In almost 50% of the Dutch population, the mandibular incisors do not contact the maxillary ones. An open bite is usually based on an interposition of the tongue and can be combined with other functional disturbances as digit sucking. A large open bite with an excessive facial deformity can be treated adequately, after facial growth is completed, by a combined orthodontic-surgical approach, in which a good cooperation between the orthodontist and the oral surgeon is essential. The correction of the facial deformity is of a permanent nature. That does not always apply to the open bite due to interposition of the tongue. Often it is not possible to arrive at complete contact by orthodontic or surgical means. The improvement realized can fade away partly in the years following.