Fig1: Horizontal incisions
A. Internal bevel incision—First/ basic incision. It starts
from a designated area on the gingiva and is directed to an area at or near the crest of the alveolar bone (Fig. 2).
Fig .2: Varying locations of internal bevel incision for different
flapsGiven with the help of 11 or 15 no. surgical blade. Morris in 1965 introduced internal bevel incision which separated the pocket wall from the rest of the mucoperiosteal flap and produced a healthy thin and flexible margin. It is also called as reverse bevel incision because its bevel is in reverse
direction from that of gingivectomy incision. Objectives:
It accomplishes three important objectives:
1. It removes the pocket lining.
2. It conserves the relatively uninvolved outer surface of the gingiva.
3. It produces a sharp, thin flap margin for adaptation to the bone–tooth junction. Indications: Primary incision of flap surgery is given if;
1. There is a sufficient band of attached gingiva.
2. Thick gingiva (such as palatal gingiva).
3. Deep periodontal pockets and bone defect.
4. Desire to lengthen clinical crown.
B. Crevicular/Sulcular incision—Second incision. It is made from the base of the pocket to the crest of the alveolar bone (Fig.1B). This incision is carried around the entire tooth with the help of 12 no. surgical blade. Its purpose is to facilitate the removal of the inflammatory granulation tissue surrounding the cervical area (cervical wedge) left after reflecting the primary flap.
1. Narrow band of attached gingiva.
2. Thin gingiva and alveolar process.
3. Shallow periodontal pocket.
4. Desire to lessen postoperative gingival
recession for esthetic reasons in the maxillary anterior region.
5. As a secondary incision of usual flap surgery.
6. Bone graft or GTR procedure: Desire to preserve as much periodontal tissue (especially interdental papilla) as possible to completely cover grafted bone and membrane by flap.
C. Interdental incision: Third incision. This incision is made in a horizontal direction and close to the surface of the bone crest, thereby separating the soft tissue collar from the root surfaces and alveolar bone (Fig. 1C). Given by Orban’s knife. The third incision facilitates secondary flap removal as a single piece.
II. Vertical Incision/Oblique releasing incision: Vertical incision must extend beyond the mucogingival line. It should be made at the line angles of a tooth either to include the papilla in the flap or to avoid it completely.Thus, vertical incision should be placed on the tooth surface rather than on interdental gingiva (Fig.3). Vertical incision in lingual and palatal areas are avoided. These should be designed so as to avoid short flap mesiodistally with long apically directed horizontal incision because this could jeopardize the blood supply to the flap. Given with the help of 11 or 15 no. surgical blade.
Fig. 3: Vertical incision
II. Thinning incision: Extends from gingiva towards the base of the flap in palatal flap and distal wedge procedures. Given with the help of 11 or 15 no. surgical blade.
Fig. 4: Cut-back incision
IV. Cut-back incision: Made at apical aspect of releasing incision and directed towards base of the flap in laterally positioned flap (Fig. 4). Given with the help of 11 or 15 no. surgical blade.
V. Periosteal releasing incision: Made at the base of flap severing the underlying periosteum. Given with the help of 15 or 15C no. surgical blade.
DEFINITION OF PERIODONTAL FLAP
It is the portion of gingiva and or alveolar mucosa surgically separated from the underlying tissues to provide visibility and access to the bone and root surface.
OBJECTIVES OF PERIODONTAL FLAP
i. Provide access for root surface detoxification.
ii. Reducing probing depth including those that extend to or beyond the mucogingival junction.
iii. Preserve/create an adequate zone of attached gingiva.
iv. Permits access to underlying bone for treatment of osseous defects.
v. Facilitate regenerative procedures.
PRINCIPLES OF FLAP DESIGN
According to Hupp (1993), the following principles should be followed for flap design.
Prevention of flap necrosis:
• The apex of the flap should never be wider than the base
• The flap sides should either run parallel to each other or preferably converge moving from the base of the flap to the apex of the flap
• Length of the flap should be no more than twice the width of the base
• The base of the flaps should not be excessively twisted or stretched
• Whenever possible, an axial blood supply should be included in the base of the flap. Prevention of flap tearing:
• Vertical releasing incisions should be placed one full tooth anterior to the sites of any anticipated bone removal
• Vertical incision should be started at the line angle of the tooth or in the adjacent interdental papilla and carried obliquely apically into the unattached gingiva.
