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Interceptive treatment for localized impactions – LR3

Case review – Localized impaction

This 9yr/male presented with a previous history of the premature loss of the lower right deciduous canine. The lower right canine is crowded out within the orthopantomogram:

04/2018 pretreatment OPG showing impacted LR3
04/2018 pretreatment OPG showing impacted LR3


The pretreatment photos show a lower centreline shift to the right side, and loss of space for the emergence for the lower right canine:

pretx intraoral montage impacted LR3 mixed dentition montage

In the simulation below, activated root control attachments to upright the lower right lateral, lower right central and lower left central incisor can be seen within the simulation. As the molar relationship is already class I on the right side, passive attachments were placed on the buccal segment on the right side.

Total treatment time 8 weeks

Total aligners required : 8 aligners, weekly aligner change

Special features: Mixed dentition relief features (for erupting permanent dentition and potentially mobile deciduous dentition has been placed for patient comfort and to prevent interference with normal dental development)

Post treatment records:

In the OPG, uprighting of the incisor roots and space coordination has allowed for the normal eruption of the LR3.



Retention was carried out using Whitesmileclear retainers with mixed dentition relief:

POST TREATMENT INTRAORAL Impacted LR3 mixed dentition
POST TREATMENT INTRAORAL Impacted LR3 mixed dentition


Localized, mixed dentition intervention has clear benefits here:

  1. The coordination of space for the LR3, reducing the severity of the malocclusion
  2. The LR1 has been moved away from a region of frenal traction, preventing future attachment loss.
  3. The centrelines are now coordinated

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