Horizontal Root Fracture

• •Recent trauma to the front teeth — a fall, sports hit, fight, or motor-vehicle accident — followed by mobility of the tooth.
• •The tooth feels loose, sits at a slightly different height than its neighbors, or is displaced backward.
• •Bleeding from the gum around the tooth shortly after the injury.
• •Discoloration of the crown days or weeks later (gray, pink, or yellow) as the pulp responds to the injury.
• •A horizontal line visible on a periapical X-ray, sometimes only seen on a second-angle (off-axis) image.

Direct trauma is the cause in essentially every case — sports impacts, falls, bicycle and skateboard accidents, vehicle accidents, and assaults. Upper central incisors are by far the most commonly affected because of their exposed position. Adolescents and young adults are the highest-risk group.

A horizontal fracture often does not show clearly on a single straight-on X-ray; the standard of care is to take two or three angled periapical films and a J. Morita Veraview X800 CBCT scan in Endo Mode (80 µm voxel, 40 × 40 mm limited field of view) — the small-volume protocol the AAE/AAOMR Joint Position Statement on the Use of CBCT in Endodontics recommends for trauma cases. Pulp vitality testing is performed at the initial visit and repeated over months because the pulp's response after trauma can be delayed.

If the fracture is in the apical third (near the root tip), the tooth is usually splinted for 4 weeks and the pulp is monitored — many of these heal with calcified or connective-tissue union and never need a root canal. Fractures in the middle third generally require splinting plus root canal therapy of the coronal segment if the pulp becomes necrotic. Fractures in the cervical third (near the gumline) carry the poorest prognosis and may require extraction, decoronation, or orthodontic extrusion. The treatment framework follows the International Association of Dental Traumatology (IADT) guidelines and the AAE Treatment Options for the Compromised Tooth decision guide.