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Peri-operative Management
of Impacted Third Molars
Dr Chamara Atukorala MDConsultant Oral and Maxillofacial Surgeon
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Impacted tooth is a one that has not erupted to its functional position in the occlusion and
does not show clinical or radiological features indicating that it may erupt.
Causes
• Angulation• Hard or soft tissue obstruction• Pathological lesions• Lack of space
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
The management of asymptomatic, disease-free
ITM is controversial, the best evidence currently
available neither supports nor refutes extraction
.
(Symptomatic ITM?)
Available GuidelinesLocal- NoneForeign
NICEAAOMS
What is a Guideline ?
Guidance
1.1 The practice of prophylactic removal of pathology-free ITM should be discontinued .1.2 The standard routine programme of dental need be no different.
1.3 Surgical removal of ITM should be limited to patients with evidence of pathology. Such pathology includes unrestorable caries, non-treatable pulpal and/or periapical pathology, cellulitis, abcess and osteomyelitis, internal/external resorption of the tooth or adjacent teeth, fracture of tooth, disease of follicle including cyst/tumour, tooth/teeth impeding surgery or reconstructive jaw surgery, and when a tooth is involved in or within the field of tumour resection.
1.4 The evidence suggests that a first episode of pericoronitis, unless particularly severe, should not be considered an indication for surgery.
The Guidelines boil down to waiting for some pathology to develop, (such as decay in the wisdom tooth or the adjacent tooth, gum disease around the wisdom tooth,infection around the tooth crown, cellulitis, abscess and
including cyst / tumour,tooth / teeth impeding surgery or reconstructive jaw surgery )
Why Do British Practice This ?
This is regarded by some as supervised neglect.
The American Association of Oral & Maxillofacial Surgeons (AAOMS), the professional organization representing more than 8,500 OMF surgeons in the USA .
• “Asymptomatic” does not mean “Disease Free ” Pathology is always present before symptoms appear. Once damage has occurred, it is not always treatable
• 25% of wisdom teeth patients who perceive themselves as asymptomatic actually already have inflammatory periodontal disease. Blakey GH, Marciani RD, Haug RH, et.al: Periodontal pathology associated with asymptomatic third molars; Journal of Oral and Maxillofacial Surgery. 2001;60:1227-1233
• The risk of future disease requiring removal of retained wisdom teeth in asymptomatic patients who retain their wisdom teeth, exceeds 70% after 18 years of follow-up. Venta I, Ylipaavalniemi P, Turtola L: Clinical outcome of third molars in adults followed during 18 years. J Oral Maxillofac Surg. 62:182, 2004
• 20 years after UK adopts the “National Institute of Clinical Excellence” (NICE) guidelines, volume of third molar surgeries decrease, with a corresponding increase in mean age for surgical admissions and an increase in “caries” and “pericoronitis” as etiologic factors. Renton T, Al-Haboubi M, Pau A, Shepherd J, Gallagher JE: What has been the United Kingdom’s experience with retention of third molars? J Oral Maxillofac Surg. 70:48-57, 2012, Suppl 1
• Retention of third molars is associated with increased risk of second molar pathology in middle-aged and older adult men. Nunn, ME, et al. Retained Asymptomatic Third Molars and Risk for Second Molar Pathology. Nunn et al. J DENT RES published online 16 October 2013.
AAOMS firmly supports the surgical management of erupted and impacted third molar teeth, even if the teeth are asymptomatic, if there is presence or reasonable potential that pathology may occur
caused by or related to the third molar teeth. November 10, 2011
Indications for removal of ITM identified in the Parameters and Pathways published by the
AAOMS include
1. Pain , 2. Carious tooth , 3. Pericoronitis
4. Facilitation of the management of progression of periodontal
disease
5. Nontreatable pulpal or periapical lesion
6. Acute and/or chronic infection (e.g., cellulitis, abscess)
7. Ectopic position (malposition, supraeruption, traumatic
occlusion)
8. Abnormalities of tooth size or shape precluding normal function
9. Facilitation of prosthetic rehabilitation
10. Facilitation of orthodontic tooth movement and promotion of
stability of the dental occlusion
11. Tooth in the line of fracture complicating fracture
management
12. Tooth involved in surgical treatment of associated cysts and
tumors
13. Tooth interfering with orthognathic /or reconstructive surgery
14. Preventive or prophylactic removal, when indicated, for patients with
medical or surgical conditions or treatments (e.g., organ transplants, alloplastic
implants, bisphosphonate therapy, chemotherapy, radiation therapy)
15. Clinical findings of pulp exposure by dental caries
16. Clinical findings of fractured tooth or teeth Impacted tooth
18. Internal or external resorption of tooth or adjacent teeth
19. Patient’s informed refusal of nonsurgical treatment options
20. Anatomic position causing potential damage to adjacent teeth
21. Use of the third molar as a donor tooth for tooth transplant
22. Tooth impeding the normal eruption of an adjacent tooth
23. Resorption of an adjacent tooth
24. Pathology associated with the tooth follicle
25. Abnormality of size or shape precluding normal function
When managing a patient with asymptomatic, disease-free ITM, one must carefully review the risks and
benefits of extraction or retention, and heavily weight the patient’s treatment
preference.
