 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.