Pierre Robin sequence (PRS) is a craniofacial malformation characterized by micrognathia and glossoptosis, with or without cleft palate. A subset of infants with PRS will suffer from airway obstruction severe enough to merit surgical intervention. Surgeries for PRS include tongue lip adhesion, tracheotomy, gastrostomy, and bilateral mandibular distraction osteogenesis. Distraction osteogenesis refers to a process in which a bone is lengthened after an initial osteotomy by means of separating the two resulting segments slowly over time. In the neonatal mandible, hardware used for distraction may be implanted beneath the skin or affixed externally. Each device has its advantages and disadvantages, however external devices are less expensive, do not typically require preoperative computed tomography scanning, may be adjusted easily throughout the distraction process, and are easily removed following consolidation, avoiding a second invasive procedure and lengthy anesthetic. This video presents the technique of neonatal mandibular distraction osteogenesis using multivector external distractors.
Neonatal mandibular distraction osteogenesis using multivector external distractors.
Robin sequence (RS) is a craniofacial malformation characterized by micrognathia and glossoptosis, with or without cleft palate. A subset of infants with RS will suffer from airway obstruction severe enough to merit surgical intervention. Surgeries for addressing chronic hypoventilation and failure to thrive in the context of RS include tongue lip adhesion, tracheotomy, gastrostomy, and bilateral mandibular distraction osteogenesis. In appropriately selected patients with RS, neonatal mandibular distraction osteogenesis allows for save decannulation of a tracheostomy or avoidance of tracheostomy tube placement altogether. Similarly, there is a dramatic improvement in oral feeding postoperatively, allowing for avoidance of supplemental nasogastric or gastrostomy feeding in 85-95% of infants following mandibular distraction.
Neonatal mandibular distraction osteogenesis is not an aesthetic procedure. Over 50% of children born with RS do NOT require immediate surgical intervention for airway and feeding issues. Many children with syndromic forms of PRS (Stickler syndrome, Cerebrocostomandibular syndrome) do very well following early distraction osteogenesis, while other syndromes of primary growth disturbance (Treacher Collins syndrome, Nager syndrome) require secondary procedures in childhood and beyond. Children with absent mandibular condyles are not candidates for early mandibular distraction. Children with significant respiratory problems independent of glossoptosis (choanal atresia, severe tracheomalacia, bronchopulmonary dysplasia, severe congenital heart disease) are not appropriate candidates for this procedure. Children with neurological impairment will still have problems with aspiration, hypotonia, and impaired swallow after jaw distraction and are not good candidates for neonatal mandibular distraction.
Neonatal flexible bronchoscope for nasal fiberoptic intubation, cotton eye pads, soft tissue surgical instruments, Senn retractors, calipers, multiple straight and curved osteotomes, #9 periosteal (dental) elevator, malleable retractors, piezoelectric system, nerve hook, Depuy/Synthes multi vector external distraction devices and distraction instrument kit.
Bedside flexible laryngoscopy Serial capillary blood gas measurements to document chronic respiratory acidosis and hypercarbia Sleep study (optional) Genetics consultation Echocardiogram (recommended) PICC line placement for postoperative sedation and TPN administration
Mandibular angles and inferior border of bodies marked bilaterally Incision planned 1 finger breadth below mandible Subfascial flap raised from inferior border of submandibular gland, with dissection between fascia and gland until inferior border of mandible is reached Buccal and lingal cortices of mandible exposed to inner angle superiorly, posterior/inferior ramus posteriorly and just posterior to mental foramen anteriorly Vertical or inverted L osteotomy planned through antegonial notch, assuring adequate bone stock and space for posterior k-wires in ramus
Advantages: In cases of suspected Stickler syndrome or isolated Robin sequence, preoperative imaging is not necessary. Hardware removal is a brief, simple, outpatient procedure that does not require incisions or any dissection that would put the facial nerves at risk a second time. As opposed to distraction using buried linear distractors, external devices allow for immediate correction and resolution of asymmetry or open bite deformity that may develop during activation phase. The relative flexibility of the k-wires places less strain on the temporomandibular joint than more rigidly affixed internal hardware There is no hardware between the bone and masseter, leading to less scarring and fibrosis of the muscle itself. Disadvantages: The use of an external device requires placement of percutaneous k-wires that pass through the perifacial skin; trochar incision are therefore in the cheeks and are not hidden External devices require daily pin care and maintenance by nursing and families, even during the consolidation phase. Hardware loosening or dislodgment is rare but can occur. Overcorrection is required and more regression is expected using external devices compared to buried devices.
Bleeding, infection, device malfunction, damage to developing teeth, injury to inferior alveolar nerve, facial nerve injury, premature consolidation, fibrous union, regression and failure to achieve goals, mandibular asymmetry, need for additional procedures later in childhood, facial scarring.
No conflicts of interest
Dr. Mark A. Vecchiotti acted as assistant surgeon in this case.
Scott AR. Surgical Management of Pierre Robin Sequence: Using Mandibular Distraction Osteogenesis to Address Hypoventilation and Failure to Thrive in Infancy. Facial Plast Surg. 2016 Mingo K, Lander TA, Sampson DE, Tibesar RJ, Sidman JD, and Scott AR. Use of external distraction devices eliminates the need for preoperative computed tomography in infants with isolated Pierre Robin sequence. JAMA Facial Plast Surg 2016 Mar 1;18(2):95-100. Tsang C, Adil E, and Scott AR. Neonatal mandibular distraction osteogenesis. Operative Techniques in Otolaryngology 2015 Sep;26(3):131-135. Fauman KF, Durand C, Durgham R, Vecchiotti MA, and Scott AR. A sedation protocol limiting length of stay following airway surgery in infants and children. Laryngoscope. 2015 Sep;125(9):2216-9 Handley SC, Mader NS, Sidman JD and Scott AR. Predicting the need for surgical airway intervention in infants with micrognathia. Otolaryngo Head Neck Surg. 2013 May;148(5):847-51. Scott AR, Tibesar RJ and Sidman JD. Pierre Robin Sequence – Evaluation, Management, Indications for Surgery and Pitfalls. Otolaryngol Clin North Am. 2012 Jun;45(3):695-710, ix. Scott AR, Tibesar RJ, Lander TA, Sampson DE and Sidman JD. Mandibular distraction osteogenesis in children under three months of age. Arch Facial Plast Surg 2011 May-Jun;13(3):173-9. Tibesar RJ, Scott AR, McNamara C, Sampson D, Lander TA and Sidman JD. Distraction Osteogenesis of the Mandible for Airway Obstruction in Children: Long-term Results. Otolaryngol Head Neck Surg 2010; 143:90-96
Review Neonatal Mandibular Distraction Osteogenesis with Multivector External Devices.