Computer-aided measurement and grading of cranial asymmetry in children with and without torticollis.

Our aim was to develop a simple, non-invasive method that could be used to objectively record cranial symmetry over time. We utilized this new method to investigate the relationship between torticollis and progressive plagiocephaly. From 1995 to 1999, the head shapes of 419 torticollis patients and 1 211 normal children were evaluated. We used Ezeform strip, a splint material, to make a permanent ring of the head circumference. Each head ring was recorded, scanned, and analyzed. An asymmetric index (AI) was designed. Double-blind comparisons of clinical assessment with AI values demonstrated a good agreement. Asymmetry of the cranium was found with similar frequency in torticollis and normal babies up to 12 months old. After 1 year of age, the deformity persists in patients with torticollis into their adolescence, while the normal group shows increased symmetry. This new recording system offers an objective and efficacious methods for following the natural history of cranial asymmetry.