Novel Management of Masticatory Myositis in Three Dogs with a Selective Janus Kinase (JAK-1) Inhibitor

Masticatory myositis (MM) is an inflammatory myopathy reported in dogs and is characterized by inflammation of the masticatory muscles (temporalis, masseter, and pterygoid muscles). Immunosuppressive therapy is the current recommended treatment for MM and may involve glucocorticoids, cyclosporine, azathioprine, mycophenolate mofetil, leflunomide, or a combination of these treatments that are slowly tapered to the lowest effective dose. However, side effects from multimodal medical therapy and complications associated with MM relapses have been reported. The purpose of this case series was to report oclacitinib as a treatment alternative to traditional medical management of MM. The intent of this alternative is to manage side effects from glucocorticoid use. Oclacitinib (1mg/kg per os q12h) was used solely for treatment of MM in three dogs. The dogs were followed up to >6 months after oclacitinib administration. An increase in oral range of motion, as determined by gape angle, was noted in all three dogs. However, a corresponding drop in antibody titers (2M fiber) did not occur. All dogs showed improvement in overall clinical management of MM, side effects from glucocorticoids, and clinical signs related to chronic prednisone use. Larger controlled trials with consistent measurements (interincisal distance, gape angle) and 2M fiber antibody titers are indicated to further assess validation of oclacitinib treatment of MM. The clinical outcome of all dogs was considered successful.

Application of a maxillary transfacial approach to the caudal oral cavity and orbitozygomaticomaxillary complex in dogs

Surgical access and visualization for excision of large pathologic lesions of the orbitozygomaticomaxillary complex (OZMC) and caudal oral cavity can be a challenge in veterinary oromaxillofacial surgery and may limit one's ability to perform such procedures. Combined intra- and extra-oral approaches as well as commissurotomy have been advocated in the past. However, each of these approaches present unique limitations specific to each approach. A transfacial approach that ameliorated these limitations could be advantageous. In this descriptive cohort study, we investigate the application and outcomes of a maxillary transfacial approach to the OZMC and caudal oral cavity in six client-owned dogs. The approach is based on the Weber-Ferguson approach for human applications and provided excellent exposure of the intended region in all six patients. We contend the maxillary transfacial approach provides some advantages to the more conventional combined intra-oral/extra-oral approach or commissurotomy for excision of large pathologic lesions of the OZMC and caudal oral cavity.

Corrigendum: Analysis of the approach angle to medial orbitotomy that avoids accidental neurotrauma in the mesaticephalic dog skull utilizing 3D computer models and virtual surgical planning

[This corrects the article DOI: 10.3389/fvets.2023.1185454.].

Analysis of the approach angle to medial orbitotomy that avoids accidental neurotrauma in the mesaticephalic dog skull utilizing 3D computer models and virtual surgical planning

This study was conducted to determine an approach angle to medial orbitotomy that avoids accidental neurotrauma in mesaticephalic dogs. Medical records of dogs with mesaticephalic skulls that were presented to the veterinary medical teaching hospital for head computed tomography (CT) between September 2021 and February 2022 were reviewed. Descriptive data were queried, and CT findings were analyzed. Dogs greater than 20 kg and possessing a disease-free orbitozygomaticomaxillary complex (OZMC) on at least one side of the skull were included in this study. Digital imaging and communications in medicine (DICOM) files of head CT studies were imported into medical modeling software, and the safe approach angle for medial orbitotomy was determined using three-dimensional (3D) computer models and virtual surgical planning (VSP) principles. Angles were measured along the ventral orbital crest (VOC) from the rostral cranial fossa (RCF) to the rostral alar foramen (RAF). The safe approach angle at four points from rostral to caudal along the VOC was measured. The results at each location were reported as mean, median, 95% CI, interquartile ranges, and distribution. The results were statistically different at each location and generally increased from rostral to caudal. The variances between subjects and the differences between locations were large enough to suggest a standard safe approach angle in mesaticephalic dogs cannot be determined and should be measured for each patient. A standardized approach angle to medial orbitotomy is not possible in the mesaticephalic dog. Computer modeling and VSP principles should be implemented as part of the surgical planning process to accurately measure the safe approach angle along the VOC.

Morphological quantification of the maxillary canine tooth in the domestic dog (Canis lupus familiaris)

Canine tooth shape is known to vary with diet and killing behavior in wild animals and the relationship between form and function is driven in part by selective pressure. However, comparative investigation of the domestic dog (Canis lupus familiaris) is of interest. How do they compare to their wild counterparts? This study sought to quantify and characterize the morphology of the canine tooth in the domestic dog, and to provide a preliminary investigation into the variance in canine tooth morphology across individual dogs of varying breeds. Three-dimensional (3D) models generated from micro-computed tomography (µ-CT) studies of 10 mature maxillary canine teeth from the domesticated dog (Canis lupus familiaris) were used to quantify key morphological features and evaluate variance among dogs. Results show that, utilizing modern imaging and model building software, the morphology of the canine tooth can be comprehensively characterized and quantified. Morphological variables such as second moment of area and section modulus (geometrical parameters related to resistance to bending), as well as aspect ratio, ridge sharpness, cusp sharpness and enamel thickness are optimized in biomechanically critical areas of the tooth crown to balance form and function. Tooth diameter, second moment of area, section modulus, cross sectional area, tooth volume and length as well as enamel thickness are highly correlated with body weight. In addition, we found preliminary evidence of morphological variance across individual dogs. Quantification of these features provide insight into the balance of form and function of the canine tooth in wild and domesticated canids. In addition, results suggest that variance between dogs exist in some morphological features and most morphological features are highly correlated with body weight.

