27 - Principles of Surgery I Amanda

Question 1

Indications for periodontal surgery (Deas Question)

Answer 1

1) Access for debridement
2) Pre-prosthetic sx (tori removal; tuberosity removal)
3) Regeneration (GTR; GBR)
4) Crown lengthening
a. Functional
b. Esthetic
5) Residual deep PD
6) Access for debridement
7) Sinus elevation
8) Surgically facilitated orthodontic
9) Exploratory surgery - possible vertical root fracture
10) Lack of attached tissue
11) Treat gingival enlargement
12) Placing an implant
13) Frenectomy
14) Apicoectomy
Biopsy

Question 2

Surgical anatomy: considerations for maxilla (Deas Question)

Answer 2

1) Greater Palatine
a. 7, 12, 17 depending on palatal vault
2) Incisive canal
3) Pneumatized sinus that is thin
4) Palatal tissue
5) Keratinized tissue - varies around teeth
a. Thinnest around PM
6) Shallow vestibule
a. Zygomatic arch
7) Tuberosity
8) Palatal tori - common in women
9) Coronoid process of mandible
10) Nasal floor
11) Root prominences
a. Fenestrations more common in maxillary arch
12) Canine eminence
13) Anterior nasal spine
14) Infraorbital
15) Rugae
Palatal tubercles

Question 3

When thinking about the greater palatine, where is it located depending on your vault? (Deas Question)

Answer 3

7, 12, 17

Question 4

Surgical considerations: mandible considerations (Deas question)

Answer 4

1) Mandibular Tori (27% - Sonnier; more common in males, dentate pt
2) Lingual nerve
3) IAN
4) Tongue
5) High floor of mouth
6) Mental nerve - coronally positioning flaps
7) Mylohyoid ridge - dissect it away to coronally advance a lingual flap
8) Prominent external oblique ridge - hard to reflect
a. Shallow vestibule
9) Lingual concavity when placing implant
a. PM to M area
10) Anterior loop - 5 mm anterior
11) Thick cortical plates (anterior mandible)
12) Anterior lingual arteries
a. If placing implant in anterior and you have not reflected lingual flap and you perforate and do not know you perforated
b. FOM will start to rise = how you know if you don’t dissect
13) Bony dehiscence (Elliot and Bowers)
a. Canine
14) Mental symphysis
a. Could possible harvest autogenous bone
15) Thin phenotype of bone - roots move through alveolous
Genial tubercles

Question 5

Do you need to remove the pocket epithelium during our incisions for surgery?

Answer 5

Nah - Smith et al showed that there was no difference when you remove it and when you don’t

-BL: Removal of pocket epithelium is not of critical importance when using flaps for accessibility and when aiming at re-adaptation. The crevicular flap may heal by way of a long junctional epithelium which appears to be maintained in health with adequate maintenance. If CT attachment is desired, a reverse bevel incision, which leaves connective tissue exposed and thus enhances the potential for reattachment, is indicated. The crevicular flap is less technically difficulty and less time consuming to perform than the Modified Widman flap.

13 pt-
Compared MWF and sulcular incisions

Question 6

What is better for pocket reduction: flap surgery (ie MWF) or SRP?

Answer 6

Lindhe and Nyman- they result in statistically SIMILAR pocket reduction (but, pockets that were still >6 mm treated with SRP did need sx)

BL: SRP is as effective as sx approach in terms of gingivitis resolution and average probing depth reduction

15 pt
Treated 3 quads in each pt with MWF, mod Kirkland flap and SRP with strict maintenance

Question 7

Is it necessary to remove all the granulation tissue?

Answer 7

Lindhe and Nyman - NOT critical for promotion of healing of tissue

Question 8

Does it matter if you SRP prior to surgery or can you just take a pt with severe periodontal dz into phase II (surgery)?

Answer 8

Aljateeli et al - get better results when you SRP (phase I) first in regards to PROBING DEPTH reduction, but either way you will get improvement in PD and CAL from baseline

21 subjects finished

• Control group: phase I –> phase II
• Test group: phase II
• Control group had sig GREATER probing depth reduction
• NO difference between groups in regards to CAL
• NO difference for bone gain

Question 9

If you treat portions of your patient’s mouth with surgical treatment, will it have any affect untreated sites?

Answer 9

Radvar et al - YUP
BL: PDs at untreated sites can undergo reduction concurrent with the surgical treatment of adjacent sites. As such it may be indicated to reassess the surgical plan during the later stages and consider a revision of the treatment plan based on the findings

20 pt completed study - tx with OFD/osseous

Question 10

Do different flap designs playa role in gingival circulation post op?

What are some basic guidelines to follow for flap design based on your above answer?

