title: Age-dependent closure of bony defects after frontal orbital advancement.
abstract: BACKGROUND
  The ability of the immature skull to spontaneously heal large bony defects created after craniofacial procedures was examined over a 25-year period of craniofacial surgery at the Children's Hospital of Philadelphia.
  
  
  METHODS
  Only patients who underwent frontal orbital advancement and reconstruction, had at least 1 year of documented follow-up, and had the presence or absence of a bony defect documented on clinical examination were included. The sex, age at operation, diagnosis, history of a prior craniectomy, and presence or absence of a postoperative infection were determined for each patient. A variety of statistics were applied to the data.
  
  
  RESULTS
  Eighty-one patients met the inclusion criteria. A statistically significant association between age at operation and closure of bony defect was demonstrated. Children who closed a bony defect after frontal orbital advancement and reconstruction were significantly younger than those children who had a persistent bony defect. Iterative regression analyses demonstrated that a transition point between closure and the inability to close bony defects occurred between 9 and 11 months of age. Closure of bony defects was not statistically associated with sex, prior craniectomy, an FGFR mutation, or a postoperative infection in the regression analysis.
  
  
  CONCLUSIONS
  Healing of bony defects after frontal orbital advancement and reconstruction is significantly related to age at initial operation, with a mean age for closure of less than 12 months. Between 9 and 11 months of age, a change occurs that results in an increasingly lower probability of bony defect closure; thus, all other considerations being equal, initial frontal orbital advancement and reconstruction would ideally take place before this occurs.
authors.affiliation: Philadelphia, Pa. From the University of Pennsylvania, Virginia Mason Medical Center, and Children's Hospital of Philadelphia.
authors.forename: Keith T
authors.initials: KT
authors.lastname: Paige
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Vega
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Kelly
authors.forename: Scott P
authors.initials: SP
authors.lastname: Bartlett
authors.forename: Elaine
authors.initials: E
authors.lastname: Zakai
authors.forename: Abbas F
authors.initials: AF
authors.lastname: Jawad
authors.forename: Nicole
authors.initials: N
authors.lastname: Stouffer
authors.forename: Linton A
authors.initials: LA
authors.lastname: Whitaker
mesh_terms: D000367:Age Factors; D001861:Bone Regeneration; D002675:Child, Preschool; D003399:Craniotomy / Q000009:adverse effects*; D005260:Female; D005624:Frontal Bone / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D009915:Orbit / Q000601:surgery*; D019651:Plastic Surgery Procedures; D014947:Wounds and Injuries / Q000209:etiology / Q000503:physiopathology*