According to modern epidemiological surveys, the prevalence of adenoid hypertrophy in children and adolescents ranges from 42% to 70%. Adenoid hypertrophy can lead to airway obstruction; thus forces a child to breathe through their mouth, thus affecting the normal development of the dental and maxillofacial area, and can lead to malocclusion. Long-term mouth breathing can cause sagittal, vertical and lateral changes in the maxillofacial area. In this article, we review the current research status relating to the association between adenoid hypertrophy, oral breathing and maxillofacial growth and development in children and adolescents. We also discuss the personalized formulation of treatment plans.