Masato Kaku, Saiji Shimoe, Yuichi Mine, Tsuyoshi Taji, Takeshi Murayama & Hiroki NikawaBritish Dental Journalvolume 239, pages774–777 (2025)
Kaku, M., Shimoe, S., Mine, Y., Taji, T., Murayama, T. and Nikawa, H. (2025). Transient apical breakdown during orthodontic incisor intrusion treated with non-steroidal anti-inflammatory drugs: a case report. British Dental Journal, [online] 239(11), pp.774–777. doi:https://doi.org/10.1038/s41415-025-9103-7.
Introduction
The apical dental pulp tissue shows several biological reactions to orthodontic tooth movement- a type of trauma. Previous evidence dictates that excessive or continuous orthodontic forces can reduce pulpal blood flow, damage apical blood vessels, and cause inflammation, potentially leading to pulp necrosis and apical root resorption, especially in vital teeth.
A condition called Transient Apical Breakdown (TAB) can occur during pulp repair within a year after trauma or orthodontic treatment, presenting as periapical radiolucency and crown discoloration. Despite these signs, endodontic treatment is usually unnecessary because pulp function often recovers spontaneously, sometimes accompanied by root canal obliteration. TAB is relatively uncommon, more likely in younger patients, and can be mitigated by anti-inflammatory drugs such as loxoprofen.
The authors report a case of TAB in an adult undergoing orthodontic intrusion of a maxillary central incisor, which improved following loxoprofen treatment.
Case presentation
A 24-year-old woman seeking treatment for a gummy smile refused recommended orthognathic surgery. Examination revealed a severe deep bite, excessive gingival display, a Class I molar relationship, and a congenitally missing mandibular right lateral incisor, with all third molars present except the maxillary right third molar.
Treatment
The treatment involved intruding the maxillary anterior teeth using Temporary Anchorage Devices (TADs), creating space for the missing mandibular right lateral incisor, and later prosthetic replacement for the missing mandibular right lateral incisor.
During treatment, the maxillary right central incisor developed grey discoloration, pulp non-responsiveness, and pain, while moderate apical root resorption was noted in the right lateral incisor. Orthodontic forces were removed, and the patient was treated with loxoprofen (60mg, three times daily for seven days), leading to recovery of pulp vitality and resolution of discoloration.
Two years later, the gummy smile and deep bite were corrected, the missing incisor was restored, and four-year follow-up showed stable aesthetics, root canal obliteration in the central incisor, and root remodelling in the lateral incisor.
Discussion
Transient apical breakdown (TAB) during orthodontic treatment is rare, and its mechanism is not fully understood, but it likely involves non-infectious inflammation of the apical pulp caused by reduced blood flow or vascular rupture from orthodontic forces. TAB and apical root resorption may share the same inflammatory pathway, as observed in this patient, and animal studies show similar inflammatory markers that can be reduced with NSAIDs. In this case, removing orthodontic force and administering loxoprofen led to recovery of pulp vitality and crown colour, suggesting that force removal is the primary treatment for TAB, with NSAIDs aiding inflammation control.
Conclusion
This case suggests that TAB and apical root resorption during orthodontic treatment result from periapical inflammation, and both can improve with removal of orthodontic force and NSAID treatment.
Research Summary Written By: Malak Baho, University of Manchester – BDS 4