5a. Resective Osseous Surgery Crown Lengthening

Types of Osseous Defects

- 1-walled defect - 2-walled defect (called Craters, Bu-Li) - 3-walled defects (moat-like defects) - 4-walled defects (as seen in extraction sites) - combination 3-2-1 - it is determined by the number of walls remaining - the greatest regeneration is in the 3 and 4-walled defects

Rationale for a Surgical Flap Approach (Why do you need to do surgery?)

- Access, access, access = Visualization and access for debridement of the root surfaces, osseous defects and the soft tissue wall of the periodontal defect + Limitations of closed S/RP include size of the curettes, narrow pocket, root features such as fluting and concavities "after 5" curettes and mini curettes aren't the solution + And you need access to work on the osseous defects (ostectomy or osteoplasty)

Apically Positioned Flaps: Facial Flap

- for the purpose of pocket reduction

Gingival Pocket (Pseudopocket)

- formed by gingival enlargement (increased bulk of gingiva) without periodontal attachment loss, no apical migration of the junctional epithelium

Resective Osseous Surgery: 2. Radicular Blending

- gradualizes bone over radicular surfaces (osteoplasty) - not necessary if vertical grooving is normal

Advantages of Apically Positioned Flaps

- predictable reduction of probing depth - results are relatively immediate, no prolonged waiting to determine outcomes like there is with GTr

Types of Pockets

- pseudo (gingival) pockets (left pic) - suprabony pockets - infrabony pockets - types of pockets and tissue type, will determine the results that you can predict from your therapy

Radiographic Examination

- radiographs can't see everything - DOES NOT identify the presence of periodontitis or extent of bony defects. - CANNOT accurately document the number of bony walls and the presence or extent of bony lesions on the facial/Lingual walls. But may show: - Presence of angular bone loss and root trunk length - Serve as a means of evaluating the success of therapy and documenting the patient's longitudinal stability. - Correlate clinical findings with the radiographic examination

Resective Osseous Surgery: 1. Vertical Grooving

- reduces the thickness of the bony housing (osteoplasty) - contraindicated in: + root proximity + thin alveolar housing

Controversy of Osseous Resective Surgery

- surgical elimination of pockets (including osseous surgery) offers no advantage for maintaining the teeth and their support over more conservative forms of treatment - Osseous surgery caused more marked loss of periodontal attachment 2+ mm) in initially shallow sites than other treatments and got considerable periodontal damage on areas not initially affected by periodontitis 5-year randomized control clinical trial: - no significant difference found in plaque and gingival index scores between treatments - no advantage of osseous surgery in enhancing patient plaque control

Positive Architecture

- there is a scalloped architecture - the interproximal bone is located coronally to the facial or lingual surface

Resective Osseous Surgery: 4. Gradualizing Marginal Bone

- to eliminate Widow's Peaks (forms at line angles after interproximal flattening) - blends the radicular surface - minor ostectomy

What is the progosis fo infrabony defects? (important)

- untreated, progressive infrabony defects have a poor long term prognosis

Full Thickness (mucoperiosteal) Flap

- used for resective or GTR surgeries - epithelium, connective tissue, and periosteum - interdental papilla is split beneath the contact point of the two approximating teeth to allow reflection of buccal and lingual flaps

Resective Osseous Surgery: 3. Flattening Interproximal Bone

- used on one-walled interproximal defects - minor ostectomy - if skipped, can cause increased pocket depths

Periodontal Probing and Sounding

- walking the prove to accurately assess the osseous defect Probing and Exploration: - pocket depth - location of the base of the pocket relative to the MGJ and attachment level on teeth - number of bony walls - furcation defects

Evaluating Alveolar Bone Architecture

- when evaluating the alveolar crest, you must evaluate the location of the CEJ between two adjacent teeth to help you to determine whether the bone loss is horizontal or vertical - you need to determine if resective osseous surgery or regeneration should be used to treat the osseous defects

What are the procedures to correct osseous defects? (important)

