This article describes  vertical control (leveling the arch) and anteroposterior control to correct the pseudo-class III case.

Tristar showcase: This is a case of pseudo-class III malocclusion treated with aligner, describing the biomechanics that can level the curve of Spee effectively and was planned as such to align the upper lower crowded teeth with a series of aligners throughout the process.

Other important features in this aligner treatment plan include: creating space via expansion prior to levelling the curve of Spee. Class III elastics are required to aid the correction of the Antero – Posterior discrepancy.

The brief description of the problem list is:

  • Class III profile.
  • Reduced mandibular planes angle.
  • Moderate lower arch crowding, deep curve of spee exacerbated by overerupted incisors.
  • Moderate upper arch crowding, lingually displaced due to traumatic bite.
  • Class III bite dimensions, the patient initially bites edge to edge and then overcloses to a class III relationship.

The Treatment Plan

  • Bite ramps to disclude overclosure and attachment placement to provide anchor points for lower incisor intrusion via Tristar attachment template.
  • Expansion first (forward in upper, lateral in lower).
  • Once space is gained, lower incisor intrusion.

What are the key features to correct this malocclusion?

Diagnosis:

  • Recognizing the malocclusion and severity

Treatment Plan and Bio mechanics:

  • Recognizing and planning stepwise correction of the malocclusion
  • Expansion first, recognition of the need for space prior to intrusion of lower incisors
  • Simultaneous, efficient correction via Class III elastics 5/16

Materials:

  • Precise Tristar AT (Attachment template) to provide blue bite ramps for disclusion and accurate template placement of attachments.
  • Consistent force delivery for expansion and engagement into attachments for intrusion of lower incisors.