Skeletal malocclusion is caused by discrepancy in shape, size and/or position of one or both jaws; e.g., if one of the jaws is too large or too small, or if one of them is too large and the other one is too small. For these patients a simple alignment of dental arches provides little help since their teeth are not in proper occlusion since the jaws don’t match each other. Skeletal malocclusion is often accompanied by an incorrect facial profile. The profile is too convex if the lower jaw is too small; or too concave if the lower jaw is too big, the upper jaw is too small, or both. Orthodontic treatment alone is insufficient for successfully correcting skeletal malocclusions when the chewing function and the facial aesthetics is also a desired outcome in addition to occlusion. Surgery, on one or both jaws, is usually performed to correct the position of the jaws, improve the chewing function, enhance the facial features, and reduce airway related problems.
If the jaw interrelation is correct in a patient, the dental malocclusion may be the result of an incorrect inclination or crowding of the teeth. In these cases orthodontic treatment alone, usually with the help of braces, is sufficient to achieve a stable correct occlusion.
The development of skeletal malocclusion may be caused by genetic and environmental factors. It is not known exactly which of the two has the greater influence on the development of different types of malocclusion. Numerous studies are being conducted on siblings and twins to figure out possible causes of malocclusion; however, current research provides evidence that no less than 40% of skeletal malocclusions are moderated by genome; whereas, dental malocclusion and dental compensations are mostly influenced by environmental factors.