3D Laser scanning as a method of studying craniofacial growth

Objective: The aim of the study was to test the validity and reliability of a portable 3D laser scanning device for use in field studies of craniofacial growth. Design and Setting: The study evaluated the use of a 3D optical laser device for image capture of inanimate objects and clinical subjects at the University Dental Hospital in Cardiff. Materials and Methods: Image capture a full size phantom head and 30 clinical subjects was conducted in a reproducible and controlled environment using two portable Minolta Vivid 900 cameras assembled as a stereo pair. Repeated scans were made of the inanimate objects to determine the reliability of the system. Each of the live patients received one laser scan at two different occasions 2 minutes apart T1and T2). Results: The results showed that the parameters and volumetric changes measured by the laser scans were not statistically significant from the actual measurements (p<0.05). The results showed that the mean error of linear lengths was 0.56, SD=0.26mm (max=0.86mm, min=0.22mm). The mean difference of the merged composite face at T1 and T2 was 0.313, SD 0.082 mm. Aligned facial maps of the merged scans (T1, T2) showed that 90% of the created composite facial scans correlated to one another with an error up to 0.85mm indicating a high reproducible soft tissue morphology between facial scans. Conclusions: The portable 3D optical laser scanning device is a valid and reliable device for the measurement and evaluation of facial growth in field studies.