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4.
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thumbs, hypoplastic genitalia, and distinctive facies. Am J Med Genet A 2010;152:1915–1918 Molina FD, Santos FC, Falleiros LR Jr, et al. Microscopical evaluation of extracellular matrix and its relation to the palatopharyngeal muscle in obstructive sleep apnea. Microsc Res Tech 2011;74:430–439 Pereira V, Sell D, Ponniah A, et al. Midface osteotomy versus distraction: the effect on speech, nasality, and velopharyngeal function in craniofacial dysostosis. Cleft Palate Craniofac J 2008;45:353–363 Nohara K, Tachimura T, Wada T. Prediction of deterioration of velopharyngeal function associated with maxillary advancement using electromyography of levator veli palatini muscle. Cleft Palate Craniofac J 2006;43:174–178 Guyette TW, Polley JW, Figueroa A, et al. Changes in speech following maxillary distraction osteogenesis. Cleft Palate Craniofac J 2001; 38:199–205 Mink van der Molen AB, Janssen K, Specken TF, et al. The modified Honig velopharyngoplasty—a new technique to treat hypernasality by palatal lengthening. J Plast Reconstr Aesthet Surg 2009;62:646–649 Lavanya T, Cohen M, Gandhi SV, et al. A case of a Dandy-Walker variant: the importance of a multidisciplinary team approach using complementary techniques to obtain accurate diagnostic information. Br J Radiol 2008;81:242–245 Janulewicz J, Costello BJ, Buckley MJ, et al. The effects of Le Fort I osteotomies on velopharyngeal and speech functions in cleft patients. J Oral Maxillofac Surg 2004;62:308–314
Neonatal Mandibular Distraction in a Patient With Treacher Collins Syndrome Bruno Carlo Brevi, MD, Massimiliano Leporati, MD, Enrico Sesenna, MD Abstract: 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. Key Words: Pierre Robin, micrognathia, mandibular distraction, neonates, grade III mandibular deformities, transmandibular distraction device From the Maxillo-Facial Surgery Division, Head and Neck Department, University Hospital of Parma, Parma, Italy. Received June 1, 2014. Accepted for publication August 19, 2014. Address correspondence and reprint requests to Massimiliano Leporati, MD, Maxillo-Facial Surgery Division, Head and Neck Department, University Hospital of Parma, via Gramsci 14, 43100 Parma, Italy; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001303
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P
ierre Robin first described neonatal upper airway obstruction secondary to micrognathia in 1934. He listed 3 criteria, today termed the Robin sequence: micrognathia, glossoptosis, and resultant respiratory insufficiency with or without cleft palate. Micrognathia can cause upper airway obstruction in neonatal patients because of posterior tongue collapse. Most children born with micrognathia are asymptomatic or can be treated with conservative management, such as prone positioning, positive rendering of the nasal airway, and/or nasopharyngeal intubation.1,2 The condition may be caused by an inherent (genetic) syndromic mandibular growth problem or isolated nonsyndromic micrognathia. Some patients experience significant respiratory and/or feeding distress, necessitating aggressive treatment.3 Traditionally, the most commonly used procedures in difficult cases have been tongue-lip adhesion and tracheostomy.4 More recently, bilateral mandibular distraction osteogenesis has become an accepted alternative treatment of the most severe cases of Pierre Robin sequence. This technique has consistently and successfully resolved clinical respiratory and feeding problems. The procedure has the advantage of being truly curative, increasing mandibular projection, advancing the base of the tongue, and widening the oropharyngeal space.5,6 Two types of device have been used for craniofacial osteodistraction: externally and internally placed devices first clinically applied extraoral distraction osteogenesis in children with congenital craniofacial anomalies, such as Nager syndrome.a7–9 Most major centers, including ours, use submerged or semiburied distraction devices to conduct mandibular distraction osteogenesis for management of a compromised neonatal airway. Such devices have major advantages over external instruments, but their application is monodirectional. When a miniaturized internal device is used (and no other type of internal device is appropriate for use in a neonate), the direction of the distraction vector is fixed.10–12 In the current report, we present the case of a neonate with Treacher Collins syndrome who exhibited major respiratory distress that was treated via mandibular distraction osteogenesis. The total absence of an ascending ramus and bilateral condyles (reminiscent of grade III hemifacial microsomia [HFM]) suggested that the use of a regular monodirectional internal distraction device was inappropriate; thus, we positioned an external device via an intraoral approach and anchored its position firmly using 2 transfixing Kirschner wires and 2 bicortical pins.13–15
CLINICAL REPORT A male neonate was referred to our department for evaluation of a severe craniofacial deformity. His Apgar score was 7 in the first minute of life and 8 at minute 5. His weight was 4040 g, his cranial circumference was 35.5 cm, and his height was 54 cm. Developing clinical issues included severe respiratory distress, treated initially with a Mayo tube. Cerebral, cardiac, and abdominal ultrasonographic scans were negative for anatomic malformations. Endoscopic airway evaluation revealed a normal tracheobronchial tree. Computed tomography and magnetic resonance imaging revealed severe mandibular and zygomatic hypoplasia with absence of the mandibular ramus and bilateral condyles, cleft palate, orbital dystrophy, microtia, malformation of the middle ear, lack of an external auditory canal, as well as impairment of the nuclei of the seventh and eighth cranial nerves. Genetic assessment revealed the presence of the Treacher Collins Franceschetti syndrome (Online Mendelian Inheritance in Man 606847) mutation at locus 5q32-q33.1. On day 6 of life, persistent respiratory distress rendered tracheostomy necessary (Figs. 1, 2). The feeding problem was initially managed via gavage, but weight increase was inadequate, and a percutaneous endoscopic gastrostomy tube was placed at the age of 2 months. The case was discussed in a multidisciplinary environment featuring a maxillofacial surgeon, a © 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015
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FIGURE 1. Preoperative lateral view of the patient.
FIGURE 3. Intraoperative image showing the final position of the external distractor.
pediatrician, and an anesthesiologist. We sought to eliminate the tracheostomy tube because long-standing tracheostomy is known to cause problems. When planning distraction, we considered the particular anatomic features of our case. Wide mandibular advancement, adjustment of the angle between the maxillary and mandibular occlusal planes via counterclockwise rotation of the mandibular plane, as well as reconstruction of the absent mandibular ramus were considered necessary. Obviously, achievement of these objectives was impossible using a standard monodirectional semiburied device. We decided to use an external multiplanar instrument and performed mandibular distraction when the infant was 3 months of age.
