Periodontal Aesthetic Surgery Recession and Crown Lengthening_30th April 2018_8am

Question 1

What is the purpose of mucogingival surgery?

Answer 1

• Correct soft/hard tissue defects or deficiencies

- Done via soft tissue repositioning or grafting

Question 2

What is crown lengthening?

Answer 2

-Procedure done to increase the height of a tooth crown to better facilitate prosthodontic restoration. Includes removal of soft tissue and sometimes bone (remember that gingiva will creep back up if bone is not removed)

• Can do soft tissue only if bone is already at correct height to accomodate biological width
• Remember that reducing bone height gives some leeway re. biological width (Dr Kaur usually keeps biological width at 3mm just in case we mess up and go down an extra mm we don’t intrude on it)
• usually done for 2-3 teeth at once

Question 3

What are the indications for crown lengthening?

Answer 3

Aesthetics of anterior maxillary:

• Excessive gingival display
• Wearing due to bruxism

Exposure of sound tooth structure
-Inadequate amount of tooth structure for restorative therapy

• Subgingival location of fracture lines (to assess fracture)
• To reach subgingival caries
• Take impression of subgingival margins (sometimes can get away with jsut removing soft tissue without bone for this)

Question 4

What factors shoudl you take into consideration for crown lengthening?

Answer 4

• Perio status, endodontic status + tooth prognosis
• Apical extent of fracture, caries, perforation, old interproximal restorations
• Root anatomy (length & form)
• Crown root ratio
• Level of alveolar crest/thickness of radicular bone (radiographs + probing)
• Location of furcations
• Esthetic concerns
• Gingival width + thickness
• Interdental width

Question 5

What are some contra-indications to root lengthening?

Answer 5

• Extensive periodontal disease
• Risk of severe furcation involvement
• Extensive caries in furcation
• apical extent of fracture/caries greater than 4-5mm

Question 6

What are some methods to carrying out crown lengthening?

Answer 6

• Gingivectomy (usually for impressions and subgingival caries)
• Modified Widman Flap with or without osseus resection
• Apically repositioned flap with or without osseus resection (focuses on one tooth rather than 2-3, uses vertical incisions and cut flap slightly more apically to leave a few mm of gingiva on tooth to be removed)–>normally done if short keratinised gingiva
• Lasers and electrosurgery
• Forced tooth eruption (if more erupted then will have more length)

Question 7

What length should the keratnised gingiva/attached gingiva be and why?

Answer 7

1-2mm minimum

Else brushing on alveolar mucosa which can get inflamed

Question 8

What are the indications for surgical correction of recession?

Answer 8

• Increase in recession
• Persistent inflammation (due to exposure of alveolar mucosa)
• Aesthetic concern
• Dentinal hypersensitivity
• Age ???

Question 9

What are the contraindications to surgical correction of recession?

Answer 9

• Complex MHx

- No changes to recession

Question 10

What are the classifications of recession?

Answer 10

Class I: Does not extend to mucogingival junction, no bone loss in interdental (100% root coverage achievable)

CII: Recession to or beyond mucogingival junction, no interdnetal bone loss (100% root coverage achievable)

CIII: Recession to or beyond mucogingival junction, some interdental bone loss or malposition of tooth (50-70% root coverage achievable)

CIV: Recession to or beyond mucogingival junction, severe bone and/or soft tissue loss in interdental area and/or severe tooth malposition (root coverage unpredictable and require adjunctive treatment)

Question 11

What is the prevalence of recession

ONly do this if you feel you have spare brain space

Answer 11

-1-19% of children
50% 18 to 64
88% over 65

Question 12

What are pedicle grafts? what are the types of pedicle grafts?

Answer 12

-Soft tissue grafts that are still attached to the gingiva, usually used with thick gingiva (type I)

types:
Lateral sliding flap: Raise flap and move it laterally to coover recession site, provided there is sufficient interdental bone (will leave some raw tissue at the site it is removed from but this will re-epithelialise)
*Do NOT move a flap from a recession site to another recession site, you’ll make it worse

Coronally repositioned flap: Cut flap and reposition it more coronally

Question 13

What are free soft tissue grafts? What are the types?

Answer 13

-When tissue graft is taken from elsewhere and placed usually used with type II biotype

Free gingival graft (used for deheisence): Take graft from palate (donor site), create pouch in recipient site (i.e. cut a space for graft to go in), and place graft in, stretching part of graft across deheisence and burying the ends in CT to provide blood supply (will have big gaping hole in palate, also has white discoloration at recipient site)

Subepithelial connective tissue graft: Only taking CT: basically same as free gingival graft but you leave epithelium behind allowing you to close it back (leaves a hole but covered by epithelium)–>more commonly used

Question 14

What are the pros and cons of lateral sliding flap?

Answer 14

+Only require one surgical site

• Can only be done in Type I biotype
• Can not heal larger defects as limited by elasticity of tissue
• Healing mainly through long junctional epithelium
• Leaves raw tissue exposed which heals over time
• Can’t be moved from recession site to recession site

Question 15

What are the pros and cons of coronally repositioned flap?

Answer 15

+ Healing area more coronally placed–> better for low smile line
+ Only require one surgical site
+ Final outcome more predictable
-Can only be done in type I biotype
-Healing mainly by long junctional epithelium
-Healing of defect size limited by elasticity of gingiva

Question 16

What are the pros and cons of free gingival craft?

Answer 16

+ Can remove more tissue to cover larger defect size vs pedicle grafts
+ Can be used in biotype II
+ Healing can repair bone, cementum, CT
-Leaves a hole in the palate
-Large flap needed to provide vascularisation, which may not work
-Can have discoloration
-Heal via secondary intention

Question 17

What are the pros and cons of subepithelial CT graft?

Answer 17

\+ Can be used in biotype II
\+ Can removed 
\+ Less discoloration
\+ Heals by primary intention
- Leaves hole in palate but can be covered by epithelium