26 - Osseous Surgery - Hunter

Question 1

Do you need osseous surgery or you can apically position the flap without osseous?

Answer 1

Olsen: Longitudinal study comparing apically repositioned flaps w/ and w/o osseous surgery

12 patients w/ moderate periodontitis

At 5 year follow up: Resulted in fewer residual pockets and less inflammation than flap curettage (2.3x greater bleeding 4+ mm pockets), especially in 5-8mm pockets.

Question 2

Is osseous better than MWF or SRP?

Answer 2

Kaldahl

One of the only studies that is truly statistically significant in this lit packet

Compared coronal scaling,S SRP, SRP + MWF, or SRP + FO

Results:

MWF has greater PD reduction than SRP at first, but later evens out

In moderate and deep pockets, sustained CAL gain is possible for RP, MW, and FO. Attachment gains were significantly greater for deeper sites than shallow sites.

CS is not as favorable as other treatment modalities (duh)

No stastically significant difference in outcome between FO, SRP, MWF.

Question 3

What’s better SRP, Osseous, or MWF?

Answer 3

Becker

5 year longitudinal study of moderate to severe perio dz (16 patients)

No statistically significant difference between the three procedures

BL: Periodontal therapy, with proper OH and regular maintenance, can maintain periodontal health. SRP, OS and MW similarly effect PD reductions with slight changes in CAL after 5 years. Any treatment in a 1-3mm PD was detrimental to CAL and PD at 5 years.

Question 4

What’s better fibre retention osseous resective surgery osseous surgery in treatment of Shallow infrabony defects?

Answer 4

Cairo:

shallow = less than 3 mm

Significantly more bone is removed in traditional osseous group ~1mm

the fibReORS group had significantly less post-operative discomfort (requiring fewer analgesics), less dentinal hypersensitivity, and greater esthetic outcomes

FibReORS compares favorable to ORS in regards to reduced post-operative PDs and less recessions. Also has greater patient satisfaction.

Question 5

What is fibre retention osseous surgery?

Answer 5

Carnevale in 2007 proposed Fibre retention osseous surgery. It uses the CT attachment instead of the base of the osseous defect as the reference for performing osseous surgery. After flap reflection the perio probe is used to determine the location of fibers remaining on the root surface and within the infrabony defect. Then osseous surgery is limited to the most coronal portion of this CT attachment located within the infrabony defect.

Question 6

What is better for the treatment of shallow intrabony defects traditional ORS or FibREOS?

Answer 6

Aimetti:

FibReORS has equal amounts of PD reduction with less CAL loss
Good option in 3 mm or less defects

Question 7

What is the ultimate goal of osseous resective surgery? Explain how we get there

Answer 7

Schluger

Stated that Pocket elimination is a goal of surgery,

soft tissue form and depth ultimately depend on hard tissue, physiologic osseous contours must be attained to assist in pocket elimination

YOU MUST ADDRESS THE BONE

Question 8

Isn’t osseous surgery harmful to our periodontal patients because we are removing supporting bone?

Answer 8

Selipsky review paper

Larato (1970) showed that ostectomy removed insignificant amounts of supporting bone height 0.6 mm on circumferential average

Greatest amount of resected is mid-buccal, mid-lingual or palatal surfaces next to interproximal defects with usually only 1 mm removed.

Buccal and lingual bone removal appears less important in terms of tooth support than interproximal bone because of their smaller surface area, especially more posteriorly.

Question 9

Why should I use an apically positioned flap versus a gingivectomy?

Answer 9

Nabers

attached gingiva should be conserved since it is keratinized and best suited to function in areas of mastication.

alveolar mucosa cannot withstand the friction of food during mastication.

Standard gingivectomy procedure can result in marginal tissues composed of nonkeratinized alveolar mucosa, which is not desirable.

Pockets extending beyond the mucogingival junction may be treated by apically repositioning of the flap. Pockets are eliminated and attached gingiva is preserved.

Question 10

Name some advantages and disadvantages of an apically positioned flap

Answer 10

Friedman

Advantages of the apically repositioned flap:

1. Rapid healing by primary intention and fewer adverse post-op sequelae
2. Maximum bone coverage preventing macroscopic sequestration and minimizes alveolar crest loss
3. Control of post-op amount of gingiva with thinning incision
4. Retaining the mucogingival complex allows for deepening of shallow vestibules and frenum repositioning without producing a large wound
5. Useful when only 1 or 2 teeth are involved, avoiding exposure of bone on healthy adjacent teeth
6. Controlled surgery

Disadvantages:
1. Technically difficult: precise suturing and flap thinning necessary

2. Difficult when faced with little pre-op gingiva
3. Poor access in mandibular molar region with shallow vestibule (double flap (split thickness) procedure recommended)

Question 11

How do you define bony defects in osseous surgery?

