Evaluation of the difficulty of the impacted tooth removal

Evaluation of the difficulty of the impacted tooth removalWaseem Khalid Mahmood 2019-2020

Evaluation of the difficulty of the impacted tooth removal

1- the orientation of the tooth
2- the depth of the tooth
3-type of impaction like soft tissue impaction , bony impaction , tooth to tooth impaction.
4 –root shape like bulbous root or thin spindly roots.
5 – bone density (texture of the investing bone)
6-relation to the inferior dental canal .

7 – patient age

8 – degree of mouth opening
9- general buildup of the patient .
10 – the relation of the impacted tooth to the external oblique ridge and to the internal oblique ridge
11 _approximate to vital structures.

Before the surgical procedure the following should be done

1- proper clinical and radiographic evaluation of the condition.
2-classification of the impacted tooth to evaluate the difficulty of the surgical
procedure .
3- selection the time for surgical procedure.
4- explain the condition to the patient
5 – select type of anesthesia

Winter’s lines(WAR) lines

1-White line: it is an imaginary line draw along the occlusal surface of erupted first and second molars extend posteriorly over 3rd molar region . Its benefit is to determine the angulations of an impacted tooth and its relationship with occlusal surface of erupted 2nd molar(depth).
2- Amber line: It is a line drawn from the surface of bone laying distally to the 8 and to the crest of interdental septum or alveolar septum between 6 and 7. it determine the amount of bone removal
3-Red line : it is draw perpendicular from amber line to an imaginary point of elevator application located mesially to the CEJ except in Disto angular impaction. It is used to measure the depth of the impacted tooth.
Note: Any tooth with red line length more than (5 mm) it is better to remove it under G.A.

White Line

Amber Line
Vertical Impaction with caries
Point of application



Horizontal Impaction

Red Line

Mesio-angular Impaction

Disto-angular Impaction

Selection the time for surgical procedure
Early removal
1- the impaction should be documented
2 –ball in a socket syndrome
Late removal increase difficulty due to long root and dense bone.
The best time for removal when only 2/3 of the root had completed .

Development of mandibular third molar

The mandibular third molar tooth germ is usually visible radio graphically by age 9 years and cusp mineralization is completed at age 11 years.


At age 11 years the tooth is located within the anterior border of the ramus with it,s occlusal surface facing almost directly anteriorly
.crown formation is usually complete by age 14 years
At age 16 y the roots are approximately 50 % formed

At age 18 years the roots are completely formed with an open apex .

At age 24 years 95% of all third molars that will erupt have completed their eruption.

The change in orientation of the occlusal surface from mesial inclination to a vertical inclination occurs primarily during root formation .during this time the tooth rotates from horizontal to mesioangular to vertical . most third molars do not follow this typical eruption sequence and instead become impacted tooth

There may be differential root growth between the mesial and distal root ,which causes the tooth to either remain horizontally inclined or rotates to a vertical position depending on the amount of root formation.
Under development of the mesial root result in mesioangular impaction.
Over development of the mesial root result in over rotation of the third molar into a distoangular impaction
Overdevelopment of the distal root lead to mesioangular or horizontal impaction

Theories of impacted lower third molars

Orthodontic theory (arch-tooth dyscerpancy)
Nodine polygenic theory (elemination of unused teeth)
Mandelian theory (heriditary theory)
Pathological theory
Endocrinal theory
Nature theory( by A.J MacGreger):
Increase size of brain with sacrifice jaw size
• without decrease of tooth size
• Change of diet habits


The patient
The condition should be explained to the patient in a simple easy way directing his attention to possible complication that may arise from leaving the tooth in position .

Choice the type of anesthesia

Local anesthesia or general anesthesia
The indications for G.A may include :
1 – procedures lasting more than 45 minutes .
2 – uncooperative patient
3- level C impacted lower 8
4- class 3 impacted lower 8 .
5 – very apprehensive patient
6 – multiple impacted teeth removal