Early Mandibular Distraction Osteogenesisin Pierre Robin Sequence

Pierre Robin Sequence• Pierre Robin case report 1926• one in 9000 births• micrognathi, glossoptosis, cleft palate. • Theories:

– fetal head positioning, frequently associated with oligohydramnios.

– a delay in neurological maturation – rhombencephalic dysneurulation

• rare familial cases reported - localized intrinsic failure of mandibular growth may be a factor in some cases.

• Catchup mandibular growth in most, but mandibular dimensions will remain below age-matched norms.

Early Considerations• varying degrees of airway obstruction and

feeding difficulties.• mechanism - falling back of the tongue into the

oral pharynx. • Immediate supportive measures required in over

70 percent of affected infants. • Caouette-Laberge ( 1994) clinical classification of

respiratory symptoms:– group I, adequate respiration in prone position and

bottle feeding;– group II, adequate respiration in prone position but

feeding difficulties requiring NGT;– group III, children with respiratory distress requiring

respiratory support and NGT.

Early Management

• Supportive measures • Lying prone• Tongue-lip adhesion

– Kirschner (2003) - >40% Group III infants required tracheostomy after tongue-lip adhesion

– Denny (2004) - additional 1.9 secondary procedures

• Nasopharyngeal airway• Tracheostomy (12-42%)• K wire fixation, genioglossus stripping

Problems with tracheostomy

• Increased morbidity– Donnelly, Int J Pediatr Otorhinolaryngol. 1996

• n=29; 41% complication rate (<1yo- 64%)• 25 months average decannulation

– Midwinter, J Laryngol Otol. 2002 • n-=143; 46% complication rate• 25 months mean decannulation• Mortality 2.7%

– Carr, Laryngoscope. 2001• N=142; 43% serious complications• Mortality 0.7%

Problems with tracheostomy

• Poorer Speech Outcomes– Jiang, Int J Pediatr Otorhinolaryngol. 2003

• Affects speech and language development in those with and without neurological disorders.

• Risk factors: age at tracheostomy, and duration.• Better outcome with early decannulation

– Simon, Int J Pediatr Otorhinolaryngol. 1983• All children decannulated during the linguistic stage

exhibited specific spoken language delays • phonological impairment proportional to duration

Problems with tracheostomy• Prolonged

– Tomaski, Laryngoscope 1995• Average 3 years decannulation in PRS

• Carer Impact

• Financial Burden

• Developmental Problems– Singer, Dev Med Child Neurol. 1989

• n=130• Slower growth rate• Higher risk of behavioural problems• Most will require special educational intervention

Mandibular Distraction: Background

• External traction with halo (Callister 1937)

Mandibular Distraction: Background

• External traction with pulley/ weight (Longmire, Sandford 1940)

Mandibular Distraction: Background

• Mandibular DOG– McCarthy 1992, Molina/Ortiz-Monasterio 1995

• Use in children with airways obstruction– Moore, David 1994– Cohen 1999

• Use in Pierre Robin– Denny 2001,2002– Monasterio 2002– Burstein 2005 (internal resorbable device)

Mandibular Distraction: Background

• External distractor (Denny 2002)– linear Howmedica distraction device

Mandibular Distraction: Background

Mandibular Distraction: Background

Mandibular Distraction: Background

• Internal resorbable device

Early Distraction: Controversies

• Conservative management alone– 20-40% will not respond to positioning or glossopexy

• Rapid distraction– 2mm/day vs 1mm/day– In goats – demyelination noted at 2mm/day (Hu, J Oral

Maxillo Surg 2001)

• Effect on dentition– Screw holes– Infraalveolar nerve

• Effect on subsequent mandibular growth• Facial scarring

Indications for early distraction in Pierre Robin

• Failure of conservative measures to improve respiration and feeding

• Documented tongue base obstruction

• Center with expertise In distraction