Basic flap requirements:
• Base of the flap must be wide enough to maintain an adequate blood supply
• Flap must be big enough to expose any underlying bone defects
• No important vessels or nerves should be damaged in raising the flap
• Incisions must allow movement of flap without tension.
CLASSIFICATION OF PERIODONTAL FLAPS
Classification of periodontal flaps
A. According to flap reflection or tissue content:
a. Full thickness flap
b. Split-thickness flap
B. According to management of papilla:
a. Conventional flap
b. Papilla preservation flap
C. According to flap placement after surgery:
a. Non displaced flap
b. Displaced flap:
• Apical displaced flap
• Coronal displaced flap
• Lateral displaced flap
Full-thickness/mucoperiosteal flap: It consists of the complete mucoperiosteum i.e surface epithelium, connective tissue and periosteum which is raised by a periosteal elevator (Fig. 5A).
Consists of Consists of
1. Epithelium 1. Epithelium
2. Connective tissue 2. Connective tissue
Incision ends on bone Incision ends on root surface
Fig. 5: A. Full thickness and B. Partial thickness flap
Indication: A full-thickness flap is used to expose the bone surface in osseous surgery.
1. Area where treatment for osseous defect with mucogingival problem is not required.
2. Thin periodontal tissue with probable osseous dehiscence and osseous fenestration.
3. Area where alveolar bone is thin.
Split-thickness/mucosal flap: Gingiva is dissected from the underlying periosteum which is left on the bone and consists of epithelium and thin layer of connective tissue (Fig. 5B). Sharp dissection is used to produce a partial thickness flap. Partial-thickness flap is prepared while holding and pulling the flap edge with tissue pliers, turning the blade toward the gingival margin. The flap is dissected slowly from an apico-occlusal direction. To prevent flap penetration, use the side of the blade and hold it parallel to the periosteum to make the incision. Indications: Partial thickness flaps are especially useful for augmentation of the attached gingiva. This is done by positioning the flap apically or laterally. Partial thickness flap is employed, when exposure of bone is to be avoided as in the case of fenestration/dehiscence. Advantages: The flap can be attached firmly to the desired position with a periosteal suture if the reflected flap is displaced apically and the thin marginal bone can be protected by the periosteum-connective tissue bed. Disadvantages: The biggest problem of a partialthickness flap is with the thickness of the remaining periosteum-connective tissue bed on the bone. If it is less than 0.5 mm, the remaining periosteum-connective tissue may become necrotic, with decreased protective effect for the alveolar bone. However, the partial-thickness flap is a difficult technique and causes much discomfort because of postoperative swelling.
VARIOUS FLAP PROCEDURES FOR POCKET ELIMINATION
MODIFIED WIDMAN FLAP PROCEDURE
Historical perspective: In 1918, Widman introduced Widman flap surgery. In 1965, Morris revived this technique and called it as unrepositioned mucoperiosteal flap. The same procedure was presented in 1974 by Ramfjord and Nissle who called it the modified Widman flap.
The advantages of Modified Widman flap over Original Widman flap procedure are i) close adaptation of soft tissue to root surface, ii) minimum trauma to alveolar bone and iii) access to adequate instrumentation of the root surface.
Objectives: The main purpose of the modified widman technique is to facilitate instrumentation on root surfaces by exposing them and to remove the pocket lining. Resdiual deposits of subgingival calculus left in deep pockets are thus removed.
Blade no. 11, 12, 15, Bard Parker handle no. 3, Periosteal elevator and Curettes.
• Incision and flap reflection: The internal bevel incision is the initial incision starting 0.5 to 1 mm from the gingival margin to the alveolar crest (Fig. 6A).
Fig. 6A: Internal bevel incision of modified widman flap
Scalloping follows the gingival margin. Care should be taken to insert the blade in such a way that the papilla is left with a thickness similar to that of the remaining facial flap. The gingiva is reflected with a periosteal elevator. A crevicular incision is made from the bottom of the pocket to the alveolar bone,
circumscribing the triangular wedge of tissue containing the pocket lining. After the flap is reflected, a third incision is made in the interdental space, coronal to the bone, with an interproximal
knife (Fig. 6B).
