Adenoid hypertrophy may cause abnormal breathing habits in children, which may cause abnormal development of soft and hard tissues of the maxillofacial region. Hypertrophic adenoids can cause the mandible to rotate backwards, forming a Class Ⅱ malocclusion. Recent studies have shown that such patients may progress to a Class Ⅲ malocclusion due to insufficient maxillary development. This article mainly discusses the mechanism, types and treatment of adenoidal hypertrophy and the formation of dental and maxillofacial deformities in children. The literature review results showed that adenoid hypertrophy causes abnormal mouth breathing habits, which causes patients to have a high arch, upper anterior labial tilt, mandibular retraction and other typical facial features; additionally, the buccal muscle strength is increased, resulting in upper and lower jaw arch stenosis, increasing the degree of dental and maxillofacial deformity in patients. However, some studies have found that hypertrophic adenoids are not directly related to dental and maxillofacial deformities. Such patients should be evaluated by a multidisciplinary team of orthodontists, otolaryngologists, and pediatricians to better provide effective treatment.