Deep overjet is when the incisal edge of the maxillary incisors exceeds the labial cut 1/3 of the mandibular incisors during occlusion, and inwardly inclined patients need to move their lower teeth outward during orthodontic treatment. Normal overjet is when the incisal edges of the maxillary incisors are within the labial 1/3 of the mandibular incisors and the incisal edges of the mandibular incisors are within the lingual 1/3 of the maxillary incisors, but if more than one of these is considered to be a deep overjet, then it is considered to be a deep overjet. Patients with deep overjet are often combined with either maxillary protrusion or entropion, and mandibular teeth are also categorized as protruding and entropic, with protruders needing to retract their teeth inward during orthodontic treatment, and entropic patients needing to hold their teeth in place during alignment, when they will be moved outward. Therefore, whether or not to move the lower teeth outward during orthodontic treatment of deep overjet needs to be judged according to the condition of the lower front teeth. It is recommended that patients with misaligned teeth go to the dentistry department of a regular hospital for consultation.