Treatment of a large radicular cyst – enucleation or decompression ? Le č enje velike radikularne ciste – enukleacija ili dekompresija ?

Introduction. Radicular cysts treatment involves surgical approach, more or less aggressive. However, treatment of large cystic lesions, including radicular cysts, causes some of dilemmas concerning the choice of the surgical method, especially the degree of radicalism. Case report. We presented a 65-year-old male patient with large radicular cyst in the mandible. A large elliptical multilocular radiolucency, located in the left side of the mandible, being in close vicinity to the mandibular canal, was registered at the orthopantomographic radiography. There was a risk of pathological fracture of the mandible. However, the cyst was completely removed by enucleation without intraoperative and postoperative complications. Conclusion. The presented case support the opinion that careful enucleation of large mandibular cysts may be done without complications, such as damages of surrounding anatomical structures or mandibular fracture. The authors indicate reasons for strong support of the undertaken surgical approach of treating large radicular cysts in the mandible.


Introduction
The most common cysts of adult jaws are inflammatory (radicular) cysts 1 , which occur after tooth pulp necrosis or insufficient root canal treatment.In children, however, noninflammatory (developmental) cystic lesions are much more frequent than inflammatory ones 2 .
Radicular cysts treatment involves more or less aggressive surgical approach.Although enucleation of jaw cysts, the so-called "cystectomy", and primary closure of the defect still represents the "state of the art procedure" 3 , enabling spontaneous bone healing 4,5 , more conservative approach, comprising just decompression of the cystic cavity as the primary procedure, has become popular recently, especially in case of large jaw cysts (> 3cm 2 ) 6,7 .
The aim of this report was to present an adult patient with a large radicular cyst in the mandible, unusually multilocular, being in the close vicinity of the mandibular canal and with a serious risk of pathological jaw fracture, which is completely removed by enucleation without intraoperative and postoperative complications.

Case report
A 65-year-old male patient was admitted to the Department of Oral Surgery, Military Medical Academy in Belgra-Correspondence to: Stevo Matijević, Department of Oral Surgery, Clinic for Dentistry, Faculty of Medicine of the Military Medical Academy, University of Defence, Crnotravska 17, 11 000 Belgrade, Serbia.Phone.: +381 11 3608 307.E-mail: drmatijevic@yahoo.comde, because of expansion of the mandibular buccal cortex on the left side, as well as a large peri-mandibular soft tissue swelling.Intraoral examination revealed gangrenous roots of the left first and second mandibular premolars.On the panoramic radiography, a large elliptical multilocular radiolucency, located in the left side of the mandibular body, could be noticed (Figure 1).Due to the existing infection at the time of examination, we made intraoral incision for drainage and commenced with antibiotic therapy (amoxicillin/clavulanate and metronidazole, orally).Seven days later, the symptoms of infection subsided and the patient underwent an incisional biopsy of the lesion under local anesthesia (4% Articain hydrochloride TM , 3M ESPE).As the left mandibular canine was nonvital, endodontic treatment was performed.A few days later, a pathological finding confirmed the diagnosis of radicular cyst.

