Opportunities for targeted therapies: trametinib as a therapeutic approach to canine oral squamous cell carcinomas

Oral tumors are relatively common in dogs, and canine oral squamous cell carcinoma (COSCC) is the most prevalent oral malignancy of epithelial origin. COSCC is locally aggressive with up to 20% of patients showing regional or distant metastasis at the time of diagnosis. The treatment of choice most typically involves wide surgical excision. Although long-term remission is possible, treatments are associated with significant morbidity and can negatively impact functionality and quality of life. OSCCs have significant upregulation of the RAS-RAF-MEK-MAPK signaling axis, and we had previously hypothesized that small-molecule inhibitors that target RAS signaling might effectively inhibit tumor growth and progression. Here, we demonstrate that the MEK inhibitor trametinib, an FDA-approved drug for human cancers, significantly blocks the growth of several COSCC cell lines established from current patient tumor samples. We further show clinical evidence that the drug is able to cause significant tumor regression in some patients with spontaneously occurring COSCC. Given the limited treatment options available and the high rate of owner rejection of these offered options, these findings provide new hope that more acceptable treatment options may soon enter the veterinary clinic.

Morphological study of pulp cavity anatomy of canine teeth in domestic cats using micro-computed tomography

An understanding of the pulp cavity anatomy of individual teeth is essential for success during endodontic therapy. The objective of this study was to document pulp cavity anatomy and summarize numerical data of maxillary and mandibular canine teeth of domestic cats using micro-computed tomography (micro-CT). Thirty-nine canine teeth from eleven domestic cat cadaveric specimens were extracted and prepared for scanning. Segmentation of the pulp cavity was performed using the Avizo (v2022.2) software package. The morphological features of the pulp cavity including overall shape, configuration, presence of apical deltas and lateral canals was recorded. A quantitative analysis was performed on thirty-one teeth to explore associations between pulp cavity volume and length, apical delta length, maximum apical delta foramina number and cusp-to-tip length using a linear mixed model. Correlation between pertinent continuous variables was assessed using a Pearson's correlation test. Most pulp cavities exhibited varying curvature and ranged from a cylindrical configuration in the coronal third to an ovoid configuration in the middle to apical third. A ribbon-like flattened canal was observed in 6/31 teeth (19%). All canine teeth depicted an apical delta with various configurations except for two teeth that showed a single canal exiting at the apex. In 15/31 teeth (48%), the primary root canal within the apical delta could be clearly identified and in 16/31 (52%) the primary root canal was indiscernible. The results showed that the pulp cavities of maxillary canine teeth were significantly larger and longer and the cusp-to-tip length was longer, when compared to mandibular teeth. The apical delta length was negatively correlated to the volume of the pulp cavity. No specimens depicted lateral canals. This study revealed that the anatomy of the canine tooth pulp cavity in cats can vary considerably and should be a consideration when performing thorough debridement, shaping and obturation of the endodontic system.

Trends of regenerative tissue engineering for oral and maxillofacial reconstruction in veterinary medicine

Oral and maxillofacial (OMF) defects are not limited to humans and are often encountered in other species. Reconstructing significant tissue defects requires an excellent strategy for efficient and cost-effective treatment. In this regard, tissue engineering comprising stem cells, scaffolds, and signaling molecules is emerging as an innovative approach to treating OMF defects in veterinary patients. This review presents a comprehensive overview of OMF defects and tissue engineering principles to establish proper treatment and achieve both hard and soft tissue regeneration in veterinary practice. Moreover, bench-to-bedside future opportunities and challenges of tissue engineering usage are also addressed in this literature review.

Repair and remodeling of the mandibular head of the condylar process in four immature dogs

Spontaneous repair and remodeling of the mandibular head of the condylar process is a rarely reported outcome following condylectomy. This clinical report describes the spontaneous repair and subsequent remodeling of the mandibular head of the condylar process in four immature dogs that sustained traumatic injuries, necessitating surgical intervention through arthroplasty via partial or complete condylectomy, or caudal mandibulectomy. In subsequent evaluations, it was observed that all dogs exhibited clinically functional TMJs, as evidenced by an appropriate range of motion. These findings were corroborated by the owners' reports of the patient's normal eating and drinking abilities. Conventional and cone-beam computed tomography studies demonstrated the repair and remodeling of the osseous tissues of the mandibular head of the condylar process. Histopathology was unavailable to assess the novel tissues. No evidence of intraarticular or extraarticular ankylosis or osteoarthritic changes was observed.

