Transverse maxillary deficiency is a key factor in various malocclusions, influencing facial growth, function, and long-term stability. With modern 3D imaging, clinicians can diagnose transverse problems early and plan more precise and individualized treatments. Early maxillary expansion, when indicated, supports better airway function, balanced facial development, and improved oral mechanics. Today, the concept of “Transverse First” is no longer limited to growing patients. New skeletal expansion appliances such as MARPE have transformed treatment possibilities for late adolescents and adults. These devices allow true maxillary widening even after skeletal maturity, offering valuable benefits for correcting malocclusions, improving airway dimensions in patients with obstructive sleep apnea, and supporting healthier temporomandibular joint function. This presentation highlights how early and late transverse corrections, enhanced by digital technologies, can significantly improve functional outcomes and facial harmony. A series of clinical cases will illustrate the impact of 3D diagnosis and modern expansion techniques across all age groups.

Learning Objectives:

1. Identify transverse maxillary deficiency across all ages and understand its impact on function, growth, and stability.
2. Explain how modern expansion techniques, such as 3D-printed Hyrax in growing patients and MARPE in adults enable precise skeletal correction.
3. Evaluate clinical outcomes of transverse-first treatment using digital planning and contemporary expanders to improve occlusion, airway health, and facial harmony.