Fig. 6B: Crevicular incision and interdental incision of modified widman flap
• Cervical wedge: The gingival collar is removed with the help of curette.
• Curettage, scaling and root planing: Tissue tags and granulation tissue are removed with a curette. The root surfaces are checked and are scaled and planed, if necessary. Residual periodontal fibers attached to the tooth surface should not be disturbed.
• Bone architecture is not corrected unless it prevents good tissue adaptation to the neck of the teeth. Every effort is made to adapt the facial and lingual interproximal tissue adjacent to each other in such a way that no interproximal bone remains exposed at the time of suturing. The flaps may be thinned to allow for close adaptation of the gingiva around the entire circumference of the tooth and to each other interproximally.
• Suturing: The flaps are replaced in their origina position and secured by interdental suturing (Fig. 6C).
Fig. 6C: Modified widman flap sutured
• Postoperative management: The operated site is covered with periodontal surgical pack and postoperative instructions are given thereafter.
UNDISPLACED FLAP PROCEDURE
It is also called as internal bevel gingivectomy because the soft tissue pocket wall is removed with the initial incision. Objectives
i. To reduce or eliminate pocket by removing pocket wall.
ii. To improve accessibility for instrumentation.
Pocket marker, Blade no. 11, 12, 15, Bard Parker handle no. 3, Periosteal elevator and Curettes.
Procedure (Fig. 7)
• Mark bleeding points: The pockets are measured with a periodontal probe and bleeding points are produced on the outer surface of the gingiva to mark the pocket bottom with the help of pocket marker.
• Incision and flap reflection: The initial, internal bevel incision is made following the scalloping of the bleeding marks on the gingiva. The incision is usually carried to a point apical to the alveolar crest,
depending on the thickness of the tissue. The thicker the tissue is, the more apical will be the ending point of the incision. Then crevicular incision is made from the bottom of the pocket to the bone to detach the connective tissue from the tooth. Full thickness flap
is reflected with a periosteal elevator. The third incision, i.e. interdental incision is made with an interdental knife, separating the connective tissue from the bone. The triangular wedge of tissue created by the three incisions is removed with a curette.
• Removal of granulation tissue: The area is debrided, removing all tissue tags and granulation tissue with sharp curettes.
• Curettage, scaling and root planing: After the necessary scaling and root planing, the flap edge should rest on the root—bone junction.
• Suturing: A continuous sling suture is utilized to secure the facial and the lingual or palatal flaps. This
type of suture, which uses the tooth as an anchor, is advantageous to position and hold the flap edges at the root—bone junction. The area is covered with a periodontal pack.
• Postoperative instructions are given thereafter.
Fig. 7: Undisplaced flap
APICALLY DISPLACED FLAP PROCEDURE
In 1954, Nabers described the repositioning of the attached gingiva. For the first time, a mucoperiosteal flap was apically positioned after treatment. He utilized one vertical releasing incision which is placed mesially to the area of the deepest pocket. Later in 1957, he introduced the inverse bevel incision of which he called the “repositioning incision” which includes the internal incision from the gingival margin to the alveolar crest. This incision, he stated, would permit an easier flap reflection and result in a thinner gingival margin. In that same year, Ariaudo and Tyrrell modified Nabers’ technique and
recommended two vertical releasing incisions instead of just one to facilitate the mobilization of the flap. At this point, the only difference from the flap design of Widman is the apical positioning. Finally, in 1962, Friedman published the technique in his paper and coined the term
“apically repositioned flap”. In his paper, he described the use of inverse beveled incision to thin the marginal tissue and the papillae. This thinning incision eliminates thick gingival margin and papillae with large triangular pieces of interdental tissue. A thick tissue would be difficult to be eliminated from the already raised flap and also created problem in approximation of tissue for primary intention healing, resulting in bulbous or ledging tissue upon healing. This flap designed could be referred to as the partial full-thickness flap since the marginal papillae was partially disected with the inverse bevel incision, then this incision continue to include the mucoperiosteum of the full thickness flap. Goldman in 1982 introduced another variation of which he followed the full thickness flap with a partial dissection, allowing the use of periosteal suture to position the flap. This flap design, he called the tertiary flap or the partial-fullpartial- thickness flap. Today, the word “reposition” is replaced by the term “position” since reposition means place the flap back to where it was before. The flap can
be positioned apically or reposition, depending on each individualized case. The sling suture is recommended for better flap placement. Pocket elimination is achieved
only by apically positioning of the flap. Objectives:
i. To eliminate pocket by apically positioning the soft tissue wall of the pocket.
ii. To preserve/increase the width of attached gingiva.
iii. To improve accessibility.