Case report: Spontaneous mandibular body regeneration following unilateral subtotal mandibulectomy in a 3-month-old French bulldog

Objective

To document a case of spontaneous regeneration of the mandibular body following subtotal mandibulectomy in a juvenile dog.

Case summary

A 3-month-old male intact French bulldog was presented with papillary oral squamous cell carcinoma located at the dorsal aspect of the molar region of the left mandible. Initial biopsy of the mass was performed by the primary care veterinarian. Complete clinical staging revealed no signs of metastasis. Computed tomographic images of the head showed minimal contrast enhancement of the mass with no signs of periosteal or bone involvement. Subtotal mandibulectomy was performed. Histopathology indicated complete excision of the tumor. The patient returned 8-weeks later for follow up and cleft palate surgical repair, at which time bone was noted in the mandibulectomy area on palpation. Repeat computed tomography of the head revealed complete regeneration of the left mandibular body from the level of the ramus to the mandibular symphysis. No treatment for malocclusion was necessary due to the reformation of a functional mandible.

Clinical relevance

The present case demonstrates that spontaneous regeneration of the mandibular body is possible following subtotal mandibulectomy in immature dogs. Subtotal mandibulectomy is a radical procedure that can lead to long term complications including mandibular drift, malocclusion, and oral pain. This case report provides evidence that these sequelae may be mitigated or eliminated in young patients undergoing this procedure.

Piezosurgical bone-cutting technology reduces risk of maxillectomy and mandibulectomy complications in dogs

OBJECTIVE

To report the complication rate of dogs undergoing oral oncological surgery when using a bone-cutting piezoelectric unit for osteotomies.

CLINICAL PRESENTATION AND PROCEDURES

Retrospective cohort evaluation of medical records from 2012 through 2022 for canine patients that underwent mandibulectomy or maxillectomy for the treatment of oral neoplasia at the Companion Animal Hospital at Cornell University. Cases were included if osteotomy was performed using a piezoelectric unit. Medical records were then reviewed for documentation of intraoperative hemorrhage and administration of blood products.

RESULTS

41 maxillectomies and 57 mandibulectomies met the inclusion criteria (98 in total). Only 1 (1.02%) case was associated with excessive surgical bleeding requiring administration of blood products.

CLINICAL RELEVANCE

Results of this study show that intraoperative hemorrhage requiring the use of blood products during or immediately after a mandibulectomy or maxillectomy is rare when using a piezoelectric unit to perform osteotomies, and is substantially lower than that previously reported when using oscillating saws or other bone-cutting devices for maxillectomies.

Microspatial distribution of trace elements in feline dental hard tissues: early life exposure to essential and toxic elements

Introduction

Trace elements play a key role in dental tissue development, as dental hard tissues accumulate both essential and toxic trace elements during mineralization. Characterization of the spatial accumulation pattern of trace elements may provide insight into exposure to toxic elements over time and to the nature of disease processes affecting the hard dental tissues. Here, we present the first report of the use of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to map the microspatial distribution of multiple trace elements, essential and toxic, across feline dental hard tissues.

Methods

Eleven teeth were extracted from 8 cats. Nine teeth were from 7 cats diagnosed with idiopathic tooth resorption on intraoral radiographs prior to extraction. Two teeth were included from a cadaver that had no signs of tooth resorption on intraoral radiographs. The normal dental tissue was analyzed from each sample using LA-ICP-MS to map the microspatial distribution of essential and toxic trace elements across feline enamel, dentin, and cementum.

Results

Results showed a higher accumulation of barium and strontium in coronal dentin as compared to root dentin. The timing of the accumulation mirrors nursing timelines seen in teeth from human and non-human primates, consistent with barium and strontium being sourced from maternal milk. Results also showed a higher uptake of lead in the coronal dentin, suggesting this lead exposure was likely passed from mother to offspring.

