Comparison of Micro-Computed Tomography and Digital Intraoral Radiography to Determine the Accuracy of Digital Radiographic Measurements of Mandibular Molar Teeth in Dogs.

INTRODUCTION: The purpose of this study was to compare root and root canal width measurements between digital intraoral radiography (IOR) and micro-computed tomography (µCT). The accuracy of IOR measurements of canine mandibular molars was scrutinized to assess feasibility of developing a model to estimate animal age based on dentinal thickness. MATERIALS AND METHODS: Thirty-nine canine mandibular first molars were imaged using µCT and IOR. For each tooth, the root and root canal width of the mesial and distal roots were measured by a single observer at 3 marked sites on µCT and IOR. Two different software programs were used to measure the radiographs. The radiograph measurements were compared to each other and to the µCT measurements. The µCT images were considered the anatomic reference standard for structural representation. RESULTS: The data collected demonstrated IOR bias and variability throughout all measurement sites, with some sites being more affected than others. Neither IOR system produced unbiased measurements that closely reflected the µCT measurements consistently. The overall lack of agreement between measurements demonstrated the difficulties in developing a standardized protocol for measuring root and root canal width for the first molar teeth in dogs. CONCLUSION: Developing a protocol to accurately measure and compare µCT and IOR measurements is challenging. Designing a measurement system that would allow for universal application to age dogs would require continued research utilizing a standardized approach to overcome the limitations identified in this article.

Evaluation of Gingivitis in Pregnant Beagle Dogs.

Periodontal disease (PD) in pregnant women has been correlated with negative impacts on pregnancy outcomes including low birth weight, preterm labor, and increased neonatal mortality. This study aimed to explore similar associations in dogs. Medical, dental, and reproductive records of healthy female beagles producing one or more litters within a research breeding facility were evaluated over a 1.5-year period. Dental scoring (1-6) was based on a facility-developed, subjective assessment of gingivitis and calculus deposition following parturition. Assessment of periodontitis was not performed. Statistical analyses were performed to find correlations between the dam's dental score and pregnancy outcomes (length of gestation, litter size, stillborn, and failure to thrive puppies). Dam age, litter size, and perinatal mortalities were controlled in the statistical models. Data were collected from 808 dams, 1344 litters, and 7197 puppies; 75.3% of the 1344 dam scores were categorized as dental score 3 or less with a mean of 2.7. None of the evaluated pregnancy outcomes had any significant correlations with the severity of dental scores. The lack of a significant relationship between dental score and pregnancy outcomes may be the result of the low number of dogs with severe gingivitis and calculus deposition, the variability of dental score timing postparturition, and/or the subjective facility-generated dental scoring method that did not include universally accepted methods for gingivitis and periodontitis assessment. Studies involving more animals with severe PD utilizing objective, universally accepted methods for gingivitis and periodontitis assessment are warranted to say with confidence no association exists.

Radiographic evaluation and comparison of the patellar ligament following tibial plateau leveling osteotomy and tibial tuberosity advancement in dogs: 106 cases (2009-2012).

OBJECTIVE To radiographically evaluate and compare changes in the patellar ligament of dogs following tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA). DESIGN Retrospective case series. ANIMALS 106 dogs that underwent TPLO (n = 59) or TTA (n = 47) for unilateral rupture of the cranial cruciate ligament at a private veterinary hospital from August 2009 through September 2012. PROCEDURES Medical records were reviewed to collect information on dog signalment, surgical procedure, whether arthrotomy had been performed, pre- and postoperative measurements of patellar ligament angle (PLA) and tibial plateau angle (TPA), and preoperative and follow-up measurements of patellar ligament thickness. RESULTS For dogs that underwent TTA, thickening of the distal portion of the patellar ligament was identified radiographically in 43 (92%) dogs at the first follow-up examination and 36 (77%) at the second follow-up examination. For dogs that underwent TPLO, these numbers were 57 (97%) and 54 (92%), respectively. A significant decrease in patellar ligament thickness was identified between the first and second follow-up examinations for TTA but not TPLO. Mean ± SD PLA following TTA was 89.46 ± 5.54°, representing a mean difference from the preoperative PLA of 11.86 ± 5.3°; following TPLO, mean TPA was 12.61 ± 4.03°, representing a mean difference from the preoperative TPA of 16.74 ± 7.13°. CONCLUSIONS AND CLINICAL RELEVANCE Patellar ligament thickening occurred following TPLO and TTA in dogs. The clinical relevance of this thickening remains unknown.