The position of the flap displacement varies depending on the:
1. Thickness of alveolar margin in operating area.
2. Width of attached gingiva.
3. Clinical crown length necessary for an abutment.
Procedure (Figs 8A to D)
• Incisions and flap reflection: First incision, internal bevel incision is made 1 mm from the crest of the gingiva and directed towards the crest of the alveolar bone.
The beveling incision should be given a scalloped outline to ensure maximal interproximal coverage of the alveolar bone, when the flap subsequently is repositioned. Second incision, crevicular incision is made, followed by the elevation of the full thickness mucoperiosteal flap. Third incision, interdental incision is given and the wedge of the tissue that contains pocket wall is removed. Vertical incision extending out into alveolar mucosa (i.e. past the mucogingival junction) are made at each end points
of the internal bevel incision, making the apical repositioning of the flap. For full thickness flap, periosteal elevator is used to reflect the flap.
Figs 8A to D: Apically positioned flap
• Removal of granulation tissue: Marginal collar tissue and granulation tissue are removed with curettes.
• Scaling and root planing: Scaling and root planing is done carefully with scalers and curettes.
• Osseous recontouring: Alveolar bone crest is recontoured with the help of bur and bone chisels.
• Apical positioning and suturing: The flap is reflected to the base of the vestibule. Once released, the flap tends to contract and fold up so that apical positioning takes place. Flap is displaced apically so that edge just covers the newly recontoured alveolar crest. Interrupted sutures should be placed first at the mesial and distal vertical incisions. Full thickness flap is sutured using sling suture while partial
thickness flap is secured with direct loop suture or a combination of loop and anchor suture. Periodontal dressing is applied on the operated site over the dry foil.
• Postoperative instructions are given thereafter.
1. Eliminates periodontal pocket- Apically repositioned flap results in pocket elimination and the formation of a normal/physiological length of junctional epithelium whereas the replaced flap results in the formation of a long junctional epithelium which may adhere to the root surface. The long junctional epithelium is inherently less stable than the
physiological junctional epithelium and demands much higher frequencies of recall for maintenance than pocket elimination procedures.
2. Preserves attached gingiva and increases its width.
3. Establishes gingival morphology facilitating good hygiene.
4. Ensures healthy root surface necessary for the biologic width on alveolar margin and lengthen clinical crown.
1. May cause esthetic problems due to root exposure.
2. May cause attachment loss due to surgery.
3. May cause hypersensitivity.
4. May increase the risk of root caries.
5. Possibility of exposure of furcations and roots, which
complicates postoperative supragingival plaque
PAPILLA PRESERVATION FLAP
In 1985, Takei et al proposed surgical approach called as Papilla preservation technique. Later, Cortellini et al described modifications of this flap designs. It is the procedure which incorporates the entire papilla in one of the flaps by means of crevicular and interdental incisions to sever the connective tissue attachment and a horizontal incision at the base of the papilla, leaving it connected to one of the flaps.
i. Diastema region.
ii. Bone grafting areas.
i. Narrow embrasures.
• Incisions: Crevicular incisions are made at the facial and proximal aspects of the teeth without making incisions through the interdental papillae. Subsequently, crevicular incision is made along the
lingual/palatal aspect of teeth with a semilunar incision made across each interdental area with the blade perpendicular to the outer surface of gingiva and extending through the periosteum to the alveolar process (Fig. 9A). Semilunar incision should dip apically atleast 5 mm from the line angles of teeth, which will allow the interdental tissue to be dissected from the lingual/palatal aspect so that it can be elevated intact with the facial flap.
• Reflection of flap: A curette or interproximal knife is used to carefully free the interdental papilla from the underlying hard tissue. The detached interdental tissue is pushed through the embrasure with a blunt instrument (Fig. 9B). A full–thickness flap is reflected with a periosteal elevator on both facial/ palatal surfaces. The exposed root surfaces are thoroughly scaled and root planed and bone defects carefully curetted.
