Early Mandibular Distraction Osteogenesis in Pierre Robin Sequence

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)


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


• 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)


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




• 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

Documents

Early Mandibular Distraction Osteogenesis in Pierre Robin Sequence