3 - Dentoalveolar Flashcards

Question 1

Q

Question 2

Q

3rd Molar Classification

Answer

A

Descriptive
- Lower Third Molars
- Winters Angulation Classification
  - Mesio - 45%
  - Vertical - 40%
  - Horizontal - 10%
  - Distoangular - 5%
  - Buccoangular
  - Linguoangular
  - Inverted
- Upper Third Molars
- Archer Classification
  - 1 - Mesio
  - 2 - Disto
  - 3 - Vertical
  - 4 - Horizontal
  - 5 - Buccal
  - 6 - Palatal
  - 7 - Inverted
Assessment of Difficulty
- WHARFE
  Maximum Score 16
  - Winter’s Angulation Classification
  - Height of mandible
  - Angulation of 2nd Molar
  - Root morphology
  - Follicle size
  - Exit pathway
- Pell and Gregory
  - Ramus assessment - Roman Numerals
    - I - Anterior to ramus
    - II - 50% within ramus
    - III - completely within ramus
  - Occlusal plane
    - A - At occlusal plane
    - B - Between occlusal plane and CEJ
    - C - Below CEJ
- Winter’s Line
  - White Line - Occlusal place
  - Amber Line - Bone level
  - Red Line - Perpendicular to occlusal plane to elevation point
    Distance between Amber line to point of elevation is measured
  - Interpretation
    - <5mm - LA
    - >5mm - GA
    - Every 1mm increases difficulty by 3x
- Pedersen Classification
  - Pell and Gregory + Winters angulation
- Lim Classification (Upper wisdom teeth)
  - Archer + Relationship to the sinus and 7s

Question 3

Q

3rd Molar complications

Answer

A

General risks with surgery
Specific risks
- Nerve
  - IAN
    - Nguyen 2014
  - Lingual
    - Pichler 2001
      - Temp 2% (7% with retraction)
      - Perm 0.5%
- Infection
  - Ren 2007
    - 4% - Abx
    - 6% - No Abx
- Dry socket
  - Ren 2007
    - 6% - Abx
    - 14% - No Abx
- Fracture
  - 1 in 25 000

Question 4

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3rd Molar Difficulty Assessment

Question 5

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3rd Molar Epidemiology and Overview

Answer

A

Carter and Worthington 2016
- Impaction rate 25% of population
- 75% have 4 wisdom teeth
- 25% have 0-3 wisdom teeth
Impaction theory
- Differential rate of growth of mesial and distal roots
- Inadequate arch space
- Tooth developmental lags behind jaw growth so can’t influence it
- Processed diet, better hygiene -> less dental loss -> inadequate space

Question 6

Q

3rd Molar Indications and Contraindications

Answer

A

Indications

Pathology - NICE 2000
- Periodontal
- Caries
- Infective
  - Periapical
  - Abscess
- Neoplastic
- Fracture
- Resorption 2nd Molar
Prophylactic Removal
- AAMOS 2014
  - Perio pocketing >5mm on 7s or in general
  - Orthodontic or orthognathic interference
  - Prosthodontics - Denture interference
  - Symptomatic
    - Food impaction
  - Medical
    - Immune suppression - Organ transplant
    - Radiotherapy and Chemotherapy
    - Implants - Joint prosthesis or other alloplastic implant
    - Occupational
      Prevention of mandible fracture - 2.8x Zhou
      - Military
      - Professional contact sport
- Hyam 2018
  - Disease negative, Symptom negative
    - Patient
      - Med Hx
      - Finances
      - Social
      - Occupational/Hobbies
    - Dental
      - Difficulty
      - Proximity to nerve & Risk of complications
    - Surgeon
      - Experience

Contraindications

<12 yrs old - Unable to predict whether tooth will erupt
>40 yrs old - Risk potentially outweigh benefits
Medically compromised and unfit for surgery
Limited MO
Unable to accept IAN risk
Surgeon experience

