Total or posterior mandibular alveolar osteotomy was performed on 12 patients for vertical open bite (2), mandibular alveolar hypoplasia (short-face syndrome) (7), and posterior arch discrepancies (3). Follow-up periods were from nine to 48 months. Most cases showed excellent stability. Permanent damage to the inferior alveolar nerve was found in five of the 21 operated sides (25%). Damage to the tooth pulps was considerable. Two molars had to be removed and apicoectomy or endodontic treatment was carried out on ten others. Although the method is technically difficult, it can be recommended in selected cases because of its excellent stability and predictable end results.