Answer 11

Ochsenbein :

Bony craters may be identified according to morphology and depth:
shallow = 1-2 mm deep medium = 3-4mm deep
deep = 5 mm or more

Question 12

What are indications of an apically positioned flap?

Answer 12

Friedman

Indications:

1. Areas where the base of the pocket is near, at, or apical to the mucogingival junction
2. Sufficient gingiva will remain after thinning and manipulation of the flap

look at Figure 3 in this article according to Aaron

Question 13

How are root trunks classified?

Answer 13

Ochsenbein

Maxillary
short = 3 mm
average = 4 mm
long = 5 mm

Mandibular
short = 2
average = 3
long = 4

Question 14

What type of furcations are most prone to furcation invasion?

Answer 14

Larato - those that are in close proximity to the CEJ

Question 15

Why should one not use the buccal approach in crater reduction?

Answer 15

Ochsenbein

Buccal recession, reverse architecture, buccal radicular bone sacrifice, inadequate buccal interdental space between molars

Question 16

What is the most common interdental crater and how is it managed?

Answer 16

Oschsenbein = shallow interdental crater, managed with a palatal approach

Question 17

How do you manage a medium interdental crater?

Answer 17

Ochsenbein

Buccal and palatal approach

Question 18

What technique should you not use to treat deep craters?

Answer 18

Ochsenbein

Resection - limited value

Question 19

What is the preferred approach for osseous surgery?

Answer 19

Ochsenbein

Palatal approach - achieves pocket elimination with fewer problems. Less buccal recession, less frucal exposure, less denudation of buccal radicular surfaces

Question 20

What are the crater classifications as put forth by Ochsenbein and what is the significance?

Answer 20

Crater classification impacts treatment approach

• Class I Crater: 2-3mm osseous concavity with relatively thick B & L walls.
• Class II Crater: 4-5mm osseous concavity with wide orifice and thinner wall & a more abrupt slope to its base.
• Class III Crater: 6-7mm concavity with a sharp drop of the crater wall from the margin to a broad, flat base - frequently found without concomitant pocket depth on the buccal & palatal surfaces.
• Class IV Crater: osseous concavity of variable depth with extremely thin buccal & palatal walls - base is often wider buccolingually than the orifice; may have a B or L wall absent - least common type of crater.

Treatment via Palatal Approach:
•Class I Crater: Remove palatal wall of deformity plus sufficient palatal supporting bone to reestablish normal osseous contour.
•Class II Crater: Remove palatal wall and some buccal wall to the level of the bifurcation if necessary (approximately 2-3mm).
•Class III Crater: Removal of palatal bone is carried as far as the area can tolerate, buccal removal similar to Class II. Compromise possible, accepting residual pocket over extreme architecture.
•Class IV Crater: Primarily palatal approach due to thin walls; repositioned flap used. Minimize buccal flap reflection.

Question 21

What is the rationale for the lingual approach to mandibular osseous surgery?

Answer 21

Tibbetts

1. Mandibular posterior teeth have up to 25 degrees lingual inclination thereby giving interproximal contacts a more lingual position; this situation results in crater bases located more to the lingual.
2. Lingual embrasures wider than buccal.
3. Reduction of lingual bone is osteoplasty; reduction of buccal bone is often ostectomy. 4. Buccal aspect is typically overtreated.
4. Lingual furcation is more apical than buccal furcation.
5. Lingual CEJ’s are lower apically on the tooth and since bone follows CEJ’s, there is natural slope of bone to the lingual.

Question 22

How would you treat a 3 walled bony defect?

Answer 22

This is from Oschenbein review paper

Prichard originally described intrabony defects = defect surrounded by bony walls on three sides with the tooth root forming the fourth wall.

Oschenbein states that previous research supports that deep three wall defects are good candidates for bone regeneration. The deeper the defect, the more bone fill.

It is believed that areas of the defect that are one- or two-walled components heal with residual probing depth.

In studies of three-walled defects, only 16 out of 130 were pure three-walled defects, and most of these were shallow.

Question 23

How would you treat a residual bony defect?

Answer 23

Oschenbein

Residual Bony Defects = can be soft or hard tissue.

Soft tissue components are present in unmanaged one and two-walled defects and incomplete fill of the three-walled bony defect.

Hard tissue aspect is represented by the unfilled one or two-walled components and the unfilled part of the three-walled bony defect.

Partial regeneration is possible.
Osseous defects in the presence of excellent plaque control had bone fill, whereas those with poor plaque control had continued presence of disease.

Question 24

What are three proposed treatment mechanisms for intrabony defects?

Answer 24

Oschenbein

1. Manage one and two walled defects w/ osseous surgery and place membrane over 3 walled defect (this one has the most merit)
2. OFD, remove supporting bone on tooth adjacent to defect, place membrane
3. Place membrane over the unaltered defect, allow it to heal, and then do a second stage surgery to attempt regeneration again in residual defects