Question 7

Q

ww.3rd Molar Nerve Injury

Answer

A

AAOMS 2014
- 1% to 5% IAN (Temp + Permanant)
  0-0.9% IAN (Permanant)
- 0.4 - 1.5% Lingual (Temp + Permanant)
  0 - 0.5% Lingual (Permanant)
Nguyen 2014
- 0.68% - IAN (Temp + Permanant)
  0.24% IAN (Permanant)
- 0.15% - Lingual (Temp + Permanant)
  0.079% - Lingual (Permanant)
Pichler 2001
- 8x more likely for lingual nerve injury with retraction
  Lingual retraction was not protective for permanant nerve injury
- 6.4% - Lingual retraction (Temp + Permanant)
  0.6% - Lingual retraction (Permanant)
- 0.6% No lingual retraction (Temp + Permanant)
  0.2% - No lingual retraction (Permanant)

Question 8

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3rd Molar NICE Guideline review

Answer

A

McArdle & Renton 2012 - The effects of NICE guidelines on management of third molars
- Removal of wisdom teeth
  - Mean age increased 25 to 32 yrs old
  - Initial decrease for removal in secondary care setting by 30%
    But recent increase by over 97%
  - Caries and infection indication increased from 10% to 30%
- Population health
  Increased cost per removal of wisdom teeth
  - Increased number of extractions in the secondary care setting (specialists)
  - Increased numbers of GA vs LA

Question 9

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3rd Molar Perioperative Meds

Answer

A

Antibiotics
- Pre op antibiotics - Ren 2007
  - Dry socket: 14% to 6%
  - Surgical site infection: 6% to 4%
- Post op antibiotics - Lodi 2012
  - Indications
    - Pre op infection
    - Immunocompromised
    - Higher risk of dry socket
      - Female
      - OCP
      - Smoking
      - Pericoronitis
      - Prev dry socket
      - Difficult extraction
Steroids
- Cho 2017
  - Pre op reduces swelling and trimus
  - Post op - No evidence
Chlohexidine
- Cho 2017
  - Reduces post op infection and dry socket
  - Pre op rinse + Post op for 1/52

Question 10

Q

3rd Molar Prophylactic Removal vs Retention

Answer

A

Indications for prophylactic removal

Hyam 2018

Med Assessment
- Part of tumor resection
- Pre-medication assessment
  - Bisphosphonates
  - Anticoagulants
- Pre-geriatric assessment
- Altered mental capacity
- Reduced physical dexterity
  - Tremors
  - Neuromuscular disease
- Pre-Treatment
  - Radiotherapy
  - Chemotherapy
- Immuno-modifier therapy
  - Bacteraemia
  - Tissue-transfer patients
Dental Assessment
- Orthodontics
- Orthognathic surgery
- Prosthodontic inhibitor
- Periodontal disease
Financial
- Future loss of income during infective episodes
- One episode of recovery for removal of remaining wisdom teeth
- Insurance policy
Social
- Military or scientific personal
- Sports and Hobbies
- Availability of home and community support

Risks of retention

Bouloux 2015

3% per yr of requiring removal
65% risk overall

McArdle & Renton 2012 - The effects of NICE guidelines on management of third molars

Mean age increased 25 to 32 yrs old
Initial decrease for removal in secondary care setting by 30%
But recent increase by over 97%
Caries and infection indication increased from 10% to 30%
Retention Risks
- Caries 8, Caries 7
  - 23% higher for mesioangular - Toedtling 2019 MA
- Periodontal complication
  - Pericoronitis
  - Periodontal defect of 7
  - 38% of ppl with perio will worsen within 2 yrs - Ghaemin 2016
- Resorption of 2nd molar - 3% - Mercier 1992
- Deep space infection - 0.8% - Yoshi 2001
- Odontogenic cyst or tumor - 5% - Mello 2019
- Increased difficulty and complications with age - Pogrel 2019
  - Benefits of removal before age 25
    - 50% non impacted and 75% of impacted teeth fail to erupt - Kruger 2001
    - After age 25 there is a 3% per yr risk of extraction
      64% chance of teeth needing to be removed by age 43 - Bouloux 2015
    - Reduced incidence of infection, dry socket, nerve injury, perio pocketing - Pogrel 2012
    - 7s distant caries increases - 40% - McArdle 2019

