Anterior arch width of the dental arches increases upto the age of:

Arch width increase occurs mostly during the eruption of the permanent incisors and reach its maximum size at the time of exfoliation of the primary cuspids. The eruption of the permanent incisors occurs between 6 to 8 years. Reference: Orthodontics: Diagnosis and Management of Malocclusion and Dentofacial Deformities 3rd O P Kharbanda, pdf no 482