Tooth impaction occurs when a tooth fails to fully erupt into the dental arch by its expected eruption date. Commonly impacted teeth include third molars, maxillary canines, and premolars. Causes of impaction include local obstructions, lack of space, and systemic factors like hormonal disorders or hereditary conditions. There are three classification systems for impacted teeth based on their angulation, relationship to the anterior border of the ramus, and relationship to the occlusal plane. Mesioangular and horizontal impactions of third molars are most common and can require surgical removal.
2. DEFINITION
• IMPACTION:
• It is the tooth that has
failed to erupt completely
or partially to its correct
position in the dental arch
well beyond its eruption
date and its eruption
potential is lost.
4. CAUSES OF IMPACTION
• LOCAL CAUSES:
• Obstruction for eruption
• Lack of space
• Ankylosis of primary or permanent tooth
• Ectopic position of tooth bud
• Dilaceration of roots
• Soft tissue or bony lesions
8. Let’s talk about Angulation (which is 4
kinds)
• 1.The least difficult Impaction is
MESIOANGULAR IMPACTION. When the crown
of the mesioangular-impacted tooth is tilted
toward the second molar in a mesial direction.
9. 2. HORISONTAL IMPACTION. This type is concidered to be more difficult to
remove compared with Mesioangular Impaction.
3. VERTICAL IMPACTION. When the long axis of the impacted tooth runs
parallel to the long axis of the second molar.
10. 4. DISTOANGULAR IMPACTION The most difficult angulation for removal of
tooth. In this case third molar is distally or posteriorly angled away from
second molar.
11. Second Classification System is: Relationship to Anterior
Border of Ramus.
1. Pell and Gregory class 1 impaction. Means when the third molar is
anterior to the anterior border of ramus.
12. 2. Pell and Gregory class 2. When half of the crown is covered by
anterior portion of the ramus of mandible.
13. 3. Pell and Gregory Class 3 When the tooth is located completely within the
mandibular ramus.
14. And the last, Third Classification System is: Relationship to the Occlusal Plane.
A. When Occlusal plane of the Impacted Tooth is at the same level as the
occlusal plane of the second molar.
15. B. When occlusal plane of the impacted tooth is between
the occlusal plane and the cervical line of the second
molar.
16. C. When Impacted Tooth is below the cervical line
of the second molar.