Nonsurgical maxillary orthopedic expansion in adults has gained increasing attention since the introduction of miniscrew-assisted rapid palatal expansion (MARPE). While there is consensus on the growing unpredictability of orthopedic expansion post-puberty, additional factors influencing successful suture separation remain contentious and unclear. Recent studies and case reports have demonstrated positive outcomes not only in young adults but also in middle-aged and older patients. Noticeable individual variations in suture morphology, along with insights into suture biology that underscore the necessity of bone remodeling for suture separation, imply potential contributing factors like epigenetic regulations and estrogen-influenced bone metabolism. The expansion protocol, integrating intermission for interval bone remodeling, may enhance success in adult patients with tightly interdigitated sutures. However, uncertainties persist in achieving suture separation, particularly in males. Despite advancements, many aspects of orthopedic expansion and determinant factors remain unknown. For a better understanding of the complexities involved in suture separation robust clinical and experimental studies are required.