Intrusion - Diagnostic signs

Description Displacement of the tooth into the alveolar bone. This injury is accompanied by comminution or fracture of the alveolar socket.

The tooth can be impinging upon the permanent tooth germ.
Visual signs The tooth is displaced axially into the alveolar bone and frequently penetrating the labial bone plate where it can be palpated. The tooth may disappear completely in the tissues resembling avulsion and root fracture with complete extrusion of the coronal fragment. In this case diagnosis is based on an occlusal radiograph.

Penetration of the tooth into the nasal cavity can be diagnosed by bleeding from the nose or simple observation of the nostril.
Percussion test The test will usually give a high metallic (ankylotic) sound. However in severe intrusion cases the test will not always be possible to perform.
Mobility test The tooth is non-mobile.
Sensibility test Not reliable in primary teeth. Inconsistent results.
Radiographic findings When the apex is displaced toward or through the labial bone plate the apical tip can be visualized and appears shorter than the unaffected contralateral tooth.

When the apex is displaced toward the permanent tooth germ, the apical tip cannot be visualized and the tooth appears elongated.
Radiographs recommended  An occlusal or periapical exposure will normally show the position of the displaced tooth and its relation to the permanent successor. If the tooth is totally intruded an extra-oral lateral exposure may be indicated to make sure that the tooth has not penetrated the nasal cavity.

Dental Trauma Guide 2010 - produced in cooperation with the Resource Centre for Rare Oral Diseases and Department of Oral and Maxillo-Facial Surgery
at the University Hospital of Copenhagen - Last edited the 07-01-2014.