Join me as I describe Jassin Arnold’s lecture describing lower incisor extraction, its indications and management

Why should we use it?

o Reduces anchorage demand, entact posterior segments

o Improve dental occlusion in a shorter time frame

o Profile improves in mandibular protrusion cases Levin 1964

When should we use it? Systematic review Zhylich 2011

o Mild-moderate class 3

o Edge to edge anterior occlusion

o Crossbite with mild anterior mandibulae excess

o 4.5mm tooth size discrepancy of lower to upper Matsumoto 2010

When should we not use it?

o Severe OB

o Bimaxillary crowding

o Triangular lower incisor and minimal crowding 3mm less

o High insertion of labial frenum = gingival recession I removed

Risks of lower incisor extraction

o Black triangle

o Increased overjet and overbite

o Tendency for spaces to reopen an aesthetic zone

o Create tooth size discrepancy

Bolton’s anterior analysis

o Anterior ratio 77% 3-3 lower Vs 3-3 upper

Cases:

o Class 1

o 4mm of crowding of the lower incisors

o Bolton’s anterior analysis 87% - excess lower incisor tissue

§ = Extraction 1 lower incisor = 74.8% – TOO LOW (ideal 77%)

· = Solution strip upper 2-2 by 2mm = 78% Bolton’ ratio

o Case 2

o Molars ½ II, increased overjet 6mm, lower incisors 4mm of crowding

o Bolton’s anterior analysis 87% - excess lower incisor tissue

§ = Extraction 1 lower incisor and stripping of upper incisors = 77%

§ = Extraction of 2 upper premolars as well

· Stripping upper 2-2 to achieve ideal occlusion in the anterior 3-3 segment

· Extraction of Upper 4s to correct the increased overjet

References

Zhylich, D. and Suri, S., 2011. Mandibular incisor extraction: a systematic review of an uncommon extraction choice in orthodontic treatment. Journal of Orthodontics, 38(3), pp.185-195.