The Team

Dr. Nathan Christensen is an advocate of biomimetic dentistry (minimally invasive dentistry preserving maximum natural tooth structure) and has done extensive post- graduate work at UCLA in root canal treatment. His memberships include the American Dental Association, California Dental Association, Academy of General Dentistry and Academy of LDS Dentists.

Dr. Nathan Christensen graduated from the Hermam Ostrow School of Dentistry at USC in 2012. During his educational period he achieved and partook in many activities, including serving as the USC Student Chapter President from 2010 to 2011 and making the Dean’s list Summer 2009, Fall 2010 and Spring, Summer and Fall 2011.

Dr. Nathan Christensen volunteers service at monthly clinics. He also volunteered at the International Clinic in Belize in April of 2011. For this, he was given a humanitarian award for service to the children of Southern California and Belize.


Dr. Nathan Christensen is a member of several local and national dental organizations including:

  • American Dental Association
  • California Dental Association
  • American Academy of Cosmetic Dentistry
  • Academy of General Dentistry
  • Academy of LDS Dentists


Hemant Sachdeva, DDS, brings extensive experience in preventive and cosmetic dentistry to Rancho San Diego Dental Group in El Cajon, California.

Dr. Sachdeva was born and raised in central California. He earned his undergraduate degree from UC Berkeley and obtained his Doctor of Dental Surgery from the Herman Ostrow School of Dentistry of the University of Southern California. At USC, doctor Sachdeva also earned the Thor Award for providing outstanding service to handicapped and disadvantaged patients.

Outside of the office, Dr. Sachdeva loves using his dentistry skills to provide humanitarian service. During the course of his career, he’s traveled as far as Cambodia to provide dental service for those in need. He’s also worked with veteran and homeless populations throughout California to promote preventive oral health care and improved hygiene.

Dr. Sachdeva is fluent in English, Spanish, Punjabi, and Hindi. When he isn’t working with patients, Dr. Sachdeva enjoys hiking, camping, and playing sports such as tennis, racquetball, and golf. He welcomes any patient seeking comprehensive oral health care to Rancho San Diego Dental Group.

Dr. Jennifer Villalta is passionate about helping children improve their overall and oral health. She believes every child is unique and the dental care provided should be individualized for each child and their family. She strives to make each dental visit an enjoyable and positive experience.


Dr. Jen is a first-generation Latina who grew up in Los Angeles, where she spent her formative years. She later moved with her family to Sonoma County, where her love for pediatric dentistry began. At the age of 16, she started working at a dental office, and by 17 she obtained her Registered Dental Assisting (RDA) license. She completed her undergraduate studies and obtained her Bachelor of Science degree in Physiological Sciences at UCLA. During her time in college she continued to work as a RDA working primarily in pediatrics.


Dr. Jen returned to Northern California to obtain her Doctorate of Dental Surgery at the University of the Pacific Arthur A. Dugoni School of Dentistry, where she focused on Pediatric Dentistry. She was President of the Pediatric Dental Society, was in charge of the advanced pediatric dental clinic, and was community service director. During her time she received numerous accolades for her leadership, including the coveted Pediatric Dentistry Award presented for her superior proficiency in the field of dentistry for children.


Dr. Jen missed her Southern California roots and returned to UCLA to complete her residency in Pediatric Dentistry at the UCLA School of Dentistry, as well as simultaneously obtaining her Master of Public Health degree from the UCLA Fielding School of Public Health.


Dr. Jen is excited to be working with the team at Rancho San Diego Dental Group!  When she isn’t practicing dentistry, she enjoys being active and outdoors whether it be at the beach or exercising, and during the winters she enjoys snowboarding.

Dr. Tyler Nelson is thrilled to be practicing oral surgery at Rancho San Diego Dental Group! Although his life’s journeys have taken him far from home, he is grateful to be back.

Dr. Nelson received his Bachelor’s Degree in Spanish from Brigham Young University. During his undergraduate education, he took a “career exploration” class which required him to observe numerous professions. When he observed an oral surgeon in action, he found his passion and made up his mind rather quickly, that this was the career path for him. He still loves what he does every day.

During dental school at University of the Pacific, San Francisco, Dr. Nelson served as class president each year, and as Student Body President during his senior year. He graduated with high honors, and was accepted into the 4-year oral and maxillofacial surgery program at Highland Hospital in Oakland, CA.  During residency, Dr. Nelson was trained in IV sedation, dental implants, removal of difficult teeth, facial trauma and orthognathic (jaw repositioning) surgery. He also presented research on jaw tumors and imaging modalities for diagnosis of mandibular fractures.

Dr. Tyler Nelson is happily married to Natalie, his college sweetheart. Together, they are proud parents of 6 children. Beyond spending time with his family, Dr. Nelson enjoys running, biking, and snowboarding.

Dr. Jeff Takai, is a dental implant and gum disease specialist at Rancho San Diego Dental Group. Dr. Takai grew up in southern California where his father was also a dentist. As a result, he has been involved in dentistry in some capacity his entire life and he developed a strong passion for dentistry at a young age.

Dr. Takai completed his undergraduate schooling at UC Berkeley. He then attended University of the Pacific for dental school and earned his Doctorate of Dental Surgery. While in dental school Dr. Takai was attracted to the surgical side of dentistry and decided he wanted to become more specialized. Upon graduation, he furthered his education and training in periodontics at UC San Francisco where he completed his surgical residency in 2013.

Dr Takai is a member of the following organizations:

  • Academy of Osseointegration
  • American Academy of Periodontology
  • California Society of Periodontology
  • American Dental Association
  • California Dental Association

Dr. Takai and his wife, Sarah live in southern California where they enjoy cooking and traveling together. During his free time, Dr. Takai also enjoys reading, practicing Jiu Jitsu and playing golf.

Dr. Anke Beyer-Jordan is a passionate, experienced and caring orthodontist. She has dedicated herself to providing excellent orthodontic care, and has spent the majority of the last thirty years helping children, teenagers and adults around the world, and in southern California since 2004.

Dr. Beyer-Jordan earned her dental degree and PhD degree from Johann Wolfgang Goethe-University and Dental School in Frankfurt, Germany. After several years in private practice, she became an Assistant Professor in the Department of Oral and Maxillofacial Surgery at the University of Stellenbosch in Cape Town, South Africa where she devoted her spare time to help the underserved townships in need of dental surgery.

Dr. Beyer-Jordan found that she had a passion for orthodontics, and was accepted to the prestigious Department of Orthodontics and Dentofacial Orthopedics, Charite', Humboldt- University in Berlin, Germany where she spent her residency, post graduate training and received her degree as an orthodontist. While there, she became Assistant Professor where her advanced training and publishing focused on the research of cleft-palate patients as well as comprehensive orthodontic care. After relocating to California she obtained her dental license from the University of Southern California (USC).

She is an active member of multiple professional organizations in the U.S. and Germany. The Jordan family loves the outdoors, and with her husband of 25 years and two sons, she spends every free minute near or on the water.

Dr. Mark Karpman is the in-house endodontist at Rancho San Diego Dental Group.  Dr. Karpman is a highly trained and compassionate endodontist with over 30 years of experience.  He has remained at the top of his field by completing extensive continuing education studies throughout his career.  He truly cares about his patients, and approaches each patient's treatment plan with an unbiased approach.  Dr. Karpman is committed to providing excellence in endodontic service in a professional, caring and comfortable atmosphere, and is an integral part of the team at Rancho San Diego Dental Group.  Dr. Karpman is married with children and enjoys spending his free time playing outside with them!