We used an intraoral approach under general anesthesia to place an external device. Bilateral incisions in the sulcus of the intraoral posterior mandibular buccal region were made to permit access to the bone. We performed subperiosteal dissection, exposing the lateral mandibular body but carefully avoiding any dissection of the most proximal portion of the mandible. We paid meticulous attention to the maintenance of soft tissue and muscle attachments, as well as small bone fragments posterior to the osteotomy line, to maintain blood supply to these regions. We next performed corticotomy of the buccal cortex and external oblique ridge approximately 20 mm from the distal end of the mandible using a side-cutting bur, taking care to avoid injury to the inferior alveolar neurovascular bundle and ensuring continuity of the mandible. Two pairs of parallel fixation pins were next placed anterior and posterior to the corticotomy region. The first pin, a 1.8-mm–diameter Kirschner wire, pierced the skin at the approximate midpoint of the bone segment posterior to the osteotomy line. The wire was driven through the lateral cortex and exited the medial ramus (partially dissected subperiosteally) and the soft tissues medial to the ramus (Fig. 3). The large cleft palate allowed excellent visualization of the pin's passage across the posterior oropharynx in the region of the uvula and the distal soft palate en route to the opposite ramus. The pin first pierced the soft tissues medial to the ramus, then the medial cortex, the ramus, the lateral cortex, and, finally, the skin. The direction of the pin was always parallel to the interpupillary line.15–17 A second Kirschner pin (1.8-mm diameter) was drilled into the skin in the parasymphyseal region, then anteriorly through the mandible to the mental foramen. This procedure was also performed under direct visualization with anterior retraction of the mandibular buccal vestibular tissue. The pin, maintained parallel to the pin that had been previously placed in the posterior region, was advanced through the floor of the
mouth to contact the medial aspect of the mandible in the contralateral parasymphyseal region. Finally, the pin was advanced through the mandible and the lateral soft tissues to exit the skin. The direction of placement was identical for the first and second pins. In other words, the pins were parallel (Figs. 4, 5). The external distraction device was then locked to the pins to mark the required positions of 2 additional pins. One posterior and 1 anterior pin were positioned on either side of the mandible via bicortical drilling, and precise positioning was attained via guidance provided by the rail of the distraction device. We sought to pinch the skin and the subcutaneous tissues together before insertion of the second pin to accommodate soft tissue movement during distraction. The distractor was next provisionally placed, and all screws were tightened. Before lingual corticotomy, the precisely adjusted distractor was removed by loosening only the screws securing the device to the fixation pins. Osteotomy was completed by inserting a chisel into the corticotomy region and applying a light torque to prize the segments apart. Although Monasterio et al15 preserved the inner cortex during surgery and anticipated fracture during distraction, we believe that complete separation of the bony segments at the time of osteotomy is a better approach. The device was repositioned and activated to ensure approximately 4 to 5 mm of bilateral movement of the bony segments then deactivated to allow bone-bone contact. A multiplanar external distractor device was next positioned to allow elongation and manipulation of the mandibular angle. The distraction devices used (Leibinger multiguides) were initially placed in a straight-line (180 degrees) configuration. The buccal sulcus was closed using interrupted absorbable sutures. Distraction commenced on the first postoperative day at a rate of 1.5 mm twice daily. After 20 mm of lengthening, we began counterclockwise rotation (approximately 10 degrees per day) to manipulate the craniocaudal angle between the 2 mandibular segments until a mandibular angle of approximately 90 degrees was attained. We also controlled the extent of transverse movement to avoid excessive condyle lateralization by adjusting the angle of the distractor transversely from 180 degrees to approximately 150 degrees. After a 10-week consolidation period, the devices were removed from the pins under general anesthesia. The pins were then smoothly removed in the absence of any significant tissue resistance or bleeding. Although the length of new bone formation was theoretically 40 mm, the actual length was closer to 35 mm because the proximal segment was closer to the cranial base than initially thought. During the final procedure, we performed posterior hard/soft palatal tissue closure using the standard Von Langenbeck technique while the tracheostomy tube was in place and examined the airway via flexible endoscopy to ensure the absence of granulated tissue. Ten days after
FIGURE 2. Preoperative computed tomographic scan showing severe mandible hypoplasia.
FIGURE 4. Radiologic postoperative control showing the correct position of the distractor.
SURGICAL TECHNIQUE
© 2014 Mutaz B. Habal, MD
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FIGURE 5. Postoperative imaging showing the positioning of the mandibular distractor 5 months after the operation.
FIGURE 7. Postoperative frontal view, 3-month follow-up.
Traditionally, tracheostomy has been regarded as the most effective and definitive treatment option for infants with severe Pierre Robin sequence.18,19 Although tracheostomy is an excellent emergency option for the management of severe upper airway obstruction, longstanding tracheotomy is associated with high levels of morbidity, including tracheomalacia, chronic bronchitis, laryngeal stenosis, and a risk for death from development of a mucus plug or dislodgment of the tracheotomy tube.20–22 Tracheostomy is thus best viewed as a short-term solution to a complex problem associated with long-term morbidity.23,24 Moreover, tracheostomy does not address the anatomic problem responsible for airway obstruction.25 A sound principle of medicine is that every treatment is the least invasive option available under the circumstances. This idea is of particular importance when planning treatment of a patient with airway obstruction caused by isolated Pierre Robin sequence, which is associated with significant mandibular growth during the first year of life. The prediction of mandibular development, extent of “catch-up” mandibular growth, or adult form of maxillomandibular relationship or occlusion is not possible, but the current consensus is that catch-up growth adequate to correct the tonguebase airway obstruction begins at approximately 12 months of age.4 Clearly, such mandibular growth does not occur in syndromic infants with micrognathia because of the intrinsic anomaly. Tracheostomy tubes are difficult to remove in patients with Treacher Collins syndrome, and distraction during childhood is required in almost all instances.21–23 Distraction osteogenesis involves the biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental application of traction. This process is initiated when a traction force is applied to the separate bone segments and continues for as long as the callus tissues are stretched.26
The basic biologic requirements for successful application of distraction osteogenesis include performance of gentle osteotomy with maximum preservation of osteogenic tissues and the periosteal-endosteal blood supply, precise calculation of the direction of distraction, optimization of the rate and rhythm of distraction, as well as planning to allow sufficient time for consolidation before unrestrained functional loading. Initial bony callus formation is required before lengthening is commenced, and this so-called latency phase varies with patient age. Latency is shorter in younger infants. Approximately 2 to 5 days of latency are recommended for children aged 5 to 8 years,14 but lengthening should begin immediately in neonates because of the risk for premature consolidation.5 A similar problem is evident when considering the rate of distraction. Our commencement rate in older patients is usually 0.5 mm twice daily, but we distract the bone at least 2 mm daily in infants. Some authors have recommended a distraction rate of greater than 4 mm daily to prevent premature consolidation. Patients with grade III HFM appear not to have been considered suitable candidates for mandibular distraction osteogenesis in previous studies. Other reviews of the records of patients with Treacher Collins syndrome (with the Pierre Robin sequence) have led authors to conclude that neonatal distraction, although not used, should be considered in severe cases to avoid or terminate tracheostomy.25,26 The bony mandibular remnant posterior to the molars is extremely small in patients lacking an ascending ramus, which limits the amount of bone available for device fixation. Moreover, the small bone fragment posterior to the distraction gap is at risk for necrosis because of abnormalities in muscle and soft tissue attachments associated with an inadequate blood supply.27 Thus, the standard of care for reconstruction of the ascending ramus and the temporomandibular joint has typically involved grafting of autogenous bone and cartilage, usually featuring a rib graft. The cartilaginous portion of the graft is carved to resemble a condyle, and the bony portion is fixed to the remnant of the mandibular ramus or body.28 However, Polley and Figueroa27 as well as Cavaliere and Buchman29 described osteogenesis in a total of 3 patients with grade III HFM. The authors concluded that this procedure was a viable reconstructive option for patients with grade III mandibular deformities and that it offered many advantages over other techniques. We reviewed previous reports and followed the advice of Thompson et al,23 who suggested that neonatal distraction should be considered for the treatment of Treacher Collins syndrome to avoid
FIGURE 6. Three-dimensional computed tomographic scan showing the correct three-dimensional development of the mandible after the removal of the distractor (6-mo follow-up).
FIGURE 8. Lateral postoperative view.
this procedure, when the infant was 6 months of age, the tracheostomy tube was finally removed (Fig. 6). No problem was encountered. The postoperative course was uneventful, with spontaneous closure of the tracheostomy site and no evident airway problem when the infant was awake or asleep. After a 16-month follow-up period, the good respiratory outcome had been maintained but the feeding problem persisted. Although the child's swallowing ability was improving at the time of writing, he remained partially dependent on percutaneous endoscopic gastrostomy, probably because of a lack of muscle coordination (Figs. 7, 8).
DISCUSSION
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The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015
tracheostomy. Although distraction osteogenesis is becoming accepted as a treatment modality, the details of the technique performed on neonates may vary considerably among surgeons. Currently, 2 principal types of distraction device, external and internal, are available.30,31 The use of external devices has a long history, whereas internal devices are relatively new. The major advantage of an external device is the ability to apply multidirectional vectors during the distraction phase. The essential components of such a device are an angulation joint and 2 geared rods that are variable in length. In bidirectional devices, the middle joint is a simple hinge, whereas it is a multifunctional double ball in multidirectional devices.17,32 Thus, bony segments can be moved in almost any direction during distraction with a multidirectional device; in other words, multiplanar distraction to correct mandibular asymmetry and/or malformation can be achieved by applying force in a linear, angular, or varus-valgus direction. External devices are fixed to the bone using percutaneous pins connected externally to a distraction rod that, when activated, pushes the bone segments apart to allow new bone formation. These devices are classified as unidirectional, bidirectional, or three dimensional according to the direction of lengthening. Internal devices are becoming more popular because external devices are cumbersome during distraction and consolidation. One disadvantage of earlier internal distractors was that a second period of general anesthesia was required at the time of device removal. We use internal devices to treat most of our patients who require distraction (eg, those with nonsyndromic Pierre Robin sequence or HFM), and we have recently used resorbable devices that do not require surgical removal.20,33 A major disadvantage of internal distraction devices is the unidirectional or linear nature of movement, which requires meticulous planning of the osteotomy and distractor placement. In the case presented here, the mandibular shape and absence of a ramus prevented us from using a unidirectional device. Linear distraction would have produced a mandible that completely lacked a mandibular angle, an abnormal maxillomandibular relationship, a huge open bite, and insufficient mandibular advancement. Thus, we decided to use a multidirectional external device (Leibinger multiguide) and adopted technical expedients to overcome some typical problems encountered during distraction in neonates.30 First, neonatal bone is soft and does not allow firm placement of external devices fixed with pins, even with the use of bicortical fixation. Biomechanical stability cannot be achieved with the unilateral placement of distraction pins on the mandible. To overcome this problem, we inserted 2 Kirschner wires to transfix the proximal and distal segments. These pins pierced the skin and the underlying mandible from either side and were directed to engage the contralateral bone and emerge through the skin. Our fundamental aim was to eliminate the possibility of destabilization, which is often associated with the unilateral use of classic pins and is caused by the weight of the distractor and force applied during distraction. The distraction force is magnified by a leverage effect proportionate to the working distance between the distractor and the bone.
FIGURE 9. Physical explication of the “pin loosening.” In this case, the forces applied to the pin (gravity force and distraction force) produce a torque. This torque force makes the pin turn around its axis, increasing the risk for pin loss.
Brief Clinical Studies
FIGURE 10. Physical explication of the double-pin mechanism of action. In case of double pin, the Kirschner wire makes the 2 pins become a unique “firm unit.” In this situation, the torque on one side is balanced by the torque on the other side, creating an equilibrium situation (if the displacement vectors and the forces are the same).
Not surprisingly, the literature is replete with reports of failure caused by pin loosening. The application of 2 distractors to the same transfixed pins eliminates almost all of the abovementioned destabilizing elements (Figs. 9, 10). Usually, a single transfixed pin is inserted into each portion of the mandible; 1 pin is inserted proximal and another distal to the osteotomy line (Miloro5 2010 and Farina et al,31 2011). This technique does not allow careful management of the angle between the 2 bone segments during distraction because of the clockwise rotation of the mandibular body around the pin. The most frequent complication associated with this constraint is anterior open bite, which is managed by encouraging feeding or at least nippling during distraction to maintain the vertical position of the anterior mandibular segment or by applying an elastic headband.5,31,32 Although such measures may be effective for small but essentially normally shaped mandibles, they are not effective in patients with severe mandibular malformation associated with the absence of a ramus. The placement of an additional pin in each mandibular segment enabled us to move the bone segments in 3 dimensions and facilitated surgical planning. After a linear extension of 20 mm had been achieved, we created a 90-degree angle between the separated bone segments and continued distraction for an additional 20 mm. Thus, we completely changed the shape of the mandible, created a pseudocondyle, and achieved a nearly normal mandibular angle. To our knowledge, few authors have used osteodistraction to treat neonates in respiratory distress affected by Treacher Collins syndrome, and no group has used Kirschner wires transfixed with he aid of additional pins to control distraction vectors.3,27,29 The required consolidation period remains controversial. Some authors have proposed that 2 days is required for every day of distraction, whereas others have suggested that the required period of consolidation depends on patient age and may be determined by the extent of bone metabolism, as revealed by scintigraphy.33 We removed the distractor 8 weeks after placement, although 4 weeks may be sufficient in very young (aged < 1 y) patients.8,34
CONCLUSIONS Mandibular distraction is a useful surgical treatment of patients with Pierre Robin sequence and represents an alternative to tracheostomy. Intraoral devices have largely replaced earlier unidirectional extraoral devices and should be used when possible. In addition, the internal devices are more acceptable to parents and do not scar the skin. However, all existing intraoral devices suitable for use in neonates allow the application of only linear force. In severe instances of hypoplasticity, or when three-dimensional control of force vectors or gonial angle control is necessary, the use of bidirectional or multidirectional extraoral devices may be required. The quality of the anchorage obtained with the aid of Kirschner wires transfixed to the distal mandibular segment and symphysis is a critical factor in procedural success. When such devices are used to treat neonates, they absolutely must be stable. Moreover, the fixation of a second pin in each bone segment allows
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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the modification of force-vector orientation and the molding of a newly formed mandible.