Correlation of mineral density and elastic modulus of dog dentin using μ-CT and nanoindentation

This study sought to 1) investigate the spatial distribution of mineral density of dog dentin using µ-CT and 2) characterize the relationship between the elastic modulus and mineral density of dog dentin using nanoindentation and µ-CT. Maxillary canine teeth of 10 mature dogs were scanned with a µ-CT then sectioned in the transverse and vertical planes and tested using nanoindentation. Spatial distribution of mineral density and elastic modulus was quantified. Results demonstrated significant spatial variation in mineral density and elastic modulus. Mineral density and elastic modulus generally increased from the dentin-pulp interface to the dentino-enamel junction and from the crown base to the crown tip. Significant site dependent correlations between mineral density and elastic modulus were determined (0.021 > R2 > 0.408). The results of this study suggest that while mineral density is a mediator of elastic modulus, other mediators such as collagen content may contribute to the mechanical behavior of dog dentin.

Feline maxillary sarcoma: clinicopathologic features of spindle cell sarcomas from the maxilla of 25 cats

CASE SERIES SUMMARY

Feline maxillary sarcomas are aggressive spindle cell neoplasms that occur within the maxilla, palate and upper lip of cats. This diagnosis includes fibrosarcoma and sarcomas with indeterminate histomorphology, excluding melanocytic tumors and sarcomas that can be differentiated by histomorphology. In this study of feline maxillary sarcomas in 25 cats, the cats' ages ranged from 4 to 16 years (median 12.5). These sarcomas presented as smooth thickenings or mass lesions of the gingiva and palate, often involving both the right and left quadrants of the maxilla. Radiographic bone loss was typically absent to mild at the time of diagnosis. Histologically, feline maxillary sarcomas were composed of spindle cells with varying amounts of fibrous stroma and mild inflammation. Metastasis was not documented for any cat in the study, although clinical staging was limited. Cats were often euthanized because of local recurrence following incomplete tumor excision and local tumor progression. Median survival time from the date of histologic diagnosis was 70 days (n = 12).

RELEVANCE AND NOVEL INFORMATION

Feline maxillary sarcomas are aggressive neoplasms that may be difficult to differentiate from a benign, reactive process or other types of spindle cell neoplasms. Our findings indicate that feline maxillary sarcoma has distinctive clinical and histopathologic features, and the information provided in this paper will facilitate early and specific diagnosis of this tumor.

Virtual surgical planning and 3D printing: Methodology and applications in veterinary oromaxillofacial surgery

Virtual surgical planning is the process of planning and rehearsing a surgical procedure completely within the virtual environment on computer models. Virtual surgical planning and 3D printing is gaining popularity in veterinary oromaxillofacial surgery and are viable tools for the most basic to the most complex cases. These techniques can provide the surgeon with improved visualization and, thus, understanding of the patients' 3D anatomy. Virtual surgical planning is feasible in a clinical setting and may decrease surgical time and increase surgical accuracy. For example, pre-operative implant contouring on a 3D-printed model can save time during surgery; 3D-printed patient-specific implants and surgical guides help maintain normocclusion after mandibular reconstruction; and the presence of a haptic model in the operating room can improve surgical precision and safety. However, significant time and financial resources may need to be allocated for planning and production of surgical guides and implants. The objectives of this manuscript are to provide a description of the methods involved in virtual surgical planning and 3D printing as they apply to veterinary oromaxillofacial surgery and to highlight these concepts with the strategic use of examples. In addition, the advantages and disadvantages of the methods as well as the required software and equipment will be discussed.

Structure-function relationships in dog dentin

Investigations into teeth mechanical properties provide insight into physiological functions and pathological changes. This study sought to 1) quantify the spatial distribution of elastic modulus, hardness and the microstructural features of dog dentin and to 2) investigate quantitative relationships between the mechanical properties and the complex microstructure of dog dentin. Maxillary canine teeth of 10 mature dogs were sectioned in the transverse and vertical planes, then tested using nanoindentation and scanning electron microscopy (SEM). Microstructural features (dentin area fraction and dentinal tubule density) and mechanical properties (elastic modulus and hardness) were quantified. Results demonstrated significant anisotropy and spatial variation in elastic modulus, hardness, dentin area fraction and tubule density. These spatial variations adhered to a consistent distribution pattern; hardness, elastic modulus and dentin area fraction generally decreased from superficial to deep dentin and from crown tip to base; tubule density generally increased from superficial to deep dentin. Poor to moderate correlations between microstructural features and mechanical properties (R² = 0.032-0.466) were determined. The results of this study suggest that the other constituents may contribute to the mechanical behavior of mammalian dentin. Our results also present several remaining opportunities for further investigation into the roles of organic components (e.g., collagen) and mineral content on dentin mechanical behavior.

Impact of the Surgical Environment on the Incidence, Timing, and Severity of Complications Associated With Oromaxillofacial Oncologic Surgery in Dogs

Numerous reports describe complication rates associated with oromaxillofacial oncologic surgery in dogs, however, investigation regarding the impact of the surgical environment on the incidence of complications is under reported. The objective of this retrospective cohort study, including 226 dogs surgically treated for oromaxillofacial tumors between January 1, 1997 and December 31, 2018, is to evaluate the impact of the surgical environment on the incidence of complications in oromaxillofacial oncologic surgery in dogs. A secondary objective is to report the incidence of local complications in oromaxillofacial oncologic surgery and characterize the type, timing, and severity of complications encountered. Incidence of complications was identified to be 69.9%. No significant association was identified between the incidence, timing, or severity of complications and the training background of the clinician, physical location of the procedure, or the ostectomy instrument used. These results suggest that the surgical environment has little impact on the incidence, timing, and severity of complications in dogs undergoing oromaxillofacial oncologic surgery. The results also emphasize the importance of preparing the surgical team and the client for a high incidence of complications associated with oromaxillofacial oncologic surgery in dogs and indicate that both short-term and long-term follow up is important in these cases. Oromaxillofacial surgery performed by residents-in-training within a veterinary teaching environment with adequate supervision appears to be safe.

