Dextrose prolotherapy versus lidocaine injection for temporomandibular dysfunction: A pragmatic randomized controlled trial

Objective: Several intraarticular injections, including dextrose and lidocaine, are reported to reduce pain and dysfunction in temporomandibular dysfunction (TMD) and increase maximal jaw opening; our goal was to determine whether dextrose/lidocaine outperforms sterile water/lidocaine for TMD. Design: Pragmatic randomized controlled trial. Setting: Outpatient clinic. Subjects: Chronic (‡3 months) of moderate-to-severe (‡6/10) jaw or facial pain meeting research-specific TMD criteria. Intervention: Blinded intraarticular dextrose prolotherapy (DPT) (20% dextrose/0.2% lidocaine) versus intraarticular lidocaine (0.2% lidocaine in sterile water) at 0, 1, and 2 months. Participants were then unblinded and offered DPT by request for 9 additional months. Main outcome measures: Primary: Numerical Rating Scale (0–10 points) score for facial pain and jaw dysfunction; percentage achieving ‡50% improvement in pain and dysfunction (0, 3, and 12 months). Secondary: Maximal interincisal opening (MIO; 0 and 3 months). Intention-to-treat analysis was by joint using mixed-model regression. Results: Randomization of 29 participants (25 female, 47 – 17 years, 43 joints) produced similar groups. Three-month pain and dysfunction improvements were similar, but more DPT-treated joints improved by ‡50% in pain (17/22 vs. 6/21; p = 0.028). The MIO improved in both groups (5.6 – 5.8 mm vs. 5.1 – 7.0 mm; p = 0.70). From 3 to 12 months, minimal DPT was received by original DPT and lidocaine recipients, 0.5 – 0.9 and 0.6 – 1.5 injections, respectively, with only 2 out of 21 joints in the original lidocaine group receiving more than 1 dextrose injection after 3 months. Twelve-month analysis revealed that joints in the original DPT group improved more in jaw pain (4.8 – 2.4 points vs. 2.6 – 2.9 points; p = 0.026) and jaw dysfunction (5.3 – 2.6 points vs. 2.7 – 2.3 points; p = 0.013). More DPT than lidocaine-treated joints improved by ‡50% in both pain (19/22 vs. 5/21; p = 0.003) and dysfunction (17/22 vs. 7/21; p = 0.040). There were no adverse events; satisfaction was high. Conclusions: Intraarticular DPT resulted in clinically important and statistically significant improvement in pain and dysfunction at 12 months compared to lidocaine injection (ClinicalTrials.gov identifier NCT01617356).