Early Mandibular Distraction Osteogenesis in Pierre Robin Sequence

1
Early Mandibular Distraction Osteogenesisin
Pierre Robin Sequence
2
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.

3
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.

4
Early Management

• Supportive measures
• Lying prone
• Tongue-lip adhesion
• Kirschner (2003) - gt40 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

5
Problems with tracheostomy

• Increased morbidity
• Donnelly, Int J Pediatr Otorhinolaryngol. 1996
• n29 41 complication rate (lt1yo- 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
• N142 43 serious complications
• Mortality 0.7

6
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

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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
• n130
• Slower growth rate
• Higher risk of behavioural problems
• Most will require special educational
  intervention

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Mandibular Distraction Background

• External traction with halo (Callister 1937)

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Mandibular Distraction Background

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

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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)

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Mandibular Distraction Background

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

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Mandibular Distraction Background
13
Mandibular Distraction Background
14
Mandibular Distraction Background

• Internal resorbable device

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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

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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