REFERENCES 1. Robin P. La chute de la base de la langue consideree comme une nouvelle cause de gene dans la respiration nasopharyngienne. Bull Acad Med Paris 1923;89:37–41 2. Meyer AC, Michael EL, Sampson DE, et al. Airway interventions in children with Pierre Robin sequence. Otolaryngol Head Neck Surg 2008;138:782–787 3. Morovic CG, Monasterio L. Distraction osteogenesis for obstructive apneas in patients with congenital malformation. Plast Reconstr Surg 2000;105:2324–2330 4. Schaefer RB, Stadler JA, Gosain AK. To distract or not to distract: an algorithm for airway management in isolated Pierre Robin sequence. Plast Reconstr Surg 2004;113:1113–1125 5. Miloro M. Mandibular distraction osteogenesis for pediatric airway management. J Oral Maxillofac Surg 2010;68:1512–1523 6. Hong P, McNeil M, Kearns D, et al. Mandibular distraction osteogenesis in children with Pierre Robin sequence: impact on health related quality of life. Int J Pediatr Otorhinolaryngol 2012;76:1159–1163 7. Denny A, Kalantarian B. Mandibular distraction in neonates: a strategy to avoid tracheostomy. Plast Reconstr Surg 2002;109:896–904 8. Denny A, Amm C. New technique for airway correction in neonates with severe Pierre Robin sequence. J Pediatr 2005;147:97–101 9. Burstein FD, Williams JK. Mandibular distraction osteogenesis in Pierre Robin sequence: application of a new internal single-stage resorbable device. Plast Reconstr Surg 2005;115:61–67 10. Burstein FD. Resorbable distraction of the mandible: technical evolution and clinical experience. J Craniofac Surg 2008;19:637–643 11. McCarty JG, Schreiber J, Karp N, et al. Lengthening of the human mandible by gradual distraction. Plast Reconstr Surg 1992;89:1–8 12. Sesenna E, Magri As, Magnani C, et al. Mandibular distraction in neonates: indications, techniques, results. Ital J Pediatr 2012;38:37 13. Denny A, Amm CA, Schaefer RB. Outcomes of tongue-lip adhesion for neonatal respiratory distress caused by Pierre Robin sequence. J Craniofac Surg 2004;15:819–823 14. Rubio-Bueno P, Padron A, Villa E, et al. Distraction osteogenesis of the ascending ramus for mandibular hypoplasia using extraoral or intraoral devices: a report of 8 cases. J Oral Maxillofac Surg 2000;58:593–599 15. Monasterio F, Drucker M, Molina F, et al. Distraction osteogenesis in Pierre Robin sequence and related respiratory problems in children. J Craniofac Surg 2002;13:79–83 16. Hong P. A clinical narrative review of mandibular distraction osteogenesis in neonates with Pierre Robin sequence. Int J Pediatr Otorhinolaryngol 2011;75:985–991 17. St-Hilaire H, Buchbinder D. Maxillofacial pathology and management of Pierre Robin sequence. Otolaryngol Clin North Am 2000; 33:1241–1256 18. Cousley RR, Calvert ML. Current concepts in the understanding and management of hemifacial microsomia. Br J Plast Surg 1997; 50:536–551 19. Chigurupati R, Myall R. Airway management in babies with micrognathia: the case against early distraction. J Oral Maxillofac Surg 2005;63:1209–1215 20. Izadi K, Yellon R, Mandell DL, et al. Bradley: correction of upper airway obstruction in the newborn with internal mandibular distraction osteogenesis. J Craniofac Surg 2003;14:493–499 21. Hermann NV, Kreinborg S, Darvann TA, et al. Early craniofacial morphology and growth in children with nonsyndromic Robin sequence. Cleft Palate Craniofac Surg 2003;40:131–143 22. Scott A, Tibesar R, Lander TA, et al. Mandibular distraction osteogenesis in infants younger than 3 months. Arch Facial Plast Surg 2011;13:173–179 23. Thompson JT, Anderson PJ, David DJ. Treacher Collins syndrome: protocol management from birth to maturity. J Craniofac Surg 2009;20:2028–2035
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24. Vegter F, Hage JJ, Mulder JW. Pierre Robin syndrome: mandibular growth during the first year of life. Ann Plast Surg 1999;42:154–157 25. Judge B, Hamlar D, Rimell FL. Mandibular distraction osteogenesis in a neonate. Arch Otolaryngol Head Neck Surg 1999;125:1029–1032 26. Villani S, Brevi B, Sesenna E. Distraction osteogenesis in a newborn infant with Pierre Robin sequence. Mund Kiefer Gesichtschir 2002;6:197–201 27. Polley JW, Figueroa AA. Distraction osteogenesis: its application in severe mandibular deformities in hemifacial microsomia. J Craniofac Surg 1997;8:422–430 28. Denny A, Talisman R, Hanson P, et al. Distraction osteogenesis in very young patients to correct airway obstruction. Plast Reconstr Surg 2001:302–311 29. Cavaliere CC, Buchman SR. Mandibular distraction in the absence of an ascending ramus and condyle. J Craniofac Surg 2002; 13:527–532 30. Gateno J, Kim KW, Lalani Z, et al. Biomechanical evaluation of the pins of mandibular external distractor. J Oral Maxillofac Surg 2004;62:1259 31. Farina R, Castellon L, Nagelash E, et al. A new way to anchor the external device in mandibular distraction: three case reports with a Pierre Robin sequence. Int J Oral Maxillofac Surg 2011; 40:471–474 32. Molina F. Mandibular distraction osteogenesis: a clinical experience of the last 17 years. J Craniofac Surg 2009;20:1794–1800 33. Felemovicius J, Ortiz Monasterio F, Gomez Radillo LS, et al. Determining the optimal time for consolidation after distraction osteogenesis. J Craniofac Surg 2000;11:430–436 34. Sadakah AA, Elshall MA, Farhat AA. Bilateral intraoral distraction osteogenesis for the management of severe congenital mandibular hypopoplasia in early childhood. J Craniomaxillofac Surg 2009;37:216–224
Skin Tension Related to Tension Reduction Sutures Kun Hwang, MD, PhD,* Han Joon Kim, MD,* Kyung Yong Kim, MD, PhD,† Seung Ho Han, MD, DMSc,† Se Jin Hwang‡ Abstract: The aim of this study was to compare the skin tension of several fascial/subcutaneous tensile reduction sutures. Six upper limbs and 8 lower limbs of 4 fresh cadavers were used. At the deltoid area (10 cm below the palpable acromion) and lateral thigh (midpoint from the palpable greater trochanter to the lateral border of the patella), and within a 3 6-cm fusiform area of skin, subcutaneous tissue defects were created. At the midpoint of the defect, a no. 5 silk suture was passed through the dermis at a 5-mm margin of From the *Department of Plastic Surgery, Inha University School of Medicine, Incheon; †Department of Anatomy, College of Medicine, ChungAng University, Seoul; and ‡Inha Research Institute for Medical Science, Incheon, Korea. Received June 26, 2014. Accepted for publication August 19, 2014. Address correspondence and reprint requests to Dr. Kun Hwang, Department of Plastic Surgery, Inha University School of Medicine, 27 Inhang-ro, Jung-gu, Incheon, 400-711, Korea; E-mail: [email protected] This work was supported by a grant from Inha University (INHA Research Grant). The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001311
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
Brief Clinical Studies
4.
