Guidance eruption is a method used to create enough room for crowded lower permanent incisors.
Crowding can often be seen with the eruption of the permanent teeth of the lower jaw at 6 to 7 years old. The permanent incisors will usually compensate for this crowding by erupting behind the primary teeth. If this happens, both sets of teeth may be apparent at the same time.
Additional room for a permanent lower incisor can be achieved through either the extraction of a primary tooth, or the discing away of portion of the primary tooth. If enough room is provided, then permanent lower incisors usually glide into a straight orientation without further intervention.
Guidance eruption may reduce the need for future orthodontic movement of the permanent lower incisors. Guidance eruption may also reduce the risk of future gingival recession and periodontal concerns of the lower front incisors, however, it will not gain any room for future permanent tooth eruption. Because more crowding may be encountered at about 9 years old, the need for space maintenance or future orthodontic treatment may be warranted.