our clinical assistants

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Joanne Cox, R.D.A.

Dental Assistant

Joanne Cox, R.D.A., was born on Long Island, New York, and arrived in California at age eight. She attended Sunny Hills High School and graduated from Fullerton College in 1980. Joanne joined our office in 1994. With more than 25 years experience in the dental assisting profession, and a special emphasis on cosmetic dentistry, Joanne has become a vital part of our dental assisting team.

Joanne enjoys time with her daughter, currently attending Arizona State University. Joanne also enjoys running, tennis, skiing, and a workout at the gym.


Sandir Holland, R.D.A.

Dental Assistant

Sandir Holland, R.D.A., was born in Brazil and moved to Southern California when she was thirteen. Sandir obtained her dental assisting education in 1972. After five years of assisting in an excellent dental practice in Riverside, she joined Dr. Eriksmoen’s staff in 1978 and became part of the current staff when the dental practices merged in 1992.

Sandir has a unique ability to express her compassion to patients with anxiety toward dental procedures and assist them during their dental treatment. In addition, Sandir has become very proficient in the fabrication of provisional restorations and counseling patients to obtain their optimum dental health and aesthetic potential.

Sandir’s hobbies include drawing and painting en plein-air. She enjoys art museums, gardening, traveling, the theater and photography. She is blessed with a wonderful son and two granddaughters.


Charmaine Martin, R.D.A.

Dental Assistant

Charmaine Martin’s home town is Spokane, Washington. She received her AA degree in dental assisting from Northwest College in 1983. Prior to coming to our office, Char was on the staff of a prominent prosthodontic office with emphasis on dental implants. Char joined our staff in 1989 and she has become a vital member as an outstanding dental assistant. Char’s expertise is also being utilized at the front desk to monitor the progress of patients’ treatment and assist with scheduling.

Char enjoys snow skiing, volleyball and camping. She enjoys school activities and sports with her lovely daughter and a delightful son.


Cherie Rudolph, R.D.A.

Dental Assistant

Cherie Rudolph, R.D.A., joined our office staff in 1982 as a Dental Assistant. Raised in Thousand Oaks, California, Cherie obtained her training at Cypress College. She earned her Certified Dental Assistant (C.D.A.) and Registered Dental Assistant (R.D.A.) in 1982.

Cherie has attained a very high level of proficiency in dental laboratory procedures and dental photography as well as dental assisting. She monitors the progress of patients’ treatment and assists with communication and scheduling between the office, patients and other dental specialists.

Cherie provided invaluable assistance at autopsies for a year at the Los Angeles Coroner’s Office during Dr. Eggleston’s research project on dental amalgam.

Cherie is an accomplished soccer player, having played in competitive Soccer Leagues since childhood. She enjoys spending her recreation time attending boot camp classes, coaching soccer, and water-skiing at the River, with her husband, Tom, and their two delightful daughters.


Isumi Muto, R.D.A.E.F.

Dental Assistant

Isumi Muto, R.D.A.E.F., has been in the dental field for about 20 years. She was raised in Gifu, Japan prior to completing her degree in Art Design at the Art University of Tokyo. She moved to Los Angeles to complete her education at the Fashion Institute (FIDM).

Isumi began her dental career in Torrance with Dr. Okamoto and Dr. Yanase and completed her RDA in 2000. She finished her certification and passed her California Boards in Extended Functions at UCLA in 2002. She also has advanced training in implant Prosthodontics.

Isumi lives in West Torrance. She travels to Japan yearly to shop and spend time with family. She enjoys Yoga, walking, and spending time with friends.


Ellen Villescas

Dental Assistant

Ellen Villescas joined our office staff as a Dental Assistant in 1977. She stays current with the latest dental assisting techniques by maintaining her state x-ray license and coronal polishing license certification through continuing education courses. Ellen has become extremely proficient in the latest infection control procedures and she routinely monitors our autoclave sterilization equipment.

Ellen was raised in Morenci, Arizona and received training as a dental assistant at the Southern California College of Medical and Dental Assistants after moving to California in 1976. Ellen contributes to the community as a monthly volunteer for SOS in Costa Mesa. She has three charming daughters and delights in caring for her seven grandchildren and two great granddaughters – life is good! In her recreational time, she enjoys the movies, gardening, macramé, roller-skating, aerobics and her grandchildren’s school and athletic events.


Rhonda Villescas

Dental Assistant

Rhonda is the newest member of our team. She is very excited and enthusiastic about supporting Dr. Wittenauer with her esthetic and comprehensive dentistry. She believes in the dramatic difference excellent dentistry can make in the lives of our patients.

Rhonda was born in Morena, Arizona and moved to Oahu, Hawaii at the age of two. After spending four years in Hawaii she moved to Laguna Hills, California. After graduating from high school she attended The Fashion Institute of Design and Merchandising in which she made fashion merchandising her first career. After becoming a mother, she started her new career as a dental assistant. What she loves most about dentistry is working with the patients and continuing to learn and grow in her skills to provide the best care possible.

When Rhonda is not working she enjoys spending time with her two sons Jared, who is twenty-one, and Cason who is four years old. She also enjoys cooking and crafts.