South County Family Dental, Inc.

Mary E. Fiedler, D.D.S.

​Brandan A. Althof, D.D.S.

Our Team - Dedicated to Personalized Care

We love to see you smile.  Really, we do.  That's because we take great pride in offering the most up-to-date dental techniques in a relaxed, friendly atmosphere. We know that every great smile -- your smile! -- is the sign that we've done our job to provide the highest level of care in the industry.

Dr. Mary Fiedler founded her private dental practice in 1988 and has been helping Orange County families smile for over 30 years. Celebrating the addition of her son, Dr. Brandan Althof, joining the dental team in 2015, we changed our practice name to South County Family Dental, Inc. 

Our compassionate, professional staff is dedicated to providing you with the highest level of personalized healthcare possible. We proudly provide care for patients of all ages, and we treat each patient like a family member. Since we are dentist owned - and not tied to a large dental corporation - our primary focus is you!


Mary E. Fiedler, D.D.S.

Dr. Mary Fiedler graduated from the University of Southern California's School of Dentistry with honors in 1988.  Upon graduation, she was inducted into the Omicron Kappa Upsilon Dental Honor Society.  She earned a Bachelor of Science degree in Chemistry with academic honors from the University of California at Davis in 1984.  While at UC Davis, Dr. Fiedler was on the swim team, became a National Champion, and was inducted into their Athletic Hall of Fame in 2001.

Dr. Fiedler is trained in all facets of dentistry, with over 30 years of experience treating all ages of patients.  She provides comprehensive dental care for all of her patients including preventative care, cosmetic dentistry, implant restorations, Invisalign (certified in 2001), Orthodontics, Lumineers, white fillings, emergency care, and more.  She has taken -  and continues to take - hundreds of hours of continuing education courses in all phases of dental treatment, and participates in local study clubs with her colleagues.

Over the years, Dr. Fiedler has served as faculty at the Herman Ostrow School of Dentistry of USC and Cerritos College, where she  taught Oral Pathology to the Dental Hygiene Students. Her love of teaching dental students began early as she instructed at USC Dental School as a dental student. 

Dr. Fiedler has been happily married to her husband & high school sweetheart, Ed, for over 31 years.  They have three children, with their oldest, Brandan, joining South County Family Dental after his graduation from USC Dental School 3 years ago.  Their daughter, Alison, recently graduated with multiple honors from the University of Arizona with a Finance Degree and is now working as a financial advisor.  Their youngest daughter, Stephanie, is busy with high school, voluteering with NCL, and dance performances.   In her free time, Dr. Fiedler enjoys photography, scrap booking, swimming, traveling, family time, and volunteering with her daughter.

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Call today: 949.249.3473


Brandan A. Althof, D.D.S.

Dr. Brandan Althof, son of Dr. Mary Fiedler, graduated from the Herman Ostrow School of Dentistry of USC in 2015. He was honored on the Dean's List and was President of his dental fraternity, Delta Sigma Delta. During dental school, Dr. Althof treated patients in many areas of Los Angeles, including “Skid Row,” the LA county hospital, and the Hollenbeck nursing home. He also treated underprivileged children in various mobile clinics associated with USC. Dr. Althof believes that each patient deserves the best possible care, and is excited to continue helping families in Southern California smile.

Dr. Althof attended the University of California, Los Angeles for his undergraduate education. He graduated in 2011 with a Bachelor of Science degree in Biology with academic honors. He also graduated from Tesoro High School in 2007 with many honors including Valedictorian, National Honor Society, CSF Lifetime Member, AP Scholar with Distinction, Varsity Swimmer, Eagle Scout, and more.

Dr. Althof enjoys pursuing continuing dental education in his downtime. His most recent course certified him as a provider of Botox and Dermal Fillers.

Office Manager

Amanda Althof

Amanda Althof joined South County Family Dental, Inc. in 2013 as our terrific Office Manager. She has over 15 years of customer service and administrative experience. We are thrilled to have her as part of our dental team, and she looks forward to helping each of our patients.

Amanda graduated from the University of California, Santa Cruz in 2011, Magna Cum Laude, with Bachelor of Science degrees in English Language Literature and Film Theory.  She also graduated from Tesoro High School in 2007 with honors including Valedictorian.

In her free time, Amanda enjoys camping, water skiing, helping others, and spending time with family and friends, including her husband Dr. Brandan Althof. After friendship throughout high school college and dating for 5 years, the two tied the knot in February 2018. 

Dental Hygienist

Natalie Diaz, R.D.H.

Natalie joined South County Family Dental, Inc. after graduating from San Joaquin Valley College in 2017 with an Associate of Science degree in Dental Hygiene.  While earning her R.D.H., Natalie excelled in treating various cases of periodontal disease, a disease that affects almost half of American adults, providing preventative and therapeutic care. The faculty granted her the Hu-Friedy Golden Scaler Trophy and the Western Society of Periodontology Award upon graduation for her academic enthusiasm and comprehension in periodontology.  

Natalie immensely enjoys making personal connections with her patients while giving them the knowledge to best care for their mouth. She is also fluent in Spanish, helping our practice better communicate with our patients. In addition to helping adults, Natalie is also fantastic with children and helping them understand the importance of proper brushing and flossing for a healthy smile!
In addition to dental hygiene, Natalie enjoys practicing yoga, hanging out in the sun, spending time with friends and family, as well as working as a licensed cosmetologist on her days out of our dental office.