• Removal of granulomatous tissue: While holding the reflected flap, the margins of the flap and the
interdental tissue are scrapped to remove pocket epithelium and excessive granulation tissue. In
anterior areas, the trimming of granulation tissue should be limited so as to maintain the thickness of tissue. After reflection of flap, access to the interdental bony defect will be obtained. The bony defect is cleaned out using curette. The bone graft material is placed if required.
Fig. .9B: Reflected papilla preservation flap
• Suturing: The flaps are repositioned and sutured using criss cross mattress. The cross mattress suture
results in optimal flap closure without having suture material in direct contact with the graft material.
Alternatively, a direct suture of the semilunar incisions can be done as the only means of flap closure
(Fig. 9C). Periodontal dressing may be placed to protect the surgical area.
• Postoperative instructions are given thereafter.
i. Esthetically pleasing.
ii. Primary coverage of implant.
iii. Prevents postoperative tissue craters.
i. Technically difficult.
ii. Time consuming.
The surgical approach for palatal flap is different from other flaps because of the nature of palatal tissue which is attached and keratinized with no elastic properties.
The apical portion of the scalloping should be narrower than the line angle area because of the taper of palatal root apically. Palatal flap cannot be displaced apically nor can a split-thickness palatal flap be accomplished.
i. Areas that require osseous surgery.
ii. Pocket elimination.
iii. Reduction of enlarged and bulbous tissue.
It is contraindicated when the palate is broad andshallow. Special care must be taken performing a palatal flap due to several anatomic structures:
• Greater palatine artery and nerve may be damaged if flap reflection is extensive in molar region.
• Palatal exostoses present in molar region in 1/3rd of the patient. It creates thin tissue in the region and make proper flap margin placement difficult.
• Incisive papilla present in anterior palate.
• Presence of palatal rugae at or near the flap margin create poor gingival margin contours postsurgically.
• Incisions: The outline of initial incision for palatal flap varies and is determined with consideration for the:
i) thickness of palatal soft tissue; ii) depth of periodontal pocket; iii) necessity for osteoplasty; and
iv) clinical crown length required for restorative treatment. If the purpose of surgery is debridement then internal bevel incision is given such that palatal flap is adapted at root bone junction, when sutured. If osseous resection is to be done, then palatal incision is planned to compensate for lowered level of bone when the flap is closed.
The initial incision may be the usual internal bevel incision, followed by crevicular and interdental incisions. If the tissue is thick, a horizontal gingivectomy incision may be made, followed by an internal bevel incision that starts at the edge of this incision and ends on the lateral surface of the
underlying bone. The placement of the internal bevel incision must be done in such a way that the flap fits around the tooth without exposing the bone. The blade should be parallel to the palatal soft tissue to prepare a thin and uniform primary flap (1.5–2.0-mm thickness). Caution must be taken to avoid perforating the flap or making the flap too thin, which will cut off the necessary blood supply.
• Flap reflection: Before the flap is reflected to the final position for scaling and management of the osseous lesions, its thickness must be checked. Flaps should be thin to adapt to the underlying osseous tissue and provide a thin, knife like gingival margin.
• Scaling, root planing: With the help of scalers and curettes scaling, root planing is performed. Osteoplasty is done only if required.
• Suturing: Suture the flap’s edge at the level of the bone margin or slightly over the alveolar crest (approximately 1–2 mm above the bone margin).
• Post operative instructions are given thereafter.
Friedman developed the beveled flap, a modification of the apically repositioned flap for the periodontal pockets on the palatal aspect of the teeth. As there is no alveolar mucosa present on the palatal aspect of the teeth, it is not possible to reposition the flap in an apical direction.
A primary incision is made intracrevicularly through the bottom of the periodontal pocket and a mucoperiosteal flap is elevated. Scaling, root planing and osseous recontouring is performed in the surgical area. The palatal flap is replaced and a secondary, scalloped, reverse bevel incision is made to adjust the length of the flap to the height of the remaining alveolar bone.The shortened and thinned flap is replaced over the alveolar bone and in close contact with the root surface (Fig10).
Advantages of palatal approach procedures are esthetics, easier access for osseous surgery, wider palatal embrassure space and less resorption because of thicker bone. The only disadvantage is close root proximity.
