This systematic review evaluates the clinical effectiveness of hyaluronic acid (HA) in periodontal therapy, oral surgery, and temporomandibular joint (TMJ) disorders. Background. HA, a biocompatible glycosaminoglycan with anti-inflammatory and regenerative properties, is increasingly used in dentistry to enhance healing, reduce pain, and support periodontal regeneration. However, its efficacy compared to conventional treatments remains debated. Materials and Methods. A systematic search was conducted following PRISMA guidelines across PubMed, Scopus, and Web of Science databases (2015-2025). Twenty-one clinical studies, including randomized controlled trials (RCTs) and case-control studies, were analyzed for outcomes related to pain reduction, tissue regeneration, and functional recovery. HA improved clinical attachment levels, reduced probing depth, and enhanced wound healing in periodontal therapy and oral surgery. It accelerated healing after extractions and frenectomies. However, TMJ disorder studies showed mixed results, with some reporting pain relief and functional improvement, while others found no significant advantage over platelet-rich plasma (PRP) or corticosteroids. Variability in HA formulations and protocols influenced outcomes. HA is a promising adjunct for periodontal therapy and wound healing. However, its role in TMJ treatment remains uncertain. Further RCTs with standardized protocols are needed to determine its optimal clinical application.