Related Experiment Video
Updated: Aug 9, 2025

Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Transient apical breakdown of a discoloured maxillary central incisor during orthodontic treatment: A case report
1Department of Stomatology, Xiaoshan Traditional Chinese Medical Hospital, Hangzhou, China.
Abstract:
Transient apical breakdown (TAB) appears to be a repair process taking place in the pulp and periapical area of traumatised teeth which may display crown discoloration and have no responses to pulp sensitivity tests. Few TAB cases induced by orthodontic forces have been reported so far. Presented is a case report in which TAB occurred on the maxillary right central incisor during orthodontic treatment. The affected tooth suddenly displayed crown discoloration and had no response to pulp testing at 6 weeks after the placement Invisalign Clear Aligner appliances. Condition of the discoloured tooth was monitored by periodic recall examinations without any active treatment. Six months after the occurrence of discoloration, the affected tooth recovered to its original shade and responded normally to pulp sensitivity tests.
Related Concept Videos
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...

