Approximation and contact of the maxillary central incisor roots with the incisive canal after maximum retraction with temporary anchorage devices_ Report of 2 patients

Chung, Choi, and Kim 501
Fig 9. CBCT images of the maxillary arch and 3D superimposition before and after maximum retraction:
axial section A, before and B, after maximum retraction; 3D superimposition before and after
maximum retraction in the sagittal (C), coronal (D), and axial (E) planes. Note the changes in the tooth
positions and the remodeling of the surrounding alveolar bone, whereas the incisive canal is stable with
no distinct changes in position. Gray, Immediately after treatment; yellow, 36 months after treatment;
arrows, the incisive canal.
Fortunately, the occlusion of patient 1 was stable in
the long term, and the central incisor with severe root
resorption did not lead to specific symptoms with
regard to mobility, sensitivity, or vitality issues during
the 3-year follow-up period. However, the probing
depth of the mesiopalatal side was slightly increased
compared with the other sides. En-masse retraction
with maximum anchorage results in significant vertical
alveolar bone loss of the incisors in the palatal side. 26
Thus, anatomically, the contact with the incisive canal
in the mesiopalatal angle region of the central incisor
root may create a state similar to that of a 2-walled
defect, which calls for careful attention in the long
term.
CONCLUSIONS
Approximation of the maxillary central incisors to the
incisive canal was noted after maximum retraction in the
2 illustrated cases. Interestingly, a maxillary central
incisor root was in direct contact with the incisive canal
with apparent root resorption, but tooth vitality and the
overall occlusion were stable in the long term. When
maximum retraction of the maxillary incisors is planned,
customized 3D evaluation of the dimension and location
of the incisive canal would be advantageous in preventing
potential complications.
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American Journal of Orthodontics and Dentofacial Orthopedics September 2015 Vol 148 Issue 3