 Welcome back to OMFS lecture series, topic for the day is management of adipogenic cysts. As per the definition given by Kramer, a cyst is a pathological cavity having fluid, semi-fluid or gaseous contents that are not created by the accumulation of pus frequently but not always is lined by an epithelium. After going into the management of cysts, let's have a quick look at the pathogenesis or formation of a cyst. The first phase of cyst formation is cyst initiation. Here we should be able to recognize the stimulus for cyst initiation. For adentrogenic cysts of inflammatory origin, infection is considered as a precipitating factor. In others, cysts developed from adentrogenic epithelium like remnants of dental lamina, enamel organ or reduced enamel epithelium. The second phase is the cyst enlargement. So once initiated, the cyst continues to grow and enlarge. The following theories have been forwarded regarding enlargement of cystic lesions. The first theory is the mural growth theory, which states that active division of cells and collagenase activity results in cyst expansion. Another theory that is the hydrostatic theory explains how transduce and exudate secretions within the cyst due to an increased inflammatory activity leads to high intracystic pressure, which leads to cyst expansion, that is hydrostatic enlargement theory. There is also theory which is related to bone resorbing factors. Acid resorbing factors are also thought to be present, which aids in cyst expansion and cyst enlargement. The most commonly employed surgical methods of adentrogenic cyst management are marsupialization and enucleation. Marsupialization is also termed decompression, cystotomy or PARS-1 technique, with enucleation being termed PARS-2 technique. Today we shall be discussing in detail about marsupialization. The term marsupialization is derived from the word marsupials. What are marsupials? They are animals having a pouch in their lower abdomen to carry their young babies. Similarly, we are converting the cystic lining into a pouch through this procedure. So, the principle of marsupialization is to create a surgical window in the wall of the cyst and evacuate its cystic contents. So, if this is the cyst associated with this tooth, we are creating a window in the cortex of the bone and evacuating the cystic contents, thereby decreasing the intracystic pressure. According to hydrostatic theory, the increased inflammatory reactions within the cyst will increase the intracystic pressure. So, by creating a window and evacuating the cystic contents, we are decreasing the intracystic pressure. This will promote the shrinkage of cystic lining. The cystic lining will shrink. Once the lining is reduced, the cystic space begins to get filled by bone. How does it happen? If this is the bone and this is the cystic cavity, bone starts growing inward. That is, bone starts growing from the periphery to the center of the lesion. This is how healing of the cystic cavity takes place following marsupialization. What are the indications of marsupialization? This mainly carried out in large radicular cysts or dentiger cysts. It is an ideal procedure to perform in very young patients who have developing tooth buds. It is also used in elderly patients with debilitating conditions because this procedure is less stressful when compared to enucleation. If there are any vital structures like neurovascular bundle, vital teeth or maxillary sinus in close vicinity to the cyst, this technique is an ideal option. This preserves the vital structures. Also, eruption of a tooth can be aided with this procedure as you are creating an unhindered path for the eruption. In case of large cysts, there are chances of pathological fracture following enucleation. So, this risk can be avoided with marsupialization. Moving on to the surgical technique. Marsupialization is performed under local anesthesia or general anesthesia. Various types of incisions may be used for this procedure. For example, a circular incision and oval-shaped incision. Here is an example of oval-shaped incision and elliptical incision. A U-shaped incision is used for large cystic lesions or even an inverted U-shaped incision with a broad pedical flap. So, you may use any of these incisions according to the need. The incision outline should be slightly larger than the eventual bone opening. So, while making an incision, make sure it is slightly larger or it covers area slightly larger than the final bone opening. Also, ensure that the incision is at least 0.5 to 1 centimeter away from the gingival margin. That is the distance from the gingival margin should be at least 5 mm to 1 centimeter. This will help in managing the flap tissue later during suturing. So, once the incision is placed, a flap is elevated starting from the intact bone in case of a U-shaped incision. The next step is to remove the bone that is enclosing the cyst. You know that the cyst has enlarged and grown within the bone. Therefore, in case the cortical bone surrounding the cyst is intact, you may create a small window opening to gain access to the cystic lining. As you can see in this diagram, the yellow portion is the bone surrounding the cyst. The pink color you see within the given incision is the cystic lining. You are removing the intact bone covering the cyst or the cystic lining using a round bar. But in case if the cyst has grown so much that it has perforated the cortex, then the remaining bone, the remaining bone surrounding the cyst will be axial-like. It will be only as thick as an axial. Therefore, it is gently picked up using a tissue-holding faucet. You don't need to create a special window or use any special instrument to remove the bone in case the cyst has perforated the cortical blade. You now expose the cystic lining. After removing the bone that encloses the cystic lining. The cystic lining is exposed. And next, a stab incision or a cross incision. As you can see in the diagram, you give a cross incision in the lining to expose the cystic lumen. Once you give the stab incision, the lining just bursts like a balloon and all the contents will just flow out. Then the cystic contents are evacuated using a pressure suction. Remember here that you are