Please tell me if an underbite can also make my cheekbone underdeveloped?

Yes : Generally most underbite problems are characterized by a deficiency in the growth of the upper jaw which will give the appearance of a flatten "cheekbone" area and a large, protrusive lower jaw. Early treatment of these problems is recommended to avoid surgery later once growth has ceased. If you are already an adult, often you will need jaw surgery and braces to correct your underbite.

Cause: The cause of your upper jaw to lower jaw malrelationship may be small upper jaw, large lower jaw, or both. Underbite doesn't cause underdeveloped cheekbones. Your upper jaw may be too narrow or positioned too far back. Please see a fully qualified Orthodontic Specialist for an initial exam (usually free) to determine the nature of your malocclusion, and the treatments available.

Most Likely: Almost invariably a narrow or under-developed maxilla can cause the effect of underdeveloped cheekbones. See an orthodontist for examination and diagnosis. Good luck!