A potential iatrogenic adverse consequence of treating maxillary incisor proclination with retraction mechanics is a decrease in the:

 # A potential iatrogenic adverse consequence of treating maxillary incisor proclination with retraction mechanics is a decrease in the:

A. Depth of the nasolabial angle due to soft tissue retraction

B. Vertical height of the alveolar process in the anterior mandible

C. Maxillary incisor root proximity to the nasal floor and palatal cortex

D. Posterior arch width due to transverse forces

The correct answer is C. Maxillary incisor root proximity to the nasal floor and palatal cortex

When maxillary incisors are retracted (moved backward) to correct proclination (forward tipping), the entire tooth structure, including the root, moves posteriorly. The root apices of the maxillary incisors are naturally close to the nasal floor superiorly and the palatal cortical plate posteriorly. Significant retraction, especially with bodily movement or lingual tipping, can push the root apices closer to these anatomical boundaries. This decreased proximity (i.e., the distance becomes smaller) increases the risk of root resorption or fenestration/dehiscence (where the root penetrates the bony plate).