Craniofacial Skeletal Measurements Based on Computed Tomography: Part II. Normal Values and Growth Trends

Abstract

Current diagnosis and surgical correction of craniofacial anomalies would benefit from accurate quantitative and standardized points of reference. A retrospective study was undertaken to define normal values for a series of craniofacial measurements and to evaluate the growth patterns of the craniofacial complex through axial computed tomography (CT). Fifteen measurements were taken from 542 CT scan series of skeletally normal subjects. The measurement values were then divided into 1-year age categories from 1 to 17 years, and into four age groups for those under 1 year of age. The normal range and growth pattern of measurement values for the cranial vault, orbital region, and upper midface are presented. The overall size of the cranio-orbito-zygomatic skeleton reaches more than 85 percent of adult size by age 5 years. The cranial vault grows rapidly in the first year of life but growth levels off early. The upper midface grows at a slower rate in infancy, but continues to grow later in childhood and early adolescence. Knowledge of the differential growth patterns and normal measurement values in the craniofacial region will help improve diagnostic accuracy, staging of reconstruction, precision of corrective surgery, and follow-up of patients.

Three dimensional CT reconstruction: a comparison between 2D, 3D CT and original anatomical structures

“…It therefore gave a comprehensive picture of the possible dimensional distortions that may occur in the three dimensional reconstructed image. Measurement errors in the z-plane of 3D reconstructed virtual images were reported in previous studies [1,6]. Error in the z plane mainly due to manipulation of viewer controls by CT technicians, calibrations of CT data to 3D CT data, and investigator error.…”

“…However, the measurement of distances on 3D reconstructed image may include some sources of error. Occasionally, various landmarks cannot be well identified and deviations of the actually, defined corresponding points can be observed particularly, when the landmarks are positioned on large bone surfaces [2]. The 3D reconstruction phase is also subjected to errors namely threshold value determination and volume averaging effect.…”

“…The landmarks of measuring points were positioned in different planes and thus were difficult to identify. In the literature, the accuracy and reproducibility for linear measurements in 2D CT is reported to be excellent, but the use of metallic markers has significantly influenced the ease with which points could be defined [2].…”

“…Their findings based on metallic markers and do not reflect the clinical reliability of the methods. Only one article has dealt with validation of 3D CT without use of metallic markers [1]. They concluded that 3D CT measurement techniques are superior to those in which measurement obtained directly from the original CT slices.…”

“…The accuracy of 3D CT imaging program MediCAD surgical stimulation software has been done in various studies [3][4][5]7,12,13]. These studies also showed that linear measurement accuracy of 3D CT reconstructed image was not precise [1]. The reconstructed 3D CT images are much more refined now.…”