Medical Directors - Nexus Dental Systems - A Turn-key Solution for Obstructive Sleep Apnea.

Our Medical Directors

Nexus Dental Systems Medical Directors represent a highly select group of board certified sleep physicians with a keen interest in collaborative care to deliver the very best treatment individualized to the patient. Our medical directors have years of experience in sleep medicine and have distinguished themselves within the specialty as patient centric providers who support an interdisciplinary approach to patient care. They offer a combination of in-person and telemedicine encounters within their state emphasizing a convenience care model.

We are visionaries behind distinctive brands with convergent, complementary capabilities who have created an innovative ecosystem to change the future of dental medicine.

Our Medical Directors

Jamila Battle, MD
Raleigh, NC
Jamila Battle, MD is a multi-licensed triple board-certified sleep medicine physician who provides sleep solutions across multiple states. If you have a sleep disorder that you’re ready to put to bed, Dr. Battle can help. She’s treated countless patients who struggle with major sleep problems such as hypersomnia, insomnia, restless legs, circadian rhythm, and breathing disorders, including sleep apnea.Although Dr. Battle didn’t set out to become a sleep expert when she enrolled in medical school, her indirect path to sleep medicine is what helps her take a more comprehensive approach to her patients’ sleep disorders and their overall health.She attended Duke for undergraduate education, UNC Chapel Hill for medical school and completed training in Family Medicine at University of Michigan, Ann Arbor. After training, she came to realize that although diet and exercise were widely regarded as the two main pillars of optimal health, there was a missing third and fourth pillar that was just as essential — sleep/environment and meditation/connection. Dr. Battle decided she wanted to incorporate the other two pillars of health into her medical practice, so she completed advanced training and obtained additional board certifications in Sleep Medicine and Addiction.In addition to helping patients sleep, lose weight, and achieve optimal health, Dr. Battle serves as adjunct professor at the University of North Carolina Family Medicine, is author of #1 Amazon best seller “from Abuse to Abundance and creator of RebootRepairRebirth®, an online healing recovery system. This innovative model aids those who are suffering to forgive themselves, so they can become fully integrated and capable of self-love. Reboot your soul by speaking your truth and ending the isolation. Repair by getting help and consciously healing your mind, heart, and body. Celebrate your Rebirth as a wiser, loving and centered being. Live life abundantly. She enjoys an individualized/patient-centered approach which focuses on YOU!For more information, visit or
Yefim Cavalier, MD
Boca Raton, FL

Dr. Yefim Cavalier is a board certified Neurologist and Sleep Disorders Specialist residing in Boca Raton, Florida. He understands the implications of poor sleep quality on the neurological, cardiovascular and general health concerns of his patients. He is particularly interested in the interplay between sleep disorders and cognitive decline — an area of research that has gained significant attention in recent years. Dr. Cavalier’s focus on patient education and individualized treatment is critical to ensuring patient engagement and satisfaction in attaining optimal health.

Bertrand de Silva, MD

Bertrand de Silva, M.D., F.C.C.P. is a graduate of the St. Thomas Hospital Medical School, University of London, England 1986. He was awarded a Medical Research Council Scholarship as well as Medical Research Council Fellowship. He was also awarded a $2 million Research Grant by Burroughs Wellcome Foundation and became a Burroughs Wellcome Research Foundation Scholar. He completed his Internship at Kern Medical Center, Bakersfield and Internal Medicine training at USC County Hospital, Los Angeles and a Pulmonary, Critical Care and Sleep Fellowship at Cedars Sinai Hospital. He is board certified in all these fields.
Dr. Bertrand de Silva is currently a Staff Intensivist for Sound Physicians Intensivist Group at St.Bernadine’s Medical Center in San Bernardino, for Benchmark at Palomar Regional Medical Center in Escondido. He is the Medical Director of the Sleep Services at St Judes Fullerton, at Preferred Sleep Solutions in Fullerton. He serves as a national consultant to American Imaging Management, AIM Specialty Health (Anthem Subsidiary) in developing the National Sleep Apnea Treatment and Diagnosis Clinical Guidelines.

