Ectopic eruption of the maxillary canine quantified in three dimensions on cephalometric radiographs between the ages of 5 and 15 years.

The eruption paths of 20 ectopic maxillary canine teeth (10 right, 10 left) were measured in three dimensions on annual lateral and depressed postero-anterior cephalometric radiographs of 15 patients between the ages of 5 and 15 years and compared with the eruption of normal canines. It was found that between the ages of 8 and 12 years ectopic canines on the left side moved more anteriorly than the normally erupting canines and the same was true of the right canines between the ages of 7 and 12 years. While the ectopic canines moved occlusally, their vertical movement was less than normal which accounts for the clinical finding that canines are impacted in the palate at a high level. The average palatally ectopic canine always moves palatally, and never shares in the buccal movement shown by normally erupting canines between the ages of 10 and 12 years. It was interesting to find that the differences between growth of normal and ectopic canines in the lateral plane of space are present as early as 5-6 years.