Powerful Potential for 3D Printing in Medicine

Researchers at the University of Michigan are exploring the clinical implications for 3D printing, and how it can improve the lives of our patients.

A vastly inclusive collaboration that spans more than 30 departments across the university, medical 3D printing transcends excellence in science to address the physical and emotional needs of patients. Finding cures for potentially devastating conditions like tracheobronchomalacia helps drive quality care and engagement, as care teams experience firsthand the trailblazing developments that create endless possibilities for our patients. Learn more about the work we do:

3-D Printed Airway Splint

3D Airway Splint

Our researchers are using 3D printing to investigate a treatment for severe cases of tracheobronchomalacia. Tracheobronchomalacia is a rare condition in babies characterized by a floppy, underdeveloped windpipe, which causes the baby’s airway to frequently collapse. Severe cases, although rare, have high morbidity and mortality.

As an answer to this rare condition, the research team developed a biodegradable device, which is designed using computer-aided design based on the patient’s imaging data and manufactured using a laser-based 3D printing system. The patient-specific tracheobronchial splint is sewn around the patient’s floppy airway to expand the affected area and provide support and protection during airway growth. Over about three years, the splint is resorbed by the body. To date, this technology has been used to save the lives of three babies. Today the team is in the final stages of FDA approval to begin a randomized controlled trial to look at the effectiveness of the device.

3-D Printed CPAP Masks for Obstructive Sleep Apnea

3D Printed CPAP masks

Obstructive sleep apnea—the most common form of sleep apnea—is a condition in which breathing repeatedly starts and stops during sleep. If untreated, sleep apnea can cause daytime sleepiness, lack of energy, fatigue and tiredness, and may raise risk for serious health conditions, including high blood pressure, stroke and heart attack.

The standard treatment for sleep apnea is Continuous Positive Airway Pressure (CPAP), which requires the patient to wear a mask while sleeping. The mask fits against the face and supplies a constant air pressure, keeping the airway open and preventing obstruction. Although CPAP therapy is highly effective, it requires an adequate seal of the mask against the face. This proves difficult for children with structural facial anomalies who are unable to wear a standard CPAP mask.

Our researchers are using 3D printing to customize CPAP masks for these children. Using 3D photography or a CT scan, a virtual, three-dimensional model of the patient's face is created. This model is then used to determine the patient's direct facial contour, which allows for the virtual modeling and 3D printing of a customized mask insert. The 3D-printed insert is filled with soft silicone and placed into a standard RespironicsTM mask. The result is a custom CPAP mask, tailored to the specific anatomy of the patient. Outcomes to date have been positive, with the first patient achieving an 80% reduction in mask leak and a 25% reduction in residual Apnea Hypopnea Index. The team is currently in the midst of a pilot clinical trial to treat ten patients with craniofacial disorders and sleep apnea.

Additional Projects

David Zopf, M.D., Colleen Flanagan, M.S.E., and Scott Hollister, Ph.D.


In addition to the aforementioned projects, our team is using 3D printing for the following applications:

  • Fetal airway
  • Temporal bone and other presurgical planning, training and testing models
  • PEKK Osteofab airway splint
  • Nasal stent
  • External ears (with condrocytes and stem cells)
  • Nasal constructs (with condrocytes and stem cells)
  • Trachea extensions (with condrocytes and stem cells)
  • Larynx extensions (with condrocytes and stem cells)
  • Larynx (with bionics)
  • 3D-printed face masks for athletics and trauma rehab
  • 3D scaffolds for bone and joint regeneration
  • 3D scaffolds for ears and noses
  • 3D scaffolds for prefabricated free flaps
  • 3D-printed templates for reconstructive surgery
  • PEKK/ PCL hybrid implant for mandibular defect reconstruction

Our Team

Glenn E. Green, M.D.

