The Caldwell-Luc procedure is a surgical technique used to treat chronic sinusitis, particularly when it involves the maxillary sinus (the sinus located in the cheekbones). It's named after George Caldwell and Henry Luc, the surgeons who popularized the procedure. During the Caldwell-Luc procedure, an incision is made in the gum line above the upper back teeth, allowing access to the maxillary sinus. The sinus membrane is then opened, and the diseased tissue or blockages are removed. This procedure aims to improve drainage from the affected sinus and promote healing.