Sunday, 13 June 2010

Case Report, Class II, Dental Subdivision.

  • Patient female, age 13 years, 
  • with a full distal on the left side and full neutral on the right. 
  • Overjet 6mm, Overbite 4mm
  • Lower midline 4mm off to the left, from the facial midline, 
  • Upper midline on. 

(asymmetry on the lower jaw, dental class II, subdivision)

Treatment options in this case:
  1. Unilateral bite jumping device, preferably herbst on the wire, however appliances like Forsus, Twin Force etc would be suitable.
  2. Segmented approach, open door mechanics on the lower to correct the midline discrepancy and advance lower left dentition mesial (possible need of one screw to assure absolute anchorage). Finishing full neutral on both sides.
  3. Functional treatment, maxilator, twin block etc, with an asymmetric advancement of the mandible during the construction bite (the construction bite would probably have to be with a slight discrepancy of the lower midline, that would be then corrected on the full fixed phase.)
Treatment followed, is close to the second option of a segmented approach, as far as the force system applied, however it is with light wire approach on the lower (Australian round) and a rectangular TMA on the upper, during the working phase, to differentiate the resistance to sliding and build up anchorage on the upper, while sliding is allowed on the lower jaw, due to the light round wire.
The above is supported with asymmetric class II elastics.

After initial leveling, on the upper 17x25TMA and on the lower 0.016AUS are inserted.
An open coil activated 4mm from 36 to 33 and support of class II elastics to avoid of 36 distalizing.

After 3 months the overjet is eliminated, and the midlines are on.
Please notice the proclination of the lower front in this phase which is diminished with slenderizing 3-3 and increasing the overbite by retracting 3-3 (check final pictures)

The same approach was applied separately on 34 and 35 and lastly without an open coil and only with class II elastics 36 was mesialized.

Full length of treatment was exactly 12 months and braces were removed with some minor issues of finishing due to the patients will.

Final Intraoral:

Before and after comparison of overjet:

12 months treatment, no bite jumping or functional treatment mechanics applied.

Case treated at the Aarhus Dental School, Orthdontic Department, by Dimitris Galaktopoulos, DDS, under the supervision of Bo Bloch DDS, MsD


  1. It is an easy and consistent way of solving subdivisions, at the cases where the asymmetry is at the lower jaw.


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