McSherry P, Richardson A
Division of Orthodontics, Queen's University of Belfast, UK.
Eur J Orthod. 1999 Feb;21(1):41-8. doi: 10.1093/ejo/21.1.41.
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.
在15名5至15岁患者的年度侧位和后前位头颅侧位X线片上，对20颗异位上颌尖牙（10颗右侧，10颗左侧）的萌出路径进行三维测量，并与正常尖牙的萌出情况进行比较。结果发现，8至12岁之间，左侧异位尖牙比正常萌出的尖牙向前移动更多，7至12岁之间右侧尖牙也是如此。虽然异位尖牙向咬合方向移动，但其垂直移动小于正常情况，这就解释了临床上尖牙高位腭侧阻生的表现。平均腭侧异位尖牙总是向腭侧移动，在10至12岁之间，从不参与正常萌出尖牙所表现出的颊向移动。有趣的是，早在5至6岁时，正常尖牙和异位尖牙在空间侧平面上的生长差异就已存在。