Osteoplasty: - reshaping the bone without removing tooth-supporting bone Ostectomy/Osteroectomy: - removal of tooth-supporting bone

Post-Surgery (important)

Post-Op (1 week and 2-3 weeks): - CHX rinse - suture removal in 1-3 weeks (resorbable vs. non-resorbable) - removal of dressing - rinse with cotton pellet and saline - prophy every 2 weeks to remove plaque biofilm Healing: - 2-3 weeks: + attachment of flaps to bone - up to 6 months: + complete maturation and remodeling + wait this long before taking the impressions for the provisional restorations = minimum 6 weeks in posterior = minimum 12 weeks in max. anterior segment = up to one year: if esthetics is very critical for restorations

Secondary Flap

??? (class capture slide 57)

Principles of Osseous Resective Surgery

- Gingival tissue contour is closely dependent on the contour of the underlying alveolar bone and the proximity and anatomy of adjacent tooth surfaces - Plaque-induced periodontitis often results uneven alveolar bone crest - To establish and maintain shallow pockets and optimal gingival contour after periodontal surgery osseous reshaping and elimination of osseous craters/angular bony defects is proposed to be needed in addition to elimination of soft tissue pockets

Papilla Preservation Flap

- Incorporates the entire papilla in one of the flaps by means of crevicular interdental incisions - Horizontal incision at the base of the papilla on the palate. No incision across the interdental papilla

Disadvantages/Complications of Osseous Resective Surgery

- Increased food impaction - More open embrasures - Increased tooth root hypersensitivity - Transient or long standing increased tooth mobility - Root caries if home care and diet is poor - Unaesthetic root exposure - Clinical attachment removal with ostectomy procedure - creation of recession even though the goal of pocket reduction was achieved

Probing Maxillary Molar Functions challening during surgery

- Mesial furcation place the probe 2/3rds toward the palate and under the line angle - The entry point for the distal furcation is under the contact area ½ way bucco lingually

Re-Evaluation of Tissue Response to Phase 1 Non-Surgical Treatment

- Oral hygiene instructions (OHI) - SRP, polish - re-eval. = determine next phase 1. periodontal maintenance determined by patient's needs OR 2. referral to Grad. Perio. for periodontal surgical therapy/definitive pocket elimination

Conclusions of this Lecture

- Osseous resective surgery can be used successfully to arrest periodontitis - Treatment application is limited to chronic periodontitis cases with slight to moderate loss of periodontal support - Good plaque control is essential to prevent recurrent periodontal breakdown - Procedures that do not include resection of supporting alveolar bone (modified Widman/access flap procedures, S/RP may be equally effective. - clinical crown lengthening to avoid violation of the biologic width and the supracrestal fiber attachment and it's consequences in our synchronous meeting

Osteoplasty (osseous resective surgery)

- Osseous resective surgery uses a combination of osteoplasty and ostectomy to re-establish a "positive" bony architecture around the teeth - is the reshaping of the alveolar process to achieve a more physiologic form without removing alveolar bone attached to the tooth - leveling of interproximal craters (craters are 2-walled defects) - elimination of bony walls of circumferential osseous defects Objectives: - to enhance flap placement and adaptation at suturing during modified Widman flap and/or apically positioned flaps - it is used to remove facial and/or lingual bony ledges, incipient furcation involvements or shallow facial/lingual intrabony defects

Treatment Planning Phase 2 Surgical

- Periodontal surgery: decision to proceed + Persistence of PD + Bleeding On Probing + Suppuration + PD of 5 mm or more + Residual plaque or calculus subgingivally + Good supragingival plaque control (Patients with poor home care will have more attachment loss post-surgery)

Contraindications to Osseous Resective Surgery (relative/absolute) (important)

- Periodontitis with advanced loss of periodontal support (may result in removal of too much supporting alveolar bone from the teeth) - Significant preoperative tooth mobility - Significant caries risk - Poor oral hygiene

Q7&8 A primer for osseous surgery (Importance of classifying bony defects)