Question 11

Q

Apicectomy Indications and Contraindications

Answer

A

Indications
- Orthograde root re-treatment not possible
  - Dense GP
  - Post core crown in situ
  - Broken instument
  - Complex root anatomy
  - Calcified canals
- Iatrogenic displacement of material into root apex
- Fracture of 1/3 distal root tip
- Persistent lesion despite adequate Endo
Contraindications
- Re-treatment not attempted
- Poor prognosis of tooth
- No coronal seal
- Apex near IAN or sinus
- Short roots

Question 12

Q

Apicectomy Outcomes

Answer

A

Retrograde filling material - Ma 2016 (Cochrane review)
- No difference in material
Outcomes - Beck-Boichsitter 2018
- 60% over 5 yrs, 50% over 10yrs
  - Retrograde filling improves survival by 10%
- Surgical vs Non surgical management - Del Fabbro 2007
  - No difference is success outcome

Question 13

Q

Canine impaction eruption prognosis

Answer

A

Liu 2008
CBCT study
- 45% - Buccal
- 40% - Palatal
- 10% - Mid alveolus
Prognosis of eruption
- Ericson and Kurol 1987
  Midline of lateral is the demarcation line
  - 91% - if lateral to midpoint of lateral
  - 64% - if medial to midpoint of lateral
- Warford 2003
  Broken into 4 zone based on the lateral
  - 94% - Lateral to lateral border of lateral incisor
  - 62% - Between lateral border and midpoint of lateral incisor
  - 13% - Between midpoint and medial border of lateral incisor
  - 1% - Medial to medial border of lateral incisor
Sequelae of nil treatment - RCSEng 2016 Guidelines
- 66% - Root resorption on laterals
  *

Question 14

Q

Canine impaction risk factors

Answer

A

Systemic
- Syndromes
  - Gardners
  - Cleidocranial dysplasia
  - Downs
- Metabolic
  - Hypothyroidism
  - Hypopituitary
- XRT
Local factors
- Trauma
- Cleft
- Crowding
- Ankylosis of C
- Pathology
- Supernumerary
- Root dilaceration

Question 15

Q

Canine impaction theories

Answer

A

Genetics - Peck 1994
- Factors supporting genetics
  - Anomalies associated with impacted canines
  - Bilateral occurrence
  - Gender predilection - more common in females
  - Familial occurrence
  - Population differences
Guidance theory - Becker 1995
- Missing lateral
- Peg lateral

Question 16

Q

Canine impaction treatment options

Answer

Study These Flashcards

A

*

Question 17

Q

CBCT signs re proximity to IAN

Answer

Study These Flashcards

A

Ghai and Choudhury 2018
- Inter-radicular position of nerve
- Thinning of lingual cortex
Intraop nerve exposure = 20% risk of injury (Tay 2004)
Loss of cortical integrity of canal = 12% risk of IAN injury (Park 2010)
Therefore identify features associated with increased IAN exposure
- Ghai and Choudhury 2018
  - Inter-radicular position of nerve
  - Thinning of lingual cortex
- Cortical defect of canal >3mm
- Dumbell/teardrop shape canal

Question 18

Q

Coronectomy Indications & Contraindications

Answer

Study These Flashcards

A

Indications
- OPG signs (1 out of 3 high risk Rood signs) - Blaeser
  Increases nerve injury risk from 1% to 3%
- CBCT signs
  - Loss of cortication >3mm
  - Roots straddle nerve
  - Compression of nerve against cortex
  - Dumbell/Teardrop shaped canal
- Social or occupational reasons why nerve injury is more critical
Contraindications
- Patient factors
  - Can’t attend followup
  - Immunosuppressed
  - Adjuvant chemoradiotherpy
- Pathology
  - Caries to pulp
  - Periapical pathology
  - Mobile root
  - Nerve lies adjacent to crown (Horizontal impaction)