Ashwin Gowda, MD
Austin, TX

Ashwin Gowda, MD is board certified in sleep medicine and psychiatry. He has been providing care to those in South Austin since 2002 and is currently the Medical Director of Texas Sleep Medicine. His medical practice offers consultations, sleep studies (in the lab and at home studies) and all ongoing care to ensure the best possible outcome. Common sleep disorders diagnosed and treated include snoring/obstructive sleep apnea, restless legs syndrome, insomnia, parasomnias and circadian rhythm disorders.
Dr. Gowda is board certified in Sleep Medicine and Psychiatry. His education includes a one-year medical internship at Robert Wood Johnson Hospital in New Brunswick, New Jersey, and a three-year residency in psychiatry at the Mayo Clinic in Rochester, Minnesota and a one year fellowship in sleep medicine at SUNY (State University of New York) in Stony Brook, New York.
Above all else, Dr. Gowda finds fulfillment in contributing to the well-being of every person he cares for. Dr. Gowda is married and has 3 boys. When he’s not helping people get a good night’s sleep, he enjoys spending time with his family, exploring the Austin food scene, bicycling and playing tennis.

Joe Krainin, MD
Jacksonville, FL

Dr. Joseph Krainin is board-certified in the fields of Sleep Medicine and Neurology. He specializes in the remote diagnosis and management of sleep apnea and is licensed to practice medicine in 46 states.

Christopher Lettieri, MD
Annandale, VA

Dr. Christopher J. Lettieri, MD, FCCP, FAASM is the Senior Director – Insomnia, in US Medical Affairs at Idorsia Pharmaceuticals. In addition, Dr. Lettieri is a Professor of Medicine at Uniformed Services University and currently serves as the Education Coordinator and Director of Respiratory Therapy at Johns Hopkins – Suburban Hospital. Prior to Idorsia, he previously worked as a Medical Asset Lead and Senior Medical Director for GlaxoSmithKline.
Dr. Lettieri retired as a Colonel in the U.S. Army, where his previous assignments included the Pulmonary & Critical Care Medicine Consultant to the Army Surgeon General, Senior Medical Advisor to the Joint Chiefs of Staff, Director of Global Health Engagements, Assistant Deputy Commander for Medical Services at the Walter Reed National Military Medical Center, Chief of the Walter Reed Sleep Disorders Center, and Sleep Medicine Fellowship Program Director at the National Capital Consortium. Dr. Lettieri serves on numerous academic and editorial boards related Pulmonary, Critical Care, and Sleep Medicine topics.

asim roy medical director ohio
Asim Roy, MD

Asim Roy is the medical director of the Ohio Sleep Medicine Institute and an assistant clinical professor at Northeast Ohio Medical University. He is board certified in sleep medicine and neurology and works in close collaboration with health care providers to deliver coordinated sleep medicine care to adult and pediatric patients. His comprehensive approach includes thorough patient interviews and, if needed, diagnostic polysomnography or home sleep testing. Dr. Roy takes a comprehensive approach in treating patients and has expertise in accessing alternative therapies for sleep disordered breathing.

He is the author of various articles, chapters and books, covering, among other topics, sleep and neurological disorders, obstructive sleep apnea, restless legs syndrome, narcolepsy, idiopathic hypersomnia, cataplexy and REM sleep behavior disorder and parasomnias. Dr. Roy completed his neurology residency at Georgetown University as Chief Resident and his sleep and neurophysiology fellowship at the Cleveland Clinic Foundation.

A big proponent of education, he trains medical professionals on sleep disorders management (i.e. including medical students and residents). He has been the principal investigator of multiple research trials. He is a member of the American Academy of Sleep Medicine, American Academy of Neurology, American Medical Association and Columbus Medical Association.