Virtual Surgical Planning and 3D Printing in Veterinary Dentistry and Oromaxillofacial Surgery

Virtual surgical planning and three-dimensional (3D) printing are preoperative processes requiring the acquisition of high-quality imaging data. A surgical treatment plan is created and rehearsed virtually as the operator manipulates the 3D images of the patient within the software. When the operator is satisfied with the plan, including anticipated osteotomies, tumor excision margins, and reconstruction options, physical 3D prints can be produced. This article introduces the reader to the basic concepts involved in virtual surgical planning and 3D printing as well as their implementation in veterinary oromaxillofacial surgery.

Incidence and Risk Factors for Surgical Site Infections Following Oromaxillofacial Oncologic Surgery in Dogs

Antibiotic stewardship in veterinary medicine is essential to help prevent resistant bacterial infections. Critical evaluation into the benefits of prophylactic use of antibiotics during veterinary surgical procedures is under reported and additional investigation is warranted. The objectives of this paper were to determine the incidence of surgical site infection in dogs that underwent oromaxillofacial oncologic surgery and to identify risk factors for the development of surgical site infection. In this retrospective cohort study including 226 dogs surgically treated for oromaxillofacial tumors between January 1, 1997 and December 31, 2018, the incidence of surgical site infection was determined to be 7.5%. Univariable logistical regression models were used to evaluate potential risk factors for development of surgical site infections including signalment, tumor type, antibiotic protocol, time under anesthesia, location of surgical procedure (dental suite vs. sterile operating room), specific comorbidities, and surgical margins obtained. Anesthetic events lasting greater than 6 h were significantly associated with development of infection. Signalment, comorbidities, administration of anti-inflammatory and immunosuppressive medications, tumor type, histological margin evaluation, surgical procedure location, and antibiotic protocols were not significant contributors to development of infection. Use of antibiotic therapy in this cohort was not protective against development of infection and may not be routinely indicated for all oromaxillofacial oncologic surgeries despite common promotion of its use and the contaminated nature of the oral cavity. Anesthetic time significantly contributed towards the development of infection and use of perioperative antibiotics for surgical procedures lasting >6 h may be routinely warranted.

Generalized Dentin Dysplasia in a Four-Year-old dog

Dentin dysplasia is an autosomal-dominant genetic abnormality that occurs in humans and results in diffuse radiographic dental abnormalities and variable tooth discoloration due to an underlying defect in secondary dentinogenesis. This case report presents distinctive radiographic and histopathologic dental abnormalities in a dog that are consistent with generalized dentin dysplasia. These findings are similar to but not completely analogous to any specific clinical type of dentin dysplasia in humans. Grossly, the majority of the teeth in this case were discolored and most were determined to be vital. Dentin dysplasia should be included in the list of differential diagnoses of discolored teeth and notably this form of discoloration does not necessarily indicate loss of vitality.

The canine furcation cyst, a newly defined odontogenic cyst in dogs: 20 cases (2013-2017)

OBJECTIVE

To characterize clinical, radiographic, and histologic features of canine furcation cysts (CFCs) in dogs and to propose possible mechanisms of CFC development.

ANIMALS

20 client-owned dogs with CFCs biopsied between January 1, 2013, and December 31, 2017.

PROCEDURES

Medical records of the Center for Comparative Oral and Maxillofacial Pathology at the University of Wisconsin-Madison were retrospectively searched to identify records of dogs that had surgical biopsy specimens of mandibular or maxillary cavitary lesions diagnosed as odontogenic cysts and that met additional inclusion criteria. Biopsy sample submission records, medical records, clinical and radiographic images, and histologic samples were reviewed. Clinical, radiographic, and histologic features were evaluated.

RESULTS

Mean body weight and age of affected dogs were 23.5 kg (51.7 lb) and 8.2 years, respectively. All 20 dogs had a unilateral cyst, with the right (n = 13) or left (7) maxillary fourth premolar tooth affected and viable in all dogs. A predominant clinical sign was a fluctuant swelling of the buccal gingiva and mucosa overlying the CFC, and enucleation of the cyst lining, with or without extraction of the affected tooth, resolved the lesion in most dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Our findings indicated that CFC is an odontogenic cyst of uncertain etiopathogenesis and that complete evaluation of the clinical, radiographic, and histologic features of the lesion in affected patients is necessary to distinguish a CFC from other odontogenic cysts and tumors in dogs. Defining CFCs in terms of characteristic features permits accurate diagnosis and appropriate treatment of these previously unclassifiable odontogenic cysts in dogs.

