title: Comparative study of cranial anthropometric measurement by traditional calipers to computed tomography and three-dimensional photogrammetry.
abstract: Craniofacial anthropometry by direct caliper measurements is a common method of quantifying the morphology of the cranial vault. New digital imaging modalities including computed tomography and three-dimensional photogrammetry are similarly being used to obtain craniofacial surface measurements. This study sought to compare the accuracy of anthropometric measurements obtained by calipers versus 2 methods of digital imaging.Standard anterior-posterior, biparietal, and cranial index measurements were directly obtained on 19 participants with an age range of 1 to 20 months. Computed tomographic scans and three-dimensional photographs were both obtained on each child within 2 weeks of the clinical examination. Two analysts measured the anterior-posterior and biparietal distances on the digital images. Measures of reliability and bias between the modalities were calculated and compared.Caliper measurements were found to underestimate the anterior-posterior and biparietal distances as compared with those of the computed tomography and the three-dimensional photogrammetry (P < 0.001). Cranial index measurements between the computed tomography and the calipers differed by up to 6%. The difference between the 2 modalities was statistically significant (P = 0.021). The biparietal and cranial index results were similar between the digital modalities, but the anterior-posterior measurement was greater with the three-dimensional photogrammetry (P = 0.002). The coefficients of variation for repeated measures based on the computed tomography and the three-dimensional photogrammetry were 0.008 and 0.007, respectively.In conclusion, measurements based on digital modalities are generally reliable and interchangeable. Caliper measurements lead to underestimation of anterior-posterior and biparietal values compared with digital imaging.
authors.affiliation: Cleft Palate and Craniofacial Institute, Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, St Louis Children's Hospital, St Louis, Missouri 63110, USA.
authors.forename: Derick A
authors.initials: DA
authors.lastname: Mendonca
authors.forename: Sybill D
authors.initials: SD
authors.lastname: Naidoo
authors.forename: Gary
authors.initials: G
authors.lastname: Skolnick
authors.forename: Rachel
authors.initials: R
authors.lastname: Skladman
authors.forename: Albert S
authors.initials: AS
authors.lastname: Woo
mesh_terms: D002508:Cephalometry / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010780:Photogrammetry / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012886:Skull / Q000033:anatomy & histology*; D014057:Tomography, X-Ray Computed / Q000379:methods*