5.
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thumbs, hypoplastic genitalia, and distinctive facies. Am J Med Genet A 2010;152:1915–1918 Molina FD, Santos FC, Falleiros LR Jr, et al. Microscopical evaluation of extracellular matrix and its relation to the palatopharyngeal muscle in obstructive sleep apnea. Microsc Res Tech 2011;74:430–439 Pereira V, Sell D, Ponniah A, et al. Midface osteotomy versus distraction: the effect on speech, nasality, and velopharyngeal function in craniofacial dysostosis. Cleft Palate Craniofac J 2008;45:353–363 Nohara K, Tachimura T, Wada T. Prediction of deterioration of velopharyngeal function associated with maxillary advancement using electromyography of levator veli palatini muscle. Cleft Palate Craniofac J 2006;43:174–178 Guyette TW, Polley JW, Figueroa A, et al. Changes in speech following maxillary distraction osteogenesis. Cleft Palate Craniofac J 2001; 38:199–205 Mink van der Molen AB, Janssen K, Specken TF, et al. The modified Honig velopharyngoplasty—a new technique to treat hypernasality by palatal lengthening. J Plast Reconstr Aesthet Surg 2009;62:646–649 Lavanya T, Cohen M, Gandhi SV, et al. A case of a Dandy-Walker variant: the importance of a multidisciplinary team approach using complementary techniques to obtain accurate diagnostic information. Br J Radiol 2008;81:242–245 Janulewicz J, Costello BJ, Buckley MJ, et al. The effects of Le Fort I osteotomies on velopharyngeal and speech functions in cleft patients. J Oral Maxillofac Surg 2004;62:308–314
Neonatal Mandibular Distraction in a Patient With Treacher Collins Syndrome Bruno Carlo Brevi, MD, Massimiliano Leporati, MD, Enrico Sesenna, MD Abstract: 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. Key Words: Pierre Robin, micrognathia, mandibular distraction, neonates, grade III mandibular deformities, transmandibular distraction device From the Maxillo-Facial Surgery Division, Head and Neck Department, University Hospital of Parma, Parma, Italy. Received June 1, 2014. Accepted for publication August 19, 2014. Address correspondence and reprint requests to Massimiliano Leporati, MD, Maxillo-Facial Surgery Division, Head and Neck Department, University Hospital of Parma, via Gramsci 14, 43100 Parma, Italy; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001303
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P
ierre Robin first described neonatal upper airway obstruction secondary to micrognathia in 1934. He listed 3 criteria, today termed the Robin sequence: micrognathia, glossoptosis, and resultant respiratory insufficiency with or without cleft palate. Micrognathia can cause upper airway obstruction in neonatal patients because of posterior tongue collapse. Most children born with micrognathia are asymptomatic or can be treated with conservative management, such as prone positioning, positive rendering of the nasal airway, and/or nasopharyngeal intubation.1,2 The condition may be caused by an inherent (genetic) syndromic mandibular growth problem or isolated nonsyndromic micrognathia. Some patients experience significant respiratory and/or feeding distress, necessitating aggressive treatment.3 Traditionally, the most commonly used procedures in difficult cases have been tongue-lip adhesion and tracheostomy.4 More recently, bilateral mandibular distraction osteogenesis has become an accepted alternative treatment of the most severe cases of Pierre Robin sequence. This technique has consistently and successfully resolved clinical respiratory and feeding problems. The procedure has the advantage of being truly curative, increasing mandibular projection, advancing the base of the tongue, and widening the oropharyngeal space.5,6 Two types of device have been used for craniofacial osteodistraction: externally and internally placed devices first clinically applied extraoral distraction osteogenesis in children with congenital craniofacial anomalies, such as Nager syndrome.a7–9 Most major centers, including ours, use submerged or semiburied distraction devices to conduct mandibular distraction osteogenesis for management of a compromised neonatal airway. Such devices have major advantages over external instruments, but their application is monodirectional. When a miniaturized internal device is used (and no other type of internal device is appropriate for use in a neonate), the direction of the distraction vector is fixed.10–12 In the current report, we present the case of a neonate with Treacher Collins syndrome who exhibited major respiratory distress that was treated via mandibular distraction osteogenesis. The total absence of an ascending ramus and bilateral condyles (reminiscent of grade III hemifacial microsomia [HFM]) suggested that the use of a regular monodirectional internal distraction device was inappropriate; thus, we positioned an external device via an intraoral approach and anchored its position firmly using 2 transfixing Kirschner wires and 2 bicortical pins.13–15
CLINICAL REPORT A male neonate was referred to our department for evaluation of a severe craniofacial deformity. His Apgar score was 7 in the first minute of life and 8 at minute 5. His weight was 4040 g, his cranial circumference was 35.5 cm, and his height was 54 cm. Developing clinical issues included severe respiratory distress, treated initially with a Mayo tube. Cerebral, cardiac, and abdominal ultrasonographic scans were negative for anatomic malformations. Endoscopic airway evaluation revealed a normal tracheobronchial tree. Computed tomography and magnetic resonance imaging revealed severe mandibular and zygomatic hypoplasia with absence of the mandibular ramus and bilateral condyles, cleft palate, orbital dystrophy, microtia, malformation of the middle ear, lack of an external auditory canal, as well as impairment of the nuclei of the seventh and eighth cranial nerves. Genetic assessment revealed the presence of the Treacher Collins Franceschetti syndrome (Online Mendelian Inheritance in Man 606847) mutation at locus 5q32-q33.1. On day 6 of life, persistent respiratory distress rendered tracheostomy necessary (Figs. 1, 2). The feeding problem was initially managed via gavage, but weight increase was inadequate, and a percutaneous endoscopic gastrostomy tube was placed at the age of 2 months. The case was discussed in a multidisciplinary environment featuring a maxillofacial surgeon, a © 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015
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FIGURE 1. Preoperative lateral view of the patient.
FIGURE 3. Intraoperative image showing the final position of the external distractor.
pediatrician, and an anesthesiologist. We sought to eliminate the tracheostomy tube because long-standing tracheostomy is known to cause problems. When planning distraction, we considered the particular anatomic features of our case. Wide mandibular advancement, adjustment of the angle between the maxillary and mandibular occlusal planes via counterclockwise rotation of the mandibular plane, as well as reconstruction of the absent mandibular ramus were considered necessary. Obviously, achievement of these objectives was impossible using a standard monodirectional semiburied device. We decided to use an external multiplanar instrument and performed mandibular distraction when the infant was 3 months of age.