Excision of Extensive Orbitozygomaticomaxillary Complex Tumors Combining an Intra- and Extraoral Approach With Transpalpebral Orbital Exenteration

The junction of the bones of the orbit, caudal maxilla and zygoma intersect to form an anatomically intricate region known as the orbitozygomaticomaxillary complex (OZMC). Given the critical role of the OZMC in the structure, function and esthetics of the skull and midface, tumors in this region present unique challenges to the oromaxillofacial surgeon. Attempts to achieve histologically clean tumor margins in a cosmetically pleasing manner requires excellent intra-operative visualization. Additionally, minimized intra-operative and post-opertive complications is of paramount importance. In this manuscript we describe a combined intra- and extraoral approach to extensive tumors of the OZMC that incorporates orbital exenteration as a technique, which allows for excellent intra-operative visualization and mitigate intra- and post-operative complications. In addition, we describe our experience utilizing the technique in five clinical cases.

Biological Behavior of Canine Acanthomatous Ameloblastoma Assessed With Computed Tomography and Histopathology: A Comparative Study

Canine acanthomatous ameloblastoma (CAA) appears to have variable biological behavior with some tumors presenting with slow growth and minimal bone loss while others grow rapidly and cause severe cancellous and cortical bone destruction. The primary aim of the study is to elucidate if variations (grades) of CAA can be identified based on both histological and diagnostic imaging indices, and to compare markers of more aggressive behavior between these 2 commonly used diagnostic tools. This study evaluated 45 cases of CAA and confirmed that there is high degree of variability in tumor invasiveness as measured with computed tomography, with predominantly intraosseous tumors being significantly associated with more invasive behavior. However, the analysis also identified that there was very little correlation between computed tomographic and histological appearance of the tumor. CAA tends to have a highly uniform and predictable histological pattern, with tumors that aggressively invade bone (as seen on CT) not showing features of atypia that might be helpful in predicting the biological behavior of the neoplastic cells. Thus, reliance on diagnostic imaging as a measure of biological behavior is recommended for treatment planning as well as possible creation of a variant/grading scheme. Prospective studies are required to evaluate if differing variants of CAA as based on diagnostic imaging should be treated differently, and how this would affect long term clinical outcome.

Presentation, Diagnostic Imaging, and Clinical Outcome of Conventional Ameloblastoma in Dogs

A noninductive tumor of odontogenic epithelium occurs within the tooth bearing regions of the jaw in dogs and fits the conventional definition of ameloblastoma, which is distinct from, and less common than, canine acanthomatous ameloblastoma. In order to clarify the clinical and radiological features of this uncommon odontogenic tumor in dogs, we performed a retrospective study of 20 dogs that were diagnosed between 2007 and 2015. Follow-up information was obtained for 17 of 20 dogs. The study group of dogs showed no apparent age, breed, or gender predilection. Conventional ameloblastoma is typically slow growing, well demarcated, and locally destructive. Tumors most commonly occurred as a mass or focal bony swelling within the maxilla (13/20) or mandible (7/20). Based on cases with available diagnostic imaging, as either dental radiographs or computed tomographic images, the tumors were usually intraosseous and caused mixed lytic/proliferative bone changes. Nevertheless, conventional ameloblastomas did not aggressively infiltrate adjacent tissues and recurrence was not observed within the study group, even in patients with narrow surgical margins or treatment by cyst enucleation.

Extensive Maxillary Odontomas in 2 Dogs

Two immature male dogs were presented for the treatment of extensive maxillary compound odontomas. In both cases, clinical evaluation and diagnostic imaging revealed extensive lesions invading and displacing anatomical structures of the maxilla. Histopathology confirmed the diagnoses in both cases. One dog was treated with partial rostral maxillectomy, and the other dog was treated with enucleation of the cystic lining and removal of tooth-like structures through a lateral rhinotomy utilizing an intraoral approach. This report illustrates the growth potential of maxillary compound odontomas in 2 dogs and highlights their subclinical appearance and excellent prognosis despite their extensive nature.

The Influence of Axial Grooves on Dislodgment Resistance of Prosthetic Metal Crowns in Canine Teeth of Dogs

The reported failure rate for full veneer crowns of canine teeth of dogs is suboptimal, particularly in teeth with naturally poor retentive features, such as those with low height/diameter (H/D) ratios or high convergence angles (CAs). The objective of the present study was to evaluate the application of axial grooves in an effort to develop a crown preparation design that enhances the retention of full veneer crowns in dogs. Crown dislodgment testing was performed on cast alloy dies of canine teeth with unfavorable retention features (low H/D and high CA) prepared with (n = 14) and without axial grooves (n = 15) to evaluate the force required to dislodge a cemented full veneer crown. The crown/die units were secured within a universal testing machine and a load was applied at the 45° oblique direction from distal to mesial to replicate the vector encountered during biting-pulling action. The maximum force required to cause crown dislodgment was recorded for each crown. Statistical analysis revealed a significant increase in force required for crown dislodgment when axial grooves were included in the crown preparation design ( P < .001). Crown retention is improved in canine teeth with otherwise poor retention features when axial grooves are made in the labial and palatal/lingual walls during crown preparation.

Successful Treatment of Mandibular Nonunion With Cortical Allograft, Cancellous Autograft, and Locking Titanium Miniplates in a Dog

Discontinuities of the mandible can occur for a variety of reasons including primary pathology of bone, pathologic fracture secondary to periodontal disease, and segmental resection for the treatment of neoplasia. Surgical intervention is necessary in many cases to establish normal occlusion and normal mandibular function. Rigid stabilization and treatment of these defects can be challenging due to the limited availability of bone for fixation as well as limited soft tissue coverage. This case report describes successful treatment of a nonunion fracture using cortical allograft and locking titanium miniplates. Complete osseointegration and bone healing were achieved, allowing for complete return to normal occlusion and function.

Composite Resection of Tumors of the Rostral Maxilla and Dorsolateral Muzzle Utilizing an Upper Lip-Sparing, Combined Approach in Dogs

Tumors of the rostral maxilla that involve both the oral mucosa and the dermis or subdermis of the dorsolateral muzzle provide unique challenges for the oromaxillofacial surgeon. Traditionally described approaches to such lesions may involve an intraoral incision that extends and involves the upper lip to envelope the involved dermis of the dorsolateral muzzle. However, such an approach unnecessarily resects upper lip tissue resulting in a large defect that likely requires advanced skin flaps or grafts for reconstruction. Such flaps are technically challenging and introduce potential for significance postoperative complications. In this article, we provide a detailed description a combined intra- and extraoral approach that allows for composite resection of tumors of the rostral maxilla that also involve the dorsolateral muzzle. The described technique allows for excellent intraoperative visualization and provides a superior cosmetic outcome that minimizes postoperative complications. In addition, we describe our experience utilizing the technique in three clinical cases.

Suspected Lateral Periodontal Cyst Presenting Concurrently with Canine Acanthomatous Ameloblastoma in a 2-Year-Old Standard Poodle

Lateral periodontal cysts (LPCs) are odontogenic epithelial cysts composed of nonkeratinized epithelial cells that are in the category of developmental cysts, rather than inflammatory cysts. Lateral periodontal cysts are rare both in people and domestic animals; they are associated with vital teeth and located lateral to a tooth root. Lateral periodontal cysts are typically asymptomatic lesions that are characterized radiographically as a unilocular lucency with well-defined corticated borders. Canine acanthomatous ameloblastoma (CAA) is the most common odontogenic neoplasm in dogs and rarely presents as a cystic lesion. This case report describes the diagnosis and treatment of a cyst that occurred as a swelling apical to a gingival mass that was diagnosed histologically as CAA. Surgical management by conservative gingivectomy, cyst enucleation, and bone grafting was an effective treatment in this patient.

Apical Microleakage in Root Canals Obturated With 2 Different Endodontic Sealer Systems in Canine Teeth of Dogs

An apical dye leakage test was utilized to compare 2 endodontic sealer systems commonly used in veterinary endodontic treatment. Rotary instrumentation followed by injection of 2 different sealers (GuttaFlow 2 and AH Plus) and a single master cone obturation technique were compared. Following obturation and restoration, specimens were immersed in India ink for 48 hours. A tooth mineral clearing technique was utilized to render the tooth samples transparent. Subsequently, the apices were evaluated for prevalence and magnitude of apical dye penetration under magnification. Statistical analysis of the results revealed no significant differences in the prevalence or magnitude of apical dye penetration between groups.

The Influence of Force Direction on the Fracture Pattern and Fracture Resistance of Canine Teeth in Dogs

Biomechanical studies of the elongated canine tooth of animals are few, and thus our understanding of mechanical and physical properties of animal teeth is limited. The objective of the present study was to evaluate the influence of force direction on fracture resistance and fracture pattern of canine teeth in an ex vivo dog cadaver model. Forty-five extracted canine teeth from laboratory beagle dogs were standardized by hard tissue volume and randomly distributed among 3 force direction groups. The teeth were secured within a universal testing machine and a load was applied at different directions based on testing group. The maximum force to fracture and the fracture pattern classification were recorded for each tooth. After correcting for hard tissue cross-sectional area in a multivariate analysis, no significant difference in the amount of force required for fracture was apparent between the different force direction groups. However, the influence of force direction on fracture pattern was significant. The results of this study may allow the clinician to educate clients on possible causal force directions in clinically fractured teeth and, thus, help prevent any contributing behavior in the future.

Detection of Pulpal Blood Flow In Vivo with Pulse Oximetry in Dogs

Objective

The aim of the present study was to investigate the ability of pulse oximetry to detect blood flow within the canine tooth of dogs.

Materials and methods

Dogs aged 18–138 months presenting for oral treatment and meeting the inclusion criteria underwent pulse oximetry evaluation of at least one canine tooth. Oxygen saturation (SpO₂) and pulse rate values were acquired from vital canine teeth of 38 clinical patients (representing 40 total teeth) with a handheld pulse oximeter and compared to a control area. SpO₂ values from the tooth and control area were recorded every 5 s for three 60-s intervals. The sensors were repositioned after each 60-s interval.

Results

The vital teeth consistently recorded SpO₂ values significantly lower than the control area. The mean vital tooth SpO₂ was 85.9% (median = 87%; SD = 8.6), and the mean control area SpO₂ was 97.7% (median = 98%; SD = 1.8). An age-related significant difference was noted in vital tooth SpO₂ values.

Conclusion

In conclusion, the present data support the possible use of pulse oximetry to detect blood flow in canine teeth. However, there was no significant correlation between SpO₂ values in the vital tooth and in the control areas. Additionally, the results were not definitive, and validation of the modality with additional studies of non-vital canine teeth is needed before clinical use can be recommended.

Treatment of Bignathic Malocclusions With Multistage Active Force Orthodontic Movements in a Cat

Untreated malocclusions may lead to negative oral health sequelae including, but not limited to, pain, dental trauma, periodontal disease, and endodontic disease. Thus, orthodontic treatments of malocclusion in companion animals are often pursued for reasons other than cosmesis. Treatment may provide a pain-free, functional occlusion with the opportunity for the best possible long-term oral health. This report describes the multistage orthodontic treatment of a bignathic malocclusion in a cat, highlighting the complexities and complications that may arise with orthodontic movement of multiple teeth.

The Influence of Crown Height to Diameter Ratio on the Force to Fracture of Canine Teeth in Dogs

Previous work suggests that the tooth height to diameter ratio (H/D) may have an influence on the fracture resistance of dog canine teeth. Thus, it can be hypothesized that canine teeth with distal abrasion or teeth already requiring pulpal manipulation may benefit from a reduction in height and that an ideal H/D exists that balances tooth fracture resistance and tooth function. Therefore, a study was performed to investigate the influence of H/D on force to fracture and probability of fracture of canine teeth in dogs. Thirty extracted canine teeth from laboratory Beagle dogs were standardized by hard tissue volume and evenly distributed among three groups; unaltered H/D (group A), 10% reduction in H/D (group B), and 20% reduction in H/D (group C). The teeth were potted in clear autopolymerizing orthodontic acrylic and then secured within a universal materials testing machine. A displacement was applied at a speed of 1-mm/min to the distoocclusal line angle at an angle of 45 degrees to the long axis of the crown. The maximum measured force at the time of fracture represented the maximum force to fracture. A linear regression model showed a significant inverse relationship between H/D and force to fracture (p = 0.043; 95% CI-55.2 to -0.09). A margin of safety (MoS) analysis was performed to determine the probability of fracture by comparing normal force distributions of the measured force at fracture to that reported in a previous study, representative of normal biting-pulling loads on canine teeth. When 100% of the load was applied to a single unaltered canine tooth the probability of fracture was 36.7%. Decreases in H/D of 10% and 20% resulted in a decreased probability of fracture by 24.1% and 60.4%, respectively. A paired MoS analysis was conducted wherein the applied loads were distributed across 2 maxillary canine teeth according to their relative heights. Within the pair, a 20% decrease in H/D decreased the probability of fracture of that tooth by 86.5%, but increased the probability of fracture of the unaltered contralateral canine tooth by 54.4%. The findings of this study support the hypothesis that teeth with a lower H/D are more resistant to fracture. However, given the potential impact of crown reduction of a single canine tooth on the load redistribution to the remaining unaltered canine teeth, further investigation is needed to determine what H/D would be ideal. In addition, future studies could elucidate in which clinical scenarios the concept of H/D reduction could be implemented. The results of this study may have implications on the successful long-term management of traumatized canine teeth in dogs.

The Influence of Axial Grooves on Dislodgment Resistance of Prosthetic Metal Crowns in Maxillary Fourth Premolar Teeth of Dogs

The reported failure rate for full veneer crowns in dogs is suboptimal, particularly in teeth with naturally poor retentive features such as the maxillary fourth premolar tooth of dogs. Although the data regarding crown retention on the maxillary fourth premolar in dogs are limited, there are data that suggest the crown failure rate could be similar to that of the canine tooth. Thus, methods to improve retentive features of the preparation design should be pursued. The objective of the present study is to quantify the influence of axial grooves on the dislodgment resistance of full veneer metal crowns in dogs. Crown dislodgment testing was performed on cast alloy dies of the maxillary fourth premolar tooth with unfavorable retentive features prepared with and without axial grooves, to quantify the difference in force required to dislodge a cemented full veneer crown. The force required to cause crown dislodgment was recorded for each crown. Statistical analysis revealed a significant increase ( P < .001) in the force required for crown dislodgment in teeth prepared with axial grooves compared to those prepared without axial grooves.

Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography

The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT.

Quantitative Comparison of Mathematical Models to Measure Surface Area of Canine Teeth Prepared to Receive Full Veneer Crowns in Dogs

OBJECTIVE

This study was performed in order to determine if mathematical modeling of the canine teeth in dogs could be utilized to provide an accurate and reliable estimation of crown surface area that could be used in both a research and a clinical setting.

MATERIALS AND METHODS

Actual surface area (aSA) calculations for 32 stone dies of clinical crown preparations were acquired utilizing a tridimensional (3D) laser scanner and 3D computer-aided design and manufacturing (CAD/CAM) software applications. These calculations were used as a control. Seventeen unique mathematical models from eight geometric shapes were used to calculate estimated surface area (eSA) of each stone die. Linear association and agreement between eSA and aSA calculations were assessed with multiple statistical methods.

RESULTS

All methods of eSA showed a significant linear association with aSA. Five of the mathematical models [right elliptical frustum (H3), right elliptical cone (G3), right pyramidal cone (A3), right circular frustum (F2), and right circular cone (E1)] were superior to the other 12 models.

CONCLUSION

The H3 mathematical model based on the right elliptical frustum provided the most accurate estimate of crown surface area of dog teeth. However, H3 requires the use of laser scans and a 3D CAD software program. As a result, this model would be recommended for research applications. The E1 mathematical model was similar in accuracy to H3 and, given it requires only two measurements and a comparatively simple equation for calculation, this method would be recommended for clinical chair-side use.

