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A procedure to reconstruct the coloboma of the lower lid and to reposition the lateral canthus in the Treacher Collins deformity is presented. A composite upper lid flap forms the basis of the method. The results are satisfactory on long-term follow-up.
Two techniques of calvarial bone grafting (split-thickness and single-table) are reviewed. A new vascularized bone flap based on the temporal vasculature is presented. The indications and relative advantages of each are discussed. The calvarial bone flap is emphasized and strongly recommended. Since the flap is vascularized and contains membranous bone, it is particularly suited for bone grafting in clinically unfavorable recipient sites, such as scarred or irradiated beds or the hypoplastic zygomatic-maxillary complex in the Treacher Collins syndrome.
The clinical use of a temporal periosteal bone flap for the reconstruction of a malar bone in a patient with the Treacher Collins syndrome is presented. The temporal muscle functions as an axial carrier of the periosteum that induces osteogenesis in young children, whereas the bone segments may serve as a nucleus for further bone formation from the periosteum. Correction of the eyelid coloboma was obtained by the rotation and advancement of a temporopalpebral flap.
Nager's syndrome, which has the facial features of Treacher Collins syndrome, preaxial upper limb defects, short stature, and frequently subnormal intelligence, is very rare. Five new cases have been collected. In four, there was virtually total absence of the soft palate. This has been described in two patients in the past. Differing methods of correcting this are presented.
This paper describes an alternative means of reconstruction of the Treacher Collins zygomatic deficiency and presents a consecutive patient series with long-term follow-up documented by clinical and quantitative means employing CT-derived craniofacial skeletal measurements. Eight children (mean age at operation 10.5 years) underwent bilateral zygomatic reconstruction with full-thickness, T-shaped calvarial bone grafts contoured three-dimensionally and then inset and stabilized with plate-and-screw fixation, with exposure provided only by a coronal incision. Orbital floor defects and graft donor sites were repaired with fixed split-thickness cranial bone. No complications occurred during surgery, and donor sites healed without clinical defect. Zygomatic augmentation was achieved in all patients, with follow-up ranging from 24 to 50 months (mean 35 months). CT scanning done before surgery, immediately afterward, and again 1 year or more later demonstrated significant increases in lateral orbital wall length, lateral orbital distance, interzygomatic arch distance, and zygomatic arch length. The late postoperative scans showed that these changes were maintained. However, effective treatment of the surrounding soft-tissue and eyelid deficiencies remains an unsolved problem.
Eighty-two-day-old male Wistar rats were selected to study the pattern of craniofacial growth following resection of the zygomatic arches. Rats were divided into three groups: group I (n = 14), the control group; group II (n = 15), with unilateral resection of the zygomatic arch; and group III (n = 8), with bilateral resection. Direct dry skull and cephalometric measurements show increased facial projection and decreased transverse facial width on the side of the resected arch. If the results are extrapolated to the growth pattern of patients with the Treacher Collins syndrome, we can conclude that the zygomatic arch acts as a "moderator" in the morphologic development of the face.
We believe that the extended SMAS technique may be useful in selected facial cleft patients. In three Treacher Collins patients, this technique produced a modest improvement in the quantity and quality of the malar soft tissue that had not been achieved after orbitozygomatic or maxillomandibular surgery.
A new combination of basically known techniques is described for the correction of Treacher Collins syndrome. The patients are treated in two to three operative sessions beginning early in the second decade of life. The main components are a chin advancement simultaneously with malar osteotomies in a first operation. In the second operation, the chin prominence is moved further forward by a simultaneous vertical movement of the maxilla, sagittal split osteotomy and body osteotomy of the mandible, together with a further chin advancement. Additional finishing touches may ask for a third intervention. Since there is a large variability of expression of the different signs, the techniques have to allow for a good deal of flexibility. The study of 10 patients reflects the considerable variations in the condition at the outset and the adequacy of the basic treatment protocol. The results of malar osteotomies are better than those of pure onlay augmentation. Despite the complexity of the maxillomandibular osteotomies, occlusal results are reasonably stable, and aesthetic improvement is considerable. The adaptation of the treatment to the individual patient resulted in modifications of direction of movement for different segments but also in omission of parts of the standard osteotomies. As a consequence, a modified treatment plan will be used as often as the standard program. The causes for the two not satisfying results are explained, and they demonstrate the limitations of the concept.
