Computer morphometrics was used to analyze 21 adult patients who underwent total maxillary advancement; ten had bone grafting behind the tuberosity and 11 did not. Each group was subclassified as those with idiopathic maxillary deficiency and those with cleft lip and cleft palate; all patients were treated by the same basic operative technique. The results of the study indicate that those patients who had bone grafts had optimum stability. However, individuals with maxillary deficiency who undergo minimal advancements (less than 0.5 mm) can have overcorrections at surgery and, therefore, do not require bone grafts for good stability.