Prevalence and some clinical characteristics of equine cheek teeth diastemata in 471 horses examined in a UK first-opinion equine practice (2008 to 2009)

Bacterial Periodontitis in Horses: An Epidemiological Study in Southern Italy

Equine periodontal disease (EPD) is a painful oral inflammatory syndrome characterized by multifactorial pathogenesis. Although it is well known that bacterial proliferation and consequent gingivitis are caused by the decomposition process of food residues, in hypsodont species, the pathogenetic role and the different bacterial species involved in the progression of EPD must be fully clarified. This study aimed to investigate the association of bacteria, including the complex red bacteria (RCB), with EPD, and to evaluate possible EPD risk factors. Bacterial species, including Treponema denticola, Tannerella forsythia, Porphyromonas gingivalis (belonging to the RCB), Fusobacterium nucleatum, Veilonella parvula, and Prevotella intermedia, were investigated in 125 oral swabs from healthy and EPD-affected horses using real-time multiplex PCR. Subsequently, possible risk factors (i.e., age, gender, and breed of the animals and type of feed used) were evaluated using univariate and multivariate analyses. Tannerella spp. and Treponema spp. were detected in a significantly higher proportion of horses affected by EPD than in healthy animals, although pathogens belonging to RCB were detected in low number of horses. At the same time, none of the investigated pathogens was significantly associated with a particular stage of disease severity. Horses aged older than 20 years were at higher risk of EPD. The high rate of coinfection, statistically associated with EPD, supports the hypothesis that EPD is a complex syndrome characterized by the possible simultaneous involvement of several pathogens and an increased risk depending on the animal's age. Constant oral hygiene is the best prevention to prevent and treat the disease, especially in old animals.

Malocclusions and Dental Diseases in Privately Owned Horses in the Mazovia Region of Poland

Dental disorders, a term encompassing both malocclusion and dental disease, constitute a serious health problem in horses worldwide. As horse populations differ among countries and regions, a geographically specific characterization of the occurrence of various dental disorders may be helpful for local equine practitioners. This study investigated the prevalence and frequency distribution of selected malocclusions and dental diseases in horses housed in the Mazovia region of Poland, with attention paid to variations among age, gender, and breed categories. Routine dental examinations were conducted on 206 privately owned horses (n = 206). Disorders were recorded using a dental chart and classified as either malocclusions or dental diseases. Out of all examined horses, 95% demonstrated at least one dental disorder, with a roughly equal distribution of these disorders among incisor teeth (31%) and cheek teeth (31% each for premolars and molars). More specifically, there were disorders noted in 14 incisors, 3 canines, 2 wolf teeth, and 15 cheek teeth. Across all age, gender, and breed groups, malocclusions of incisor, premolar, and molar teeth occurred with a higher prevalence than did dental diseases. Curvatures and calculus were the most commonly reported pathologies in incisor teeth, whereas sharp enamel points and caries predominated in cheek teeth.

Studies on Age-Related Changes in Equine Cheek Teeth Angulation and Dental Drift

Background

Cheek teeth (second through fourth premolars and first through third molars) diastema is a common and painful equine disorder caused by the absence of effective tight interdental contact between these teeth. Limited objective information is available on the angulation of equine cheek teeth that control dental drift or on mesial or distal equine cheek teeth drift that should normally prevent this disorder.

Objectives

To measure the angulation of the mesial and distal cheek teeth in horses of different ages, quantify age-related cheek teeth mesial and distal dental drift, and measure the cheek teeth row length in horses of different ages.

Study Design

Retrospective review of computed tomographic images of equine heads.

Methods

Case details and CT images from clinical equine cases that had undergone standing CT head examination were collated.

Three sets of measurements were acquired from each head. “Head size” calculated as the distance between the caudal aspect of the orbit and the caudal aspect of the naso-incisive notch was used to standardize measurements in different sized heads. The length of the cheek teeth rows measured from the mesial aspect of the Triadan 06 occlusal surface to the distal aspect of the Triadan 11 occlusal surface. The rostro-caudal (antero-posterior) position and angulation of the mandibular and maxillary Triadan 06 and 11 teeth were measured in relation to reference lines drawn on CT images.