Question 19

Q

Coronectomy Outcomes

Answer

Study These Flashcards

A

Pitros 2020 SR
doi.org/10.1016/j.bjoms.2020.07.015
Combined data from 4 RCT (including Renton Study)
- IAN injury
  - Renton
    - Coronectomy - 0%
    - Failed Coronectomy - 8%
    - Surgical Removal - 19%
  - 1.3% - Coronectomy
    7.4% - Surgical Removal
    OR - 0.16
    Reduces nerve injury by 84%
- Dry Socket
  - 2.8% - Coronectomy
    5.4% - Surgical removal
- Infection
  - 3.0% - Coronectomy
  - 3.5% - Surgical removal
- Root migration - Leung & Cheung 2018 RCT
  - Young patients more at risk
  - Average 2mm (up to 6mm)
  - 90% migration in the first 6month, 5% after 24 months
  - 2.3% requiring removal

Question 20

Q

Coronectomy Technique

Answer

Study These Flashcards

A

Renton 2013 update
- Buccal triangular flap
- No lingual retraction
- Fissure bur to expose tooth
  Do not drill below CEJ
- Fissure bur used to section the tooth at CEJ
  Drill only as far as the pulp chamber (to protect lingual nerve)
- Elevator to fracture the crown from tooth but care must be taken not to apply excessive force
- Check for mobility of roots
- Rose tip bur to trim enamel spurs
  Ensure cementum several mm below alveolar crest
- Leave pulpal tissue to maintain vitality to the root
- Primary closure
  Post op Chlorhex, No abx
Pogrel 2004
- Pre op abx
- Buccal flap with relieving incision
  Lingual flap raised
  Broad base retractor - Walter lingual retractor
- Crown completely sectioned at 45 degree angle
  Removed with tissue forceps
- Fissure or Round bur to reduce remaining enamel
- Ensure cementum 3mm below CEJ
- Primary closure

Question 21

Q

Factors affecting difficulty of wisdom teeth

Answer

Study These Flashcards

A

Patient Factors
- Renton 2001
  - Patient weight
  - Age
  - Ethnicity
- Proximity to IAN
  - Rood signs
  - CBCT signs
Surgical Factors
- Dental Factors
  - Classification
    - WHARFE
    - Pell and Gregory
    - Winter’s Line
    - Winter’s Classification
  - Renton 2001
    - Application depth
    - Bone impaction
    - Root formation

Question 22

Q

Hyperdontia & Hypodontia Causes

Answer

Study These Flashcards

A

Hyperdontia
- Cleidocranial dysplasia
- Ehler Danlos
- Fabry Disease
- Gardners syndrome
- Cleft lip and palate
- Crouzon
Hypodontia
- Craniofacial microsomia
- Treacher collins
- Kabuki syndrome
- Cleft lip and palate
- Ectodermal dysplasia
- Gorlin goltz syndrome
- Downs syndrome

Question 23

Q

Indications for pre radiotherapy extractions

Answer

Study These Flashcards

A

Ben David 2007
- Teeth with unrestorable caries
- Caries extending to gingival margins
- Large compromised restorations with pocketing >5mm
- Periodontal disease
  - Mobile teeth
  - Significant pocketing
  - Advanced recession or furcation involvement
- Severe erosion or abrasion
- Non functional teeth
- Primary closure and alveoloplasty

Question 24

Q

Rood Signs

Answer

Study These Flashcards

A

High Risk
- Darkening of the root
- Deviation of canal
- Interruption of white line
Low Risk
- Deflection of root - Possibly clinically significant
- Narrowing of root - Possibly clinically significant
- Bifid root apex
- Narrowing of canal

3 - Dentoalveolar Flashcards

(24 cards)