Frontal sinus trephination, also called mini-anterior frontal sinusotomy, is a traditional method of sinusitis surgery. An array of problems of the frontal sinus and recess can be treated with trephination. For example, the trephination is used for chronic or persistent frontal sinusitis, patients who need revision surgery for the frontal sinus and patients who have undergone functional endoscopic sinus surgery (FESS).

The frontal sinus areas that cannot be accessed during endoscopic procedure can be accessed using trephination.  For example, lateral and superior parts of the sinus are not accessible with endoscopes. If trephination is accurately placed over the frontal sinus pathology site, better views of the sinus are possible, reducing the need for dissection. Skull base defects, fibro-osseous lesions and neoplasms related to the frontal sinus cannot be managed just with endoscopic approaches.

The surgery prevents the infection from spreading into the frontal bone and intracranial region. Since advanced antibiotics can treat acute frontal sinusitis, the trephination is more popular for chronic frontal sinusitis than acute conditions. If a tiny catheter is left within the trephine, corticosteroids and topical antibiotics can be instilled and irrigation is possible every day, as a result, chronic inflammation resolves faster.

The sinusitis surgery can be used with endoscopic surgery methods in case of frontal sinus mucoceles and chronic frontal sinusitis. In this combined approach, trephination enables to place a catheter and stent within the frontal recess and prevents chances of stenosis. This combined method gives easy and quick entry to the sinus.

The trephination method uses a trephine for making a small burr hole in the frontal bone to enter into the frontal sinus(s). The surgeons use a trephine, drill, gouge, chisel, trocar and needle for trephination. A trephine with an endoscope can be used to examine the mucosa of the sinus. After trephination process is complete, nasal decongestants and intravenous antibiotics are administered.

The sinusitis surgery can be completed using any of two approaches: antero-inferior and anterior. The antero-inferior method, developed by Silcock, is the most popular approach, which is performed under general or local anesthesia. Ogston pioneered the median anterior trephination technique. The median anterior trephination uses a trephine to remove bony part, giving access to both the frontal sinuses.