Our excellent dental team is here to serve you. We are dedicated to making your visit to Randall Dental Associates as comfortable and pleasant as possible. We care about our patients and are always happy to answer your questions. We welcome you to contact our office today to learn more about us and to schedule an appointment with our dentist in Lewisville, Texas. Call today to meet Dr. Holbrook and his team.


Gregory S. Holbrook, DMD

Dr. Gregory S. Holbrook graduated from Oregon Health Sciences University in 1996 with a Doctorate of Dental Medicine. After graduating, he bought a dental practice in Salmon, Idaho and has practiced in Idaho for the past 21 years. While living there he developed a love for the outdoors, including hiking, hunting, fishing, snow skiing, white water rafting and much more. He enjoys camping and spending time in the outdoors with his family.

Dr. Holbrook has been married to his wife, Holly, for 26 years, and they have six children, two girls and four boys. Dr. Holbrook is a very active member of his faith, and has spent many hours in service to those in need around him. He also has taken opportunities to participate in humanitarian service around the world, including El Salvador, Guatemala, and China. He enjoys this service immensely and plans to do more.

Dr. Holbrook’s mission is to assess needs, relieve suffering, restore confidence, and reach out to serve. He is committed to listen to his patients concerns first and foremost, and assess needs while offering the latest and best dental treatments available. His patients often comment that they feel comfortable and at ease with Dr. Holbrook because of his gentle touch and calm demeanor. Dr. Holbrook has over 20 years of experience in all phases of clinical dentistry, specifically cosmetic, implant, and sedation dentistry. He strives to educate himself and update his skills regularly by attending continuing education and professional development courses.

Connie Crittendon – Health Relationship Coordinator

Originally from Enterprise, Alabama, Connie moved here in 1997 and joined her brother-in-law’s dental practice on Main Street in Lewisville, Texas. When he retired in 2005, she joined Randall Dental Associates, along with many wonderful patients. Connie has had the great pleasure of working with wonderful people over the last 17 years. The staff, as well as the patients, has become part of her extended family.Connie has been married to her best friend, Bubba, since 1986. They are blessed to have one son, David, and a wonderful daughter-in-law, Jennifer. Connie loves spending time with her family. Her parents live in Mt. Pleasant, Texas, and two of her three sisters live in the Austin area.In her spare time, she enjoys working her gift box business with her mom. They stay very busy with craft shows, especially during the fall season. Connie enjoys watching college football, NASCAR racing, and movies. And with the encouragement of one of her best friends, Julie, she is beginning to enjoy the practice of yoga.

Julie Costly, RDH, BS – Registered Dental Hygienist

Born in Southern California but raised in the Texas Panhandle, Julie is a native Texan by heart. She graduated summa cum laude from Texas Woman’s University with a bachelor’s degree in health sciences and a minor in biology. She has been a registered dental hygienist for 15 years.Once an avid runner, Julie has completed two Boston Marathons. Although she enjoyed running, she now spends a lot of time outside of the office on the yoga mat. She recently completed her 500-hour yoga teacher training certificate and enjoys teaching Hatha yoga. Julie enjoys spending time in the kitchen with her husband, LC. His Cajun cuisine keeps her fueled up for her yoga practice. Julie loves watching football, movies, and time with friends and family. She works hard to keep your smile beautiful and healthy. She looks forward to seeing you in our office for your next dental cleaning!

Ashton McBee

Ashton is Texas born and raised. She grew up in the small town of Chico, Texas. She chose to work in the dental field because she always had a wonderful experience at her dentist and orthodontic appointments growing up, and she has always enjoyed helping others. As the liaison between Dr. Holbrook and our patients, it is her job to help make sure that you and your family are comfortable and receive the best care possible. When she is not at the office, Ashton spends her free time with her family and her sweet fur child, Oakley. She enjoys staying active in the gym, shopping, and traveling with her better half, James.