We used an intraoral approach under general anesthesia to place an external device. Bilateral incisions in the sulcus of the intraoral posterior mandibular buccal region were made to permit access to the bone. We performed subperiosteal dissection, exposing the lateral mandibular body but carefully avoiding any dissection of the most proximal portion of the mandible. We paid meticulous attention to the maintenance of soft tissue and muscle attachments, as well as small bone fragments posterior to the osteotomy line, to maintain blood supply to these regions. We next performed corticotomy of the buccal cortex and external oblique ridge approximately 20 mm from the distal end of the mandible using a side-cutting bur, taking care to avoid injury to the inferior alveolar neurovascular bundle and ensuring continuity of the mandible. Two pairs of parallel fixation pins were next placed anterior and posterior to the corticotomy region. The first pin, a 1.8-mm–diameter Kirschner wire, pierced the skin at the approximate midpoint of the bone segment posterior to the osteotomy line. The wire was driven through the lateral cortex and exited the medial ramus (partially dissected subperiosteally) and the soft tissues medial to the ramus (Fig. 3). The large cleft palate allowed excellent visualization of the pin's passage across the posterior oropharynx in the region of the uvula and the distal soft palate en route to the opposite ramus. The pin first pierced the soft tissues medial to the ramus, then the medial cortex, the ramus, the lateral cortex, and, finally, the skin. The direction of the pin was always parallel to the interpupillary line.15–17 A second Kirschner pin (1.8-mm diameter) was drilled into the skin in the parasymphyseal region, then anteriorly through the mandible to the mental foramen. This procedure was also performed under direct visualization with anterior retraction of the mandibular buccal vestibular tissue. The pin, maintained parallel to the pin that had been previously placed in the posterior region, was advanced through the floor of the
mouth to contact the medial aspect of the mandible in the contralateral parasymphyseal region. Finally, the pin was advanced through the mandible and the lateral soft tissues to exit the skin. The direction of placement was identical for the first and second pins. In other words, the pins were parallel (Figs. 4, 5). The external distraction device was then locked to the pins to mark the required positions of 2 additional pins. One posterior and 1 anterior pin were positioned on either side of the mandible via bicortical drilling, and precise positioning was attained via guidance provided by the rail of the distraction device. We sought to pinch the skin and the subcutaneous tissues together before insertion of the second pin to accommodate soft tissue movement during distraction. The distractor was next provisionally placed, and all screws were tightened. Before lingual corticotomy, the precisely adjusted distractor was removed by loosening only the screws securing the device to the fixation pins. Osteotomy was completed by inserting a chisel into the corticotomy region and applying a light torque to prize the segments apart. Although Monasterio et al15 preserved the inner cortex during surgery and anticipated fracture during distraction, we believe that complete separation of the bony segments at the time of osteotomy is a better approach. The device was repositioned and activated to ensure approximately 4 to 5 mm of bilateral movement of the bony segments then deactivated to allow bone-bone contact. A multiplanar external distractor device was next positioned to allow elongation and manipulation of the mandibular angle. The distraction devices used (Leibinger multiguides) were initially placed in a straight-line (180 degrees) configuration. The buccal sulcus was closed using interrupted absorbable sutures. Distraction commenced on the first postoperative day at a rate of 1.5 mm twice daily. After 20 mm of lengthening, we began counterclockwise rotation (approximately 10 degrees per day) to manipulate the craniocaudal angle between the 2 mandibular segments until a mandibular angle of approximately 90 degrees was attained. We also controlled the extent of transverse movement to avoid excessive condyle lateralization by adjusting the angle of the distractor transversely from 180 degrees to approximately 150 degrees. After a 10-week consolidation period, the devices were removed from the pins under general anesthesia. The pins were then smoothly removed in the absence of any significant tissue resistance or bleeding. Although the length of new bone formation was theoretically 40 mm, the actual length was closer to 35 mm because the proximal segment was closer to the cranial base than initially thought. During the final procedure, we performed posterior hard/soft palatal tissue closure using the standard Von Langenbeck technique while the tracheostomy tube was in place and examined the airway via flexible endoscopy to ensure the absence of granulated tissue. Ten days after
FIGURE 2. Preoperative computed tomographic scan showing severe mandible hypoplasia.
FIGURE 4. Radiologic postoperative control showing the correct position of the distractor.
SURGICAL TECHNIQUE
© 2014 Mutaz B. Habal, MD
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FIGURE 5. Postoperative imaging showing the positioning of the mandibular distractor 5 months after the operation.
FIGURE 7. Postoperative frontal view, 3-month follow-up.
Traditionally, tracheostomy has been regarded as the most effective and definitive treatment option for infants with severe Pierre Robin sequence.18,19 Although tracheostomy is an excellent emergency option for the management of severe upper airway obstruction, longstanding tracheotomy is associated with high levels of morbidity, including tracheomalacia, chronic bronchitis, laryngeal stenosis, and a risk for death from development of a mucus plug or dislodgment of the tracheotomy tube.20–22 Tracheostomy is thus best viewed as a short-term solution to a complex problem associated with long-term morbidity.23,24 Moreover, tracheostomy does not address the anatomic problem responsible for airway obstruction.25 A sound principle of medicine is that every treatment is the least invasive option available under the circumstances. This idea is of particular importance when planning treatment of a patient with airway obstruction caused by isolated Pierre Robin sequence, which is associated with significant mandibular growth during the first year of life. The prediction of mandibular development, extent of “catch-up” mandibular growth, or adult form of maxillomandibular relationship or occlusion is not possible, but the current consensus is that catch-up growth adequate to correct the tonguebase airway obstruction begins at approximately 12 months of age.4 Clearly, such mandibular growth does not occur in syndromic infants with micrognathia because of the intrinsic anomaly. Tracheostomy tubes are difficult to remove in patients with Treacher Collins syndrome, and distraction during childhood is required in almost all instances.21–23 Distraction osteogenesis involves the biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental application of traction. This process is initiated when a traction force is applied to the separate bone segments and continues for as long as the callus tissues are stretched.26
The basic biologic requirements for successful application of distraction osteogenesis include performance of gentle osteotomy with maximum preservation of osteogenic tissues and the periosteal-endosteal blood supply, precise calculation of the direction of distraction, optimization of the rate and rhythm of distraction, as well as planning to allow sufficient time for consolidation before unrestrained functional loading. Initial bony callus formation is required before lengthening is commenced, and this so-called latency phase varies with patient age. Latency is shorter in younger infants. Approximately 2 to 5 days of latency are recommended for children aged 5 to 8 years,14 but lengthening should begin immediately in neonates because of the risk for premature consolidation.5 A similar problem is evident when considering the rate of distraction. Our commencement rate in older patients is usually 0.5 mm twice daily, but we distract the bone at least 2 mm daily in infants. Some authors have recommended a distraction rate of greater than 4 mm daily to prevent premature consolidation. Patients with grade III HFM appear not to have been considered suitable candidates for mandibular distraction osteogenesis in previous studies. Other reviews of the records of patients with Treacher Collins syndrome (with the Pierre Robin sequence) have led authors to conclude that neonatal distraction, although not used, should be considered in severe cases to avoid or terminate tracheostomy.25,26 The bony mandibular remnant posterior to the molars is extremely small in patients lacking an ascending ramus, which limits the amount of bone available for device fixation. Moreover, the small bone fragment posterior to the distraction gap is at risk for necrosis because of abnormalities in muscle and soft tissue attachments associated with an inadequate blood supply.27 Thus, the standard of care for reconstruction of the ascending ramus and the temporomandibular joint has typically involved grafting of autogenous bone and cartilage, usually featuring a rib graft. The cartilaginous portion of the graft is carved to resemble a condyle, and the bony portion is fixed to the remnant of the mandibular ramus or body.28 However, Polley and Figueroa27 as well as Cavaliere and Buchman29 described osteogenesis in a total of 3 patients with grade III HFM. The authors concluded that this procedure was a viable reconstructive option for patients with grade III mandibular deformities and that it offered many advantages over other techniques. We reviewed previous reports and followed the advice of Thompson et al,23 who suggested that neonatal distraction should be considered for the treatment of Treacher Collins syndrome to avoid
FIGURE 6. Three-dimensional computed tomographic scan showing the correct three-dimensional development of the mandible after the removal of the distractor (6-mo follow-up).