“A strong indication for removal of impacted third molar should be complemented with a strong contraindication to its retention”
– Mercier P., Precious D., Risk and benefits of removal of impacted third molars, IJOMS 21:17, 1992.
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Radiological Investigations
Radiographs Intra Oral
IOPAOcclusal views
Extra OralDPT (OPG)Lateral Oblique Views
CTCone Beam CTConventional CT
Radiological Assessment Helps In
Classification of the ITM Localisation and orientation of the ITM Assessment of the crown and root
morphology of the ITM Assessment of the ramal bone cover Assessment of the second molar tooth and
its root morphology Relationship of the ID canal to the roots of ITM Associated pathological lesions with the ITM
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Systematic classification of the position of
Impacted Third molar ( ITM) teeth helps in
– Assessing the best possible path of removal of the ITM
– Managing difficulties encountered during removal
Prediction of operative difficulty before the extraction of ITM allows a design of treatment that minimises the risk of complications.
Both radiological and clinical information must be taken into account.
Classification of Impacted Mandibular 3rd Molars
1. ADA-AAOMS Classification
2. Nature of the overlying tissues
3. Winter’s Classification
4. Pell & Gregory’s Classification
ADA-AAOMS Classification
Impacted tooth-with overlying soft tissue.
Impacted tooth-Partial bony impaction.
Impacted tooth-complete bony impaction .
Impacted tooth-complete bony impaction with unusual surgical complications.
Nature of the overlying tissues
Soft Tissue Impaction. is usually the easiest of type of impacted tooth to remove.
Hard Tissue ('Bony') Impaction.
– Partial Bony. The superficial portion of the tooth is covered only by soft tissue but the height of the tooth's contour is below the level of the surrounding alveolar bone.
– Complete Bony. The tooth is completely encased in bone so that when the gingiva is cut and reflected back, the tooth is not seen. These are often the most difficult tooth to remove
Winter's Classification
Mesioangular - 45% Vertical - 40% Horizontal - 10% Distoangular – 5% Inverted
• Bucco-version• Linguo-version• Transverse
Pell & Gregory's Classification
Based on the relationship between the ITM to the ramus of the mandible (lower jaw) and the 2nd molar (based on
the space available distal to the 2nd molar).
Class A. The highest portion of impacted 3rd molar is on a level with or above the occlusal plane.
Class B. The highest portion of impacted 3rd molar is below the occlusal plane but above the cervical line of the
of 2nd molar.
Class C. The highest portion of impacted 3rd molar is below the cervical line of the of 2nd molar.
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Assessment
Case historyGeneral medical status of the patient ( Fitness to undergo ITM surgery)
Extra oral examinationMouth opening and TMJFacial form, mental nerve functioning
Intra oralSurgical site ITM in question
Assessment of the degree of difficulty of the ITM surgery
Assess the radiological features
Assessment of the degree of difficulty of the surgery
WAR (Winter’s) Lines
WHARFE’s ASSESSMENT by McGregor (1985)
PEDERSON’S DIFFICULTY INDEX
Category Score
1. Winters classification
HorizontalDistoangularMesioangular
Vertical
2210
2. Height of mandible
1-30mm31-34mm35-39mm
012
3. Angulation of 3rd molar
1° - 50°60° - 69°70° -79°80° - 89°
90°+
012344. Root shape Complex
Favourable curvatureUnfavourable
curvature
123
5. Follicles NormalPossibly enlarged
Enlarged
012
6. Exit (Path of exit)Space availableDistal cusp coveredMesial cusp coveredBoth cusp covered
0123
Total 33
WHARFE’s ASSESSMENT by McGregor (1985)
PEDERSON’S DIFFICULTY INDEX
• Very difficult : 7 to 10• Moderataly difficult: 5 to 7• Minimally difficult : 3 to 4
ScoringMesio angular1
Horizontal 2
Vertical 3
Distoangular 4
Level A 1
Level B 2
Level C 3
Class I 1
Class II 2
Class III 3
Radiological features indicating a close association between IAN and ITM
If the ID nerve is closely associated indicating a high risk of injury ; best is to assess using advanced imaging methods
Cone Beam CT Conventional CT
Important Anatomical Structures
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
ITM Management options
*Observation and periodic review
*Surgery
**Conventional
***Intra Oral
****Buccal Approach
****Lingual Split Technique
****BSSO
***Extra Oral Approach
• **Coronectomy
• ** Staged Removal
Planning
Observation and periodic review
For patients who elect retention, the frequency of follow ups should be designed
to match the symptoms or disease associated with ITM
( physical and radiographic examination every 12 to 24 months by a health care professional trained to evaluate third
molars.)
