Total Mouth Periodontitis Score as a Research Tool to Quantify Oral Health in Yucatan Minipigs

Abstract

Introduction: Minipigs are a popular model for many organs in the translational research ecosystem due to their similarities to humans.  Minipigs develop naturally occurring periodontal disease, making them a compelling model in orofacial studies.  However, periodontal disease influences the inflammatory status, the oral and gastrointestinal microbiome, and could impact the results of studies in porcine models. The present study aimed to adapt the canine total mouth periodontitis scoring (TMPS) system for use in Yucatan Minipigs and to compare the TMPS calculated from a full mouth evaluation to a more efficient TMPS QUICKSCORE. 
Materials and methods: Computed tomographic images of the skull were obtained from twenty miniature Yucatan pigs (2-13 years, 65-92kg). All animals underwent an oral exam to assess gingival bleeding and periodontal pocket depth. Tooth root area measurements were obtained from CT images of two young, healthy miniature pigs and were used to calculate a weighting factor for each location; buccal and palatal/lingual for incisors and canines, and mesial buccal, distal buccal, mesial palatal/lingual, and distal palatal/lingual for premolars and molars. Weighting factors were used to calculate the contribution of gingivitis and periodontitis to the overall burden of periodontal disease in the mouth (TMPS FULLSCORE). An abbreviated score utilizing a subset of locations was calculated (TMPS QUICKSCORE). Lin’s concordance correlation coefficient was used to assess concordance between FULLSCORE and QUICKSCORE. Spearman's correlation was used to compare scores with age and clinical parameters.
Results: Clinically younger animals had less severe disease compared to older animals, although gingival bleeding was present in all animals.  The age of the animal was correlated with periodontal pocket depth but not with the degree of gingival bleeding. The extent of periodontal disease was positively correlated with periodontal pocket depth and gingival bleeding.  High concordance between TMPS FULLSCORE and QUICKSCORE was found.
Conclusion: The current TMPS scoring system provided a fast and convenient way to quantify and monitor periodontal disease in Yucatan Minipigs. The TMPS is a helpful metric to describe the level of disease in animals, as advanced periodontal disease has downstream effects that alter findings in many body systems.