first bona fide mouse model of human metopic craniosynostosis and a new model for midfacial hypoplasia.     

Understanding the molecular basis of Apert syndrome

Apert syndrome, first described in 1906, is one of the most severe of the craniosynostosis syndromes and is further characterized by midface hypoplasia, syndactyly, and other visceral abnormalities. Affected individuals generally require lifelong management by a multidisciplinary team of health care specialists. Apert syndrome results almost exclusively from one or the other of two point mutations in fibroblast growth factor receptor 2. Tremendous scientific advances have been made recently in understanding the molecular basis for Apert syndrome through clinical genetic, biochemical, and structural approaches. In this review, the authors provide the clinician with a basic overview of these findings and their therapeutic implications.     

Airway obstruction and sleep apnea in children with craniofacial anomalies

Children with severe craniofacial anomalies and breathing problems are rare, and the accumulated experience of their treatment is limited. LeFort III midface advancements have been tried by many craniofacial teams, but no consensus has yet been reached as to the effectiveness of this procedure. In this report of seven patients with craniofacial malformations and severe breathing problems, three had a LeFort II midface advancement, one had release of bilateral temporomandibular joint ankylosis, and two had tonsillectomies. Two patients without a tracheostomy suffocated, four had a long-term tracheostomy, and one was cured by a unilateral tonsillectomy. It was concluded that LeFort III midface advancement is ineffective in these types of cases without a very stable postoperative retention, and it was suggested that all patients with severe craniofacial anomalies and breathing problems, regardless of their planned subsequent treatment, should have a tracheostomy as an initial measure.     

Midface position after LeFort III advancement

Nineteen of 30 patients who had midface advancement procedures between 1972 and 1980 had sufficient cephalometric data to be included in this retrospective study. The position of the midface in relation to the cranium and mandible was evaluated immediately postoperatively and for a period of 2 to 11 years (mean 5.8 years). At 1 year, midface position after LeFort III advancement was stable in 12 of 19 patients. Of these 12 patients, 8 showed some evidence of downward and/or forward movement of the midface. The remaining 7 patients showed a minor degree of midface relapse in the first year of follow-up. In 15 of 19 patients, at 2 years or more postoperatively, the final position of the midface was either at, anterior to, or inferior to its immediate postoperative location. Correction of exorbitism remained stable in all but one patient, who required a second advancement of the orbital segment. Three patients required subsequent LeFort I osteotomy to correct class III occlusion. Prognathism was determined to be secondary to mandibular growth, not midface relapse.     

The skeletal anatomy of mandibulofacial dysostosis (Treacher Collins syndrome)

Three-dimensional osseous surface re-formation imaging from CT scans was used to examine the facial skeletons of 14 living patients with mandibulofacial dysostosis. Partial to complete aplasia of the zygomatic process of the temporal bone, mild hypoplasia to aplasia of the frontal process of the zygoma, antimongoloid slant of the transverse orbital axis, and hypoplasia of the medial pterygoid plates and muscles are common to all patients examined. Deformities of the zygoma, zygomatic process of the frontal bone, mandible, and lateral pterygoid plates and muscles vary from minimal to severe, including aplasia. The body of the zygoma is the least affected part of the bone. Right-left asymmetry characterizes these deformities in all patients. The most consistent skeletal aplasia (cleft) in mandibulofacial dysostosis involves the zygomatic process of the temporal bone rather than the zygoma itself.     

Incorporation of titanium mesh in orbital and midface reconstruction

Several authors have demonstrated the safety and effectiveness of titanium in orbital reconstruction. One question posed by clinicians is what happens to large pieces of titanium in communication with the paranasal sinuses or nasal-oral-pharyngeal area. This question becomes increasingly relevant as titanium is used to reconstruct extensive defects for which the destruction of bony architecture requires the placement of mesh in proximity to these areas. The objective of this study was to examine the gross and histologic soft-tissue response to large segments of titanium mesh in the setting of orbital and midface reconstruction, particularly when exposed to the nasal-oral-pharyngeal area and paranasal sinuses. In this study, large segments of titanium mesh were used in eight patients to reconstruct orbital and midface defects, with direct communication between the mesh and nasal-oral-pharyngeal area and paranasal sinuses. Four patients had suffered self-inflicted gunshot wounds; as a result, much of their midface was missing, including the inferior and medial orbital floor, maxilla, nose, naso-orbital-ethmoid complex, and hard palate. Extensive sheets of titanium mesh were used to reconstruct their medial and inferior orbital walls, nasal bridge, and maxilla. In the fifth patient, titanium mesh was used to reconstruct the maxilla after resection of a squamous cell carcinoma of the nasolacrimal duct. In the sixth and seventh patients, mesh was used to reconstruct the nasal bridge after severely comminuted nasal fractures resulted in the loss of bone and mucosa. Finally, the eighth patient had titanium mesh used to replace cocaine-induced bone loss involving the left medial orbital floor and wall and part of the maxilla. On gross examination by either endoscopy or direct inspection, all eight patients had rapid soft-tissue incorporation of the titanium mesh. Initial examination typically revealed budding of soft tissue through mesh interstices, followed by progressive incorporation. One patient's mesh was covered in only 15 days. Two patients underwent biopsies of this newly formed soft tissue. One had biopsies performed at 3, 15, and 31 months after the original operation. Biopsy examination at 3 months revealed incorporation of the titanium with fibrous soft tissue covered by ciliated respiratory epithelium, goblet cells, and squamous epithelium with metaplasia. In addition, the dense, acute inflammation present at 3 months evolved into mild, chronic inflammation at 31 months. The second patient had a single biopsy 4 months after secondary orbital reconstruction for delayed enophthalmos. Biopsy examination revealed a fibrous soft-tissue sheath lined by squamous epithelium with metaplasia. Again, mild chronic inflammation was present within the soft tissue. This study provides evidence of titanium's compatibility with soft tissue. The mesh underwent progressive incorporation with soft tissue that was then resurfaced by indigenous cells, including respiratory epithelia and goblet cells. This phenomenon occurred despite communication with the nasal-oral-pharyngeal area and paranasal sinuses.