What are winters lines in regard to impacted teeth?

Answer 1

Winter's Lines (WAR)

The position & depth of the mandibular 3rd molar can be

determined using the Winter's Lines(WAR). These are 3

imaginary lines (red, amber & white) "drawn" on the dental

X-ray (these days, normally an OPG / DPT).

White Line

The white line is drawn along the occlusal surfaces of the

erupted mandibular molars & extended over the 3rd molar

posteriorly. It indicates the difference in occlusal level of

the 1st & 2nd molars & the 3rd molar.

Amber Line

The amber line represents the (height of the) bone level.

The amber line is drawn from the surface of the bone on

the distalaspect of the 3rd molar (or from the ascending

ramus) to the crest of the inter-dental septumtwixt the 1st

& 2nd molars. This line denotes the margin of the alveolar

bonecovering the 3rd molar and gives some indication to

the amount of bone that will need to be removed for the

tooth to come out.

Red Line

The red lineis an imaginary line drawn perpendicular from

the amber line to an imaginary point of application of an

elevator. Usually, this is the cemento-enamel junctionon

the mesialaspect of the impacted tooth (unless, it is the

disto-angular impacted tooth where the application point

is the distal cemento-enamel junction). The red line

indicates the amount of bone that will have to be removed

before elevation of the tooth i.e. the depth of the tooth in

the jaw & the difficulty encountered in removing the tooth.

With each increase in length of the red line by 1mm, the

impacted tooth becomes 3 x more difficult to remove (as

opined by Howe). If the red line is < 5mm, than the tooth

can be removed under just LA; anything above, a GA or

LA Sedationwould be more appropriate.