An Innovative Intracystic Negative Pressure System to Treat Odontogenic Cysts

Odontogenic cysts are a group of conditions arising from tissues involved in odontogenesis, usually containing air, fluid, or semisolid material.1 They expand due to a combination of osmotic pressure and release of growth factors.1,2 Kubota et al3 estimated the intracystic fluid pressure for the keratocystic odontogenic tumor (337.6 ! 126.0 mm Hg/cm2 ), dentigerous cyst (258.2 ! 160.9 mm Hg/cm2 ), and radicular cyst (254.0 ! 157.3 mm Hg/cm2 ). Radiographically, they are uni or multilocular radiolucencies. The gold standard for accurate diagnose is histopathologic examination. Treatment options include enucleation, curettage, marsupialization/decompression, and en bloc resection.3 In 2004, marsupialization has regained the attention of surgeons.4 We present the results obtained with the Evacuator for Odontogenic Cysts (Evocyst), a handcrafted device by means of intracystic negative pressure (INP) is applied. The Evocyst (Fig. 1A) was designed based on a tubing system previously described by one of us (Fig. 1B).5 It has intraoral and extraoral parts connected by male/female Luer locks. The intraoral unit is composed of irrigation and decompression tubes. The irrigation tube is a needle port and, attached to it, an IV tube used for decompression. The posterior ends of both tubes are placed inside the cavity. The anterior end of the decompression tube has a female Luer lock, which is a modification to the unit previously reported.5 This part of the device is secured to teeth with wire. The extraoral unit is an active negative pressure, closed drainage system with a male Luer lock at the end of the tubing used to connect the intraoral unit. The system provides a negative pressure of approximately 45 mm Hg. Irrigation with normal saline solution (NSS) 0.9% is done through the intraoral unit’s needle port. We evaluated retrospectively 5 patients with odontogenic cystic lesions in which the Evocyst was used (Table 1); 100% of the entities were not visible at the 3-month follow-up imaging. Our observations suggest that during the course of treatment a high rate of bone healing took place. This experience is initial and must not be taken as conclusive.