Stephen Stuart, MD
Prescott, AZ
Jagdeep Bijwadia, MD
St. Paul, MN

Dr. Jagdeep Bijwadia is board certified in internal medicine, pulmonary, and sleep medicine. He is founder and CEO of a national sleep telemedicine practice (Sleepmedrx) serving all 50 US states. He also serves as Chief Medical Officer for Whole You and is a clinical consultant for Ectosense. He currently holds a faculty position as Assistant Professor in the Department of Pulmonary Critical Care and Sleep Medicine at the University of Minnesota and has a private practice in Saint Paul, Minnesota. Dr. Bijwadia has been named top doc by the Minneapolis magazine as well as US News and World Report. He served as president for the Minnesota Sleep Society from 2016 to 2018 and is active in promoting sleep health in Minnesota. He also has an MBA from the University of St. Thomas in Minneapolis.

Amalia Geller, MD
Las Vegas, NV

I am a board-certified Pediatric Neurologist with subspecialty board certification in Sleep Medicine and additional post graduate fellowship training in Epilepsy and neurophysiology. My post graduate training in Child Neurology was at the University of California at San Diego. Neurophysiology and Epilepsy fellowships were performed at University of California at Irvine and I completed a Sleep Medicine fellowship at the University of Texas Southwestern in Dallas. As a Child Neurologist with academic and private practice experience, I observed the impact of sleep disordered breathing on child development. In particular, I saw how imperative it was to manage sleep difficulties in children with Epilepsy because chronic sleep deprivation leads to a lowered seizure threshold. I also observed that children with behavioral problems and academic issues (ADD etc.) were more prone to breathing disordered sleep.I am primarily focused on children with developmental and neurological conditions such as autism, epilepsy, ADD and other genetic disorders. These children in particular have an increased risk or are prone to cranial facial malocclusion based on genetic and epigenetic factors. Because this involves a more complete approach to pediatric sleep medicine, I have included collaboration with Sleep Dentists. It is not enough to refer a child for a tonsillectomy and a sleep study. We must look at the child’s overall development, malocclusion and craniofacial abnormalities to formulate a treatment plan. Newer, cutting-edge technologies are utilizing stem cell stimulation to grow bone and develop appropriate facial structures and correct malocclusions. This is what makes my approach to pediatric sleep unique. I include on my team the pediatric sleep dentist, the oral myofascial therapist and orthodontists. My vision is to develop a comprehensive pediatric sleep program that is designed to treat the child’s underlying malocclusion as the root cause of their breathing disordered sleep. A comprehensive holistic integrative approach is what is imperative to treat children as a whole in order for them to achieve their maximum potential.

Barbara Hutchinson, MD
Annapolis, MD

Dr. Barbara Hutchinson is the President and Managing Partner of Chesapeake Cardiac Care in Bowie, Maryland. She earned her undergraduate degree from the University of the West Indies in Trinidad in Chemistry and Biochemistry. She migrated to the US and completed a PhD in Cardiovascular
Pharmacology at Howard University, Washington DC before going to the University of Maryland Medical School, Baltimore MD where she completed her medical degree. She went on to complete her Internal Medicine Residency and Cardiology Fellowship at the University of Maryland Medical Center in
Baltimore Maryland. She is certified in both cardiovascular medicine and sleep medicine by the
American Board of Internal Medicine.

Dr. Hutchinson provides cardiovascular and sleep care in Bowie Maryland and recognizes the role that
sleep plays in cardiovascular health. She is a fellow of the American College of Cardiology, member of the American Academy of Sleep Medicine, American Academy of Cardiovascular Sleep Medicine, Past
President of the Association of Black Cardiologist and currently sits on several medical advisory and non-
profit boards.

Dr. Hutchinson has been involved in clinical trials for over 30 years serving as clinical research
coordinator, sub investigator and principal investigator. Areas of clinical research have included congestive heart failure, hyperlipidemia, atrial fibrillation, hypertension, myocardial infarction, and coronary artery disease. She has several publications and has presented both nationally and internationally on cardiovascular disease and sleep. She is currently the Medical Director of Flourish Research, Bowie.

Dr. Hutchinson is passionate about preventing untimely death from heart disease, by addressing and treating all risk factors including sleep. She also wants to bridge the gap in clinical trials to ensure that study populations reflect the real-world population for drugs and devices, by being intentional about
inclusion of underrepresented groups in all facets of clinical research.

