 Today, we shall continue with management of Audentogenic cysts. It has been told in the previous lecture that marsupilization and enucleation are the two commonly employed surgical modalities of Audentogenic cysts. Enucleation is also called as decompression, cystotomy or parche 1 technique. Parche 2 or Waldman's method is marsupilization followed by enucleation in the management of a cyst. Enucleation is otherwise called as cystectomy, which means complete removal of the cyst with its lining. Again, enucleation is of three types, enucleation with packing with primary closure and with reconstruction followed by primary closure. Today, we shall be discussing enucleation in detail. What is the principle of enucleation? The two key words to remember here are cyst lining and primary closure. This lining is completely removed in enucleation and the defect is sutured, which later heals by primary intention. That means the flap is sutured back to cover the cyst cavity. Therefore, enucleation allows for the cystic cavity to be covered by a mucoperiosteal flap and the space fills with blood clot which will eventually organize and form normal bone. So this is the main difference from marsupilization. What happens in marsupilization? The cystic cavity along with the lining is converted into a pouch after packing, whereas in enucleation the cavity is allowed to fill with blood which will eventually form bone. So this is the principle of enucleation. So remember this. What are the indications of enucleation? Many small cysts which measures up to 2 cm in diameter. Medium or large cysts at a safe location means where there are no vital structures in close vicinity to the cyst. Any recurrent lesions or any lesion which is notorious for its recurrence. For example, odontogenic keratocyst. These are the common indications of enucleation. Moving on to advantages and disadvantages of enucleation. As told earlier enucleation enables primary closure that assists in rapid healing of the cavity. Postoperative maintenance is not as difficult as in marsupilization and most importantly pathological examination of the entire cystic lining can be done because the lining is completely excised. After primary closure we are not able to observe the healing of the cavity as in marsupilization. In young persons the unreptured teeth in a dentigerus cyst will be removed with the lesion therefore the dentition will be affected. Removal of large cysts will weaken the mandible thus making it prone to jaw fractures. High risk of damage to adjacent vital structures and pulpal necrosis are also a downside of enucleation. Enucleation followed by packing is one method which is employed in infected large cysts or where there is a wound dehiscence after primary closure. Hence here switches are not placed instead the cavity is packed with gauze containing medication similar to that in marsupilization. So this is the first type of enucleation where the cyst cavity after enucleation is packed with a gauze and left open. Moving on to the second type of enucleation that is enucleation with primary closure. From exam point of view students are expected to explain this technique and these steps when asked about enucleation. So these are the basic steps of enucleation in any adentrogenic cysts. Enucleation can be performed under local anesthesia, conscious sedation or general anesthesia. In any case before the incision is demarcated the area should be infiltrated with local anesthesia containing vasoconstrictor. This helps in easy separation of the cystic lining from the periosteum. We shall now discuss each step in detail as this case as an example. The image on the left is a radiograph showing radipolar cyst associated with the decayed right mandibular first molar and the image on the right shows its clinical appearance. The first step after local anesthesia is to incise the soft tissue around the necks of the involved tooth and the adjoining teeth on either side. This image is that of after flap elevation so I have marked the incision line in blue colour here. So you first take the incision around the necks of the involved tooth in this case the right side mandibular first molar and its adjoining teeth. In case of idensilus area the incision is placed on the alveolar crest. This is the centre of alveolar crest. You make the incision deep down to the bone that means the blade should hit the bone while incising the soft tissue. Then releasing incisions are given at either ends like this. This is the crevicella incision you then give the releasing incisions on either side which extends into the buccal sulcus so that the base of the flap is broader. Important things to remember while placing an incision is plan the incision such that its margins lie on the soft bone after wound closure. Also whenever possible a buccal or a labial or a labial approach is preferable because of superior visibility and accessibility. After placing the incision a full thickness mucoperiostal flap is elevated using a periostal elevator. The next step is to create a window on the outer cortex. This is to expose the cystic lining within. If the bone is intact a window is cut with chisel or a burr. If the bone is thin the perforated bone can be peeled off with a periostal elevator again. In this picture holes are made using a burr which are then joined for the removal of the cortical plate. So while performing this procedure be very careful not to perforate the cystic lining. Now that the buccal plate has been removed and adequate access has been obtained the next step is to remove the entire lesion in toto with the lining with the cystic lining. So how is it possible? The lining is gently separated from the cavity with the broad end of a periostal elevator. You can use either a periostal elevator or a queaded or a spoon excavator or even a Mitchell's Trimmer. So these are few instruments used to remove the lesion in toto from within the cavity. Here the edge of the instrument is applied on the cavity wall. The edge is inserted between the cavity lining and the cavity wall with the concave surface of the instrument facing the lining. Make sure that the concave surface is what that is facing the lining. Else you may perforate the cystic lining. There are high chances of perforation to the cystic lining if you use the convex side towards the lining. You then do a careful dissection throughout the cystic wall from one end. You proceed with dissection throughout the entire cystic wall to separate the lining from the periosteum or any attached vital structures. Once the dissection is complete the cyst with its intact lining and the contents within is delivered out using hemostats as you can see in this picture. So this is how a cyst is enucleated. After the cyst has been removed in toto the teeth that are required to be removed are now extracted and a pisectomy is performed for any endodontically restored teeth. So how do you manage the cavity after cystic session? The cavity is first irrigated using saline and bitadine. It is debrided and inspected for any remnants of cystic lining. Make sure you don't leave any remnants of cystic lining within the cavity. The irregular bone margins are smoothened and hemostasis is achieved before closing. During enucleation of the aggressive cysts like odontogenic keratocyst it is advisable to perform chemical characterization. It can be done with carnoid solution. Carnoid solution is a powerful fixative and it has been found to reduce the percentage of recurrence. So carnoid solution is applied on the cavity walls. Make sure the solution is applied only on the cavity walls. It should not spill onto the soft tissues around. So apply the solution on the walls for about 3 minutes using a small cotton ball. The cavity is cleansed again and closed in layers. You may also pack the cavity with materials like resorbable sponge containing antibiotics or thrombin. This additional step can help eliminate dead space. So that's all about the enucleation of cysts with primary closure. The third type of enucleation is followed by reconstruction and then primary closure. This technique is employed in cases where an aggressive enucleation has led to an inferior border discontinuity of the mandible or a fracture of the surgical site. Here a stainless steel or titanium plate is used to fix the fracture. You may also place a titanium mesh or autogenous bone grafts for example iliac crest or costo contour graft to reconstruct any bone defect post enucleation. Reconstruction will always require an intermaxillary fixation for about 4 to 6 weeks before a functional load can be applied. Thus we have discussed the principles, indications, advantages, disadvantages, various types and steps of enucleation. Thanks for watching the video.