As the treatment of malocclusion evolved, the anteroposterior position of this tooth was seen as an important concept. Innumerable authors have voiced their opinions about how this tooth should be related to the mandible, to the dentofacial complex and to the musculature. The position of this tooth has a critical effect on facial aesthetics, and it can be said that it deserves all of the attention it has been given. However, from the standpoint of stable treatment, the prime objective of orthodontic treatment , the vertical relation of the mandibular incisor to the mandible has been almost completely ignored for the last seventy years. The volumes of American literature pertaining to the position of this tooth seldom if ever mention its vertical relation to the mandible.
Many orthodontists pay no attention to whether the mandibular incisor is intruded in treatment.
When this tooth is appreciably intruded it is the most unstable of all anatomical changes . Also many orthodontists purposely intrude the mandibular incisors and then wonder why the overbite relapses. There has been much interest in stable treatment results in recent years. The interincisal angle is an important cause of overbite. When a deep overbite develops, accompanied by a large interincisal angle, it tends to force the crowns of the mandibular incisors lingually and the apices of the maxillary incisors labially.