A Comparative Study of Radiography and Computed Tomography in Detecting Periapical Infections in Alpacas (Vicugna pacos)

Alpacas are frequently affected by dental pathologies, with periapical infection of the cheek teeth being a significant concern. While radiography is commonly used as the primary diagnostic imaging modality, it has known limitations, particularly due to anatomical superimposition. Computed tomography (CT), with its superior spatial resolution, allows for more detailed evaluation and can detect early or subtle changes that may not be visible on radiographs. To date, direct empirical comparisons between radiography and CT in diagnosing apical infections in alpacas have not been documented. In this study, 158 teeth from 19 alpacas were assessed using both radiography and CT, evaluating 16 diagnostic parameters. Inter-modality agreement demonstrated variable consistency across assessed features: No agreement was observed for certain findings such as pulpar changes and the presence of cementomas. Agreement was weak for features including periodontal ligament space widening, periapical halo, lamina dura visibility, root lysis and fragmentation, sequestration, cortical destruction, clinical crown fractures, and the overall impression of periapical infection. Moderate agreement was found for radicular changes, periapical sclerosis, periosteal reaction, mandibular expansion, and alveolar bone alterations. Overall, CT identified more dental abnormalities than radiography, highlighting its value as a complementary diagnostic tool for detecting periapical infections in alpaca cheek teeth.