Michael Lacey, MD
Marietta, GA

Dr. Michael Lacey is a Neurologist who sub-specializes in Sleep Medicine. After graduating from the University of Virginia in Charlottesville he later earned a medical degree from the Eastern Virginia Medical School. He remained at Eastern Virginia to complete two years of Internal Medicine training and then a 3 year neurology residency- and was selected Chief Resident in Neurology his final year. He then completed a fellowship at Emory University, specializing in Neuromuscular Disorders and Epilepsy. He received extensive training in Sleep Medicine in his Neurology residency and in his first several years of practice. He is Board Certified by the American Board of Psychiatry and Neurology in both Neurology and Sleep Medicine, by the American Board of Sleep Medicine, and holds the position of Medical Director of the Atlanta School of Sleep Medicine, teaching physicians, nurse practitioners, physician’s assistants and sleep technicians the basics, diagnosis, treatment and current trends in Sleep Medicine. He maintains a private practice in the specialties of Neurology and Sleep Medicine, and participates extensively in clinical research in the areas of Sleep Medicine and Neurology as Medical Director of Neurotrials Research, Inc, and has participated in over 300 clinical trials in the areas of Sleep Medicine and Neurology. Professional memberships include the American Academy of Sleep Medicine, the American Academy of Neurology, the Medical Association of Georgia, and the the Georgia Association of Sleep Professionals.

Matthew Troester, MD
Scottsdale, AZ

Matthew Troester, DO, FAASM, is one of only two Pediatric Neurologists in the Southwest quadruple board certified in Neurology with special competence in Child Neurology, Sleep medicine, Clinical Neurophysiology, and Epilepsy. After graduating Phi Beta Kappa from the University of Kansas, Dr. Troester completed his medical training at the Arizona College of Osteopathic Medicine–Midwestern University. Dr. Troester then completed his pediatric residency at St Joseph’s Hospital and Medical Center and three years of Pediatric Neurology residency at Barrow Neurological Institute. He went on to do fellowship training in Epilepsy, Clinical Neurophysiology and Sleep Medicine also at Barrow.

A highly engaged member of the American Academy of Sleep Medicine (AASM), he is a former member of the AASM Childhood Sleep Disorders and Development Steering Committee, an author of the AASM Quality and Outcome Measure on Pediatric Sleep Apnea, an author of AASM/CDC Consensus Conference on Healthy Sleep Duration for Children, a past member of the AASM Presidential Telemedicine Committee, co-author of the last 4 versions of the AASM Scoring Manual, and currently serves as Vice Chair of the AASM Scoring Manual Editorial Board.

He has twice chaired the AASM national intensive sleep scoring course, directed the pediatric track at AASM Sleep Trends and chaired the AASM board review kick starter at the annual APSS meeting.

Dr. Troester has years of experience as a principal investigator in various pharmaceutical trials.

He is an expert in sleep pharmacology and the more complicated overlap of clinical neurophysiology and sleep medicine.

Lee Surkin, MD
North Carolina

Lee A. Surkin, MD is triple board certified in sleep medicine, cardiovascular disease and nuclear cardiology and has over 22 years of practice experience. His undergraduate degree in biology was done at Brandeis University followed by a masters degree in human nutrition at Columbia University.

He graduated with his MD from Hahnemann University in Philadelphia and did his internal medicine and cardiology training at Yale University.

Dr. Surkin has been in private practice in eastern NC where he founded a cardiology practice followed by a sleep medicine practice followed by a medical weight loss practice and merged all into a multi-specialty group that places a strong emphasis on wellness and prevention. Dr. Surkin also founded a sleep medicine practice in NY where he sees patient utilizing telemedicine.

Dr. Surkin was also one of the first sleep physicians in NC to offer home sleep apnea testing and has been on the cutting edge in offering new and innovative treatments across a broad spectrum of his areas of expertise.

He is a national leader in advancing the recognition of the strong association between sleep disorders and cardiovascular disease and founder of the American Academy of Cardiovascular Sleep Medicine.

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