Jaw-dropping new surgical approach | Nature Reviews Rheumatology

Scaffold-free tissue-engineered disc implants could be a viable early treatment option for degenerative pathologies of the temporomandibular joint (TMJ), according to new research published in Science Translational Medicine. Using a new surgical approach and animal model, the researchers demonstrate the safety and healing potential of such implants in early-stage TMJ disc disease.

Dysfunction of the TMJ is a common cause of pain and disability and can have multiple underlying causes (including injury and arthritis). Changes in the TMJ disc (such as disc thinning) are an early sign of TMJ degeneration and dysfunction. To address a lack of reparative treatments for TMJ pathologies, the authors investigated the use of scaffold-free tissue-engineered implants for repairing disc thinning.

The researchers used rib cartilage cells to engineer scaffold-free allogeneic TMJ disc implants using a previously tested methodology. These implants had similar biomechanical and biochemical properties to native discs and were durable, safe and well-tolerated immunologically when implanted in Yucatan minipigs.

“To achieve secure fixation of the implant to a defect, we had to develop a novel surgical approach,” states corresponding author Kyriacos Athanasiou. The surgery involved dissecting a horizontal pouch in the lateral region of the disc and removing a circular fenestration from the inferior lamina (mimicking disc thinning), creating two defects (a pouch and a fenestration). This approach provided biomechanical protection of the implant and enabled the researchers to test the reparative properties of the implant.

The implant prevented degenerative changes in the TMJ of minipigs and improved disc integrity as indicated by an increase in stiffness and closure of the TMJ disc defects compared with the empty defect (untreated) control.

“The implant prevented degenerative changes in the TMJ of minipigs and improved disc integrity”

“We are excited to see tissue engineering emerging as a viable strategy to address some of the most difficult musculoskeletal afflictions,” states Athanasiou. “Eventually, it is our hope and objective that we will be able to move this work toward clinical use.”