Classification and Epidemiology of Traumatic Dentoalveolar Injuries in Dogs and Cats: 959 Injuries in 660 Patient Visits (2004-2012)

The objective of this study was to determine the epidemiology of traumatic dentoalveolar injuries (TDI) in dogs and cats and to evaluate the applicability of a human classification system for TDI in dogs and cats. All patients diagnosed with a TDI were identified from the University of Wisconsin-Madison School of Veterinary Medicine Dentistry and Oral Surgery Service case log and the hospital patient processing software. The study population consisted of 621 dogs and cats, in a total of 660 patient visits from 2004 to 2012, admitted for oral treatment and subsequently diagnosed with at least one TDI Medical records including diagnostic imaging studies were reviewed to group the injury according to a classification system used in humans for TDI. Patient signalment, tooth injured, and number of injuries per patient were recorded and tabulated. The overall prevalence of TDI was 26.2%. The mean +/- SD number of TDI per patient was 1.45 +/- 0.85. All 14 classes of TDI recognized by the classification system utilized in humans were identified, and all (100%) TDI identified in this study were classifiable using this system. Enamel-dentin-pulp fracture was the most common TDI (49.6%). The most commonly injured teeth were the mandibular or maxillary canine teeth (35.5%). The most common age for dogs and cats with TDI were 3-6 years (33.0%) and 7-10 years (31.3%). With a frequency of 1 in 4 animals, TDI are common and represent a significant pet health concern. Most TDI are considered severe and require timely, and sometimes immediate, treatment. The adoption and utilization of a complete classification system, such as the one used in this study, is recommended in order to improve future epidemiological study of TDI in animals.

Effect of particle size on calcium release and elevation of pH of endodontic cements

BACKGROUND/AIM

Elevation of pH and calcium ion release are of great importance in antibacterial activity and the promotion of dental soft and hard tissue healing process. In this study, we evaluated the effect of particle size on the elevation of pH and the calcium ion release from calcium silicate-based dental cements.

MATERIAL AND METHODS

Twelve plastic tubes were divided into three groups, filled with white mineral trioxide aggregate (WMTA), WMTA plus 1% methylcellulose, and nano-modified WMTA (nano-WMTA), and placed inside flasks containing 10 ml of distilled water. The pH values were measured using a pH sensor 3, 24, 72, and 168 h after setting of the cements. The calcium ion release was measured using an atomic absorption spectrophotometer with same sample preparation method. Data were subjected to two-way analysis of variance (anova) followed by post hoc Tukey tests with significance level of P < 0.05.

RESULTS

Nano-WMTA showed significant pH elevation only after 24 h (P < 0.05) compared with WMTA, and after 3, 24, and 72 h compared with WMTA plus 1% methylcellulose (P < 0.05). Nano-WMTA showed significantly higher calcium ion release values compared to the other two groups (P < 0.05).

CONCLUSIONS

Nano-modification of WMTA remarkably increased the calcium ion release at all time intervals postsetting, which can significantly influence the osteogenic properties of human dental pulp cells and as a consequence enhance mineralized matrix nodule formation to achieve desirable clinical outcomes. However, the increase in pH values mainly occurred during the short time postsetting. Addition of 1% methylcellulose imposed a delay in elevation of pH and calcium ion release by WMTA.

Evaluation of the Natural Crown Convergence Angle of Dog Carnassial Teeth

A limiting factor in achieving an ideal crown preparation design is the natural morphology, principally the convergence angle, of the tooth. The natural convergence angle of the carnassial teeth in the dog has not been reported. The aim of the study reported here was to establish the natural crown convergence angle of the maxillary fourth premolar and mandibular first molar teeth in the dog. The natural convergence angle of the carnassial teeth in dogs was large and was not significantly associated with patient weight, age, or skull type.

Nomenclature and Classification of Odontogenic Tumors - Part I: Historical Review

Odontogenic tumor nomenclature and classification is frustrating for both physicians and veterinarians. There has been and continues to be an evolution of the terms and taxonomy used in veterinary and human literature. In this historical review, we aim to provide veterinarians a fundamental basis for understanding how the etymology for odontogenic tumors has evolved over the past two centuries.

Nomenclature and Classification of Odontogenic Tumors - Part II: Clarification of Specific Nomenclature

Accurate identification of odontogenic tumors is critical for productive communication and an important foundation for useful comparative epidemiologic studies of odontogenic tumors in both domestic animals and humans. This manuscript illuminates the subject of veterinary odontogenic tumor nomenclature and will serve as a foundation for future updates in nomenclature and classification of odontogenic tumors.

Traumatic Dentoalveolar and Maxillofacial Injuries in Cats

Practical relevance:

Maxillofacial and traumatic dentoalveolar injuries can cause pain and inflammation, and reduce function of the mouth, impacting a cat’s quality of life. Many traumatically induced feline fractures have been reported to involve the mandible or skull and, in cats with maxillofacial trauma, traumatic dentoalveolar injuries are particularly prevalent. Traumatic dentoalveolar injuries can also often be found in otherwise healthy cats.

Clinical challenges:

Some traumatic dentoalveolar injuries require emergency treatment; timely recognition and managment is therefore important for achieving the optimal outcome. Multiple approaches exist for the management and repair of maxillofacial traumatic injuries. However, those for traumatic dentoalveolar injuries may be more limited.

Audience:

This review is aimed at feline and general practitioners, as well as veterinarians with expertise in dentistry.

Evidence base:

The authors draw on their clinical experience and evidence from the literature, where appropriate, to produce an overview of foundation guidelines. It is hoped that this will serve as a stimulus for deeper consideration as to what constitutes ‘best practice’ principles for cats with traumatic dentoalveolar and maxillofacial injuries.

Effect of preparation surface area on the clinical outcome of full veneer crowns in dogs

Crown therapy is commonly used in veterinary medicine to provide support to teeth which have previously fractured, received root canal therapy, have significant wear, or experienced other detrimental removal of tooth substance. As with several aspects of veterinary medicine, many of the recommendations or guidelines for crown therapy originate from human dentistry, which are then transferred to veterinary patients. Due to the significant difference in the anatomy of teeth and function of the oral cavity between humans and dogs, these guidelines need to be studied to determine the appropriateness of their use in veterinary patients. This article evaluates the relationship between surface area of the preparation and clinical outcome of full veneer crown therapy of the canine tooth in dogs. Although there appeared to be a positive relationship between preparations with greater surface area and successful clinical outcome, it was not found to be statistically significant.