Distraction osteogenesis has become an accepted method of treatment for patients requiring reconstruction of hypoplastic mandibles. We present a quantitative analysis of volumetric changes after distraction osteogenesis in a series of 10 patients. Group I (n = 5 patients, 3 unilateral craniofacial microsomia, 1 Goldenhaar syndrome, and 1 bilateral craniofacial microsomia) underwent unilateral distraction of the mandible. Group II (n = 5 patients, 1 Nager syndrome, 1 bilateral craniofacial microsomia, 1 developmental micrognathia, and 2 Treacher Collins syndrome) underwent bilateral distraction of the mandible. Predistraction and postdistraction axial and three-dimensional computed tomographic (CT) scans were digitized and transferred to a computer for analysis with image-processing software to determine the changes in volume of the mandible and bony regenerate. The CT-derived volume method was validated by scanning three dry cadaver mandible specimens and comparing the volume data with those derived from a water-displacement method. The difference between the two methods was less than 5 percent. The mean distracted length, as recorded from the calibrated device, was 22.6 mm in the 10 patients. In the unilateral distraction group, the mean increase in hemimandibular bone volume was 2.8 cc, with a mean percentage increase of 27 percent in the distracted hemimandible. In the bilaterally distracted patients, the mean increase in total mandibular volume was 7.9 cc, with a mean percentage increase in bone volume of 25 percent. This study represents the first attempt to quantify the increase in bone volume resulting from distraction osteogenesis. Quantitative volumetric analysis of CT scans is an accurate method to measure the amount of bone regenerate in patients undergoing distraction osteogenesis of the mandible or the extremities. The concept and utility of quantifying the volumetric changes in bone following distraction osteogenesis may become more important as multiplanar devices are developed and used in other areas of the craniofacial skeleton.
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Distraction osteogenesis is an effective technique for reconstruction of the congenitally deficient mandible. However, the age at which it is best performed remains under discussion. Distraction performed at an early age, while possibly allowing the face to develop with a more normal functional matrix, may entail a higher rate of complications. Additionally, it is possible that subsequent asymmetric growth of the mandible may necessitate serial distraction. To address this issue, the clinical records and cephalometric radiographs of all patients less than 48 months of age undergoing mandibular distraction at New York University Medical Center between August of 1989 and August of 1997 were examined. There was a total of 14 patients ranging in age from 19 months to 43 months. Nine patients had a diagnosis of unilateral craniofacial microsomia, three had Treacher Collins syndrome, one had Nager syndrome, and one had bilateral developmental micrognathia. The average amount of distraction was 27 mm (range, 23 to 39 mm) in unilateral cases and 24 mm in bilateral cases (range, 15 to 31 mm). The period of clinical follow-up averaged 32.6 months (range, 12 to 92 months). All patients showed significant improvement in craniofacial appearance, and in four patients, long-term tracheostomy tubes were removed. There were two major complications. In one patient with craniofacial microsomia, there was a relapse in the early postretention phase related to the presence of a dentigerous cyst. This required removal of the cyst and repeat distraction. In the patient with Nager syndrome, a coronoid ankylosis developed requiring surgical release. There were no other major complications. The scars required revision in only two of the patients. Cephalometric analysis of the patients in the study revealed a differential in the rate of growth between the affected and the unaffected side in all cases of craniofacial microsomia. The affected side always grew at a slower rate than the contralateral side after the distraction process was complete. This led to a progressive asymmetry of the rami, clinically expressed by some degree of facial asymmetry and an occlusal cant. For this reason, secondary distraction was required in one patient and is planned in a second. Initial overcorrection of the patient would seem to minimize the likelihood that secondary distraction will be necessary. Distraction osteogenesis for reconstruction of the mandible in this subset of young patients was a safe and effective technique for improving the craniofacial skeletal form and appearance, with minimal associated morbidity. Longer follow-up is necessary to assess the full impact of growth in these cases.
