Characterization of the Maxillary Complex in Unilateral Cleft Lip and Palate Using Cone-Beam Computed Tomography

Deficiencies in maxillary growth have often been implicated in suboptimal results of cleft lip and palate therapy. Cone-beam computed tomography provides an opportunity to look at the dimensions of the maxillary complex in three dimensions in a way that is not possible with lateral cephalograms or dental models. The purposes of this preliminary study were to outline a new set of 18 cone-beam computed tomographic measurements, apply them to 6 patients with unilateral cleft lip and palate (UCLP), and contrast them to a comparable sample of 7 normal young adults. The patients with UCLP were treated with a single protocol by a single surgeon and orthodontist. The 18 measurements had a mean intrarater reliability of 0.95 and ranged from 0.40 to 2.23 for the individual measurements. The mean interrater reliability was 1.01 and ranged from 0.40 to 2.45 for the individual measurements. Significant differences between the patients with UCLP and control subjects (combined sex samples) were found in palate length, anterior palate thickness, overall sagittal maxillary length, and premaxillary height (Mann-Whitney U tests, P <or= 0.037). The body of the maxilla and its heights appear less affected. These methods and preliminary findings lay the groundwork for larger scale and prospective studies that evaluate such dimensional data in conjunction with positional data and other vital outcomes of cleft lip and palate therapy such as speech and occlusion.