Introduction It has been hypothesized that if hypoplasia of the maxilla occurs in one plane of space, such as the sagittal plane of many skeletal Class III patients, it will occur in multiple planes of space, including transverse. With the advent of Cone-Beam Computed Tomography CBCT, better assessment of skeletal transverse widths can be appreciated using various landmarks in the maxilla. The aim of this study was to compare the linear widths of anterior and posterior maxillary skeletal landmarks and their subsequent anterior-to-posterior ratios in a group of Class I and Class III patients using pretreatment CBCT images. Method Pretreatment CBCT images of forty-nine skeletal Class I patients with normal maxillary growth and thirty Class III patients with maxillary sagittal hypoplasia were evaluated. Linear transverse measurements were determined from anterior and posterior maxillary landmarks using coronal CBCT slices. Results Widths measured between maxillary canine root apices were significantly narrower for Class III patients, while widths measured between the greater palatine foramina were significantly wider for Class III patients compared to the Class I population P .05.No statistically significant differences were noted between the populations in first molar palatal root apices or infraorbital foramina width.