Meet the Doctors

Gary Mar, DDS

Dr. Mar, a founding partner of Rancho Niguel Dental Group, opened the practice in Laguna Niguel in 1991. He is a graduate of the University of Southern California School of Dentistry where he earned his doctorate and was a clinical instructor in the Department of Periodontology. He is a member of the American Dental Association, California Dental Association, and Orange County Dental Society, where he currently serves as a member on the Council on Peer Review.


Katie Stern, DDS

A native of Oregon, Dr. Stern completed both her undergraduate education and dental education at the University of Southern California where she graduated with honors. As an associate of the practice since 2004, she is a certified provider for both Invisalign teeth straightening and Lumineers restorations. Dr. Stern is a member of the American Dental Association, California Dental Association and Orange County Dental Society.


Allen A. Ontiveros, DDS

Born and raised in Orange County, Dr. Ontiveros received a B.S. in Biological Sciences from the University of Southern California, Doctor of Dental Surgery (DDS) and B.S. in Dental Science from the University of California, San Francisco. Upon graduation, Dr. Ontiveros returned to Laguna Hills and begun practicing dentistry. Dr. Ontiveros has been an active member of the American Dental Association, California Dental Association and the Orange County Dental Society for over 25 years. 


Leila Manshadi, DDS

Dr. Manshadi was born and raised in Southern California where she received her B.S. from the California State University, Fullerton. She obtained her DDS degree from the University of the Pacific Arthur A. Dugoni School of Dentistry in San Francisco, and started practicing soon after graduation. She is part of the American Dental Association, the California Dental Association, and the Orange County Dental Society. 

Dr, Manshadi’s mission is to provide high quality dental care to each of her patients and ensure everyone is happy and comfortable in her care. 

On her down time, Dr. Manshadi loves to be by the beach and spend time with her family and friends.