FIGURE 8. Lateral postoperative view.
this procedure, when the infant was 6 months of age, the tracheostomy tube was finally removed (Fig. 6). No problem was encountered. The postoperative course was uneventful, with spontaneous closure of the tracheostomy site and no evident airway problem when the infant was awake or asleep. After a 16-month follow-up period, the good respiratory outcome had been maintained but the feeding problem persisted. Although the child's swallowing ability was improving at the time of writing, he remained partially dependent on percutaneous endoscopic gastrostomy, probably because of a lack of muscle coordination (Figs. 7, 8).
DISCUSSION
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The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015
tracheostomy. Although distraction osteogenesis is becoming accepted as a treatment modality, the details of the technique performed on neonates may vary considerably among surgeons. Currently, 2 principal types of distraction device, external and internal, are available.30,31 The use of external devices has a long history, whereas internal devices are relatively new. The major advantage of an external device is the ability to apply multidirectional vectors during the distraction phase. The essential components of such a device are an angulation joint and 2 geared rods that are variable in length. In bidirectional devices, the middle joint is a simple hinge, whereas it is a multifunctional double ball in multidirectional devices.17,32 Thus, bony segments can be moved in almost any direction during distraction with a multidirectional device; in other words, multiplanar distraction to correct mandibular asymmetry and/or malformation can be achieved by applying force in a linear, angular, or varus-valgus direction. External devices are fixed to the bone using percutaneous pins connected externally to a distraction rod that, when activated, pushes the bone segments apart to allow new bone formation. These devices are classified as unidirectional, bidirectional, or three dimensional according to the direction of lengthening. Internal devices are becoming more popular because external devices are cumbersome during distraction and consolidation. One disadvantage of earlier internal distractors was that a second period of general anesthesia was required at the time of device removal. We use internal devices to treat most of our patients who require distraction (eg, those with nonsyndromic Pierre Robin sequence or HFM), and we have recently used resorbable devices that do not require surgical removal.20,33 A major disadvantage of internal distraction devices is the unidirectional or linear nature of movement, which requires meticulous planning of the osteotomy and distractor placement. In the case presented here, the mandibular shape and absence of a ramus prevented us from using a unidirectional device. Linear distraction would have produced a mandible that completely lacked a mandibular angle, an abnormal maxillomandibular relationship, a huge open bite, and insufficient mandibular advancement. Thus, we decided to use a multidirectional external device (Leibinger multiguide) and adopted technical expedients to overcome some typical problems encountered during distraction in neonates.30 First, neonatal bone is soft and does not allow firm placement of external devices fixed with pins, even with the use of bicortical fixation. Biomechanical stability cannot be achieved with the unilateral placement of distraction pins on the mandible. To overcome this problem, we inserted 2 Kirschner wires to transfix the proximal and distal segments. These pins pierced the skin and the underlying mandible from either side and were directed to engage the contralateral bone and emerge through the skin. Our fundamental aim was to eliminate the possibility of destabilization, which is often associated with the unilateral use of classic pins and is caused by the weight of the distractor and force applied during distraction. The distraction force is magnified by a leverage effect proportionate to the working distance between the distractor and the bone.
FIGURE 9. Physical explication of the “pin loosening.” In this case, the forces applied to the pin (gravity force and distraction force) produce a torque. This torque force makes the pin turn around its axis, increasing the risk for pin loss.
Brief Clinical Studies
FIGURE 10. Physical explication of the double-pin mechanism of action. In case of double pin, the Kirschner wire makes the 2 pins become a unique “firm unit.” In this situation, the torque on one side is balanced by the torque on the other side, creating an equilibrium situation (if the displacement vectors and the forces are the same).
Not surprisingly, the literature is replete with reports of failure caused by pin loosening. The application of 2 distractors to the same transfixed pins eliminates almost all of the abovementioned destabilizing elements (Figs. 9, 10). Usually, a single transfixed pin is inserted into each portion of the mandible; 1 pin is inserted proximal and another distal to the osteotomy line (Miloro5 2010 and Farina et al,31 2011). This technique does not allow careful management of the angle between the 2 bone segments during distraction because of the clockwise rotation of the mandibular body around the pin. The most frequent complication associated with this constraint is anterior open bite, which is managed by encouraging feeding or at least nippling during distraction to maintain the vertical position of the anterior mandibular segment or by applying an elastic headband.5,31,32 Although such measures may be effective for small but essentially normally shaped mandibles, they are not effective in patients with severe mandibular malformation associated with the absence of a ramus. The placement of an additional pin in each mandibular segment enabled us to move the bone segments in 3 dimensions and facilitated surgical planning. After a linear extension of 20 mm had been achieved, we created a 90-degree angle between the separated bone segments and continued distraction for an additional 20 mm. Thus, we completely changed the shape of the mandible, created a pseudocondyle, and achieved a nearly normal mandibular angle. To our knowledge, few authors have used osteodistraction to treat neonates in respiratory distress affected by Treacher Collins syndrome, and no group has used Kirschner wires transfixed with he aid of additional pins to control distraction vectors.3,27,29 The required consolidation period remains controversial. Some authors have proposed that 2 days is required for every day of distraction, whereas others have suggested that the required period of consolidation depends on patient age and may be determined by the extent of bone metabolism, as revealed by scintigraphy.33 We removed the distractor 8 weeks after placement, although 4 weeks may be sufficient in very young (aged < 1 y) patients.8,34
CONCLUSIONS Mandibular distraction is a useful surgical treatment of patients with Pierre Robin sequence and represents an alternative to tracheostomy. Intraoral devices have largely replaced earlier unidirectional extraoral devices and should be used when possible. In addition, the internal devices are more acceptable to parents and do not scar the skin. However, all existing intraoral devices suitable for use in neonates allow the application of only linear force. In severe instances of hypoplasticity, or when three-dimensional control of force vectors or gonial angle control is necessary, the use of bidirectional or multidirectional extraoral devices may be required. The quality of the anchorage obtained with the aid of Kirschner wires transfixed to the distal mandibular segment and symphysis is a critical factor in procedural success. When such devices are used to treat neonates, they absolutely must be stable. Moreover, the fixation of a second pin in each bone segment allows
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Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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the modification of force-vector orientation and the molding of a newly formed mandible.
