A distinctive clinical manifestation of a successful Rapid Maxillary Expansion is:: (A) Anterior crossbite, (B) Posterior crossbite, (C) Midline diastema, (D) Open bite
Answer is C. Rapid maxillary expansion (RME) results in rapid correction of the cross-bite occurring in 2–6 weeks. A midline diastema may appear which is suggestive of the mid-palatal split. This diastema would close spontaneously due to the recoil of the stretched trans-septal group of gingival fibres.
Reference: Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities 3rd O P Kharbanda, pdf no 2403