Results

Significant mesial drift occurred in the maxillary and mandibular Triadan 11s. Despite their distal angulation, the upper and lower Triadan 06s also drifted mesially. The mean angulation of Triadan 06 and 11 mandibular teeth (17.8 and 26.2°, respectively) was almost double that of maxillary teeth (9.2 and 13.3°, respectively) with both Triadan 11s having greater angulation than the 06s. Cheek teeth angulation only significantly decreased in the mandibular 06s. Cheek teeth arcade lengths decreased with age, but these decreases were not significant.

Main Limitations

Limitations include the relatively small sample size.

Conclusions

In the population of horses used for this study, age related mesial drift occurred in both Triadan 06 and 11s, and the angulation of these teeth did not decrease with age in most arcades.

Tooth Elongation of Maxillary Second Premolars and Mandibular Third Molars and Associated Periodontal Disease in Horses: A Retrospective Study

Periodontal disease has been identified in horses and donkeys through the millennia at a prevalence of up to 75% and is a leading cause of tooth loss in horses. We hypothesize that there is a correlation between tooth elongations and periodontal disease. Dental records of all client owned horses examined by a single AVDC/equine board certified practitioner in 2016-2018 were analyzed. Inclusion criteria consisted of the examination finding of tooth elongation of one of the following teeth pairs 106/107, 206/207, 310/311, or 410-411. The included cases were then examined for the finding of periodontal disease in Stages 1-4 (PD 1-4). Bayesian correlation analysis revealed significant positive correlations of elongations and periodontal disease existed between PD1 and proximal tooth pairs 106-107 and 206-207, PD2 and PD4 with all four tooth pairs, and PD3 with 106-107. Clinically, early diagnosis and treatment of newly formed elongations, or prevention of their formation altogether through diligent dental prophylaxis could prove key in preservation of teeth through prevention of the associated development of periodontal disease in the horse.

Investigation of Oral Microbiome in Donkeys and the Effect of Dental Care on Oral Microbial Composition

The objective of this study was to investigate the oral microbial composition of the donkey and whether basic dental treatment, such as dental floating, would make a difference to the oral microbial environment in donkeys with dental diseases using high-throughput bacterial 16S rRNA gene sequencing. Oral swab samples were collected from 14 donkeys with various dental abnormalities on day 0 (before treatment) and day 20 (twenty days after treatment). It is the first report focusing on the oral microbiome in donkeys with dental diseases and the impact of common dental procedures thereon. Identified in group Day 0 and group Day 20, respectively, were 60,439.6 and 58,579.1 operational taxonomic units (OTUs). Several taxa in Day 0 differed significantly from Day 20 at the phylum and genus levels, but no statistically significant difference was observed in richness and diversity of Day 0 and Day 20. The results also indicated that a larger-scale study focusing on healthy donkey oral microbiome, as well as the correlation of dental diseases and oral microbiomes at different time frames following more specific and consistent dental treatment, are warranted.

The use of the geometric morphometric method to illustrate shape difference in the skulls of different-aged horses

The geometric morphometrics method (GMM) is a technique to study scale and shape relationships of structures using Cartesian geometric coordinates rather than linear, areal (of area), or volumetric variables. GMM has been of great value in many biological studies, but does not appear to have been used to examine equine skulls.

In this exploratory study, twenty-nine normal equine heads of three different age groups: <5 years old (N = 9), 6–15 years old (N = 10) and > 16 years old (N = 10) were examined.

Computed tomography (CT) bone window DICOM images were reconstructed into isosurfaces (3-dimensional contoured surfaces), onto which landmarks were added using Stratovan Checkpoint® software. Data from 29 landmarks were analysed using MorphoJ analysis, which applies a Procrustes fit, prior to reducing data dimensionality through principal component (PC) analysis. PCs with and without allometry were considered. Allometric shape described by PC1 accounted for 27% of variance. Loading pertaining to: the pterygoid process, bilaterally; caudal aspect of hard palate; tip of nasal bone; ethmoid sinuses, bilaterally; caudal aspect of the ventral conchal bulla, bilaterally and caudal aspect of the vomer bone suggest that these anatomical structures are predictive of age group. When allometric effects (shape variation explained by size) were removed, PC1 was unable to distinguish horses by age group. Allometric shape differences could distinguish the youngest versus the two older age groups. The potential applications of GMM in equine diagnostic imaging are wide ranging and include the investigation of changes in the equine skull with respect to genetics and characterisation of conformation-related diseases affecting the teeth, jaws and sinonasal compartments.

