American Board of Orthodontics (ABO) Practice Exam

Significant maxillary setback can lead to negative airway and soft tissue effects, making this the most appropriate choice. When the maxilla is positioned further back in the facial structure, it can obstruct the upper airway, potentially leading to challenges such as sleep apnea or other breathing issues. The shift in the position of the maxilla can also influence the configuration of the soft tissues in the face, which might result in a less favorable aesthetic outcome, including changes to the lips' position or the overall facial profile.

Addressing the other options, positive airway changes would suggest an improvement in airflow, which is not typically associated with significant maxillary setback. A neutral soft tissue effect implies that there would be no significant changes to the soft tissues, which is unlikely due to the dramatic alteration in jaw position. Finally, while decreased stability can be a concern in orthodontic treatment, it is not as directly tied to the significant repositioning of the maxilla as the negative airway and soft tissue effects. These factors make "negative airway/soft tissue effect" the most accurate identification of potential complications following significant maxillary repositioning.