Glenn E. Green, M.D., is an associate professor of otolaryngology at the University of Michigan who is a leader in the translation of 3D printing into clinical practice. He has a clinical interest in communication disorders and improving interventions for breathing, speech and hearing. Dr. Green has developed surgical techniques and devices for complex airway reconstruction and is co-inventor, along with Scott Hollister, Ph.D.,of a life-saving, 3D-printed tracheal splint, as well as a number of other medical devices. He is the director of ongoing translational trials of 3D-printed medical devices in both humans and animals. 

Dr. Green has won several awards, including the Innovation Award from Popular Mechanics (2013 Breakthrough Awards, New York City).  He has over 50 publications related to both his clinical and his research work, including theNew England Journal of MedicineScience Translational MedicineNature Genetics and JAMA.  Dr. Green has been widely featured in media, including Scientific American, the New York TimesForbes, the New Yorker magazine andGood Housekeeping.  His constructs are on featured on display at the British Science Museum in London.


Scott Hollister, Ph.D. 

Scott Hollister, Ph.D.

Scott J. Hollister, Ph.D. is a professor of biomedical engineering and mechanical engineering, as well as an associate professor of surgery at the University of Michigan, where he directs the Scaffold TIssue Engineering Group. Dr. Hollister's research interests are in the computational design, 3D printing and fabrication, as well as characterization of biomaterial systems for tissue reconstruction. He is co-inventor, along with Glenn Green, M.D., of a life-saving, 3D-printed tracheal splint, as well as a number of other medical devices and implants.

Dr. Hollister has won several awards, including the Breakthrough Innovation Award from Popular Mechanics (2013 Breakthrough Awards, New York City). He has authored over 130 publications on designing, 3D printing, computational modeling of medical devices and implants, as well as tissue engineering, including manuscripts in the New England Journal of Medicine, Science Translational Medicine, Nature Materials and Scientific Reports. His work has been featured on the Today Show, NPR, CNN, U.S. News & World Report, the New York Times, IEEE Spark, the Huffington Post, the New Yorker magazine, Mashable.com and CBC Canada. His constructs are on featured display at the British Science Museum in London. Dr. Hollister has a significant interest in developing, designing and 3D printing medical devices and implants for pediatrics, including his work with Dr. Green.


David Zopf, M.D., M.S. 

 David A. Zopf, M.D., M.S. is an assistant professor of pediatric otolaryngology at the University of Michigan. He is also a part of the Scaffold Tissue Engineering Group in the Department of Biomedical Engineering. Beginning in 2011, Dr. Zopf has cultivated several innovations in medical 3D printing. Dr. Zopf is a member of the biomedical team - along with Dr. Glenn Green and Dr. Scott Hollister - that developed a life saving, patient specific, 3D printed airway splint. Dr. Zopf was first author of the landmark New England Journal of Medicine article detailing this innovation. Dr. Zopf lead pre-clinical testing in a novel animal model for tracheobronchomalacia, which has paved the way for an upcoming clinical trial. 

Dr. Zopf now leads the development of 3D printing for craniofacial applications including scaffolds for auricular reconstruction and microtia repair, as well as nasal scaffolds for partial and total nasal reconstruction. Dr. Zopf has also used 3D printing to develop artificial rib for surgical simulation of auricular reconstruction and airway reconstruction. He has utilized 3D printing for several other applications in surgical simulation, including simulation and rehearsal in skull base surgery. He is additionally using 3D printing to enhance illustration of disease processes for patient and family education. Dr. Zopf continues to find further applications for the versatile tool of 3D.

3-D Printing in the News 

New Study Shows how babies' lives were saved by 3D printing

Researchers report promising results from first-ever cases of severe tracheobronchomalacia treated by custom-designed airway splints at U-M. Read more.

 Baby's life saved after 3D printed devices were implanted at U-M to restore his breathing. Read more.

National magazine honors creators of life-saving, 3D-printed airway splint. Read more.

Related People

Dr. David Zopf

David A. Zopf, M.D., M.S.

Assistant Professor, Department of Otolaryngology-Head and Neck Surgery
Affiliate Professor, Biomedical Engineering