The effects of sagittal expansion with a cemented expansion appliance were studied in nine noncleft macerated human maxillae ranging from 1-10 years. It was found that opening of the premaxillo-maxillary suture did occur in the youngest maxilla. Movement of the incisor roots through the labial cortical plate was observed in seven specimens. In one maxilla, dislocation of the maxillary tuberosity occurred. The results of this investigation suggest that it seems questionable that sagittal expansion using cemented appliances in noncleft human maxillae will in most instances result in breaking the ossification of the premaxillo-maxillary suture together with the interlocking serrations.