Table 1.

Inclusion and exclusion criteria.

Inclusion criteria
Lack of contact between the lower central incisors and the upper central incisors or palate
Early or intermediate mixed dentition
Visceral swallowing pattern
Exclusion criteria
Age less than 6 or more than 10 years old
Sucking habits not ceased for at least 6 months prior to intake
History of myofunctional therapy
Mental retardation
Orofacial congenital deformities or orofacial syndromes
Muscular or connective tissue disorders
Macroglossia or ankyloglossia
Obstructed nasal airway