Final answer:
Maxillary skeletal arch expansion is easiest in preadolescent patients because their bones and sutures are still growing, allowing orthodontic interventions to be more effective. Surgery is typically for skeletally mature patients, not immature ones. Expansion increases arch space and doesn't directly impact overbite.
Step-by-step explanation:
The question pertains to maxillary skeletal arch expansion, which is a process that affects the size and shape of the dental arch and overall facial structure. Concerning the option given in the question, maxillary skeletal arch expansion is indeed easiest in preadolescent patients, which is option (A). This is because the bones are still growing and the sutures (growth plates) in the skull have not yet fused. At this stage, orthodontic interventions such as palatal expanders can be used effectively to widen the maxillary arch and correct related dental issues, such as crowding or crossbite. In contrast, option (B) is incorrect because surgical intervention is usually reserved for skeletally mature patients where the sutures have already closed, thus requiring more intensive procedures to achieve similar results. Option (C) is incorrect because maxillary skeletal arch expansion aims to increase, not decrease, the arch space to accommodate dental alignment. Lastly, option (D) mentions an increase in overbite, which isn't a direct consequence of maxillary expansion as overbite is related to the vertical relationship of the anterior teeth.