Cleft palate midface is both hypoplastic and displaced.

Despite significant advances in cleft lip and palate treatment, anatomical controversies remain. Some have proposed that the width of the cleft is due to alveolar segmental displacement. Others suggest that the width is due to palatoalveolar hypoplasia. Improving our understanding of cleft anatomy may have implications for presurgical orthopedics and tissue engineering therapies. Palatoalveolar impressions of 17 noncleft children and 11 children with complete (alveolar, primary, and secondary) unilateral cleft palates were taken. Maxillary tuberosity positions and maxillary volumes were compared. Tuberosity position was determined by facebow transfer of palatoalveolar casts into geodetic datum boxes, and identification of the Cartesian coordinates (x, y, z) of the tuberosities relative to the box surfaces and Frankfurt horizontal. Maxillary volume was determined by immersing the palatoalveolar casts and measuring sand displacement. A significant difference was noted in the average tuberosity to contralateral tuberosity distance between cleft and noncleft cohorts. On average, cleft palate tuberosities were laterally displaced 8.7 mm compared with noncleft palates (P < 0.05). There was neither statistically significant alveolar segment elevation nor retroversion. A significant difference was noted in the average palatoalveolar volumes. The cleft palatoalveolar volume was 5.7 cm, and the noncleft palatoalveolar volume was 7.2 cm (P < 0.05). A palatal cleft is due to both alveolar tissue displacement and deficiency. Therefore, ideal cleft palate care should involve the correction of a displaced and deficient alveolus.