About the Doctors

M. Constance B. Greeley, D.D.S.

Dr. Greeley completed her dental degree at Temple University School of Dentistry and had specialty training in both pediatric dentistry and orthodontics. She was named to the Omicron Kappa Upsilon Dental Honor Society and is a Fellow of the International College of Dentistry. A native of Carbondale, PA, she has been in practice in Delaware since 1980.

She is a member of the staff of Christiana Care Health System and the A.I. DuPont Hospital for Children, where she serves on the Cleft Palate Team. She is Board Certified in Orthodontics. Dr. Greeley has served on the Executive Board and is past president of the Delaware State Dental Society, the first female president in the history of the Society.

Dr. Greeley serves as a Director of the Christiana Bank. She is now Past-President of the Middle Atlantic Society of Orthodontics. She is an avid supporter of Nativity Preparatory School of Wilmington. Her personal interests include fitness, theater, music and creative writing. She strives to be a role model for her patients, encouraging them to be the best that they can be.

John M. Nista, D.M.D.

Dr. Nista attended dental school at the University of Pittsburgh, completed a General Practice Residency at the Veterans Administration in Dayton, Ohio and completed his orthodontic training at Albert Einstein Medical Center in Philadelphia. He has had extensive training in surgical jaw procedures.

Originally from Pittsburgh, PA, Dr. Nista has been in practice locally since 1990. He is a member of the staff of Christiana Care and served for 17 years on the Cleft Palate Team at A.I. DuPont Hospital for Children. He is currently the President of the Delaware State Dental Society and also serves on several dental society committees.

Dr. Nista’s personal interests include golf, fishing, skiing and cooking. He is an active member of the Knights of Columbus and is currently participating in Creative Mentoring. Dr. Nista is married with two children, Jason and Sarah. Being the oldest of five children, he particularly enjoys working with young children.