Discussion

This work characterizes a baseline for elemental distribution in feline teeth linked to early life exposure to toxic elements such as lead and provides a framework for future studies investigating long-term environmental exposures to trace elements, essential and toxic, and their involvement in feline systemic and dental diseases.

Complex Feline Disease Mapping Using a Dense Genotyping Array

The current feline genotyping array of 63 k single nucleotide polymorphisms has proven its utility for mapping within breeds, and its use has led to the identification of variants associated with Mendelian traits in purebred cats. However, compared to single gene disorders, association studies of complex diseases, especially with the inclusion of random bred cats with relatively low linkage disequilibrium, require a denser genotyping array and an increased sample size to provide statistically significant associations. Here, we undertook a multi-breed study of 1,122 cats, most of which were admitted and phenotyped for nine common complex feline diseases at the Cornell University Hospital for Animals. Using a proprietary 340 k single nucleotide polymorphism mapping array, we identified significant genome-wide associations with hyperthyroidism, diabetes mellitus, and eosinophilic keratoconjunctivitis. These results provide genomic locations for variant discovery and candidate gene screening for these important complex feline diseases, which are relevant not only to feline health, but also to the development of disease models for comparative studies.

An Atypical Presentation of a Zygomatic Sialocele in a dog

A sialocele is an accumulation of salivary fluid due to leakage into the interstitial space surrounding the affected salivary gland and/or its corresponding duct. Reported causes of salivary leakage include trauma, foreign bodies, sialoliths, and neoplasia, but in many cases the etiology is not identified. Clinical signs of sialoceles associated with the zygomatic salivary gland or corresponding duct usually include exophthalmos due to periorbital salivary accumulation, whereas sialoceles associated with the mandibular or sublingual glands or ducts usually manifest as cervical, pharyngeal and/or sublingual salivary accumulation. This case report describes an atypical cervical presentation of a zygomatic sialocele in a dog that resolved after zygomatic sialoadenectomy.

The Macroscopic and Radiographic Skull and Dental Pathology of the Tasmanian Devil (Sarcophilus harrisii)

While the gross skull and dental morphology, masticatory biomechanics, dental eruption patterns, and radiographic dental anatomy has been described in the Tasmanian devil (Sarcophilus harrisii), to date no studies have comprehensively examined the prevalence and appearance of pathologic processes affecting their skulls and dentition. As such, the aim of this study was to describe macroscopic and radiographic anatomy and identify the prevalence of anatomic variations and pathological processes in Tasmanian devil dentition and skulls. To do so, anatomical and pathological findings were documented in Tasmanian devil skulls using photography and dental radiography. Assessment of skull trauma, anatomical and developmental abnormalities, periodontitis, endodontic disease, and tooth resorption was performed. A total of 28 Tasmanian devil skulls containing 1,028 teeth were examined. Evidence of postmortem trauma was common. The most common positional abnormality was palatal or buccal rotation of the premolar teeth. While the alveolar bone margin was commonly positioned apically to the cementoenamel junction (98.2%), only 14.2% demonstrated evidence of periodontitis. Tooth fractures were common, affecting 27 skulls, however radiographic signs of endodontic disease were only noted in 4.5% of affected teeth, as was non-inflammatory root resorption (2.0%). A wider root canal width, which was used as a criterion for age determination, was associated with smaller skull dimensions, incompletely erupted teeth, and subjectively less fusion of the mandibular symphysis. Through an improved understanding of what constitutes normal anatomy and the appearance and frequency of pathologic processes that affect the skulls and teeth, this knowledge can help develop a foundation for understanding the oral health and management of live animals for this endangered species.