Dental disease in alpacas. Part 1: Prevalence of dental disorders and their mutual relationships

BACKGROUND

Dental disease is a troublesome health concern in alpacas. Specifically, the occurrence of tooth root abscesses has been described in veterinary literature. Nevertheless, no objective prevalence data are available for dental disorders in alpacas.

HYPOTHESIS/OBJECTIVES

To determine the prevalence of dental disorders in alpaca herds in Belgium and the Netherlands. To study the associations between the different dental disorders encountered in alpacas.

ANIMALS

A total of 228 alpacas (Vicugna pacos) originating from 25 farms.

METHODS

This is a cross-sectional study. Dental disorders were diagnosed by dental examination of sedated animals using a dental mirror or a portable rigid oroscope.

RESULTS

At the animal level, 82% (n = 187) had dental disorders of which 74.6, 41.7, and 3.9% were cheek teeth, incisor disorders, and canine disorders, respectively. At the level of the cheek teeth, diastemata (43.1%) were most common, followed by wear abnormalities (WA; 39.6%) and periodontal disease (PD; 33.3%). A significant association was detected between the presence of diastemata and PD (odds ratio [OR], 13.1; 95% confidence interval [CI], 6.6-27.7; P < .001). Pulp exposure was significantly associated with the presence of diastemata (OR, 11.8; 95% CI, 3.8-51.5; P < .001), PD (OR, 8.2; 95% CI, 3.1-25.3; P < .001) and WA (OR, 2.9; 95% CI, 1.2-7.4; P = .002).

CONCLUSION AND CLINICAL IMPORTANCE

Dental disorders are highly prevalent in alpacas in Belgium and the Netherlands. Several dental disorders in alpacas had significant associations. To prevent the development of advanced stages of dental disease, routine dental examinations are advised to allow early detection and prompt treatment.

Dental disease in alpacas. Part 2: Risk factors associated with diastemata, periodontitis, occlusal pulp exposure, wear abnormalities, and malpositioned teeth

Background

Dental disorders, of which tooth root abscesses are best documented, are highly prevalent in alpacas. Identification of risk factors can be valuable for prevention of dental disorders in this species.

Hypothesis/Objectives

To identify risk factors associated with wear abnormalities, malpositioning, diastemata, periodontal disease (PD), and occlusal pulp exposure at the level of the cheek teeth.

Animals

Two hundred twenty‐eight alpacas (Vicugna pacos) from 25 farms.

Methods

Cross‐sectional study. Dental examinations were performed on sedated animals. Risk factors were determined by clinical examination and interview. Multivariable logistic regression was used to identify risk factors for wear abnormalities, malpositioned teeth, diastemata, PD, and occlusal pulp exposure.

Results

Mandibular swelling was significantly associated with PD (odds ratio [OR], 11.37; 95% confidence interval [CI], 3.27‐48.81; P < .001). Nearly 73% of included animals with mandibular swelling concurrently had PD. For every increase in herd size of 1 animal, the risk for PD increased by 2% (95% CI, 1‐4%; P = .01). The association between severe stages of PD and body condition score (BCS) indicates a painful situation, impairing animal welfare (P < .001). For each 1‐day increase in interval between pasture cleanings, the odds of finding pulp exposure for a single animal was estimated to increase by 1% (95% CI, 0‐2%; P = .05).

Conclusion and Clinical Importance

Simple management tools such as measuring BCS, palpating the mandible for bony swellings, removing feces from pasture on a regular basis and decreasing herd size might help identify animals at risk for dental disorders or prevent their development.

The Equine Gingiva: A Gross Anatomical Evaluation

Equine periodontal disease (ePD) usually starts with food impaction, formation of diastemata, gingival inflammation and formation of periodontal pockets. This process proceeds toward the dentoalveolar space, causing detachment of tooth supporting periodontal fibers. Although several therapeutical procedures have been proposed, ePD is often only diagnosed in advanced stages, requiring dental extraction. A similar dilemma has been observed in small animal medicine, but has been overcome by the introduction of reliable examination protocols for the early diagnosis of periodontal diseases (PD). These protocols are based on detailed anatomical descriptions of healthy gingiva, allowing for the determination of the pathognomonic signs of the onset of PD and providing a basis for grading systems and treatment plans. Consequently, proposals have also been made for periodontal examination protocols in horses. However, these protocols were widely adopted from small animal medicine assuming a similar anatomy of the equine and canine gingiva. To provide a solid anatomical basis for equine specific periodontal examinations, 20 equine heads were examined macroscopically, with special attention to the gingival sulcus, the gingival margin and the interdental papillae. Constant morphological patterns of the gingival margin and the interdental papillae were found for the vestibular and lingual/palatal aspects of the upper and lower cheek teeth arcades, as well as for the incisor arcades. A gingival sulcus measuring greater than 1 mm was present in only 6% of the investigated specimens. The inspection of the gingival margin and the interdental papillae, as well as the recognition of a gingival sulcus, may serve as criteria to establish equine specific periodontal investigation protocols.

