 Hello everyone, this is Dr. Abhilash from Hyderabad. In this lecture, I will teach you about Peridontal Flap Surgery. Introduction The goal of Peridontal therapy is to maintain the health and function of natural dentition satisfactorily preserving the aesthetics. If tooth preservation is the main objective, direct access to the infected root surface is essential. A surgical approach provides more reliable access and direct visualization of the treatment site. The treatment of Peridontal diseases has progressed with numerous surgical approaches over the years. So, the definition of a Peridontal Flap, according to Karanza, is a section of Jinjiva or Mucosa, which is surgically separated from the underlying tissue to provide visibility and access to the bone and root surface. The objectives of flap surgery are to eliminate or reduce pocket depth by resecting the pocket wall, to increase the accessibility to root deposits for scaling and root planing, to establish a Jinjival morphology which facilitates the patient's self-performed plaque control, to gain access for receptive or regenerative procedures if required, to prepare the Peridontal environment suitable to restorative and prostradontic treatment and finally, to improve aesthetics. Peridontal Flaps can be classified based on three criteria. Based on the exposure of bone after reflection, a flap can be either full thickness or split thickness or partial thickness. Based on the position of flap replacement after the surgery, it can be an undisplaced flap or a displaced flap, be it apically, coronally or laterally displaced. And finally, based on the management of interdental papilla or interdental Jinjiva, it can be a conventional flap surgery or papilla preservation flap surgery. This classification can be explained better with pictures. So, in the first category, if we reflect the entire bulk of Jinjiva, which is superficial to the bone, thereby exposing the bone, it is called a full-thickness flap. To raise a full-thickness flap, the scalpel should be oriented perpendicular or angulated towards the bone to hit it. Later, a blunt instrument like a periostial elevator is used to reflect the Jinjiva including the periosteum from the bone surface. On the other hand, if we reflect only a part of the Jinjiva, leaving some amount of Jinjiva including the periosteum on the bone surface, it is called a split-thickness or partial thickness flap. Here in this case, the alveolar bone remains unexposed. To raise a partial thickness flap, the scalpel should be oriented parallel to the bone surface without contacting the bone. That means, we are splitting the Jinjiva longitudinally into half. The reflected portion contains Jinjival epithelium and a part of the connective tissue. While the unreflected or intact portion contains the other part of connective tissue and periosteum resting on the bone. Later, the split flap is usually reflected gently with the scalpel itself. This technique is generally performed for muco-Jinjival procedures. According to the replacement or repositioning of the flap after the surgical procedure, it is called an undisplaced or unrepositioned flap when it is sutured back at the same position from where it was reflected. We are talking about the position of Jinjival margin here. Other way round, if the suturing is performed at a different position, it is called a displaced flap based on the direction in which it was displaced, apical, coronal or lateral. In the diagram, we can see that it is an apical displaced flap on the right side. And finally, when viewed from the occlusal aspect, a conventional flap procedure splits the interdental papilla into two halves, buccal and lingual or palatal flaps. Whereas, a papilla preservation flap acknowledges the importance of interdental papilla in the aesthetic zone and hence attempts to preserve the papilla by not splitting or dividing it, but rather by incorporating it into either the buccal or palatal flap by giving a semi-lingual incision near the base of the interdental papilla. Moving on to the incisions used in periodontal surgery, an incision by definition is a cut or surgical wound made by a knife, electro-surgical scalpel, laser or other such instrument. It defines the boundary between the tissue to be moved or removed and the tissue to be left in place. The incisions used in periodontal surgery can be classified as horizontal incisions which are given almost parallel to the gingival margin and vertical incisions which are given parallel to the long axis of the tooth. Horizontal incisions can be further supplied into internal bevel, crevicular and interdental incisions. So, beginning with the horizontal incisions, first one is the internal bevel incision. It is usually the first incision given in most of the flap surgeries. From historical point of view, gingivectomy procedure which uses external bevel incision was introduced much earlier than the flap surgeries for periodontal therapy. Hence, internal bevel incision is also known as reverse bevel incision because the direction of the incision or orientation of the scalpel is reversed to that of the original external bevel incision of gingivectomy which is shown by the red arrow in the picture. This incision is usually given using a number 11 or number 15 BP blade. The purpose of this incision is to eliminate the pocket wall or lining, preservation of the uninvolved outer surface of the gingiva and to provide a sharp thin gingival margin to be adapted at the tooth bone junction. Where is internal bevel incision indicated? If you see the diagram, the position of internal bevel incision is different for different flap techniques. For an undisplaced flap, the internal bevel incision should begin at the level of base of the pocket whereas for modified widman flap and apically