A preliminary assessment of cephalometric orthodontic superimposition.

The superimposition of cephalograms is a valuable tool in orthodontics. In children this task is complicated by the fact that growth changes in the reference structures used in superimposition should be taken into consideration. In this study a new method of superimposition of cephalograms taken in the natural head position (NHP) was compared with Viazis' cranial base triangle and a reference grid was used to quantitatively assess the changes in the five selected landmarks. The material consisted of 12 pairs of cephalograms of growing subjects (mean age 11.1 years) collected with a time interval of 1 year. The results revealed no significant statistical difference between the two methods and both showed high reproducibility. Both analyses were found to be suitable for individual assessment, but the new method involving the use of NHP and easy landmark identification can be considered as a useful addition.