What is the most common craniofacial difference? 

“Cleft lip and/or cleft palate. A separation that happens in the lip or the palate (roof of the mouth), or both. Cleft lip and cleft palate are the most common congenital craniofacial anomalies seen at birth.” source

How many people in the United States have craniofacial differences??

“Craniofacial disorder is a broad term that describes malformations of the face and skull that may result from birth defect, disease or trauma. In the U.S., approximately 600,000 individuals have been diagnosed with a craniofacial condition.” source