Prevalence and analysis of equine periodontal disease, diastemata and peripheral caries in a first-opinion horse population in the UK

Equine dental disease remains a widespread affliction in domestic horses, with the potential to cause significant welfare problems. This retrospective study aimed to increase understanding of this aspect of equine health by examining dental records of 932 horses, taken from a 1-year period of first-opinion practice in south-western England and southern Wales. Three grossly-identifiable dental diseases were analysed: equine periodontal disease, diastemata and peripheral caries. The prevalence of active periodontal disease, diastemata and peripheral caries were 13.9%, 8.7% and 8.2%, respectively. Periodontal disease was more common in the mandibular than maxillary arcades (P<0.001) and in the premolar (06-08) than molar (09-11) cheek teeth (P<0.001). Diastemata were also observed more frequently in the mandibular than the maxillary arcades (P<0.001) and in premolar than molar cheek teeth (P<0.001). Peripheral caries were significantly more common in molar than premolar cheek teeth (P<0.001). A positive association was demonstrated between periodontal disease and diastemata (Exp(B)=4.22; P<0.001). Increasing age was a significant risk factor for periodontal disease (P<0.001) and diastemata (P<0.001). Sex was not conclusively established as a risk factor for any dental disease.

A new understanding of oral and dental pathology of the equine cheek teeth

Equine dental disease has a high prevalence. Because of developmental, functional, and anatomic differences, limited inference can be made from brachydont dental pathology to that of equine cheek teeth. This article reviews the pathology of equine cheek teeth and their associated oral tissues, with specific information on periodontitis, pulpitis, maxillary infundibular changes, dental fractures, dental overgrowths, mucosal ulceration, and the regenerative capacity of equine teeth.

A long-term study on the clinical effects of mechanical widening of cheek teeth diastemata for treatment of periodontitis in 202 horses (2008-2011)

REASON FOR PERFORMING STUDY

Cheek teeth diastemata are a common cause of painful periodontal disease in horses, but there is limited objective information on their treatment.

OBJECTIVE

To assess the long-term response to diastema widening in clinically affected horses.

STUDY DESIGN

Retrospective study.

METHOD

Medical records from cases of cheek teeth diastemata treated by diastema widening referred to the University of Edinburgh Equine Hospital from 2008 to 2011 were analysed.

RESULTS

During this period, 302 horses were diagnosed with clinically significant cheek teeth diastemata, of which 202, median age 11 years, with severe associated periodontitis were treated by widening of 674 problematic diastemata; 89.8% between mandibular cheek teeth and 10.2% between maxillary cheek teeth, with a mean of 1.5 treatments performed per case. These 202 cases showed quidding in 76.2%; weight loss in 33.2%; bitting problems in 20.1% and halitosis in 10.9%, with 5.4% being asymptomatic. Follow-up of 92% of treated cases, a mean of 20.8 months after their initial treatment, showed that 72.6% had complete remission of clinical signs that was permanent (for the duration of this study) in 50.5% and temporary in 22%. A partial response was obtained in 17.2%, no response was obtained in 4.3%, and owners were unsure of response in 5.9%. Clinical improvement was sometimes delayed, with 19% taking >4 weeks following treatment for improvement. Inappropriate sites were burred in individual teeth of 6 horses, causing iatrogenic pulpar exposure in 2 cases, but following treatment none developed clinical signs of apical infection.

CONCLUSIONS

Diastema widening is an effective but potentially invasive treatment for horses with cheek teeth diastemata with severe periodontitis.

POTENTIAL RELEVANCE

Diastema widening by trained personnel is suitable for advanced cases of cheek teeth diastema, but many cases require repeated treatments.