Children with LI demonstrate increased SOO and IOO muscle activity during saliva swallowing and lip compression, suggesting greater muscular effort is required to achieve lip seal. This increased activity may disturb the muscular force balance essential for proper maxillofacial growth and could contribute to the development of malocclusion.
Sommerfeld et al. (Tue,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: