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Accessory canals and apical deltas have been extensively studied in human dentistry. Their clinical role as a difficult to clean reservoir for bacteria during endodontic treatments has been well described. Many papers describe in detail the pulp anatomy of equine dentition but little attention has been given to their apical ramifications. The goal of this paper is to describe the presence and anatomy of these accessory canals and apical deltas in healthy equine cheek teeth and discuss their possible relevance in the light of equine endodontics. To accomplish this, 15 maxillary and 19 mandibular healthy cheek teeth were collected ranging from Triadan 06 s to 11 s with eruption ages from 4 to 9 years. Their root anatomy was documented in detail based on micro computed tomography images. A subset of 3 teeth also underwent histological examination. Accessory canals were found in all but two teeth examined. Up to 44 accessory canals per tooth have been found with locations ranging from the root furcation down to the apex of the root and with highly variable diameters. Apical deltas in different stages of development were found in 84% of the roots. The presence of accessory canals identified on microCT images could be confirmed using histological examination although some of them were obliterated by reparative dentin. Accessory canals can be found in most equine cheek teeth and add complexity to their endodontic anatomy. This could have important implications for their treatment in case of pulp pathology. In humans, failure to remove bacterial biofilm from such canals has been associated with failure of endodontic treatment. Research on diseased equine teeth is required to gain a better understanding of their clinical relevance in horses.

The objectives of this retrospective study were to describe cheek teeth extraction by the sectioning technique, the decision making to use this technique and its potentially associated complications. Sectioning for dental extraction purpose was used in 29/461 (6.3%) of cases. Oro-sinusal fistula was the main post-operative complication, with 4/29 (13.7%) cases developing a macroscopic communication between the alveolus of the tooth extracted and the adjacent sinus compartment. All teeth where sectioning was attempted were successfully extracted. Sectioning for dental extraction appears to be a safe technique that can be used instead of or in addition too other minimal invasive cheek teeth extraction techniques. Thorough preoperative planning including oroscopic examination and medical imaging modalities are required to help in decision making, as well as excellent sedation and analgesia and horse compliance.

Scientific literature on veterinary dentistry in alpacas has historically focused on the description of tooth root abscesses. However, recent studies have shown a variety of other, sometimes preceding dental conditions to be widespread in this species. To allow the development and finetuning of treatment strategies in this species, a more thorough understanding of the underlying etiopathogenesis of dental disease is required. Histological studies focusing on normal dental and surrounding tissues might serve as a basis for this purpose. Nine teeth, extracted from seven alpacas were collected. All samples were retrieved from animals that died or were euthanized for non-dental reasons. Histological sections were prepared at three different levels in each tooth and examined using light microscopy focusing on the assessment of pulp tissue, dentin, cementum, periodontal tissues and the apical region. The histological appearance of the investigated dental tissues in alpacas showed great similarities with other hypsodont species. However, a rather rare type of dentin called “vasodentin” could be identified in all examined cheek teeth. Another species-specific finding was the extremely close proximity of varying neighboring tooth roots that seemed to be responsible for inducing massive resorptive lesions. The results of this study might contribute to a better understanding of the etiopathogenesis of some dental diseases in the alpaca.

BackgroundOral health in alpacas is often neglected until severe dental disease becomes evident under the form of a pronounced mandibular swelling with or without fistulation. Mandibular thickness measurements might serve as an easy tool to screen for early increases in thickness thereby identifying alpacas which could benefit from an oral examination.ObjectiveTo study specific risk factors, including age, gender, level of performed measurements and dental disorders, associated with mandibular thickness in alpacas. To determine suitable cutoff values for mandibular thickness at specific locations for the development of a diagnostic test to identify animals with dental disorders.Study designCross-sectional study.MethodsMandibular thickness was measured at standardized locations in 216 alpacas using a Vernier caliper. Risk factors for an increased mandibular thickness were collected through oral examination in sedated animals and by interview of the respective owner. A multivariable linear mixed model was built to identify factors associated with mandibular thickness. Cutoff values for specific dental disorders were obtained after receiver operating characteristics (ROC)-curve analysis.ResultsMandibular thickness was 0.43 ± Standard Error 0.21 mm [95% Confidence interval (CI) = 0.02-0.84 mm] higher at locations where interproximal gum recession was present (P = 0.039). Severe dental disease caused an increase in thickness of 1.90 mm (95% CI= 1.29-2.51 mm) (P < 0.001). Mandibular thickness with a cutoff of 19.4 mm showed a high accuracy for predicting severe dental disease (Se = 0.41; Sp = 0.92). Specifically, thickness at a level perpendicular to the medial canthus of the eye proved a more precise predictor for severe dental disease (AUC, 0.85; 95% CI 0.74-0.96; P < 0.001) with a lower cutoff of 18.5 mm and Sn and Sp of 0.52 and 0.82, respectively.Main limitationsNo radiographic or computed tomographic studies were available to support the diagnosis of dental and/or apical disease.ConclusionMandibular thickness measurements in alpacas can aid early detection of animals in need of specialized dental care. Most animals with an increased mandibular thickness suffer from advanced dental disease. However, routine dental examinations remain necessary to allow the early detection of dental disorders in alpacas.

