Mastication Causing Segmental Spinal Motion in Common Cervical Orthoses

the Less Institute medical research by Dr. Kingsley R. Chin

Scientific Paper

Chin KR1Auerbach JDAdams SB JrSodl JFRiew KD.

Interested medical professionals can read the full paper, as published in Spine, here.

Study Design

In vivo fluoroscopic quantification of segmental cervical spinal motion in asymptomatic volunteers during mastication.


To quantify the degree of segmental cervical spine motion in patients during mastication and while wearing several commonly used cervical orthoses.

Summary of Background Data 

Cervical orthoses are routinely used to stabilize the cervical spine after trauma or cervical fusion and are, in some cases, prescribed to be worn at all times, including during eating.


Seven volunteers with an average age of 31 years (range, 26-42 years) had 5 seconds of continuous lateral cervical fluoroscopic imaging while they chewed gum without any cervical orthosis (control) and while wearing a soft collar turned forward then backward, a Philadelphia collar, a Miami J collar, or a two-poster brace. Still images were created from the fluoroscopy video, which allowed for quantification of the amount of segmental motion.


All cervical collars produced statistically greater motion at occiput-C1 and C1-C2 when compared with no collar. The motion was greatest at the occiput-C1 junction and decreased to the C4 level. No motion was detected in any subject in any brace below C4. The two-poster brace produced the most segmental motion at occiput-C1 (6.3 degrees +/- 2.0 degrees) compared with the soft collar turned backwards (1.9 degrees +/- 1.9 degrees). No subject had any segmental motion below C2 in the soft collar. No segmental spinal motion was observed without a cervical brace.


To limit upper cervical spine segmental motion during mastication, for patients with unstable cervical spines, we propose a two-poster brace with removal of the mandibular component to allow for free mandibular action. For stable spines, we propose a soft collar turned backwards. Patients should be educated with this information.

About Author Dr. Kingsley R. Chin

Dr. Kingsley R. Chin, founder of philosophy and practice of The LES Society and The LESS Institute
Dr. Kingsley R. Chin, founder of philosophy and practice of The LES Society and The LESS Institute

Dr. Kingsley R. Chin is a board-certified Harvard-trained orthopedic spine surgeon and professor with copious business and information technology experience. He sees a niche opportunity where medicine, business and information technology meet and is uniquely experienced at the intersection of these three professions. He currently serves as Professor of Clinical and Biomedical Sciences at the Charles E. Schmidt School of Medicine at Florida Atlantic University and Professor of Clinical Orthopaedic Surgery at the Herbert Wertheim College of Medicine at Florida International University and has experience as Assistant Professor of Orthopaedics at the University of Pennsylvania Medical School and Visiting Professor at the University of the West Indies.

Learn more about Dr. Chin here and connect via LinkedIn.

About Less Exposure Surgery

Less Exposure Surgery (LES) is based on a new philosophy of performing surgery, leading the charge to prove through bench and clinical outcomes research that LES treatment options are the best solutions – to lowering the cost of healthcare, improving outcomes and increasing patient satisfaction. Learn more at

The LES Society philosophy: “Tailor treatment to the individual aiding in the quickest recovery and return to a pain-free lifestyle, using LES® techniques that lessen exposure, preserve unoffending anatomy and utilize new technologies which are safe, easy to adopt and reproducible. These LES®techniques lessen blood loss, surgical time and exposure to radiation and can be safely performed in an outpatient center. Less is more.” – Kingsley R. Chin, MD

About The LESS Institute

The LESS Institute is the world leader center of excellence in Less Exposure Surgery. Our safe, effective outpatient treatments help patients recover quickly, avoid expensive hospital stays and return home to their family the same day. Watch our patient stories, follow us on Facebook and visit to learn more.

About SpineFrontier

The above study utilized LES Technology from SpineFrontier – leading provider of LES Technologies and instruments – offering surgeons and patients superior technology and services.

Scientific Paper Author & Citation Details


Chin KR1Auerbach JDAdams SB JrSodl JFRiew KD.

Author information

    1. Division of Spine Surgery, Department of Orthopaedics, Hospital of the University of Pennsylvania and the University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.

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