Hyaluronidase is an enzyme that breaks down hyaluronic acid in connective tissue, facilitating the diffusion of injected substances and reducing tissue viscosity. In oral surgery, its primary use is as an adjunct to local anesthetics. The rationale is that by depolymerizing hyaluronic acid, hyaluronidase increases tissue permeability, allowing anesthetic agents to spread more evenly and rapidly, potentially improving anesthetic effectiveness and onset. Additionally, it has been used to manage the complications of local anesthetic administration, such as accidental intravascular injections or tissue necrosis, by promoting the dispersion of the anesthetic solution.

Evidence supporting its use in oral surgery comes from several small clinical studies and case series. Some studies report improved anesthetic diffusion and reduced postoperative edema when hyaluronidase is added. For example, research has shown more rapid onset of anesthesia and less tissue distortion in procedures such as nerve blocks and infiltration anesthesia. However, the data are somewhat mixed; not all studies demonstrate significant clinical benefits, and the evidence base is not robust or extensive. Systematic reviews note the need for larger, well-designed trials to further clarify its effectiveness and safety profile in this context.

In summary, while hyaluronidase is used in oral surgery with a logical mechanistic basis and some supporting clinical data, the overall quality and quantity of evidence rate it as moderate (3 out of 5). Its use is scientifically justified but not universally standard practice.