A group from the McGowan Institute for Regenerative Medicine used SIS to regenerate the temporomandibular joint (TMJ) in pigs

The temporomandibular joint (TMJ) is the main connection between the skull and the jawbone. When smooth operation of this joint is disturbed, pain and dysfunction in the jaw and muscles that control jaw movement occur. TMJ disorders are common, reportedly occurring in 5 to 12% of people.¹ While most cases are treated conservatively, a last-resort treatment is to remove the TMJ disc with a discectomy. While this procedure does restore temporomandibular joint (TMJ) function, it also leaves the joint space vulnerable to degradation or scarring.

Dr. Stephen F. Badylak’s group from the McGowan Institute for Regenerative Medicine created a device from small intestinal submucosa (SIS) to fill the joint space and induce remodeling.² The devices were pillows of particulate SIS enclosed in sheets of SIS. The TMJ discs were removed from both TMJs in each experimental pig, but only one was repaired with the SIS device.

Treatment outcomes were assessed at various time points up to six months after implantation. The animals were examined with MRI imaging, and the explants were examined grossly and histologically, as well as tested biochemically and mechanically. The repair was compared to the contralateral joint, which received no treatment, as well as to matched-age normal control joints. The surgery was technically difficult, with only 60% of the devices remaining in the joints. Only the repairs that had devices remaining were used for analysis.

The group reported that the devices remodeled into a site-appropriate replacement for the TMJ disc by three months. These results suggest that the SIS device is a viable option for TMJ disc replacement, potentially improving the outcome of a last-resort treatment.

1. National Institute of Dental and Craniofacial Research. Updated July 2018. Accessed April 18, 2022. https://www.nidcr.nih.gov/research/data-statistics/facial-pain/prevalence

2. Badylak SF, Brown BN, Chung WL, et al. Inductive remodeling of extracellular matrix scaffolds in the temporomandibular joint of pigs. Tissue Eng Part A. 2021 Nov 23. E-pub ahead of print. http://doi.org/10.1089/ten.TEA.2021.0123