title: Three-dimensional analysis of cranial and facial asymmetry after helmet therapy for positional plagiocephaly.
abstract: OBJECTIVE
  Helmet therapy is a non-surgical option for treating positional plagiocephaly, and its effectiveness has been validated by various researches. In addition to cranial flattening and asymmetry, ipsilateral prominence of the mid-face and relative anterior transposition of the ipsilateral ear is also common. Hence, we investigated the impact of helmet therapy on mid-facial asymmetry.
  
  
  METHODS
  Ninety-nine patients diagnosed with positional plagiocephaly and treated by helmet therapy between September 2005 and July 2012 were enrolled. Therapy was initiated at various ages: group I, <6 months (n = 35); group II, 6 months to 1 year (n = 43); group III, >1 year (n = 21). A cranial vault asymmetry index was measured at the levels of the inferior orbital rim (CVAIIOR-MF) and superior orbital rim (CVAISOR-LC) and midway from the superior orbital rim to the vertex (CVAIMID-UC). Anterior transposition of the ipsilateral ear was verified by measuring the distance (D EAR) between the actual position of the ear and its expected position relative to the contralateral ear. All variables were compared before and after helmet therapy and were categorized by age at treatment initiation.
  
  
  RESULTS
  CVAIIOR-MF and CVAISOR-LC were lower in all three age groups after helmet therapy, confirming therapeutic efficacy. CVAIMID-UC (upper level cranial asymmetry) and D EAR (mid-facial soft tissue asymmetry) also improved significantly in groups I and II which were younger than 1 year old.
  
  
  CONCLUSIONS
  In positional plagiocephaly, helmet therapy is effective in correcting both cranial and mid-facial asymmetries. Outcomes were optimal in patients <1 year of age, but older patients also showed some improvement.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Institute for Human Tissue Restoration, Severance Hospital, Yonsei University Health System, 250 Seongsan-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
authors.forename: Jin
authors.initials: J
authors.lastname: Hwang
authors.forename: Yong Oock
authors.initials: YO
authors.lastname: Kim
authors.forename: Kyu Won
authors.initials: KW
authors.lastname: Shim
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Park
authors.forename: Dae Hyun
authors.initials: DH
authors.lastname: Lew
authors.forename: In Sik
authors.initials: IS
authors.lastname: Yun
mesh_terms: D005146:Facial Asymmetry / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D007839:Functional Laterality; D006260:Head Protective Devices / Q000009:adverse effects*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D049068:Plagiocephaly, Nonsynostotic / Q000628:therapy*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015898:Tomography Scanners, X-Ray Computed