The turricephaly index: A validated method for recording turricephaly and its natural history in Apert syndrome

J Craniomaxillofac Surg. 2019 Mar;47(3):414-419. doi: 10.1016/j.jcms.2018.12.007. Epub 2018 Dec 25.

Abstract

Introduction: We present the CT scan-derived turricephaly index (TI) as a quotient of the maximal occipito-frontal length of the skull to the distance from the centre of the sella to the highest point on the vertex as a validated tool for assessing turricephaly and evaluating surgical techniques aimed at reducing it.

Materials and methods: Measurements taken from CTs of non-operated children with Apert syndrome and age-matched controls were analysed using Centricity PACS system (from the lateral scout image) and the thick-sliced Osirix tool. CTs from non-operated children with Apert syndrome were used to investigate the natural history of their turricephaly both as a group and individually.

Results: There was statistically significant agreement between measurements taken from the CT scout and Osirix for 42 control children (R2 = 0.97) and 42 children with Apert syndrome (R2 = 0.98) and between two separate observers. There was a statistically significant difference (p < 0.001) between CT scout-derived TI value between controls (1.73 ± 0.12, range 1.46-1.99) and Apert children (1.42 ± 0.15, range 1.13-1.73). Analysis of 113 CTs of 65 non-operated children with Apert syndrome showed a decrease in turricephaly with age (positive spearman correlation: r = 0.50, p < 0.001). Analysis of 37 CTs of those with multiple (>2) CT's showed a similar decrease in turricephaly in the individual child (p < 0.001).

Conclusions: TI derived from the CT scout view provides a simple, objective and validated method for assessing turricephaly. We recommend it for monitoring and for the prospective evaluation of reconstructive techniques in children with complex/syndromic craniosynostosis.

Keywords: Craniosynostosis; Turricephaly; Turricephaly index.

MeSH terms

  • Acrocephalosyndactylia / classification
  • Acrocephalosyndactylia / diagnostic imaging
  • Acrocephalosyndactylia / pathology*
  • Adolescent
  • Analysis of Variance
  • Case-Control Studies
  • Cephalometry / methods*
  • Cephalometry / standards
  • Child
  • Child, Preschool
  • Female
  • Head / anatomy & histology*
  • Head / diagnostic imaging
  • Humans
  • Imaging, Three-Dimensional
  • Infant
  • Male
  • Reference Values
  • Retrospective Studies
  • Tomography, X-Ray Computed*