Prevalence and etiology of dentoalveolar trauma in 1,592 United States military working dogs: A 1-year retrospective study

Abstract

The objective of this study was to quantify the overall prevalence and classification of traumatic dentoalveolar injury (TDI) in a large population of military working dogs (MWDs). The medical records of 1,592 MWDs undergoing routine oral exam and periodontal treatment over a 1-year period were reviewed. The MWDs were located at over 100 military veterinary treatment facilities across the globe. Patient signalment, occupational duty certification, tooth injured, and trauma etiology were recorded. The overall prevalence of TDI was 43.6%. The mean number of TDI per MWD was 1.2. Maxillary tooth fractures were the most common at 60.9% compared to mandibular tooth fractures 39.1%. The most common TDI was enamel-dentin-pulp fractures which accounted for 59.9% of all injuries. Specialized Search Dogs (SSDs) had the highest average of enamel-dentin and enamel-dentin-pulp tooth trauma. Incidental findings with an unknown cause accounted for the majority of tooth trauma 69.2% followed by housing 18.2%, bite work 6.2%, and blunt force trauma 6.0%. The frequency of TDI in the MWD population was substantial, with more than one out of every four MWDs requiring treatment. The probability of a tooth injury in the MWD population was nearly double compared to the pet dog population. Tooth type and age were significant predictors of severe tooth trauma requiring treatment. Improved understanding of MWD tooth trauma prevalence and risk factors will help drive change while maintaining deployment readiness of the team.

Keywords: canine; dentistry; fracture; military; tooth; veterinary; working dog.

Figure 1

Fracture classification (enamel-dentin-pulp and enamel-dentin) percent by total tooth count and by total MWD population count.

Figure 2

Graphical projection of the association between age in months and the percentage of TDI. Note that the enamel-dentin fractures were highest in the 24–48-month MWDs and the enamel-dentin-pulp fractures were highest in the 72 month and older MWDs. There was statistical significance between enamel-dentin-pulp fractures and age (P ≤ 0.0001).

Figure 3

Graphical projection of TDI count and the tooth type. Note that the incisor teeth had the highest incidence of enamel-dentin-pulp fractures, and the canine teeth had the highest incidence of enamel-dentin fractures. The incisor and canine teeth had a significant risk of enamel-dentin-pulp fractures (P = 0.008).

Figure 4

Graphical description of the decreasing frequency of TDI and the occurrence of enamel-dentin-pulp fractures and enamel-dentin fractures in individual teeth.

Figure 5

Clinical photographs of the most injured teeth with enamel-dentin-pulp fractures were the right maxillary second incisor tooth, the left maxillary second incisor tooth (A), the right maxillary canine tooth, and the left maxillary canine tooth (B).

Figure 6

Graphical description of TDI and MWD certification. P/EDD (Patrol/Explosive Detection Dog), EDD (Explosive Detection Dog), Untrained (not certified), DDD (Drug Detection Dog), MDD (Mine Detection Dog), Patrol, SSD (Specialized Search Dog), P/DDD (Patrol/Drug Detection Dog). There was no statistical significance between MWD certification and enamel-dentin-pulp fractures.

Figure 7

Graphical projection of average TDI and combined certification by patrol function. Note that both patrol and non-patrol MWDs had a higher frequency of enamel-dentin-pulp fractures vs. enamel-dentin fractures. There was no statistical significance between patrol function and increased risk of enamel-dentin-pulp fractures.

Figure 8

Distribution of trauma etiology. Note that unknown cause accounted for the largest proportion of trauma etiologies.

Figure 9

Clinical photographs demonstrating an enamel-dentin fracture on the maxillary third incisor (A) and enamel-dentin fracture on the right and left mandibular first incisors (B).

Figure 10

Clinical photos of extrinsic metallic staining (A) and enamel infractions (B).

Figure 11

Clinical photographs demonstrating severe distal abrasion on canine teeth (A–C) and occlusal abrasion on maxillary pre-molar and molar teeth (D).

Figure 12

Clinical photographs of trauma to the distal surface of canine teeth leading to catastrophic oblique crown fractures with propagation in the distal-mesial direction (A, B).

Figure 13

Clinical photographs demonstrating significant trauma to the distal surface of the lower mandibular canines (A) with crown shortening, endodontic therapy, and prosthodontic crown preparation (B). Crown delivery of the lower mandibular canines (C) and crown delivery of both the maxillary and mandibular canines in a young MWD to preserve a functional occlusion (D).