Alejandro Martinez, DDS
Since 2012, Dr. Alejandro Martinez has been providing comprehensive dentistry in San Antonio, Texas. He went to dental school at University of Texas Health Science Center at San Antonio and graduated in 2012. Prior to his graduate studies, Dr. Martinez attended Reagan High School and then attended University of Texas at San Antonio. He is a self-proclaimed CE junkie and is constantly on the search for ways to improve his dentistry. Dr. Martinez belongs to the Spear Education Program, which requires that he continually join education courses and study clubs run by the nation’s top dentists.

He is a member of ADA, Spear Education, Academy of General Dentistry, San Antonio Dental District Society, American Academy of Cosmetic Dentistry and Texas Dental Association. Dr. Alejandro Martinez obtained a Fellowship at the California Implant Institute. He also won the Opencare Patients’ Choice Award.

Dr. Martinez has received advanced training in cosmetic dentistry, including veneers and Lumineers®. He has done comprehensive training in surgical implant placement and implant restorations. Dr. Martinez has completed advanced training in complicated dental extractions including impacted wisdom teeth.

Dr. Martinez has a dog named Meeka, who he adores. She is a Siberian Husky who loves to run with him or accompany him on his hiking adventures.

Dr. Martinez is a musician, playing guitar, piano, drums and vocals. He has a tremendous love for all types of art. He is also attracted to anything adventurous, like mountain biking, hiking, snow skiing, wakeboarding and camping. On weekends, he loves to have a good time with friends and family.

His goal as a dentist is to continually improve and evolve as a dentist, giving our patients the best care possible while also providing knowledge to patients about their oral health and proper way to take care of their teeth and gums. He strives for excellence in his work and does his best to achieve this.

Dr. Martinez is a very easy-going person and has a great sense of humor. On average, he makes a patient laugh three to four times per visit, which helps distract any nervous patients before and during treatment. Also works perfect as an ice breaker. He says that most dentists are a little weird, and patients usually expect that.

“I like to give off a ‘cool kind of weird’ vibe. I am interested in seeing my patients smile in my dental chair — even when they might be a little bit scared. I have been told I have great empathy towards patients, thoroughness in my work and a detective eye when it comes to catching things other dentists could not.”


Sarah McMahan, DDS
Dr. Sarah McMahan has been practicing in San Antonio, Texas, since 2015. She graduated with her degree in dentistry at the University of Texas Health Science Center at San Antonio in 2015. She completed her undergraduate studies at University of Texas Austin with a bachelor’s degree in economics in 2010. Dr. McMahan continuously furthers education. She likes to do in-person CE and study club monthly. She also does weekly online courses.

Dr. McMahan is a member of the ADA and Academy of General Dentistry.

In her free time, Dr. Sarah McMahan enjoys gardening, yoga, playing with her dogs, watching University of Texas football and watching the Spurs.


Kimberly Villanueva — Dental Hygienist
Kim recently joined our team as a dental hygienist. She has been practicing for seven years. Kim got her Bachelor of Science in dental hygiene at the University of Texas Health Science Center at San Antonio. She loves working in a modern environment with fun and innovative dentists. Kim cares about providing quality care specific to each patient’s needs.
When she isn’t working, Kim enjoys socializing with friends and family. She also loves being with her fur baby named Kai.


Ashley Cheswick — Registered Dental Assistant
Ashley joined our team as a dental assistant in 2017. She loves working at Great White Dental because everyone else loves working here. Everyone in the practice is goal-oriented and only wants the best for the practice, and we all strive to be the best.
Our success lies with our patients, and her job is to make the patients feel at home and comfortable before, during and after their appointment. She wants the patients to enjoy coming in for their appointment and does everything in her power to achieve that.
Ashley is a proud mother of two children, Kolton and Paisley. In her free time, Ashley enjoys baking, spending time with kids, going to concerts and going shopping.


Gracie Maldonado — Registered Dental Assistant
Gracie has been with Great White Dental since February 2015. She attended Concorde Career College in 2014, where she received her certificate as a registered dental assistant. Gracie enjoys giving patients their smile back. She loves making a difference in a patient’s self-esteem. She likes to make her patients as comfortable and relaxed as possible during dental treatments.
Gracie grew up in a big household. She has three sisters and two brothers. There was never a dull moment in their home. Now that they are all grown, they try to get together when they can. It isn’t always easy, but they try to make it happen often.
In her free time, Gracie enjoys traveling, dancing and hanging out with friends.


Crystal Olivares — Office Manager
Crystal started working as an office manager at our practice in December 2017. She has seven years of dental experience. Crystal graduated from Kaplan College in 2012. Since starting with Great White Dental, Crystal has enjoyed working with our team and doctors.
Crystal has 16 years of customer service experience. She is committed to the success of our practice. Her job is to oversee office operations and make sure that our patients and their families have a positive experience. Her goal is to equip our team with the knowledge and customer service that she has acquired to best serve our patients and build our brand.
When she isn’t working, Crystal enjoys spending time with her three amazing sons, Evan, Isaiah and Isaac. Crystal is passionate about music; she loves to sing and loves hearing live music. She also enjoys traveling.


Carrie Graf — Office Manager
Carrie started with our practice in 2018 and attended San Antonio College of Medical and Dental Assisting, where she was certified to be a registered dental assistant. She worked as an assistant for about 11 years before transitioning to the front office aspect of the dental field.
She absolutely loves how we are a family and not just a business. Everyone has a really good rapport with each other.
Carrie has quite a bit of knowledge and experience working with dental insurance companies and does her best to maximize our patient’s benefits for them. She always tries to make sure all of our patients have pleasant and even enjoyable experiences at our office. She helps mothers with their children while they are getting their treatment. She assists the doctors from time to time when needed and can help take X-rays to help minimize the patient’s wait time.
Carrie is a proud mother and grandmother to an absolutely perfect little grandson. She loves being outdoors. She enjoys doing outdoor activities like hunting, fishing, shooting, yard work and hanging around a fire with her friends and family. Carrie likes to work out as well and loves to go hiking on trails. She enjoys live music, friends and family, road trips, and being active.