The conventional treatment of odontogenic cysts usually involves enucleation of the cyst using rotary and manual instruments; such procedures can cause trauma to the cystic epithelium or soft tissues in the region, such as sinus membrane perforation or nerve damage. The use of ultrasonic surgery may reduce the risk of damage to soft tissues. The objective of this study was to evaluate the performance of ultrasonic surgery in removing odontogenic cysts. Eighty-two cysts were removed from 68 patients over a period of 45 months. Ultrasonic surgery was used for 34 patients and conventional surgical procedures were used for 34 control patients. Two surgeons rated the cutting efficiency, visibility of the surgical field, ease of operation, and ease of cyst epithelium removal on a 100-mm visual analogue scale. The operation time was also recorded. No major intraoperative or postoperative complications were observed, and there was no cyst recurrence. Ultrasonic surgery for enucleating jaw cysts was found to increase the operation time, but also markedly increased the visibility of the operation field. In cases where cyst enucleation is performed in difficult areas that require delicate manipulation, there is less risk of damage to vital structures such as neurovascular tissues with ultrasonic surgery.
The surgical treatment of jaw cysts may include one of the following four basic methods: enucleation, marsupialization, staged combination of marsupialization and enucleation, or enucleation with curettage. Enucleation, alone or combined with other procedures, is the preferred choice of treatment for the removal of jaw cysts. The main advantage of enucleation is that a pathological examination of the entire cyst can be undertaken. Another advantage is that a total excisional biopsy (i.e. enucleation) appropriately treats the lesion. Surgical treatment usually involves direct exposure of the cystic epithelium by removal of the overlying bone lamina (if present), complete enucleation of the cyst epithelium, and management of the involved dentition and bony cavity, followed by primary wound closure.
Rotary instruments such as burrs, and manual instruments such as rongeurs and curettes, are standard instruments that are used to expose, separate, and remove the cystic epithelium from the surrounding tissues. Rotary instruments must be used with caution in close proximity to anatomical structures such as the maxillary sinus and mandibular canal, to avoid serious complications. Additionally, rotary instruments may damage the cystic membrane, jeopardizing total removal of the lesion. Residual cystic membrane fragments tend to produce recurrent cysts, hence the necessity to completely excise the cyst epithelial lining during the operation.
Ultrasonic surgery has recently emerged as a potentially safer alternative approach to using the mechanical instruments and motor-driven devices traditionally used in bone-related procedures in oral and maxillofacial surgery. Ultrasonic surgery uses an innovative device developed by Vercellotti for performing oral bone surgery. Piezoelectric ultrasonic oscillations of a modulated 25–30 kHz frequency characterize the ultrasonic surgical device. Micro-oscillations created in the piezoelectric hand-piece cause bone-cutting inserts to vibrate linearly between 60 and 210 μm. This micro-oscillational frequency allows selective cutting of only mineralized structures. The key novelty of clinically applied ultrasonic surgery devices is their precise and selective cutting properties. Ultrasonic surgery cuts mineralized tissues such as bone with micron accuracy, yet does not cut soft tissues such as blood vessels and nerves.
Atraumatic handling of the soft tissues is a prerequisite for the total removal of a cystic lesion and is technically comparable to handling the sinus membrane during sinus bone grafting. The most common complication of sinus bone grafting is sinus membrane perforation, which often negatively affects the result. Several authors have reported that ultrasonic surgery can minimize sinus perforation rates during sinus bone grafting. This advantage would be useful for surgical jaw cyst enucleation, where soft tissue preservation is necessary. Since ultrasonic surgery was originally developed for atraumatic bone surgery, its use in jaw cyst enucleation has rarely been reported in the literature. The aim of this study was to evaluate and compare the surgical efficacy of ultrasonic surgery with conventional techniques in jaw cyst enucleation.
Materials and methods
The study group consisted of 68 consecutive patients treated between February 2007 and October 2010. Inclusion criteria were: (1) the need for jawbone cyst removal, and (2) agreement to participate in the study and postoperative follow-up schedule. The exclusion criterion was any sign of malignancy. All patients were in good health except for nine who had mild (controlled) systemic diseases. Patients were informed about the surgery, postoperative recovery, and possible complications. This study was carried out in accordance with the Declaration of Helsinki on medical protocol and ethics, and all participants signed an informed consent agreement (parents signed in the case of minors).
Each patient was randomly allocated to either the ultrasonic surgery group or a conventional technique group; this latter group were operated on using manual and rotary instruments. The same surgical team performed all jaw cyst enucleation surgeries. The ultrasonic surgery group consisted of 34 patients with 43 odontogenic cysts, and the conventional surgery group consisted of 34 patients with 39 odontogenic cysts ( Table 1 ).
|Ultrasonic surgery group||Conventional surgery group||Total|
|Age||9–56 years (mean 36.1 ± 13.7)||11–64 years (mean 34.5 ± 13.3)||9–64 years (mean 35.3 ± 13.5)|
|Cyst type *|