Decompression and Enucleation of a Mandibular Radicular Cyst, Followed by Bone Regeneration and Implant-Supported Dental Restoration

Abstract

Odontogenic cysts are usually treated by enucleation (cystectomy). Limited cysts (less than 5 cm) are usually managed by primary excision (total cystectomy), whereas larger ones (exceeding 5 cm) are often decompressed or marsupialized. Because it consists only of opening a much smaller surgical window, decompression is regarded as a more conservative method of treatment: this method associates the creation of an opening (window) into the cystic cavity with the suturing of a decompressing device (plastic tube or stent) at the periphery of the cyst. Apart from releasing intraluminal pressure in the pathological cavity, this procedure helps the lesion to progressively decrease in volume "with a gradual increase in bone apposition" and preserves pulp vitality and periodontal integrity of the adjacent teeth. We are reporting a case of a mandibular radicular cyst that was treated by decompression, followed by enucleation, bone reconstruction, and restoration with two osseointegrated dental implants. The cystic cavity progressively decreased in volume and increased in bone density.

Figures

Figure 1

(a) Clinical aspect of left mandibular vestibule (premolar and molar regions). (b) Aspiration syringe yielding blood and pus from the radiolucent image. (c) OPG of the patient displaying the radiolucent image in left mandible (34 to 37).

Figure 2

CBCT reconstruction of the left mandible. (a) The sagittal reconstruction with the approximative measurement of the bone destruction (30.7 mm × 19.7 mm). (b) Para-axial cut showing the discontinuity of the buccal cortical bone. (c) Para-axial cut showing the position of the mandibular canal.

Figure 3

(a) Clinical aspect of alveolar cavities of 35 and 36, immediately after their extraction. (b) Plastic tubes secured in alveolar cavities of teeth 35 and 36 with sutures. A disposable syringe (with needle) injecting a normal saline solution (sodium chloride in water) in distal tube in order to regularly irrigate the lesions. After injection of antiseptic solution in distal tube (A), irrigating liquid is evacuated from mesial tube (B).

Figure 4

Gingival healing around decompressing devices (tubes), 3 weeks after their placement and suturing.

Figure 5

(a) Panoramic radiograph 7 months after decompression, showing a reduction of the volume of the lesion. (b) CBCT of the same time period time, the para-axial cut shows a bone healing toward the center of the lesions with approximately ±4 mm buccally and ±2.4 mm lingually. (c) Sagittal reconstruction of the CBCT shows a volume reduction of the lesion approximately.

Figure 6

(a) Six months after the beginning of decompression, a mucoperiosteal flap was performed and decompression tubes removed, leading to the roof of the radiolucent lesion. (b) Upper aspect of the bony pathological cavity, immediately after the lesion's enucleation. Notice that the bone was formed all around external surfaces of both decompression devices (tubes). (c) The pathological cavity filled with Puros® cortico-cancellous particulate allograft, a mixture of 70% cortical and 30% cancellous bone particulate. (d) Puros® biomaterial covered with collagen cones (CollaPlug®) and mucosal wound sutured with 5/0 nylon sutures.

Figure 7

(a) Clinical mucosal healing after one week. (b) Radiological aspect of the graft and surrounding bone.

Figure 8

Histopathology of the cyst. (a) Stratified squamous nonkeratinized epithelium with rete ridges and inflamed connective tissue wall (H&E × 20). (b) Cystic lumen is filled with liquid containing cholesterol crystals (H&E × 40). Mucoperiosteal flap showing the buccolingual thickness of mandibular ridge before implant placement.

Figure 9

Para-axial cuts of a control CBCT before implant placement showing a complete bone regeneration of the cyst area.

Figure 10

(a) Clinical view of the bone healing before implant placement. (b) Two Swiss Plus Zimmer® implants placed in postalveolar locations of teeth 35 and 36. (c) Clinical aspects of cover screws and sutures, immediately after implants placement. (d) Clinical aspect of restored implants (35 and 36). (e) Panoramic radiograph showing the final situation of the bone and the restored implants.