displaced flap, the incisions should begin as close to the gingival margin as possible. Thus the undisplaced flap removes the pocket wall whereas the other two types of flaps remove only the pocket lining. So the internal bevel incision is indicated in cases where there is thick gingival biotype where nausea surgery is required in cases of deep periodontal pockets and bone defects and in cases of crown lengthening for prostodontic and restorative purposes. Internal bevel incision is known as crevicular or circular incision as it is given in the gingival crevice or sulcus. It is given using a number 12 or 12 D blade. The internal bevel incision together with the crevicular incision produces a V shaped wedge or collar of tissue around the tooth. This wedge of tissue contains inflamed at granulometus lateral wall of the pocket, junctional epithelium and connective tissue fibres. Sometimes crevicular incision is used alone without internal bevel incision as in curcline flap especially in cases where the width of keratinized gingiva is inadequate. In cases where the gingival biotype and the alveolar bone is thin, where the pockets are shallow. In cases which require regenerative procedures and aesthetically important areas where internal bevel incision might cause postoperative gingival recession. Since crevicular incision results in less tissue manipulation, postoperative recession would be minimal. Finally, the third incision is the interdental incision which is given sometimes using an urban knife and mostly using BP blades number 11 and 12. It is given perpendicular to the other two incisions so as to detach the wedge of pocket wall attached to the alveolar bone crest. It is given on the facial and lingual aspects of the teeth. Then come the vertical incisions. Vertical incision is also known as oblique or releasing incision as it is given at the end or edges of horizontal incisions. These incisions are indicated in cases where we want to limit the number of teeth. For example, in the first picture the area of surgical interest is in relation to the premolars and molars. If we give the releasing incisions we can limit the flap only to that region. Without vertical incisions to raise a flap with sufficient accessibility we might have to extend the horizontal incisions to at least one to two teeth on either side. Otherwise stretching the flap during reflection or elevation might tear it at the edges. The three pictures at the bottom show where to give and where not to give a vertical incision. It should always be given at the line angles. Vertical incisions are also indicated in cases where we plan to displace the flap after the surgery. To reposition it. To displace a flap vertical incisions must extend beyond the mucogengeval junction into the alveolar mucosa. Otherwise the vertical incisions need not cross the mucogengeval junction. The advantages of vertical incisions are that they allow the ease of handling and displacement of the flap. And part of the periodontium which is healthy can be spared from reflection. Disadvantages are that they delay the healing process due to excessive tissue manipulation and cutting of the collateral blood vessels. Due to the proximity of underlying neuro vasculature in certain areas, vertical incisions can't be used freely in all the areas. Soochering a mobile tissue becomes slightly more difficult. So this was all about the incisions and now let's go ahead with various flap surgical techniques. First one is a modified Wittman flap. Historically the original flap technique proposed by Leonard Wittman in 1918 resulted in certain aesthetic problems like denudation of root surfaces and interproximal areas. In order to overcome these limitations, Ramford and Nestle modified this technique in 1974 which eliminated the need for apical displacement of the flap and auspicious recontouring. The following steps outline modified Wittman flap. As shown in the first picture, an internal bevel incision is given approximately 1 millimeter from the crest of the gingival margin parallel to the long axis of the tooth. And the scalloping of the incision should follow scalloping of the gingival margin. If pockets are less than 3 millimeter or aesthetic considerations are important, then directly a crevicular incision might be given instead of internal bevel incision. Second step is flap reflection but not the interdental incision as we all think. This is a common mistake that we make thinking that flap is reflected after all the 3 incisions but no. If we open Karanza textbook and see it says flap reflection before the interdental incision. When circular incision or crevicular incision is made from the base of the pocket to the alveolar bone, the flap is reflected and the third incision that is the interdental incision is given in the interproximal spaces, coronal to the interdental bone with a interdental knife like an urban's knife. Gingival collar is removed and the granulation tissue that is the diseased periodontium which is remaining on the bone and the tooth surface is removed with a curate. Scaling and root planing is performed, residual periodontal fibers attached to the tooth should be left intact as they might help in periodontal regeneration. Oseous correction is not performed unless it prevents the adaptation of the flap at the tooth bone junction. Then the flaps are adapted in such a way that the alveolar bone is covered completely around the teeth and interdental region. Finally suturing is done and a periodontal dressing is placed. This table shows the comparison between the original widman flap and modified widman flap. Whereas in case of original widman flap the goal is to eliminate the pocket whereas in case of modified widman flap it is healing whether by regeneration or formation of long junctional