REFERENCES 1. Robin P. La chute de la base de la langue consideree comme une nouvelle cause de gene dans la respiration nasopharyngienne. Bull Acad Med Paris 1923;89:37–41 2. Meyer AC, Michael EL, Sampson DE, et al. Airway interventions in children with Pierre Robin sequence. Otolaryngol Head Neck Surg 2008;138:782–787 3. Morovic CG, Monasterio L. Distraction osteogenesis for obstructive apneas in patients with congenital malformation. Plast Reconstr Surg 2000;105:2324–2330 4. Schaefer RB, Stadler JA, Gosain AK. To distract or not to distract: an algorithm for airway management in isolated Pierre Robin sequence. Plast Reconstr Surg 2004;113:1113–1125 5. Miloro M. Mandibular distraction osteogenesis for pediatric airway management. J Oral Maxillofac Surg 2010;68:1512–1523 6. Hong P, McNeil M, Kearns D, et al. Mandibular distraction osteogenesis in children with Pierre Robin sequence: impact on health related quality of life. Int J Pediatr Otorhinolaryngol 2012;76:1159–1163 7. Denny A, Kalantarian B. Mandibular distraction in neonates: a strategy to avoid tracheostomy. Plast Reconstr Surg 2002;109:896–904 8. Denny A, Amm C. New technique for airway correction in neonates with severe Pierre Robin sequence. J Pediatr 2005;147:97–101 9. Burstein FD, Williams JK. Mandibular distraction osteogenesis in Pierre Robin sequence: application of a new internal single-stage resorbable device. Plast Reconstr Surg 2005;115:61–67 10. Burstein FD. Resorbable distraction of the mandible: technical evolution and clinical experience. J Craniofac Surg 2008;19:637–643 11. McCarty JG, Schreiber J, Karp N, et al. Lengthening of the human mandible by gradual distraction. Plast Reconstr Surg 1992;89:1–8 12. Sesenna E, Magri As, Magnani C, et al. Mandibular distraction in neonates: indications, techniques, results. Ital J Pediatr 2012;38:37 13. Denny A, Amm CA, Schaefer RB. Outcomes of tongue-lip adhesion for neonatal respiratory distress caused by Pierre Robin sequence. J Craniofac Surg 2004;15:819–823 14. Rubio-Bueno P, Padron A, Villa E, et al. Distraction osteogenesis of the ascending ramus for mandibular hypoplasia using extraoral or intraoral devices: a report of 8 cases. J Oral Maxillofac Surg 2000;58:593–599 15. Monasterio F, Drucker M, Molina F, et al. Distraction osteogenesis in Pierre Robin sequence and related respiratory problems in children. J Craniofac Surg 2002;13:79–83 16. Hong P. A clinical narrative review of mandibular distraction osteogenesis in neonates with Pierre Robin sequence. Int J Pediatr Otorhinolaryngol 2011;75:985–991 17. St-Hilaire H, Buchbinder D. Maxillofacial pathology and management of Pierre Robin sequence. Otolaryngol Clin North Am 2000; 33:1241–1256 18. Cousley RR, Calvert ML. Current concepts in the understanding and management of hemifacial microsomia. Br J Plast Surg 1997; 50:536–551 19. Chigurupati R, Myall R. Airway management in babies with micrognathia: the case against early distraction. J Oral Maxillofac Surg 2005;63:1209–1215 20. Izadi K, Yellon R, Mandell DL, et al. Bradley: correction of upper airway obstruction in the newborn with internal mandibular distraction osteogenesis. J Craniofac Surg 2003;14:493–499 21. Hermann NV, Kreinborg S, Darvann TA, et al. Early craniofacial morphology and growth in children with nonsyndromic Robin sequence. Cleft Palate Craniofac Surg 2003;40:131–143 22. Scott A, Tibesar R, Lander TA, et al. Mandibular distraction osteogenesis in infants younger than 3 months. Arch Facial Plast Surg 2011;13:173–179 23. Thompson JT, Anderson PJ, David DJ. Treacher Collins syndrome: protocol management from birth to maturity. J Craniofac Surg 2009;20:2028–2035
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24. Vegter F, Hage JJ, Mulder JW. Pierre Robin syndrome: mandibular growth during the first year of life. Ann Plast Surg 1999;42:154–157 25. Judge B, Hamlar D, Rimell FL. Mandibular distraction osteogenesis in a neonate. Arch Otolaryngol Head Neck Surg 1999;125:1029–1032 26. Villani S, Brevi B, Sesenna E. Distraction osteogenesis in a newborn infant with Pierre Robin sequence. Mund Kiefer Gesichtschir 2002;6:197–201 27. Polley JW, Figueroa AA. Distraction osteogenesis: its application in severe mandibular deformities in hemifacial microsomia. J Craniofac Surg 1997;8:422–430 28. Denny A, Talisman R, Hanson P, et al. Distraction osteogenesis in very young patients to correct airway obstruction. Plast Reconstr Surg 2001:302–311 29. Cavaliere CC, Buchman SR. Mandibular distraction in the absence of an ascending ramus and condyle. J Craniofac Surg 2002; 13:527–532 30. Gateno J, Kim KW, Lalani Z, et al. Biomechanical evaluation of the pins of mandibular external distractor. J Oral Maxillofac Surg 2004;62:1259 31. Farina R, Castellon L, Nagelash E, et al. A new way to anchor the external device in mandibular distraction: three case reports with a Pierre Robin sequence. Int J Oral Maxillofac Surg 2011; 40:471–474 32. Molina F. Mandibular distraction osteogenesis: a clinical experience of the last 17 years. J Craniofac Surg 2009;20:1794–1800 33. Felemovicius J, Ortiz Monasterio F, Gomez Radillo LS, et al. Determining the optimal time for consolidation after distraction osteogenesis. J Craniofac Surg 2000;11:430–436 34. Sadakah AA, Elshall MA, Farhat AA. Bilateral intraoral distraction osteogenesis for the management of severe congenital mandibular hypopoplasia in early childhood. J Craniomaxillofac Surg 2009;37:216–224
Skin Tension Related to Tension Reduction Sutures Kun Hwang, MD, PhD,* Han Joon Kim, MD,* Kyung Yong Kim, MD, PhD,† Seung Ho Han, MD, DMSc,† Se Jin Hwang‡ Abstract: The aim of this study was to compare the skin tension of several fascial/subcutaneous tensile reduction sutures. Six upper limbs and 8 lower limbs of 4 fresh cadavers were used. At the deltoid area (10 cm below the palpable acromion) and lateral thigh (midpoint from the palpable greater trochanter to the lateral border of the patella), and within a 3 6-cm fusiform area of skin, subcutaneous tissue defects were created. At the midpoint of the defect, a no. 5 silk suture was passed through the dermis at a 5-mm margin of From the *Department of Plastic Surgery, Inha University School of Medicine, Incheon; †Department of Anatomy, College of Medicine, ChungAng University, Seoul; and ‡Inha Research Institute for Medical Science, Incheon, Korea. Received June 26, 2014. Accepted for publication August 19, 2014. Address correspondence and reprint requests to Dr. Kun Hwang, Department of Plastic Surgery, Inha University School of Medicine, 27 Inhang-ro, Jung-gu, Incheon, 400-711, Korea; E-mail: [email protected] This work was supported by a grant from Inha University (INHA Research Grant). The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001311
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