Answer 10

Mormann and Ciancio - Yup

Summary:
o Flaps receive their major blood supply apically.
o Blood supply was directed caudocranially.
o Blood supply to the gingiva was not homogenous.
o Gingival and periodontal vessels are independent of each other.
o The greater the ratio of flap length to flap base, the greater the vascular disturbance.
o Broader flaps result in better circulation patterns.
o Sliding flaps should extend adequately into the alveolar mucosa.
o In lateral sliding flaps, a partial thickness flap is preferred at the donor sight.
o Survival of thin flaps depends on the vascular quality of the recipient bed.

BL:

1. The base should be broad enough to include major gingival vessels.
2. Length:width ratio should not exceed 2:1.
3. Minimal tension should be created in suturing and tissues should be managed gently.
4. Partial thickness flaps to cover avascular sites need to have enough blood vessels included in them (i.e. don’t make them too thin).
5. Apical portion should be full thickness when possible.

Question 11

In regards to blood supply, what direction does it run and how does this affect your flap design?

Answer 11

Mormann, Meier, Firestone - Blood supply of facial gingiva runs apico-coronal

Don’t do the releasing incisions at mid-facial sites!! (Limit them if possible)

31 dental students (healthy)
Punched out 1.5 mm of gingiva to bone on mid-facial attached gingiva and used fluorescein angiography to eval capillary circulation within wound

Question 12

Does the periodsteal vascular plexus play a role in wound healing following flap procedures? What is the timeline of healing?

Answer 12

Nobuto - YUP

1) Day 3: new blood vessel formation from bone side of site; immature endothelial cells present
2) Day 5: tight junction formed in intercellular connections of new endothelium
3) Day 7: endothelial cells appear flattened, fibroblasts active

• Beagle dog eval at 3, 5, 7 days post op flap procedure
• Replaced flap at same position
• Used periodontal dressing

Question 13

Does microcirculation play a role with bone resorption and formation post flap surgery?

Answer 13

Nobuto - f/u longer study to his previously study with longer time points (up to day 28)

• Vascular plexus still contributes to bone remodeling process
• Angiogenesis increased blood flow and vascular permeability enabled tissue repair by respiration, transition and layered bone formation

Day 7: marked angiogenesis was observed in the granulation tissue adhering layer. New blood vessels were sinusoidal in nature with many permeable fenestrations present in the endothelium. Bone resorption by osteoclasts was occurring adjacent to the new vessels and the endothelium was extremely thin in these areas.
Day 14: activated osteoblasts were present in the resorption bays and the blood vessels adjacent to the osteoblasts were more developed and glomerulus in nature. Small vesicles were formed adjacent to the osteoblasts with almost no fenestrations.
Day 21 and Day 28: samples showed smooth alveolar bone with no resorption bays. The vascular plexus re-established itself with continuous blood vessels of smaller diameter. New blood vessels regressed and decreased in number as bone metabolism decreased.

Question 14

Does local anesthesia play a role in blood flow during flap surgery?

Answer 14

Retzepi - YUP

• LA with epi decreased blood flow by 66-75% similarly on buccal and lingual papilla
• Hyperemic response post sx may be due to production of vasoregulatory factor producing vasodilation and active angiogenesis
• Buccal flow returned to baseline around day 15; lingual flow normal around day 30

Used 2% Lido with 1:80K epi
Used doppler flowmetry
Measurement points: BL, 5 min post anesthesia [….] final was 60 days post op

Question 15

How much blood to patients loose during surgery?

Answer 15

Baab, Ammons, Selipsky

• on average: 134 mL with LARGE range around that
• Suggest: limit sx to 2 hrs bc pt lost <125mL at this time
• Always recommend your pt hydrate post surgically
• Be prepared for fluid replacement if >500 mL blood is lost

Question 16

Does the type of surgical procedure affect how much blood the pt looses? What about patient factors

Answer 16

Zigdon - blood loss during periodontal sx is MINIMAL and VARIES SLIGHTLY according to certain patient factors

• No difference in blood loss btw OFD and regeneration
• Blood loss range: 6-145.1 mL (Mean: 60 mL)
• Smokers: LOST MORE BLOOD than former and never smokers
• No sig difference between: sex, aspirin use, type of surgery, surgeon experience
• No association btw LA amount, surgical field size, length of procedure, blood loss volume
• Compared OFD and regeneration surgical procedure blood lost using fructoasamine to identify amp of blood collected
• Pt were more like our real life pt (mix bag of smokers, non smokers, HTN, some taking aspirin)

Question 17

Does it matter if your surgical patient is taking ibuprofen?

Answer 17

Braganza et al - Yeah, increased bleeding (DUH)

-Suggest: if bleeding is concern, temporarily discontinue ibuprofen during sx following medical consult

Question 18

Does it matter if I do scalloped or linear incisions during my flap procedure?