In patients with recessive infraorbital rims, alloplastic augmentation of the infraorbital rims makes the eyes appear less prominent and improves appearance. Ten patients (seven women and three men) with an average age of 30 years (range, 23 to 45 years) underwent augmentation of the infraorbital rim with alloplastic implants over a 9-year period. With an average follow-up of 3 years (range, 6 months to 6 years), reconstructions have remained stable and satisfactory, with no incidence of infection, infraorbital nerve damage, or palpebral fissure distortion. One patient underwent additional surgery to correct contour irregularities, and one patient requested implant removal 1 month after surgery.
The purpose of this study was to measure changes in the airway cross-sectional area of pediatric patients with micrognathia and obstructive airway symptoms after treatment by mandibular distraction. The measurements obtained were correlated with the clinical outcomes.Ten patients, ranging in age from 3 months to 8 years, underwent measurement and distraction. Eight patients were under 30 months of age. Six were diagnosed with Pierre Robin sequence, two with Treacher Collins syndrome, and two with Nager syndrome. All patients had retrognathia of greater than 8 mm and obstructive airway symptoms while awake that had resulted in tracheostomy (3), repeated apnea monitor triggering (5), or abnormal sleep study (2). Cephalometric analysis was performed pretreatment and posttreatment by distraction. The effective airway space was defined with the following boundaries: a horizontal line from the tip of the odontoid to the velum, the uvula tip to the tongue base along the shortest line, the tongue base down to the base of the epiglottis, and the horizontal line to the posterior pharynx. These lines were traced for each cephalogram, the outline was digitized, and the area was calculated by computer. An analysis of the square area change was done by paired t test. The range of distraction was 8 to 22 mm; the mean effective airway increase was 67.5 percent, with a range of 26 to 120 percent. Measurable airway increase occurred in all patients who underwent distraction, and all patients showed clinical improvement. Six patients with Pierre Robin sequence became asymptomatic, with normal sleep, feeding, and weight gain. Two patients with Nager syndrome and tracheostomies were decannulated and were asymptomatic postdistraction. One patient with Treacher Collins syndrome without tracheostomy became asymptomatic after mandibular distraction; one patient failed to distract because of premature consolidation and continued to require a cannula. Mandibular distraction seems to provide a consistent change in tongue base position that improves obstructive airway symptoms by increasing measured effective airway space. The potential for mandibular distraction exceeds the simple correction of malocclusion also by eliminating soft-tissue obstruction of the micrognathic airway. Airway improvement is independent of the syndrome diagnosed. Mandibular distraction osteogenesis may be useful to avoid or decannulate existing tracheostomy in infants with micrognathia.