Background:Ex vivo fracture models are frequently used in human dentistry to provide insights in the fracture mechanisms of teeth. Equine cheek teeth fractures are an important dental pathology, but there has been no research performed to examine the fracture resistance ex vivo.Objective: To evaluate the fracture resistance of equine cheek teeth and identify anatomical predictors that might influence fracture resistance in healthy teeth. It was further evaluated if the presence of a fissure caused a decrease in fracture resistance.Study design:Ex vivo experimental design.Methods: Individual cheek teeth were subjected to a compression load in a universal testing machine until fracture occurred. Testing was performed in two study groups. A first group of healthy cheek teeth was tested to examine anatomical predictors on fracture resistance. A second group comprised cheek teeth with occlusal fissures and an equal number of age- and size-matched fissure-free teeth as controls. The effect of possible predictors on fracture resistance was investigated by regression analysis.Results: In the first group, fracture resistance was significantly influenced by the location on the tooth where testing was performed in both maxillary (p < 0.001) and mandibular teeth (p < 0.001). Additional significantly associated factors were Triadan number in mandibular (p = 0.009) and the mesiodistal length of the occlusal surface of maxillary teeth (p = 0.01). Experimentally induced crown fractures that extended below the simulated bone level were more frequently associated with pulp horn exposure (p < 0.001). In the second group, significant lower fracture loads were recorded in teeth with fissures (mandibular p = 0.006; maxillary p < 0.001), compared to fissure-free teeth.Main limitations: This ex vivo model does not imitate the in vivo masticatory forces and lacks the shock-absorbing properties of the periodontal ligament.Conclusions: The methodology used in this study provides an ex vivo experimental set-up to test fracture resistance of equine cheek teeth enabling evidence-based research to examine the potentially weakening effects of tooth pathology and its treatments. Crown resistance to fracture differed along the occlusal surface of healthy equine cheek teeth, and the presence of fissures further decreased fracture resistance.

Idiopathic sino-nasal obstruction resulting in retention of large amounts of liquid in the paranasal sinus compartments was diagnosed in seven young (2. 2 ± 0.7 years) miniature-breed horses based on clinical, endoscopic, radiographic, and CT scan examinations. The most prevalent clinical signs included decreased or no airflow from the nostril(s) (7/7) and nasal discharge (6/7). The problem presented bilaterally in six of seven cases. An alternative sino-nasal communication was created through bone flap osteotomy surgery and perforation of the ventromedial floor of the dorsal conchae in all cases, followed by fixation of silicone irrigation tubes/Foley catheters in six of seven cases to keep the newly created ostium patent. This resulted in long-term resolution of the problem with good cosmetic appearance in all animals following a median period of 19 months. Premature loss of fixed tubes was reported in three cases.

Background: It has been suggested that fissures of the occlusal surface of equine cheek teeth may develop into crown fractures.Objectives: To examine the evolution of fissures present on the occlusal surface of cheek teeth. Furthermore, to investigate the presence of a fissure as a risk factor for the development of a subsequent crown fracture.Study Design: Observational longitudinal study.Methods: Bi-annual dental examinations were performed on 36 horses for 3 years. Video-recordings were made to evaluate the evolution of detected fissures. The effect of possible predictors on the development of tooth fractures was investigated by regression analysis.Results: The evolution of 785 fissures (467 type 1a, 271 type 1b, 47 type 2) was recorded. Fissure characteristics were observed to remain unchanged, disappear, become longer, shorter, change in configuration or change in color. Partial crown fractures (22 maxillary, 50 mandibular) were recorded in 52 cheek teeth in 22/36 horses. Fifty-nine of these fractures evolved from previously observed fissures (24 type 1a, 29 type 1b, 6 type 2). All fissure types proved to be a significant risk factor for the development of a crown fracture (p < 0.001), with the highest odds for type 2 fissures (OR = 14.27; 95% CI = 4.88–41.71). Other significant risk factors were the time of follow-up (p < 0.001), mandibular teeth (p < 0.001) and the lingual side of a tooth (p < 0.001). All fractures were non-complicated.Main Limitations: Some horses were prematurely lost for follow-up, which perhaps influenced the results. A longer follow-up period would have also allowed an evaluation of the risk for pulp disease on the long term subsequent to partial crown fractures.Conclusions: The presence of a fissure of any type, mandibular cheek teeth, the lingual side of cheek teeth, and time of follow-up proved to be significant risk factors for development of a cheek tooth crown fracture. Type 2 fissures showed the highest odds followed by type 1b fissures. The observed partial crown fractures demonstrated a low clinical impact whereby no tooth showed signs of development of endodontal disease.