Meet the Doctors

Brenda Nishimura DDS, FAGD

Dr. Nishimura is a Fellow of the Academy of General Dentistry and a Mentor of the Kois Center, a center that advances the education of dentists through scientifically and clinically proven techniques. She received her DDS, Doctor of Dental Surgery, degree at Case Western Reserve University in 1984 and her BS, Bachelor of Science degree from Tufts University in 1980.

She is a member of the Massachussetts Dental Alliance, Wellness Dentistry Network, American Academy of Oral System Health and American Academy of Physiological Medicine and Dentistry. She has completed her Preceptorship in the Balen Donan Method for the Prevention of Heart Disease and Stroke.

Dr B

Dr. Nishimura in order to provide the most up to date and advance care for her patients she has incorporated Oral DNA testing which identifies the specific causes for gum inflammation; Inman Aligner, which is a faster and less expensive option to Invisalign ; Cerec Crowns , with which crowns can be made in a single visit; and Cari-free products to prevent tooth decay.

Dr. Brenda Nishimura is married with three children. Her outside interests include violin, dressage horse riding, painting, golf, bridge and yoga.

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Dr. Matthew Kiernan DMD

Dr. Kiernan is a member of Boston University’s Goldman School of Dental Medicine’s class of 2022,  graduating Magna Cum Laude with his Doctorate of Dental Medicine.  He is also Dr. Nishimura’s son.

Dr. Kiernan grew up in Lexington, and attended Northeastern University, graduating Cum Laude with a Bachelor of Science in Biology in 2017

Dr Kim

Dr. Won Kyung (Christina) Kim, Periodontist

Dr. Kim is a Board-certified Periodontist. She completed her periodontal residency at Tufts University after receiving dental degree at the University of Pennsylvania and completing Advanced Education in General Dentistry (AEGD) at Lutheran medical center.

Dr. Kim serves as a Clinical Assistant Professor at Tufts University School of Dental Medicine where she enjoys teaching and interacting with dental students. Dr. Kim currently works in several private offices to provide periodontal treatments.

She specializes in gum grafts, crown lengthening, surgery, bone grafts, dental implants, and sinus lift. Dr. Kim enjoys meeting and forming relationships with new patients and she makes them feel comfortable in a dental chair.. Kim is compassionate, caring, gentle, honest, and easy to approach. She is a mother of two beautiful daughters. Dr. Kim likes to spend time with her family and she enjoys going to beaches around Boston.

Meet the Staff

John Kiernan, Office Manager John is Dr Nishimura's husband and recently retired from his career as a Chemical Engineer dealing with Water Purification and Disinfection. He is a Graduate of Northeastern University and has a Master's in Finance and Business Administration from Bentley University. His hobbies include fixing anything that breaks in the office, gardening, and golf. He is a great addition to our staff by handling improving systems.

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John Kiernan

Dona R. Roberts, EFCDA, RDH, Director of Patient Care and Finance Dona is committed to Oral Health Preservation. Dona is dedicated to enhancing the quality of life for all the people through promoting dental health education and reducing risk of oral disease-infection while increasing the health and wellness of the entire body. Dona is a Board Certified Registered Dental Hygienist, Certified Expanded Functions Dental Assistant, and former Dental Office Consultant . Dona enjoys spending time with family and friends, especially her two children, volunteering in the community, exploring the world through travel, painting, dancing , walking in nature and she is learning to play the flute.

Kim Pastena, LDA , Scheduling Coordinator Kim has been a licensed dental assistant since 2008. She has taken on a new role here at Lexington Dental Care as the Schedule Coordinator. She was formally trained at the Bryman Institute in Brighton, where she earned her dental assisting certificate. Kim is also certified in CPR, Radiology, OSHA and HIPPA. She enjoys helping patients to understand how their oral and medical health are related. She loves working with patients of all ages, making sure they always feel comfortable during their dental experience. In Kim's spare time she loves to spend time with her boyfriend and their child Jackson. Hiking, cooking and swimming are just a few of her hobbies she enjoys.

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Emily McCleary

Emily McCleary, RDH  Emily is a board certified, registered dental hygienist and has been with the practice since October 2011. She received her bachelor's degree from Forsyth School of Dental Hygiene in May 2011 and completed her master's degree in dental hygiene n December 2018. Emily enjoys building relationships with patients of all ages and helping them work towards a healthier lifestyle. In addition to hygiene, Emily enjoys hiking, kayaking, yoga, and spending time with friends and family.


Mayada Massabn, RDH Mayada is a registered Dental Hygienist with over 20 years of experience in excellence and safety in helping patients achieve their oral health goals. She completed her certificate in healthcare science at Middlesex Community College in 1996. Where she received her Associates Degree in dental hygiene in 1999. Mayada is multilingual, fluent in both English and Arabic. Outside of work, Mayada loves to cook, bake, and try fancy chocolates. She also has a passion for traveling and most importantly spending time with family and friends.

Krysta Heath, RDH, BSDH, Director of Media & Marketing Krysta is a board certified registered dental hygienist. She has been practicing since 2014. She received her bachelors' degree from MCPHS University at the Forsyth School of Dental Hygiene in 2014. She has a passion for teeth and has wanted to be in the dental field since she was three years old. In addition to working as dental hygienist, Krysta spent three years with a dental supply company in sales. She is passionate about making a visit to the dentist a positive experience. Krysta loves educating patients on the oral systemic health connection and helping them achieve their smile goals. She also specializes in teeth whitening and laser dental hygiene. Outside of dentistry Krysta enjoys working out on her peloton bike, exploring new health and wellness trends, traveling's to new places and spending time with her husband Nick and their two dogs. Kronk and Luna.

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Jacke Kenney, DA  Jacke has been a certified dental assistant since 2018. She received her certificate at Careers in Dentistry, school of assisting in Augusta, Georgia. She is also certified in Radiology, CPR OSHA and HIPPA. Jacke enjoys learning new dental techniques so she can educate her patients and make sure they achieve a healthy mouth and beautiful smile. Outside of work she enjoys spending time with her family and friends. She loves to read and especially loves animals.

Jacke Kennedy

Ashlyn Markarian, DA  Ashlyn became a member of our team January of 2022, she has more than a decade of experience in the world of dentistry. Starting her career as a registered dental assistant she graduated from Everest career institute in 2012, Ashlyn has experience in both General dentistry and Pediatric dentistry. After a few years, she decided to branched into the administrative side of dental, working as a treatment and financial coordinator and an insurance coordinator. Ashlyn is OSHA, CPR and HIPPA certified. She and husband, Daniel, got married in June 2019 and live in Woburn with their sweet 5 year old rescue dog, Princess Leia. In her free time, she loves hanging out with her loved ones, shopping and traveling.

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