Wisdom Teeth Impaction and Evaluation

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Questions and Answers

What is the typical age range when crown mineralization of third molars is usually completed?

16-18 years

8-9 years

14-16 years

12-14 years (correct)

Which of the following classifications is used to categorize the angulation of impacted third molars?

Winter classification (correct)

Smith and Johnson classification

Molloy classification

Pell and Gregory classification

Which radiographic assessment is NOT typically used when evaluating impacted teeth?

Cone Beam CT (CBCT)

Chest X-ray (correct)

OPG

Periapical

In the context of lower third molar assessment, what does a mesioangular angulation indicate?

The long axis points towards the front of the mouth Signup and view all the answers

What is one common local cause of impaction in third molars?

Retained deciduous teeth Signup and view all the answers

Which term is used to describe a tooth that has not erupted into its normal position?

Unerupted tooth Signup and view all the answers

At what age is root formation for the third molars typically half-formed?

16 years Signup and view all the answers

Which feature is NOT identified in the radiographic assessment of the lower third molar?

Size of the patient's jaw Signup and view all the answers

What characterizes a buccally deflected lower third molar?

The tooth is angled towards the cheek. Signup and view all the answers

What does the amber line represent in Winter's Lines?

The margin of the alveolar bone covering the third molar. Signup and view all the answers

In the evaluation of the roots, which of the following aspects is NOT considered?

Presence of enamel. Signup and view all the answers

What does the red line in Winter's Lines indicate?

The depth of bone needed for tooth elevation. Signup and view all the answers

What indicates an inverted impaction of the lower third molar?

The roots are directed upwards. Signup and view all the answers

Which factor does NOT make surgery for lower third molars less difficult?

Older age of the patient. Signup and view all the answers

Which of the following is NOT a sign of an intimate relationship between the lower third molar and the ID canal?

Increased distance between molars. Signup and view all the answers

What does the evaluation of the crown of the lower third molar include?

Size and shape of the crown. Signup and view all the answers

Study Notes

Wisdom Teeth

Initial calcification occurs around 8-9 years of age.
Crown mineralization typically finishes between ages 12 and 14.
Roots are usually half-formed by the age of 16.
Roots are two-thirds formed or fully formed with open apices by 18 years.
Impacted teeth fail to erupt into the normal functioning position of the dental arch.

Impaction Causes and Frequencies

Local causes include:
- Prolonged retention of baby teeth
- Malposed tooth germ
- Insufficient arch length (crowding)
- Pathologies like cysts or tumors
- Abnormal eruption path
- Cleft lip and palate
Frequency of impaction:
- Mandibular third molars
- Maxillary third molars
- Maxillary cuspids
- Mandibular cuspids
- Mandibular premolars
- Maxillary premolars
- Maxillary central and lateral incisors

Evaluation of Impacted Teeth

Clinical assessment: involves a visual examination
Radiographic assessment:
- OPG (Orthopantomogram): Offers a panoramic view of the jaw
- Periapical radiograph: Focuses on the apex of a specific tooth
- Parallex/Occlusal radiograph: Takes multiple images from different angles to show depth and positioning of the tooth
- Cone Beam CT (CBCT): Provides 3D images for more detailed evaluation

Classifications of Impacted Third Molars

Winter classification: Categorizes impacted teeth based on angulation
Pell and Gregory classification: Assesses the relationship between the impacted tooth and the second molar
Winter classification:
- Mesioangular: The impacted tooth leans towards the front of the mouth
- Distoangular: The impacted tooth leans towards the back of the mouth
- Horizontal: The impacted tooth is horizontal in relation to the second molar
- Vertical: The impacted tooth is vertical in relation to the second molar
- Inverted: The impacted tooth is inverted in relation to the second molar
- Transverse: The impacted tooth is positioned transversely across the mouth
Pell and Gregory classification: Uses a chart to classify impacted teeth based on their position relative to the second molar

Lower Third Molar Radiographic Assessment:

Features to be identified:
- Lower third molar itself:
  - Angulation: The position of the impacted tooth relative to the second molar
  - Crown: Size, shape, and presence of caries
  - Roots: Number, shape, curvatures, stage of development, and presence of resorption
  - Depth of the tooth in alveolus: How far into the bone the tooth is embedded
  - Buccal or Lingual: Is the tooth tilted towards the cheek or the tongue
- Lower second molar: To understand the position and orientation of the impacted tooth
- The surrounding bone: To assess the amount of bone surrounding the impacted tooth
- Relationship with ID canal: The position of the impacted tooth relative to the Inferior Dental Canal.
Angulation: This is the position of the long axis of the impacted tooth in relation to the long axis of the second molar.
- Mesioangular: The impacted tooth leans towards the front of the mouth
- Distoangular: The impacted tooth leans towards the back of the mouth
- Horizontal: The impacted tooth is horizontal in relation to the second molar
- Vertical: The impacted tooth is vertical in relation to the second molar
- Inverted: The impacted tooth is inverted in relation to the second molar
- Transverse: The impacted tooth is positioned transversely across the mouth
Evaluation of the Crown: Size, shape, and presence of caries
Evaluation of the Roots: Number, shape, curvatures, stage of development, and presence of resorption.
Relation to ID canal:
- Superimposition or intimate relationship?: Is the tooth directly over the canal?
- Loss of tramlines: Does the canal appear smaller than expected?
- Narrowing of tramlines: Is the canal narrowed by the tooth?
- Change in direction of tramlines: Does the tooth alter the path of the canal?
- A radiolucent band across the root: Is there a radiolucent area around the tooth?
Depth in alveolus: How far into the bone the tooth is embedded
- Winter’s lines: Imaginary lines used to assess the depth of the impacted tooth
  - White Line: Represents the difference in occlusal level of the erupted molars and the third molar.
  - Red Line: Indicates the amount of bone that needs to be removed to extract the tooth.
  - Amber Line: Helps determine the level of bone covering the third molar.

Factors that Make Surgery Less Difficult

Young patient: Usually have more elastic bone and a greater capacity for healing.
Roots 1/3 – 2/3 formed: Partially formed roots are easier to extract than fully formed roots.
Wide periodontal ligament: A wider ligament provides more space to maneuver during extraction
Large follicle: A larger follicle indicates that the impacted tooth has been actively developing, suggesting a more flexible surrounding bone.
Elastic bone: Easier to remove and shape than dense bone.

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Description

This quiz covers key aspects related to wisdom teeth, including their calcification stages and the causes of impaction. It also discusses the evaluation methods for impacted teeth, focusing on both clinical assessments and radiographic techniques. Test your knowledge on this important dental topic!