Accuracy of photographic assessment compared with standard anthropometric measurements in nonsynostotic cranial deformities.

OBJECTIVE

Anthropometric landmarks of the skull have traditionally been used to describe cranial deformities resulting from nonsynostotic plagiocephaly or brachycephaly. Recently, digital photography has become an important tool for characterizing facial and cranial pathologies. The purpose of this study was to compare standard anthropometric cranial measurements with measurements taken from cranial photographs.

PATIENTS

Standardized digital images in the supracranial view and cranial anthropometric measurements were obtained from 122 children between the ages of 3 and 15 months. The photographs were assessed using Quick Ceph® software. The cephalic index and cranial vault asymmetry index were used to indicate the degree of cranial deformity. Children were classified into plagiocephaly, brachycephaly, and the combination of both. To determine interobserver variability, two clinicians separately measured the cephalic index and cranial vault asymmetry index from digital photographs in 70 infants of the plagiocephalic group.

RESULTS

To compare interassay reliability for these methods of obtaining the cephalic index and cranial vault asymmetry index, the differences between photographically and anthropometrically derived values were plotted against anthropometrically derived values alone (Bland-Altman plots). The photographic method satisfied the limits of agreement (cephalic index, 7.51%; cranial vault asymmetry index, 6.57%) and showed slightly lower values represented by the respective bias (cephalic index, 1.79%; cranial vault asymmetry index, 3.03%). Comparison between observers revealed excellent agreement, detected by the intraclass correlation coefficient of .982 for the cephalic index and .946 for the cranial vault asymmetry index.

CONCLUSION

Our results demonstrate that digital photography is a reliable tool for quantifying cranial deformities. Furthermore, it is rapid, noninvasive, and reproducible. However, we continue to use both methods in clinical practice.