Preliminary functional analysis of the subgingival microbiota of cats with periodontitis and feline chronic gingivostomatitis

The subgingival microbial communities of domestic cats remain incompletely characterized and it is unknown whether their functional profiles are associated with disease. In this study, we used a shotgun metagenomic approach to explore the functional potential of subgingival microbial communities in client-owned cats, comparing findings between periodontally healthy cats and cats with naturally occurring chronic periodontitis, aggressive periodontitis, and feline chronic gingivostomatitis. Subgingival samples were subjected to shotgun sequencing and the metagenomic datasets were analyzed using the MG-RAST metagenomic analysis server and STAMP v2.1.3 (Statistical Analysis of Metagenomic Profiles) software. The microbial composition was also described to better understand the predicted features of the communities. The Respiration category in the level 1 Subsystems database varied significantly among groups. In this category, the abundance of V-Type ATP-synthase and Biogenesis of cytochrome c oxidases were significantly enriched in the diseased and in the healthy groups, respectively. Both features have been previously described in periodontal studies in people and are in consonance with the microbial composition of feline subgingival sites. In addition, the narH (nitrate reductase) gene frequency, identified using the KEGG Orthology database, was significantly increased in the healthy group. The results of this study provide preliminary functional insights of the microbial communities associated with periodontitis in domestic cats and suggest that the ATP-synthase and nitrate-nitrite-NO pathways may represent appropriate targets for the treatment of this common disease.

Prevalence, Radiographic, and Demographic Features of Buccal Bone Expansion in Cats: A Cross-Sectional Study at a Referral Institution

Buccal bone expansion (BBE) refers to bulbous enlargement of the periodontium in domestic cats. The origin of BBE is unknown, and some of its epidemiological, clinical, and radiographic features have not been fully characterized. The purpose of this study was to determine whether specific demographic characteristics are associated with BBE in cats; and whether BBE is associated with other relevant radiographic findings. Pertinent data were collected from archived dental radiographs and electronic medical records of 97 client-owned cats. Results showed that BBE is common in cats presented for evaluation and treatment of dental disease; that breed, sex, and age are not associated with BBE; that BBE is not associated with a pattern of horizontal alveolar bone loss/extrusion or tooth resorption; that a pattern of vertical alveolar bone loss is a typical feature of BBE; and that BBE represents a common cause of canine tooth loss in cats.

Levels of Evidence in Small Animal Dentistry and Oral Surgery Literature Over 40 Years

Veterinary dentistry and oral surgery are relatively new clinical disciplines that have rapidly evolved in the last few decades. Although clinical standards of care are supported by a growing body of literature, the extent to which peer-reviewed, evidence-based studies have contributed to advancing the practice of dentistry and oral surgery has not been assessed. The purpose of this study was to survey literature on the clinical practice of small animal dentistry and oral surgery published over the past 40 years to evaluate the levels of evidence over time, authorship affiliation, funding, and clinical subdisciplines within the field. A literature search was conducted in PubMed and the identified articles were screened for inclusion. A total of 1,083 articles were included for final analysis. Three reviewers independently assessed and assigned each article to one of nine predetermined study design categories. Systematic reviews and meta-analyses were considered the highest level of evidence, whereas expert opinion and experimental (ex vivo, in vitro, or in silico) studies were deemed the lowest levels of evidence. For statistical analysis and interpretation, study type was dichotomized into high evidence designs from which causal inference and/or associations could be derived, and low evidence designs which were purely descriptive or non-clinical experiments. No statistically significant difference in the distribution of study type was seen over time, with the majority of research in the last 5 years being largely at high risk of bias and descriptive in nature: 80.6% of articles published between 2014 and 2019 were assigned to the low evidence design tier. The type of study was found to differ by author affiliation: high evidence study designs were found more often than expected when author affiliation was multi-institutional or industrial, whereas private practice authorship was underrepresented in the high evidence design tier. To meet the increasing demand for evidence-based studies on the practice of dentistry and oral surgery in dogs and cats, researchers are encouraged to consider study design when testing hypotheses to improve the quality of research.

Frequency of clinical and radiographic evidence of inflammation associated with retained tooth root fragments and the effects of tooth root fragment length and position on oral inflammation in dogs

OBJECTIVE

To assess the frequency of clinical and radiographic evidence of inflammation (ie, evidence of inflammation) associated with retained tooth root fragments (RTRFs) in dogs and to determine whether evidence of inflammation was affected by RTRF length and position within the alveolar bone.

SAMPLE

148 RTRFs in 66 dogs.

PROCEDURES

For each dog, demographic information was recorded, and full-mouth radiographs were obtained and reviewed for RTRFs. For each RTRF, the length of the fragment was measured on intraoral radiographic images, and its location and position relative to the alveolar bone margin were recorded. The presence or absence of evidence of inflammation in association with each RTRF was also recorded. Descriptive data were generated. Generalized linear mixed models were used to identify factors associated with evidence of inflammation around RTRFs.

RESULTS

81 of 148 (54.7%) RTRFs had evidence of inflammation. For every 1-mm increase in RTRF length, the odds of inflammation increased by 17% (OR, 1.17; 95% confidence interval [CI], 1.04 to 1.34; P = 0.009). Odds of inflammation for RTRFs that protruded from the alveolar bone margin were 2.98 (95% CI, 1.02 to 8.72; P = 0.046) and 7.58 (95% CI, 1.98 to 29.08; P = 0.001) times those for RTRFs that were buried and level with the alveolar bone margin, respectively. Tooth root fragment length was a poor predictor of inflammation.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that most RTRFs were associated with evidence of inflammation and supported the current recommendation for extraction of RTRFs whenever feasible.

A multicenter experience using adipose-derived mesenchymal stem cell therapy for cats with chronic, non-responsive gingivostomatitis

BACKGROUND

The ability of mesenchymal stem cells (MSCs) to modulate immune responses inspired a series of clinical trials addressing oral mucosal inflammation. We previously reported on the safety and efficacy of fresh, allogeneic and autologous, adipose-derived mesenchymal stem cells (ASCs) to treat feline gingivostomatitis (FCGS), an oral mucosal inflammatory disease that shares similarities with human oral lichen planus.

METHODS

To meet clinical demand and goals for future commercialization, we determined the feasibility of shipping fresh ASCs to distant clinics and extended our pilot studies to expand safety and efficacy data for shipped and non-shipped ASCs in a cohort of 18 FCGS cats enrolled locally and at a few different locations within the USA.

RESULTS

We found that ASCs retained their viability, phenotype, and function after shipment. ASCs administered systemically resulted in a 72% positive response rate, identical to that noted in our previous studies. Cats that responded to ASC therapy had a significant decrease in circulating globulin concentration and histological evidence of decreased CD3+ T cells and CD20+ B cells in the oral mucosa. Responder cats also had significantly decreased percentages of CD8^lo cells in blood prior to and at 3 months post-ASC therapy. CD8^lo cells may serve as a potential "predictor" for response to systemic ASC therapy.

CONCLUSION

Fresh feline ASCs can be successfully shipped and administered to cats with FCGS. ASCs modulate the immune response and demonstrate efficacy for chronic oral mucosal inflammatory lesions that are characterized by CD8+ T cell inflammation and T cell activation. FCGS is a potentially useful naturally occurring large animal model of human oral inflammatory diseases.

Mandibular Carnassial Tooth Malformations in 6 Dogs-Micro-Computed Tomography and Histology Findings

Objective: To document the clinical, radiographic, and histological characteristics of mandibular first molar teeth with developmental abnormalities previously attributed to dens invaginatus and enamel pearls in dogs. Materials and Methods: Affected mandibular first molar teeth from dogs were evaluated grossly and via intraoral radiography. Endodontically and/or periodontally compromised teeth were extracted and subjected to some combination of micro-computed tomography, histopathology, and immunohistochemistry with anti-amelogenin antibody. Results: Six dogs with developmental abnormalities of mandibular first molar teeth were identified, representing 11 affected teeth. The condition was bilateral in 5 dogs, while in 1 dog, only one mandibular first molar tooth was present. Patient weight ranged from 1.7 to 6 kg (median = 4.09 kg). On intraoral radiographs, root convergence or parallelism was noted in 6 of 11 teeth, and root dilaceration was noted in 3 of 11 teeth. Eight teeth required extraction due to periapical lucencies or periodontitis. On micro-CT, the abnormal teeth were characterized by the presence of abnormal, heterogenous hard tissue with beam attenuation characteristics midway between that of enamel and dentin. Enamel fissures were identified in 4 of 8 teeth, while ectopic radicular enamel was identified in 2 of 8 teeth. The abnormal tissue was traversed by channels measuring 20-40 μm in diameter. Channels communicated with the enamel fissures in 2/8 teeth, the furcation in 2/8 teeth and the pulp in 4/8 teeth. The abnormal tissue was frequently surrounded by disorganized dentin. Histologic features of enamel and dentin were absent from the abnormal tissue and immunohistochemistry to detect amelogenin in the abnormal tissue was negative in all samples. Conclusion: The dental abnormalities described here correspond to a previously unrecognized developmental abnormality involving the mandibular first molar teeth in dogs. The developmental origin of the abnormal tissue could not be ascertained, and further investigations are required to determine the mode of formation, origin of the abnormal tissue, and factors associated with development. These developmental abnormalities more closely resemble molar-incisor malformation, rather than dens invaginatus or enamel pearls as described in humans. The authors propose that affected mandibular first molar teeth simply be referred to as having carnassial tooth malformations.

Incidence patterns of orofacial clefts in purebred dogs

Cleft lip (CL), cleft palate (CP) and cleft lip and palate (CLP) are the most common types of orofacial clefts in dogs. Orofacial clefts in dogs are clinically relevant because of the associated morbidity and high newborn mortality rate and are of interest as comparative models of disease. However, the incidence of CL, CP and CLP has not been investigated in purebred dogs, and the financial impact on breeders is unknown. The aims of this study were to document the incidence patterns of CL, CP and CLP in different breeds of dogs, determine whether defect phenotype is associated with skull type, genetic cluster and geographic location, and estimate the financial impact in breeding programs in the United States by means of an anonymous online survey. A total of 228 orofacial clefts were reported among 7,429 puppies whelped in the 12 preceding months. Breeds in the mastiff/terrier genetic cluster and brachycephalic breeds were predisposed to orofacial clefts. Certain breeds in the ancient genetic cluster were at increased odds of orofacial clefts. Male purebred dogs were at increased odds of CPs. Results confirm that brachycephalic breeds are overrepresented among cases of orofacial clefts. Furthermore, geographic region appeared to be a relevant risk factor and orofacial clefts represented a considerable financial loss to breeders. Improved understanding of the epidemiology of orofacial clefts (frequency, causes, predictors and risk factors) may help in identifying ways to minimize their occurrence. Information gained may potentially help veterinarians and researchers to diagnose, treat and prevent orofacial clefts.

Endodontic Microbiome of Fractured Non-vital Teeth in Dogs Determined by 16S rRNA Gene Sequencing

Dental fractures resulting in pulp exposure will lead to an endodontic infection with microbes from the oral cavity. However, data on the endodontic microbial composition in veterinary dentistry is lacking. The aim of this study was to examine the microbiome of naturally occurring primary endodontic infections in client-owned dogs. The endodontic microbiome of 10 non-vital teeth with exposed pulp cavities was assessed using a 16S rRNA gene sequencing approach. The results were compared to the microbiome of the subgingival plaque of the same teeth. Analysis revealed an abundant mixed microflora of a comparable richness and diversity and with mostly the same phyla obtained from sulcal and endodontic samples. However, further analysis revealed significant differences between sulcal and endodontic samples in the relative abundance of the most abundant phyla and genera, with the relative abundance of Bacteriodetes being significantly higher in endodontic samples. Although each sample presented a particular profile regarding the genera identified, Bacteroides was the most abundant genus in the endodontic samples. Snowella was also significantly more abundant in endodontic samples, while Porphyromonas and Fusobacterium were significantly more abundant in sulcal samples. We confirmed that the microbiome of the diseased endodontic system is comparably abundant with microorganisms to the healthy subgingival plaque indicating that previous culture-based studies of primary endodontic infections in dogs underestimated the richness and diversity of the endodontic microbiota.

Extended Subtotal Mandibulectomy for the Treatment of Oral Tumors Invading the Mandibular Canal in Dogs-A Novel Surgical Technique

Mandibular tumors in the oral cavity of dogs can be locally aggressive and infiltrative, involving adjacent soft and hard tissues. Tumors that invade the mandibular canal are considered likely to extend rostrally and caudally within that structure due to minimal tissue resistance. When this occurs, a total mandibulectomy is thought to be the treatment of choice as it allows en bloc excision of the mandibular canal. This procedure is technically challenging and time consuming. In the present report we describe a novel technique, the extended subtotal mandibulectomy, as a possible alternative in cases of mandibular body tumors that have invaded the mandibular canal. This technique allows the complete excision of the mandibular canal whilst retaining the coronoid and condylar processes.