not scraping the entire lining. You are not scraping off the entire lining from the bone. You stab into the lining to rupture it and gain access into the lumen. You are not scraping it off the bone. After the cystic contents have been evacuated, the cavity is then flushed gently with saline and betadine. Keep in mind that only the cystic contents are evacuated. That could be a fluid, semi-fluid or a gas. The cystic lining will still remain. After you perform a thorough irrigation of the cavity, the next step is suturing. So how do you manage the flap tissue with the cystic lining still within the cavity? There are two ways in which you can perform this step. First method is you may excise the flap tissue at the level of bony margin. Remember that you have raised a flap over here to expose the cystic cavity. So whatever flap is raised, you excise it at the level of bony margin. So in this case there is no suturing required and there is no flap into the cavity also. It just ends here at the bony margin. The cavity can be later packed. So this is one method. In the second method, the flap can be turned into the cavity. Whatever flap is present around the cavity, it is folded into the cavity and sutured to the lining along the bony margin. So whatever excess flap and lining are present, it is excised away. This is the difference between the first and the second method. In the first method, you excise the entire flap at the bony margin. In the second method, you fold in the flap and suture it to the cystic lining along the bony margin. So the second method gives an appearance of a pouch or a pocket with soft tissue lining and hence the term mass supplication is given for this technique. The cavity is flushed again with saline and packed with a half inch gauze impregnated with aldoform or whiteheads varnish using two pairs of forceps. As you can see in the diagram, the gauze is first laid along the floor of the cavity and the remainder is inserted in layers running side to side. The pack remains for about 7 to 14 days. By this time, the junction between the lining and the mucosal flap will be healed and later an acrylic plug can be fabricated. What is the purpose of acrylic plug? The plug maintains patency of the opening and keeps the site clean from food debris. The cavity should be maintained by daily irrigation for a prolonged period. So with this procedure, the cyst has been decompressed and when a considerable thickness of bone is formed, enucleation if necessary can be performed as a second stage surgery. Let's see what are the advantages and disadvantages of mass supplication. It is a relatively simpler technique with less morbidity. Vital structures are preserved and it makes the second surgery easy to perform. The disadvantages are that the pathological tissues are left behind because you don't excise the cystic lining here. The bone healing is slow and will take months. Hence the completion of treatment will be delayed. A continuous maintenance of the cavity is required and mass supplication doesn't always completely eliminate the need for a second surgery. That's all about mass supplication. We shall be discussing enucleation in the next lecture. Thank you. Hello and welcome back to OMFS lecture series. Today we shall continue with management of ordentogenic cysts. It has been told in the previous lecture that mass supplication and enucleation are the two commonly employed surgical modalities of ordentogenic cysts. Mass supplication is also called as decompression, cystotomy or parche 1 technique. Parche 2 or Waldman's method is mass supplication 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. Cyst 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 mucoperiostal flap and the space fills with blood clot which will eventually organize and form normal bone. So this is the main difference from mass supplication. What happens in mass supplication? 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? Any 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 vodontogenic 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 mass supplication and most importantly pathological examination of the entire cystic lining can be done because lining is completely excised. Disadvantages are that after primary closure we are not able to observe the healing of the cavity as in mass supplication. In young persons the unerepted 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 dehesence after primary closure. Hence here sutures are not placed instead the cavity is packed with gauze containing medication similar to that in mass supplication. 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 the 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 color 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 center 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 muco periostial flap is elevated using a periostial 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 periostial 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 total 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 periostial elevator. You can use either a periostial elevator or a cuted or a spone excavator or even a Mitchell's Trimmer. So these are few instruments used to remove the lesion in total 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 haemostats as you can see in this picture. So this is how a cyst is enucleated. After the cyst has been removed in total 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 cyst excision? The cavity is first irrigated using saline and betadine. 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 haemostasis is achieved before closing. During enuplication of the aggressive cysts like autotogenic keratocyst it is advisable to perform chemical corporalization. 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 enuplication of cysts with primary closure. The third type of enuculation is followed by reconstruction and then primary closure. This technique is employed in cases where an aggressive enuculation 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 caustic convol graft to reconstruct any bone defect post enuculation. 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 enuculation. Thanks for watching the video.