American Board of Orthodontics (ABO) Practice Exam

Understanding how orthognathic treatments, such as OSA (obstructive sleep apnea) splints, affect orthodontic outcomes is important. The correct answer highlights that an orthodontic side effect of OSA splints can indeed be a change in facial height.

OSA splints are designed to reposition the jaw to prevent airway obstruction during sleep. This repositioning can have significant implications for the overall craniofacial structure. By advancing the mandible, these appliances may alter the vertical dimension of the face, either augmenting or decreasing facial height depending on the individual’s growth patterns and the specific design of the splint.

In contrast, the other options reflect potential effects or outcomes that are less directly influenced by OSA splints. For example, while OSA splints may have some effect on the overbite, there isn't a direct correlation between the appliances and a straightforward increase in overbite. Similarly, although jaw growth can be influenced by several factors, the primary intention of OSA splints is airway management rather than promoting growth in a particular direction. Lastly, incisor spacing may be minimally affected, but OSA splints do not specifically reduce spacing as a primary effect. The focus of OSA treatment is more about positioning than inducing spacing