- Purpose of osseous: To maintain shallow postoperative sulci without further loss of attachment - Classification of bone craters: + Shallow 1-2mm + Medium 3-4mm + Deep 5mm + - Determine the amount of buccal bone to remove in molar areas by relationship of the base of the crater to the root trunk - Bone reduction should be done from the palatal side to avoid recession on the buccal and to take advantage of anatomical factors in the molar area

Furcations

- Root trunk = the distance from the CEJ to the furcation fornix + is a limiting anatomic factor for bone removal - Do not expose or open up furcation areas with osseous surgery - Careful management of the furcations for the best outcomes - Decisions must be made to resect/ contour the bone or attempt regeneration in the furcations

History of Osseous Resective Surgery

- Saul Schluger did it first - Shallow pockets were thought to be impossible to create unless the underlying bone topography is altered and proximal intrabony defects removed - Shallow pockets were thought to be easier for the patient and dentist to maintain

Therapeutic Goals of Osseous Resective Surgery

- To establish minimal probing depths - Create gingival soft tissue morphology that enhances oral hygiene performance - Aims to re establish a marginal bone morphology around teeth to resemble "normal bone with positive architecture " where interproximal bone is coronal to the facial and lingual bone

Periodontal Pocket

- either suprabony or intrabony - suprabony: horizontal bone loss - infrabony: vertical bone loss - a pathologically deepened gingival sulcus with destruction of supporting periodontal tissues

Negative (or Reverse) Architecture

- interproximal bone level is apical to the mid-facial and/or lingual bone

Ostectomy

- is excision of bone or a portion of bone to correct or reduce deformities caused by periodontitis in the marginal and interdental alveolar bone and includes the removal of bone that is attached to a tooth (supporting bone) Objectives: - to eliminate interdental intrabony pockets in conjunction with apically positioned or replaced flaps - is used to treat shallow (1-2mm) to medium (3-4mm) proximity intrabony defects + chronic periodontitis with slight to moderate loss of periodontal support (stage 2 or 3 periodontitis) - correct reversals in osseous architecture

Split Thickness Flap (partial thickness or mucosal flap)

- periosteum and connective tissue + used in soft tissue grafting procedures - includes only the epithelium and a layer of the underlying connective tissue - the bone remains covered by a layer of connective tissue, including the epithelium

Goals of Resective Osseous Surgery

- pocket elimination - to facilitate certain restorative and prosthetic dental procedures + exposure of dental caries (crown lengthening) + exposure of fracture roots for removal + removal of exostoses before removable/fixed prosthesis - esthetic purposes + to address altered passive eruption

Types of Alveolar Bony Architecture

A. Positive B. Flat C. Negative

Surgical Technique: Soft Tissue/Flap Management

Flap positioned: 1. Apically position buccal and thinned palatal flaps - main technique in the maxilla 2. Apically position buccal and lingual flaps in the mandible 3. continuous sling sutures can permit independent placement of the buccal and lingual flaps as discussed in the suturing handout

Surgical Technique - Managing Soft and Hard Tissue

I. Soft tissue management: - Full thickness mucoperiosteal flap reflection with thinning of the palatal flap 2. Hard Tissue management: - Thin facial and lingual bone - Remove facial and lingual lips of interproximal bony crater(flatten the craters) - Create positive architecture by removing direct facial and lingual bone - Refine facial and lingual vertical bony grooves

Resective Osseous Surgery Technique (important)

Instrumentation: - hand instruments (ostectomy) - rotary instruments (osteoplasty) - piezoelectric Steps (pic): 1. vertical grooving (osteoplasty) 2. radicular blending (osteoplasty) 3. flattening interproximal bone (ostectomy) 4. gradualizing marginal bone (ostectomy)

What bony pockets are horizontal bone loss?

Suprabony pockets (MOST COMMON)

What bony pockets are vertical bone loss?

angular or infrabony (intrabony) pockets (within the confines of bone) - classified by the number of remaining bony walls - 1,2,3 walled defects