Pathological studies of cheek teeth apical infections in the horse: 4. Aetiopathological findings in 41 apically infected mandibular cheek teeth.

This research article examined and analzyed 41 apically infected mandibular cheek teeth in horses to understand the causes and pathological changes. The study found that some teeth showed signs of recent infection while others displayed more advanced stages. Distinct types of damage patterns indicated possible routes of infection, however, in more than half of the cases, a physical path of infection could not be identified.

Methods and Sample

• The study involves examining 41 apically infected cheek teeth (CT) extracted from horses. This specific type of tooth was chosen due to the absence of any obvious causes of infection.
• The researchers used various methods including radiography, computerized axial tomography, and histology (both decalcified and undecalcified) to examine the samples. These techniques were chosen to extensively visualize the structural and pathological alterations in the infected teeth.

Findings

• In the cheek teeth with recent infections, parts of the pulp remained healthy, indicating that the infection was in an initial stage. In these samples, both soft tissues and calcified tissues had proliferative changes limited only to the apex of the tooth.
• Samples with more advanced infections exhibited a broad range of tissue damage including exposure of occlusal pulpar, filling of infected pulp chambers with dead pulp or food particles, and extensive changes in the calcified apical tissues. About 34% of the 41 CT samples exhibited this degree of infection.
• In 59% percent of the samples (24 CT), no identifiable route for infection to reach the apex of the tooth was found. These samples were believed to have infections that originated from within the tooth, referred to as anachoretic infections.

Different Causes of Infection

• Fractures involving the pulp were found in eight teeth (20% of the CT), including those that created fissure fractures between the clinical crown and infected pulps. These fractures could serve as a conduit for bacterial invasion, leading to infection.
• Vertical, full-length periodontal destruction was noted between the infected apex and the gingival margin in some teeth samples. This was believed to be the route of infection in four CT (approximately 19%).
• In a single case (2% of the CT), dysplastic changes or abnormal growth and development of tissues were assumed to be the cause of infection.