The 3rd molar is the most commonly impacted tooth in the whole dentition because of the timing of eruption and the lack of length of Jaw which has been decreasing over generations thanks to Evolution. During 3rd molar impaction of the Mandible there are many factors which should be considered before going for Surgical removal of Impacted 3rd molar. Relationship of the Impacted Mandibular third molar to the Inferior Alveolar nerve plays a major role in the surgical approach and also the post-op recovery to the patient.
The various types of relationships of Inferior Alveolar Root canal to 3rd Molar root tips are:
- Over Lapping: Inferior alveolar root canal overlaps the Root Tip
- Loss of “Roof of Canal”: The upper radio opaque line of the inf alveolar root canal in missing because of the root tip.
- Narrowing: The Inf Alveolar root canal is narrowed down in the place where it is related to the 3rd
- Deflection: The inf alveolar root canal changes its course to get away from the root tips of 3rd molar
- Di laceration of Roots: The root tips are dilacerated because of the presence Root Canal
The various factors to be considered are the Difficulty index based on
- Winter’s classification
- Height of the Mandible
- Angulation of Second Molar
- Root Shape
- Path of Exit
- Location of Inferior Alveolar Canal in relation to root of 3rd Molar
The Inferior alveolar canal is represented by 2 thin radiopaque lines in the Radiograph near the region of the root of the Molars passing slightly below them most of the times. If you can see disruption in the continuity of Canal then it indicates the presence of deep grooving of the canal by the 3rd molar Root tip.
In case only the upper radio opaque line sees break in continuity it states that only the root apex is involved with the canal.