BackgroundFrontal sinus trephination is traditionally performed through a small cutaneous incision and osteotomy, allowing irrigation of the frontal sinus. Utilizing the trephination osteotomy for endoscopic visualization and surgical manipulation requires a larger opening. This “mega‐trephination” is thought to carry an increased risk of cosmetic deformity given the increased bony removal at the anterior table. The purpose of our study was to clarify the risks of frontal sinus mega‐trephination and examine how this technique is incorporated into a modern, tertiary care rhinology practice.MethodsPatients were identified through billing records and confirmed by retrospective chart review. All patients underwent frontal sinus mega‐trephination, which is defined as an osteotomy large enough for insertion of a 4‐mm endoscope and an operative instrument simultaneously. All patients had at least 2 years of follow‐up. The primary outcome was complication rate, including cosmetic deformity.ResultsSixty‐four patients underwent frontal sinus mega‐trephination from 2006 to 2016. The most common surgical indications were chronic sinusitis (34%), mucocele (19%), osteoma (17%), acute sinusitis (11%), and inverting papilloma (9%). Ten patients (16%) underwent mega‐trephination alone, whereas the others had mega‐trephination with endoscopic sinus surgery. Twenty‐one patients (33%) had minor complications. The most common complications were self‐limited paresthesia (11%), infection (8%), and epistaxis (3%). No patient complained of permanent cosmetic deformity or required revision surgery for cosmesis.ConclusionFrontal sinus mega‐trephination is a useful tool to augment the rhinologist's armamentarium in complex frontal sinus anatomy and pathology. This procedure is well tolerated, safe, and not associated with long‐term cosmetic deformity.