Children with craniofacial anomalies often have compromise of the upper airway, a condition with potential for morbidity and mortality. In children with microretrognathia, the diminutive size and retruded position of the mandible reduces the size of the oropharynx, thereby predisposing to glossoptosis and airway obstruction. Although several authors have reported successful use of mandibular distraction osteogenesis to alleviate this type of upper airway obstruction, the physiologic relationship between changes in mandibular shape, size, and position and upper airway dynamics remains undefined. The purpose of this study was to develop methodologies to quantitatively evaluate upper airway dynamics in children with micrognathia both before and after mandibular distraction osteogenesis. The patient population consisted of four children with micrognathia who had successfully undergone upper airway stabilization by bilateral mandibular distraction osteogenesis. The data used were digitally archived computed tomographic scan data from high-resolution, thin-slice head computed tomographic scans obtained before and after mandibular distraction. Upper airway evaluation was performed in two ways: static and dynamic. Static analysis consisted of computer quantification of predistraction and postdistraction mandibular and upper airway volumes using Analyze imaging software. Dynamic analysis consisted of fabrication of rigid stereolithographic hollow cast models of the upper airway produced from computed tomographic scan data. Models were used for characterization of upper airway resistance and flow patterns as related to respiration. After distraction osteogenesis, mandibular total volume increased 32, 32, 18, and 25 percent (mean, 27 percent) and upper airway volume increased by 20, 31, 23, and 71 percent (mean, 37 percent). A significant decrease in flow resistance, both inspiratory and expiratory, was observed in the patient with the greatest upper airway volume increase (71 percent) after distraction. After distraction, the inspiratory resistance was diminished by 51 percent and the expiratory resistance diminished by 85 percent. However, the three patients with more modest upper airway volume increases of 20 to 31 percent demonstrated no statistically significant change in flow resistance after distraction. Results of this study support the conclusion that distraction osteogenesis of the micrognathic mandible increases the volume of the upper airway, roughly paralleling the increase in mandibular volume. In the biomechanical airway model studied, upper airway volume expansion has been shown to be able to decrease the flow resistance over the length of the airway, presumably secondary to an increase in the average cross-sectional area. The artificial rigidity of the stereolithographic "airway" compared with the elasticity of the human upper airway may account for the insensitivity of this model to smaller but clinically significant airway changes.
A long-term follow-up study of patients who underwent bilateral mandibular distraction is presented, and the results of patients with Treacher Collins syndrome and Nager syndrome are compared with results for other forms of congenital micrognathia. It was hypothesized that the factors responsible for the predetermined, syndrome-specific shape of the mandible in patients with Treacher Collins and Nager syndromes would alter the long-term results of linear (uniplanar) distraction of the mandible. Thus, over time, the mandibles would remodel to preoperative form while maintaining the increase in volume. To investigate this hypothesis, all patients treated with bilateral mandibular distraction who had at least 1.5 years of follow-up, including satisfactory cephalometric examinations, were retrospectively reviewed. Two groups were identified. Group 1 (n = 6) were Treacher Collins and Nager syndrome patients (ages, 2 to 13 years; mean, 5.2 years) and group 2 (n = 6) included other forms of bilateral, congenital micrognathia (ages, 1.5 to 19 years; mean, 8.4 years). Serial cephalometric measurements were recorded before distraction, after distraction, and at least 18 months after distraction. Mandibular mean linear distraction distance (as recorded on the device) averaged 24.5 mm in group 1 and 26.2 mm in group 2. In group 1, the antegonial angle (angle from the mandibular plane to the top of the antegonial notch) decreased after distraction by 3.8 degrees, and the antegonial notch height was reduced by 1.6 mm. The posttreatment morphologic change was modified significantly over time, with a 3.7-degree increase of the antegonial angle and a 1.2-mm deepening of the antegonial notch. In group 2, the immediate reduction in height of the antegonial notching was subtler; however, long-term recurrence of the antegonial notching was also observed. At the end of distraction, the mean group 1 gonial angle became 8 degrees more obtuse. In contrast, patients in group 2 developed a more acute angle (mean, 8 degrees). The mandibles of the Treacher Collins syndrome patients (group 1) maintained their more obtuse postdistraction gonial angle during the period of follow-up, whereas over time this change was reversed in group 2 patients. In conclusion, experience with bilateral mandibular distraction has demonstrated that long-term determination of mandibular form is more complex than either the amount of distraction or the direction of the distraction vector. The underlying genotype and the musculoskeletal milieu must be taken into account when planning distraction, as these factors tend to remodel the mandible into its preoperative shape over time, despite the fact that the increased mandibular volume and projection are maintained.
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Reported is an atypical, severe case of Hallermann-Streiff syndrome combined with progeria, bilateral microphthalmus, cataracts, and normal chromosome count. A plea is made for study into the teratology of abnormal chemical, metabolic, and other forces that attack the early stages of the development of the human fetus and produce multiple anomalies.