Fig. 2 -Bone defect after complete enucleation of the cystic lesion.
According to the histopathological finding, the patient was advised for surgical treatment (enucleation) of the lesion under local anesthesia.Although radiography pointed out a possible risk of injuring the mandibular canal contents, we decided to enucleate the cyst surgically.The patient was informed about the risks and adopted the surgical plan.
First, we removed gangrenous roots of the left lower premolar teeth.Surgical procedure started with incision along the superior border of the left mandible body, between the left mandibular canine and the second mandibular molar, then around the gingival margin of the left second mandibular incisor, mandibular canine and second mandibular molar, with two relaxing incisions down to the fornix.After uplifting the mucoperiosteal flap, a cortical perforation of the buccal cortex of the mandible body could be seen, as well as the membrane of the radicular cyst.After careful separation of the cystic membrane from surrounding anatomical structures and the mental nerve, lateral transposition of mental nerve was done.Then, the cyst was completely enucleated and the defect rinsed with saline (Figure 2).The filling completely blocked the defect with bone blocks (Osteovit ® , B. Braun Melsungen AG, Germany) (Figure 3), and the wound was primarily closed with 4-0 silk sutures.Postoperatively, the patient received antibiotics intramuscularly (ceftriaxon 2 g once daily) and orally (metronidazole 0.4g  3 daily) for seven days, when sutures were removed.Paresthesia in the innervation area of the inferior alveolar nerve and mental nerve was present for 15 days after surgery, after which period a normal sensation returned.Other postoperative problems were not noticed.The patient was followed-up regularly, and after a 1-year period, the control panoramic radiography showed almost normal mandibular bone structure at the site of the previous defect (Figure 4).

Discussion
Treatment of the large cysts lesions, including radicular cysts, has some of dilemmas concerning the choice of the surgical method, especially the degree of radicalism 8 .Recently, some authors, recommend conservative, less invasive surgical approach even in the treatment of large cysts, especially a method of decompression 6,7 .The crucial point of this approach is a decrease of the intracystic pressure and decrease the level of inflammatory mediators in the wall of cystic lesion 6 .Decompression includes creation of a window osteotomy; insertion of a stent, its fixation to the bone and/or adjacent soft tissue, and permanent irrigation 6 .Some reported that advantages of this method could be low morbidity and low incidence of complications, protection of adjacent anatomical structures (contents the mandibular canal), keeping mandibular continuity if there is a risk of traumatic fracture of the mandible, and in children or elderly patients 6 .
When selecting a method of surgery, one should always assess benefits and risks for any particular patient.However, it seems that the method of decompression has also some disadvantages.A major disadvantage is the fact that pathological tissue of the lesion stays in bone for a long postoperative period, especially if there is a need for subsequent enucleation.Minor disadvantages include dislocation or loss of the stent, the need for permanent irrigation, occlusion of the stent by detritus, discomfort for patients.
Thus, it seems that complete enucleation (cystectomy) of radicular cysts is still "state of the art procedure" 3 .Additionally, we filled the defect with bone substitute, although it is not warrant, as several studies have reported safe and regular bone healing after enucleation and simple closure of jaw cysts without using bone grafts even in cases of large defects 4,5 .It seemed to us that the use of bone substitute will additionally decrease the possibility of local complications due to shrinkage of blood clot postoperatively.
Although positive clinical results with the use of decompression are recently reported, we believe that it cannot routinely be a definitive method of treatment, especially in cases of large radicular cysts.In the presented case, operated on by cystectomy, damages of vital neighboring anatomical elements, and pathological fracture of mandible, were not noticed.Also, we did not see any symptom of infection postoperatively.Accordingly, the presented case supports the opinion that careful enucleation of large mandibular cysts may be done without complications.Moreover, this approach significantly lowers postoperative discomfort for the patient, including needs for frequent and long-standing postoperative follow-ups, and enables early functional rehabilitation of the patient.In other words, enucleation (immediate and complete removal of pathological tissue) as a surgical approach should be the preferred method of treating large radicular cysts.The only exception could be in younger patients, with the aim of protecting unerupted permanent teeth.

Conclusion
The presented case supports the opinion that careful enucleation of large mandibular cysts may be done without complications, such as damages of surrounding anatomical structures or mandibular fracture.The authors indicate reasons for strong support of the undertaken surgical approach of treating large radicular cysts in the mandible.

Fig. 1 -
Fig. 1 -Orthopantomographic radiography at the time of examination showing large elliptical multilocular radiolucency located in the left side of the mandibular body.

Fig. 4 -
Fig. 4 -Orthopantomographic radiography 1-year after the surgery showing a successful bone healing on the left side of the mandible.