Fig. 10: Beveled flap
DISTAL MOLAR SURGERY
Treatment of periodontal pocket on the distal surface
of terminal molar is often complicated by the presence
of bulbous fibrous tissue over the maxillary tuberosity
or prominent retromolar pad in the mandible. Deep
vertical defects are also commonly present in
conjunction with the redundant fibrous tissue. This
procedure enables the removal of thick gingival tissue
on the adjacent edentulous site. If there is an osseous
defect, it corrects the bone morphology by flattening it
and the intrabony defect may be eliminated. The
periodontal pocket is eliminated and a shallow gingival
sulcus favorable for postoperative maintenance is
Objectives of distal wedge procedure
1. To maintain and preserve attached gingiva.
2. To eliminate periodontal pocket.
3. To lengthen clinical crown.
4. To create easily cleansable gingiva-alveolar form.
The various incisions for distal molar surgery
i. Linear incision
ii. Triangular incision
iii. Pedicle incision
iv. Square, parallel incision
Fig. 11: Various incisions for distal molar surgery
Indications for the square incision:
• Long and large edentulous ridge, maxillary tuberosity and retromolar triangle
• Much tissue to be removed in the wedge area
• Sufficient existing band of attached gingiva
• Deep periodontal pockets and osseous defects on the mesial and distal aspects of the abutment.
Maxillary molars: Two parallel incisions, beginning at the distal portion of the tooth and extending to the mucogingival junction distal to the tuberosity, are made.
These incisions are usually interconnected with the incisions for the remainder of the surgery in the quadrant involved. The amount of wedge tissue to be removed (the distance between the two internal bevel incisions) is determined by a number of factors, such as i) depth of periodontal pocket, ii) thickness of the soft tissue wedge, iii) whether osteoplasty or osseous resection is necessary and, iv) clinical crown length required for abutment. A transversal incision is made at the distal end of the two parallel incisions so that a long, rectangular piece of tissue can be removed. The parallel distal incisions should be confined to the attached gingiva because bleeding and flap management becomes problem when the incision is extended into the alveolar mucosa. When the tissue between the two incisions is removed and the flaps are thinned, the two flap edges must approximate each other at a new apical position without overlapping.
Mandibular molars: Incisions for the mandibular arch differ from those used for the tuberosity, owing to differences in the anatomy and histologic features of the areas. The retromolar pad area does not usually present as much fibrous attached gingiva. The two incisions distal to the molar should follow the area with the greatest amount of attached gingiva. Therefore, the incisions could be directed distolingually or distofacially, depending on which area has more attached gingiva. Before the flap is completely reflected, it is thinned with a 15 no. blade. It is easier to thin the flap before it is completely free and mobile. After the reflection of the flap and the removal of the redundant fibrous tissue, any necessary osseous surgery is performed. The flaps are approximated similarly to those in the maxillary tuberosity area.
Advantages of distal wedge procedure
i. Maintenance of attached tissue.
ii. Accessibility for treatment of both distal furcation and underlying osseous irregularities.
Coronally Displaced Flap
Explained in chapter no. 50 Periodontal Plastic Surgery.
Laterally Positioned Pedicle Flap
It was originally developed by Grupe and Warren in 1956. In this procedure a pedicle graft is taken from a donor site and is placed on the adjoining site by moving the flap towards the recipient site and suture are placed (Rest is described in chapter no. 50 Periodontal Plastic Surgery).
Double Papilla Pedicle Flap
Explained in chapter no. 50 Periodontal Plastic Surgery.
POINTS TO PONDER
- Incisions are either coronally directed incision(external bevel incision) or apically directed incisions (Internal bevel, sulcular incision).
- Undisplaced flap is considered as Internal bevel gingivectomy. Undisplaced flap and gingivectomy procedures surgically remove the pocket wall.
- Apically positioned flap surgery, is one of the most reliable technique for the elimination of periodontal pockets.
- The flap without vertical incision is called envelope flap.
- The tissue which is left on the surface of tooth when the flap is raised is called as cervical wedge.
- Neumann flap: Neumann in 1911, introduced the flap in which the intrasulcular incision was made along with two vertical releasing incision, a full thickness flap raised and the area was curetted thoroughly to eliminate all the granulation tissue to prevent reinfection. Root was planed smooth and bone was superficially removed.
Conventional flap is the flap in which the papilla is split into facial half and lingual/palatal half.