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

## TL;DR

This study compares radiography and CT for detecting dental infections in alpacas, finding that CT identifies more abnormalities and is a better diagnostic tool.

## Contribution

The study provides the first direct comparison of radiography and CT for diagnosing periapical infections in alpacas.

## Key findings

- CT identified more dental abnormalities than radiography in alpaca cheek teeth.
- Agreement between the two modalities was weak or absent for several diagnostic features.
- CT's superior spatial resolution allows detection of subtle changes not visible on radiographs.

## Abstract

Alpacas are gaining popularity in Europe, where they are kept as pets or wool-producing animals. Their increase in number brought a new diagnostic challenge for veterinarians. Specifically, these animals are commonly affected by dental infections. The initial suspicion of dental infection is normally raised upon oral examination; however, diagnostic imaging is needed to further evaluate the portion of the dental elements that cannot be assessed upon oral examination. The imaging modalities that are commonly used for this purpose are radiography and computed tomography (CT). This study aims to compare the ability of these two modalities to detect dental infections. Overall, CT identified more dental abnormalities than radiography, highlighting its value as a complementary diagnostic tool for detecting periapical infections in alpaca cheek teeth.

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.