Answer 18

Cattermole, Wade - NAH, no difference after 12 weeks

-At week 1-2 there was greater inflammation associated with linear group, but by 3 weeks no difference between groups

18 pt - split mouth, randomized with 1 side scalloped, other linear

Question 19

To bevel your vertical release incision or not, what would you do?

Answer 19

Kon, Caffesse et al:

• Bevel that bish
• BL: shown that with wider tissue interface beveled incision sites had improved healing due to faster reorganization and prevention of epithelial ingrowth compared to vertical releasing incisions made perpendicular to bone
• Rhesus monkey (2)
• 10 flaps with 2 vertical releasing that was either incised perpendicular to bone or at an angle (beveled)
• Day 9: perpendicular group had a groove at marginal tissue; bevel did not
• Day 28: groove still present at perpendicular group and histology of perpendicular = more inflammation and slower tissue organization with larger soft tissue groove and microvascular gap
• Beveled = faster connective tissue organization and more advanced healing

Question 20

What kind of flap procedure might you consider in the maxillary anterior (ie. regeneration) sx? Does it work?

Answer 20

Takei et al: Papilla preservation technique
-Need flap to be at least 2 mm thick for blood supply
BL: All wounds healed with primary closure and normal interdental papilla at 6 MO = this is a good technique to use in anterior for esthetics and prevent exposure of any grafted material

-When used a regular flap = interdental crater

• Did use surgical dressing
• Suggested not to probe regeneration sites for at least 3 MO

Question 21

What happens to pocket epithelium following flap sx? (IE APF where pocket epi is maintained)

Does this result favor one type of incision over another?

Answer 21

Pippin: Pocket epithelium following APF degenerates and replacement by connective tissue union; degenerates completely by day 7

BL: Sulcular incisions may be PREFERRED over inverse bevel because we do not need to worry about removing pocket epithelium
-Sulcular incisions are more rapid and less difficult, and preserve entire width of keratinized gingiva compared to inverse bevel technique

-Compared APF with 1) sulcular vs 2) inverse bevel

Question 22

When looking at the readaption of a flap following surgery, what is the mechanism and how long does it take for the flap to be considered adapted to bone?

Answer 22

Hiatt et al:

BL: No permanent loss of CT or CRESTAL bone from mucoperiosteal flap surgery. 2 weeks for flaps to really be adhered to the bone.

• Mongrel dog study
• PDz –> flap sx with vertical releasing and osseous

CONCLUSIONS FROM THIS STUDY:

1. Initial attachment of the flap was through the epithelium, and the fibrin did not seem to contribute much to flap retention.
2. When properly adapted, the flap does not result in epithelial proliferation and downgrowth.
3. Ultimate strength of the epithelial attachment to the root is greater than attachment between the cells.
4. CT repair was visible at 2 days and portions of it remained adherent to the root during flap separation at one week.
5. Retained cementum may be beneficial since those areas where cementum had been planed from the root, resorption occurred before new cementum formation and CT attachment.
6. Where the flap was tightly adapted, healing is accelerated. The more fibrin accumulation, the slower the healing
7. Crestal bone resorption never exceeded 1 mm, and was always recovered by 1 month.

Question 23

Compare and contrast full thickness and split thickness flaps

Answer 23

Staffileno - BL: The split thickness flap is less traumatic and provides better flexibility and protection of existing supporting structures than full thickness flap reflection but the full thickness flap maintains the integrity of the flap tissue.
–> Clinician should consider historical response and treat the flap preparation accordingly

Review overview:
-No difference in repair of EPI and CT between 2 types of flaps -
Difference in quantitative healing of alveolar bone
–> get more necrosis/loss with full thickness and takes a few days longer to repair

Contraindications for split thickness: thin tissue (perforation), locations where flap necrosis is possible (lingual posterior mandible)

Indications for split thickness: APF, rotational or lateral positioning, suturing to periosteum, gain dimension of flap M-D with vertical incisions

Contraindication for full thickness flap: soft tissue grafts, when apical repositioning would lead to direct bone exposure

Question 24

What is some evidence showing a difference between partial thickness and full thickness flaps in regards to timing and tissue content?

Answer 24

Levin et al. -

BL:

• Correlation btw gingival collagen content and inflammation: as inflammation increased, collagen concentration decreased
• when flaps were reflected for 15 minutes = no difference btw 2 groups
• Flaps reflected for 90 min = partial thickness showed faster healing and decreased tissue reaction; as healing continued all parameters were similar except more bone resorption seen in full thickness group
• Mongrel dogs with marital and full thickness flaps in 2 quads + 1 control quad
• Exposed flaps for 15 or 90 min

Question 25

Does an gingivectomy or apically repositioned flap play a role in the location of the MGJ and width of keratinized gingiva?

Answer 25

Ainamo et al- NAH - no permanent apical shift or thicker keratinized gingiva in this study

-f/u of 18 years

Question 26

Does the location of the flap at the end of surgery matter?