epithelium. The initial incision that is internal bevel or crevicular incision is perpendicular to the long axis of the tooth in case of original widman's flap whereas in case of modified widman flap it is parallel to the long axis of the tooth. In case of original widman flap the flap is reflected completely beyond the mucogingival junction whereas in modified widman flap the reflection is minimal. We should make sure that at least 1 to 2 millimeter of healthy bone margin is visible and the collar containing epithelium and connective tissue is removed with a curette in case of original widman flap whereas it is removed with the interdental incision or the third incision itself in case of modified widman flap. Interproximal flap adaptation is not so important in case of widman flap whereas in modified widman flap it is extremely important to place the flap at the tooth bone junction. Next comes the apically displaced flap or apically reposition flap which can be used for pocket eradication or increasing the width of attached gingiva. The procedure is as follows. As seen in the first picture an internal bevel incision is made as close to the gingival margin as possible towards crest of the alveolar bone. Scalloping need not be accentuated because the flap is displaced apically but not repositioned interdently. Cravicular incisions are made, an initial elevation of the flap is done and interdental incisions are given. Then the gingival collar containing the inflamed pocket wall is removed with curettes. After doing this to displace the flap apically as already discussed during the incisions two vertical incisions are made at the edges of the flap which extend beyond the mucogingival junction to provide adequate mobility of the flap. Then all the granulation tissue is removed and thorough debriement of the area is done as shown in the second picture. Oisier surgery is performed if necessary thereafter the flap is repositioned apically and sutured. If a full thickness flap was elevated it is secured in position using sling sutures whereas if it was a partial thickness flap it is sutured to the periosteum using a direct loop suture either alone or in combination with anchor sutures. Then we have some techniques which help in reconstructive or regenerative procedures like the papilla preservation technique. In this technique the flap design is in such a way that the maximum amount of gingival tissue is retained to cover the reconstructive materials like bone grafts, GTR membranes and other agents that are placed in the pocket or bone defect. Papilla preservation flap was introduced by Take and colleagues which involves a crevicular incision around each tooth on the buckle and lingual aspects with no incisions across the interdental papilla. The papilla thus preserved is usually incorporated into the facial that is a buckle or labial flap or sometimes into the lingual or palatal flap. To include the papilla into the labial flap there should be an adequate interdental space through which it can be pushed to the other side. To do so, semilunar incisions are given individually across the interdental papilla on the lingual or palatal aspect starting and ending at the line angles and at least 5 millimeter away from the crest of the interdental papilla. Then an interproximal knife that is the Orban's knife is introduced into the semilunar incision to detach the papilla from the lingual or palatal flap and interdental papilla bone which is then reflected intact with the labial flap without thinning the tissue. After reflection surgical debridement is done as usual and regenerative materials are praised. The intact papillae are pushed back to their original position through the interdental space carefully so as not to disturb the reconstructive material. The flap is secured in place by using direct loop sutures across the semilunar incisions on the palatal aspect. So that was all about reconstructive flap techniques. Now the treatment of pockets on the distal surface of the last molars is slightly difficult due to limited accessibility and due to the presence of bulbous fibrous tissue over the maxillary tuberosity and retromolar pads. Flap technique for this region is different from the regular flap techniques. In case of maxillary molars in the first step two parallel incisions are made using number 12 BP blade beginning from the distal aspect of the last tooth extending towards but not beyond the mucosin javel junction distal to the retromolar pad. The incisions are made straight down into the underlying bone. Then a transverse incision is made at the distal end of the parallel incisions so that a rectangular chunk of tissue can be removed. The flaps are partially reflected and the underlying tissue is resected so as to undermine or thin the flaps. Procedure surgery is performed if necessary and the flaps are adapted back on the tooth or bone in such a way that there is no overlapping but close approximation of the flaps at a new apical position. Instead of the parallel incisions converging incisions can also be given where there is insufficient keratinized gin jaeva. The remaining procedure is same as that of parallel incision technique. In case of mandibular molars the two distal incisions should follow the area with greatest amount of attached gin jaeva which may not be always found directly distal to the tooth. It may be present either distollingally or distollably as shown in the pictures. The dark shaded portion that is dark pink portion is the keratinized tissue whereas lightly shaded portion is non-keratinized tissue or the allular mucoza. Hence careful assessment of the keratinized tissue is mandatory to give the incisions as shown in these pictures and the remaining procedure is similar to the treatment of mandibular molars. Thank you.