Comparative efficacy of dental implant motor–assisted versus conventional temporomandibular joint arthrocentesis for disc displacement with reduction (a randomized controlled clinical trial)

Temporomandibular joint internal derangement (TMJID), particularly disc displacement with reduction (DDwR), represents a common subtype of temporomandibular disorders (TMDs). Arthrocentesis is considered a minimally invasive option for selected patients with persistent symptoms. Standardization of irrigation delivery may improve procedural efficiency and reproducibility. To compare TMJ arthrocentesis performed using a dental implant motor–assisted irrigation system at two different power settings with the conventional manual technique in patients with DDwR, primarily in terms of maximum mouth opening (MMO), and secondarily regarding pain intensity, mandibular movements, and procedure duration. A prospective randomized controlled parallel-group clinical trial was conducted on 30 patients diagnosed with DDwR. Participants were randomly allocated into three equal groups (n = 10 each). Group A received motor-assisted arthrocentesis at 80% power, Group B at 40% power, and Group C underwent conventional syringe-based arthrocentesis. Clinical evaluation included MMO (primary outcome), pain intensity, mandibular movements, and procedure duration at 1 week and 3 months postoperatively. All groups demonstrated significant improvement in pain and mandibular movement parameters over time (p < 0.05). MMO increased significantly in all groups, with Group A showing greater improvement at 3 months (41.6 ± 1.26 mm) compared with Group B (39.0 ± 1.33 mm) and Group C (39.7 ± 1.25 mm) (p = 0.016). Procedure duration differed significantly among groups (p = 0.001), with Group A demonstrating the shortest mean operative time (14.9 ± 2.33 min). No major complications were observed; minor transient swelling occurred in both techniques. Both conventional and motor-assisted TMJ arthrocentesis resulted in significant functional improvement in patients with DDwR. The motor-assisted technique demonstrated shorter operative time; however, due to the limited sample size, these findings should be interpreted with caution and cannot be considered definitive. Larger, well-powered studies are warranted to confirm these findings. The study was registered at ClinicalTrials.gov under the identifier NCT07239037. Participant recruitment was conducted between October 2024 and July 2025 at the Outpatient Clinic of the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Alexandria University, Egypt. Registered was on 16/11/25, retrospectively registered. The delay in registry submission was related to administrative and procedural factors during the finalization of the trial documentation. Importantly, the study protocol, eligibility criteria, outcome measures, and statistical analysis plan were defined a priori and were not modified after recruitment or data collection had commenced. The trial protocol and statistical analysis plan are publicly accessible through the registry.