The subgingival microbial community of feline periodontitis and gingivostomatitis: characterization and comparison between diseased and healthy cats

Periodontitis is a common and important health problem in domestic cats. The subgingival microbiota of cats diagnosed with chronic periodontitis (CP), aggressive periodontitis (AP), and feline chronic gingivostomatitis (FCGS) are not well characterized. Thus, the aim of the present study was to characterize and compare the periodontal microbiota of periodontally healthy cats versus cats diagnosed with CP, AP, and FCGS by using next-generation sequencing. In total, 44 domestic cats were enrolled, and 139 subgingival samples were subjected to 16S rRNA gene sequencing to investigate the microbiota composition of each periodontal group evaluated. Our results identified several key genera previously described in periodontal disease (e.g. Treponema and Filifactor) and in the oral microbiota (e.g. Moraxella and Capnocytophaga) of healthy cats. Phylogenetic beta diversity analysis showed that the microbiota of periodontally healthy cats were distinguishable from diseased cats. Even though most of the genera known to be associated with periodontal disease were also identified in healthy cats, they were present at significantly lower relative abundance. Remarkably, alpha diversity was found to be higher in the disease groups compared to healthy animals. These results suggest a pathological mechanism involving opportunistic behavior. Our findings corroborate those in the current literature regarding the complexity of the subgingival microbiota of the domestic cat and reveal both differences and similarities among periodontally healthy and diseased cats.

Craniomaxillofacial Disorders and Solutions in Humans and Animals

Cross-disciplinary collaborations have initiated translational studies in an effort to harness naturally occurring diseases in companion animals to accelerate the development of new treatment modalities, drugs, and device inventions. These synergistic collaborations can identify clinically relevant models that offer the opportunity to conduct rigorous translational investigations. However, the relationship between craniomaxillofacial diseases in companion animals and humans has been widely overlooked. We report here an innovative and visionary 2-d symposium that was organized to gather professionals working on craniomaxillofacial disorders and solutions in humans and/or animals from multiple disciplines, including veterinary physicians, basic scientists, biomedical engineers, physicians, and dentists. The symposium provided a platform for junior and senior investigators and basic science and clinical researchers to network, collaborate, and develop a new clinical and translational framework for accelerated therapy development.

Morphological evaluation of clefts of the lip, palate, or both in dogs

OBJECTIVE To systematically characterize the morphology of cleft lip, cleft palate, and cleft lip and palate in dogs. ANIMALS 32 client-owned dogs with clefts of the lip (n = 5), palate (23), or both (4) that had undergone a CT or cone-beam CT scan of the head prior to any surgical procedures involving the oral cavity or face. PROCEDURES Dog signalment and skull type were recorded. The anatomic form of each defect was characterized by use of a widely used human oral-cleft classification system on the basis of CT findings and clinical images. Other defect morphological features, including shape, relative size, facial symmetry, and vomer involvement, were also recorded. RESULTS 9 anatomic forms of cleft were identified. Two anatomic forms were identified in the 23 dogs with cleft palate, in which differences in defect shape and size as well as vomer abnormalities were also evident. Seven anatomic forms were observed in 9 dogs with cleft lip or cleft lip and palate, and most of these dogs had incisive bone abnormalities and facial asymmetry. CONCLUSIONS AND CLINICAL RELEVANCE The morphological features of congenitally acquired cleft lip, cleft palate, and cleft lip and palate were complex and varied among dogs. The features identified here may be useful for surgical planning, developing of clinical coding schemes, or informing genetic, embryological, or clinical research into birth defects in dogs and other species.

Suspected Rhinolithiasis Associated With Endodontic Disease in a Cat

Rhinoliths are rare, intranasal, mineralized masses formed via the precipitation of mineral salts around an intranasal nidus. Clinical signs are typically consistent with inflammatory rhinitis and nasal obstruction, but asymptomatic cases are possible. Rhinoliths may be classified as exogenous or endogenous depending on the origin of the nidus, with endogenous rhinoliths reportedly being less common. This case report describes a suspected case of endogenous rhinolithiasis in a cat which was detected as an incidental finding during radiographic assessment of a maxillary canine tooth with endodontic disease. Treatment consisted of removal of the suspected rhinolith via a transalveolar approach after surgical extraction of the maxillary canine tooth.