Answer 26

Machtei and Ben-Yehouda - Yes, flaps positioned at or coronal to alveolar crest (≤3 mm) after flap surgery = shallower PD over 2 year period

Soon to add Penner et al

Question 27

Is there a difference in microvasculature blood flow when you used the simplified papilla preservation flap or modified Widman flap?

Answer 27

Retzepi et al -
-Simplified papilla preservation flap = faster recovery of blood flow post op compared to MWF

-Laser doppler flowmetry

Question 28

Can you get more root coverage with CONVENTIONAL coronally placed flap + enamel matrix derivative or the same procedure with microscope?

Answer 28

Andrade et al

• No difference in root coverage
• Increase in width and thickness of KT with micro
• no pain difference

Question 29

Does conservative periodontal surgery work (defined as access to roots without removal of bone/soft tissue resection)?

Answer 29

Graziani et al - Yup, improvements vary according to surgical technique but treatment of intrabony defects with this technique shows improvement and high tooth retention

**Go to abstract for good chart of actual # values

EX: with OFD/MWF expect: 
CAL gain = 1.6 mm 
PPD reduction: 2.8 mm 
Rec increase: 1.4 mm 
Residual PD: 4.4 mm

Question 30

Should you use a single or double flap approach when trying to deride deep intraossous effects?

Answer 30

Trombelli et al - It doesn’t matter

-Saw comparable results - good CAL gain and PD reduction with either single or double flap approach

Question 31

Name some contraindications and indications for split thickness flaps

Answer 31

Staffeileno - review and suggested use a split thickness when possible due to less trauma/better healing of alveolar bone

Contraindications for split thickness: thin tissue (perforation), locations where flap necrosis is possible (lingual posterior mandible)

Indications for split thickness: APF, rotational or lateral positioning, suturing to periosteum, gain dimension of flap M-D with vertical incisions

Question 32

Go through the early and late healing events of a surgical site

Answer 32

Susin -
(overlapping phases)

1) Within hour(s): Hemostasis/ Fibrin clot
vasoconstriction to limit bleeding and allow fibrin clot formation
early phase of inflammation: PMNs

2) Within day(s): Granulation Tissue and Matrix Formation
fibrin clot serves as scaffold for cell migration and proliferation (fibroblasts, osteoblasts, smooth muscle cells, leukocytes, monocytes and neutrophils)
late phase of inflammation: monocytes and macrophages
initiation of angiogenesis

3) Within week(s): Tissue formation (repair/regeneration)
proliferation of fibroblasts and osteoblasts
increased vascularity
epithelialization complete

4) Within month(s): Tissue remodeling/maturation
continuous build-up of matrix

**Disclaimer: REQUIRED READING THIS NOTECARD IS NOT ALL INCLUSIVE GO AND READ THE ABSTRACT

Question 33

Compare ePTFE vs silk sutures

Answer 33

Susin:
ePTFE: less inflammation and bacterial contamination; sufficient strength at 7 days

**Disclaimer: REQUIRED READING THIS NOTECARD IS NOT ALL INCLUSIVE GO AND READ THE ABSTRACT

Question 34

What is the importance of the fibrin clot?

Answer 34

Susin -
If stable => regeneration
Unstable ==> leads to repair (Long JE)

Question 35

What are some available bio modifications on the market?

Answer 35

Susin

1) rhPDGF-BB + β-TCP (recombinant human platelet derived growth factor + beta tricalcium phosphate)
2) EMD (Enamel matrix derivatives)
3) rhFGF (recombinant human fibroblast growth factor)
4) rhGDF-5 + β-TCP

Question 36

Why do we use membranes and bone derivatives/substitutes?

Answer 36

Susin

Membranes: exclude epithelial and CT cells, favors migration of PDL and bone cells

Bone derivatives: can be used as a carrier for growth factors, slowly resorbing materials might interfere with regeneration

**Outcomes with membrane +Biomaterials are superior to OFD BUT minimally invasive surgery alone can be equally as effective (Cortellini/Tonetti)

Question 37

What are some principles of site preparation according to Susin?

Answer 37

1) Minimize Trauma
a) Standard flap:
Immediately post op = ischemia
Day 1-7: increased blood flow (compensatory)
Day 15: return to base line
b) simplified papilla vs MWF = SPP returned to baseline in 4 days (Retzepi)

2) Root instrumentation
- Purpose to remove biofilm, endotoxin and calculus; no gold standard, use one or multiple (clinician discretion)

3) Root conditioning:
- Demineralize or chelating agents (citric acid, EDTA, tetracycline)
- Rationale: remove smear layer, endotoxin; expose collagen matrixes, fibroblast migration, adhesion of fibrin clot
* **Lack significant clinical benefits (Mariotti)