A Novel Approach: Tube-Based Bridging Drainage for Fenestration Decompression of Cysts at the Posterior Border of the Mandibular Ramus

Odontogenic jaw cysts are common intraosseous lesions with a high incidence and insidious onset, often resulting in delayed diagnosis and presentation as large cysts requiring a two-stage approach: initial fenestration decompression to reduce cyst volume, followed by secondary surgical enucleation. However, cysts in anatomically challenging locations are not always amenable to conventional fenestration. This article reports a case of an odontogenic cyst located at the posterior border of the mandibular ramus, a site posing significant surgical challenges. The cyst was deeply situated, making conventional fenestration decompression technically difficult. We innovatively applied a tube-based bridging drainage method. Intraoperatively, the mucoperiosteum at the anterior border of the mandibular ramus was incised to expose the mandible, the lateral (masseteric aspect) cortical bone overlying the cyst was removed, and a drainage tube was used to create a bypass with one end inserted into the cyst cavity and the other left open in the retromolar region. Postoperatively, the cyst volume decreased. While this tube-based bridging drainage method can achieve cyst reduction, it presents challenges such as difficulty in securing the tube and slow bone regeneration. Future research should focus on optimization of drainage tube design and fixation techniques, or stricter selection of indications. This study offers preliminary experience and proposes a novel treatment option for cysts at the posterior mandibular ramus.