Surgery
Set up of careLA +/- sedation
GA
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Steps In Surgical Removal(Buccal Access)
Anesthesia
Incision and mucoperiosteal flap design and flap reflection
Removal of bone
Sectioning of tooth/roots
Elevation/Extraction
Wound debridement and smoothening of bone
Achieve Haemostasis
Wound closure, Analgesics
Postoperative follow-up
Principles of flap design
Adaquate access
Viability of the flap ( Base> top)
Avoid vital structures
Plan ease of repositioning
Ability to extend if the need arises
Clean incisions
Types of flap designs
• Envelope flap• L- shaped incision• Bayonet shaped incision• Triangular shaped incision• Ward’s incision and Modified Ward’s incision.• Comma shaped incision.• S -shaped incision• Szmyd and modified Szmyd incision
• Berwick’s tongue shape flap.
Ward’s incision
Modified Ward’s
Envelop flapIncision Not to be extended too distally-
Bleeding from buccal vessels & other arteries
Postoperative trismus – temporalis muscle damage
Herniation of buccal fat pad Damage to lingual nerve
(lingual extention)
Triangular shaped Incision
Bone Removal
“Bone belongs to the patient and tooth belongs to the dentist”
Minimize the amount of bone removal as possible
Instead section the tooth and deliver in pieces Excessive bone removal results in poor healing
and bone defect. High risk of alveolar osteitis, post op pain and
trismus.
Once the soft tissue is elevated and retracted, the surgeon must make a judgment concerning the amount of bone to be removed.
Bone must be removed in an atraumatic, aseptic, and non–heat-producing technique, with as little bone removed and damaged as possible.
The amount of bone that must be removed varies with the depth of impaction, the morphology of roots, and the angulation of tooth.
No bone should be removed from lingual aspect so as to protect the lingual nerve from injury.
Bone removal - Moore & Gillbe’s Collar Technique
Tooth Division“Rationale of tooth sectioning is to create
a space into which impacted tooth can be
displaced & thence removed.”
Tooth is sectioned in various ways depending on the type & degree of impaction.
Tooth is sectioned ¾ of the way
towards the lingual aspect. A straight elevator is inserted into the slot made by the bur and rotated to split the tooth
Extra Oral Approach
SSO
Coronectomy
Coronectomy
What is it ?IndicationsTechniquePost op MxFollow up
Staged Removal
Debridement of Wound & Closure
• Thorough debridement of the socket by Periapical
curettage.
• Remove the follicle of the ITM.
• Smoothening of sharp bony margins by Bone file / burs.
• Thorough irrigation of the socket Betadine solution + Saline
.
• Initial wound closure is achieved by placing 1stsuture just
distal to 2ndmolar, sufficient number of sutures to get a
proper closure.
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Post Operative Instructions
• Pressure pack , Ice application
• Soft diet –1st two days
• 1st dose of analgesic should be taken before
the anesthetic effect of LA wears off.
• Avoid strenuous exercises for 1st 24 hrs.
• Avoid gargling / spitting / smoking / drinking
with straw.
• Warm water saline gargling after 24 hrs +
mouth wash regularly thereafter.
• Suture removal on 5th POD.
Antibiotics ?
Steroids?
Definition Prevalence Indications for Surgical removal,
/Guidelines Investigations and Diagnosis Classification Surgical management
AssessmentPlanningExecution
Post op Management Complications and their Management Medico-legal Background
Complications and their Management
Intra Operative
1. During incision a. Injury to facial arteryb. Injury to lingual nervec. Hemorrhage – careful history
2. During bone removal a. Damage to second molar b. Slipping of bur into soft tissue & causing injury c. Extra oral/ mucosal burns d. Fracture of the mandible when using chisel & mallet e. Subcutaneous emphysema
3. During elevation or tooth removal
a. Luxation of neighbouring tooth/ fractured restoration
b. Soft tissue injury due to slipping of elevator
c. Injury to inferior alveolar neurovascular bundle
d. Fracture of mandiblee. Forcing tooth root into submandibular
space or inferior alveolar nerve canal
f. Breakage of instrumentsg. TMJ Dislocation – careful history
Post-operative complications
• Immediate
- Hemorrhage
- Pain
- Edema
- Drug reaction
• Delayed
- Alveolitis
- Infection
- Trismus
From Medico-legal point of view to avoid getting in to problems.
• Make correct decisions • Get patient actively involved in decision making• INFORMED CONSENT• Proper investigations• Correct treatment.• Manage complications• Communicate with the patient• Be nice to your patient