Comparing Intraoral Radiography and Computed Tomography for Detecting Radiographic Signs of Periodontitis and Endodontic Disease in Dogs: An Agreement Study

OBJECTIVE

To determine whether computed tomography (CT) and intraoral radiography are interchangeable for detecting signs of periodontitis and endodontic disease in dogs.

MATERIALS AND METHODS

An agreement study was performed using 40 dogs that previously underwent intraoral radiography and CT during the same anesthetic episode. Images of each tooth were examined by two blinded observers for signs of periodontitis and/or endodontic disease. Agreement between imaging modalities and between observers was assessed using the Kappa statistic.

RESULTS

Agreement between modalities for detecting periodontitis in the maxillae ranged from poor to very good (κ 0.07-1.00) with 16/20 (80%) of the teeth having a score of moderate or better (κ ≥ 0.41). Agreement between modalities for detecting signs consistent with periodontitis in the mandibles ranged from poor to very good (κ 0.01-1.00) with 10/22 (45%) of the teeth having a score of good or better (κ ≥ 0.61); 50% of the disagreement was present in the incisors. Agreement between modalities for detecting signs consistent with endodontic disease in the whole mouth ranged from fair to very good (κ 0.21-1.00) with 30/42 (71%) of the teeth having a score of moderate or better (κ ≥ 0.41). Agreement between observers evaluating intraoral radiology ranged from poor to very good (κ 0.05-1) for detecting signs consistent with periodontitis and from fair to very good (κ 0.36-1) for detecting signs consistent with endodontic disease, in the whole mouth. Agreement between observers evaluating CT ranged from fair to very good (κ 0.35-1) for detecting signs consistent with periodontitis and from fair to very good (κ 0.36-1) for detecting signs consistent with endodontic disease, in the whole mouth.

CONCLUSION

Performing both CT and intraoral radiography may be unnecessary to detect signs consistent with periodontitis and endodontic disease in dogs based on the amount of agreement between modalities and observers when CT images are acquired and reconstructed in 0.5 or 1 mm slice thickness, except for diagnosing periodontitis in the mandibular incisors.

Reconstruction of Congenital Nose, Cleft Primary Palate, and Lip Disorders

Clefts of the primary palate in the dog are uncommon, and their repair can be challenging. The aims of this article are to provide information regarding pathogenesis and convey practical information for the repair of these defects.

Outcome of surgical endodontic treatment in dogs: 15 cases (1995-2011)

OBJECTIVE

To document the short- and long-term outcomes of surgical endodontic treatment in dogs in a clinical setting.

DESIGN

Retrospective case series.

ANIMALS

15 dogs that underwent surgical endodontic treatment.

PROCEDURES

Medical records of dogs that underwent surgical endodontic treatment at 3 institutions from January 1995 to December 2011 were reviewed. Information extracted included signalment, history, initial clinical signs, physical and radiographic examination findings, treatment, and outcome. Outcome was determined through evaluation of the pre- and postoperative radiographs as well as clinical and radiographic findings at follow-up evaluations. On the basis of radiographic findings, treatment was considered successful if the periapical lesion and bone defect created by surgery had completely healed and no new root resorption was detected; a treatment was considered to have no evidence of failure if the periapical lesion remained the same or had not completely resolved and root resorption was static.

RESULTS

15 dogs were treated by means of apicoectomy and retrograde filling following a failed or complicated orthograde root canal treatment. The mean long-term follow-up time was 15.2 months (range, 3 to 50 months). On radiographic evaluation, 10 of 15 dogs had successful resolution of the periapical disease; 5 dogs had no radiographic evidence of failure of endodontic treatment. All dogs were considered to have a successful clinical outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

Surgical endodontic treatment was an effective option for salvaging endodontically diseased but periodontally healthy teeth of dogs in which orthograde treatment was unsuccessful and nonsurgical retreatment was unlikely to succeed.