Clinicopathologic Characterization of Oral Pyogenic Granuloma in 8 Cats

This case series characterizes the clinicopathologic features and treatment of oral pyogenic granuloma in 8 cats. The cats reported here were patients originating from collaborative efforts at an academic clinical teaching hospital and a specialty dentistry/oral surgery referral practice. Although the initial biopsy results were variable, in all cases the diagnosis reflected an inflammatory process. A second clinicopathologic evaluation of these cases determined that all lesions were consistent with oral pyogenic granuloma. The location of the lesion was consistent among all cats within the present study. Lesions developed at the vestibular mucogingival tissues of the mandibular first molar teeth. We propose that malocclusion and secondary traumatic contact of the ipsilateral maxillary fourth premolar tooth with the mandibular soft tissues is a possible contributing factor in the etiopathogenic mechanism.

Optimized canine dental computed tomographic protocol in medium-sized mesaticepahlic dogs

The purpose of this study was to develop an optimized imaging protocol for canine dental imaging using single-detector row CT and multidetector row CT. Two medium-sized mesaticephalic cadaver dog heads were scanned using varying slice thickness, sequential vs. helical scanning mode, sequential CT table increment, pitch, image reconstruction algorithm, and an additional moderate edge enhancement filter. For each series, two reviewers scored dental roots as not visible (score: 0), partially visible (score: 1) or completely visible (score: 2). Sharpness of the dento-alveolar margin was scored as blurry (score: 0), sharp (score: 1) or very sharp (score: 2). Consensus reader scores were compared among CT protocols. For single-detector row CT, complete visualization of all tooth roots was only achieved with 1 mm slice thickness and image interval sequential or helical series (pitch of 1 or 2) using a high-frequency image reconstruction algorithm with or without additional edge enhancement. For four-detector row CT, complete visibility of all tooth roots was recorded in all series. For single-detector row CT, all medium frequency algorithm series yielded blurry margin scores and all other series yielded sharp margin scores. For four-detector row CT, sequential and helical 0.5 mm thickness images yielded very sharp dento-alveolar margin scores, whereas the 1 mm series yielded only sharp margin scores. Authors concluded that the optimal dental imaging protocol was a sequential mode 1 mm slice thickness and interval with a high-frequency image reconstruction algorithm and an additional moderate edge enhancement filter.

Crown preparation design: an evidence-based review

Evidence-based clinical guidelines for full metal crown preparation design are seldom encountered in the veterinary literature. The veterinary literature regarding prosthodontic treatment in companion animals is sparse and consists primarily of case reports and expert opinion based primarily on clinical experience. The goal of this manuscript is to present concepts of evidence-based practice, review common recommendations on crown preparation design from the veterinary literature, and to provide an assessment of the evidence for or against those recommendations.

Retrospective evaluation of canine and feline maxillomandibular trauma cases. A comparison of signalment with non-maxillomandibular traumatic injuries (2003-2012)

OBJECTIVES

To determine differences in signalment between maxillomandibular (MM) and non-maxillomandibular (non-MM) trauma patients to help predict the type of injury sustained.

METHODS

A medical records database was searched from December 2003 to September 2012 to identify all MM trauma patients. A random sample of non-MM trauma patients was generated for comparison. Patient species, age, sex, weight, and injury aetiology were recorded for both populations.

RESULTS

Sixty-seven MM trauma patients and 129 non-MM trauma patients were identified. Feline patients were almost twice as likely to be presented for MM trauma compared with non-MM trauma. The median weight of canine patients suffering MM injury was significantly less than that of non-MM patients (p = 0.025). A significant association existed between the causes of injuries associated with MM and non-MM trauma populations (p = 0.000023). The MM trauma patients were more likely to sustain injury as a result of an animal altercation (Bonferroni p = 0.001) while non-MM injuries were more likely to result from motor vehicle accidents (Bonferroni p = 0.001). Overall, animals that were less than one year of age with traumatic injuries were overrepresented (65/196) in comparison to the entire patient population.

CLINICAL SIGNIFICANCE

The results of this study may help guide clinicians in the evaluation and screening of trauma patients that are presented as an emergency. Cats, small dogs and animals suffering from animal altercations should all be closely evaluated for MM injury.

Clinical, Histologic, and Computed Tomographic Features of Oral Papillary Squamous Cell Carcinoma in Dogs: 9 Cases (2008–2011)

Medical records of dogs diagnosed with oral papillary squamous cell carcinoma between December 2008 and April 2011 were reviewed. Information abstracted included signalment, tumor location, tumor size, computed tomographic (CT) features, evidence of metastatic disease based on cytologic examination of lymph node aspirates and thoracic radiography, treatment, surgical margins, histologic features, and treatment outcome. Dogs included in the study were all sexually altered, predominantly large breed dogs with a mean age of 3.9-years (range, 0.5 to 9.0-years). The most common location was the rostral maxilla. Invasion of underlying bone and lymphadenopathy were evident on CT imaging in most dogs. No evidence of metastasis was found on mandibular lymph node cytology and thoracic radiography. Histologic analysis revealed similar morphologic findings for all surgically resected tumors. Surgical excision with 1–2 cm margins was complete in all cases, with a mean tumor-free interval of 12.1-months.

Comparing the degree of exothermic polymerization in commonly used acrylic and provisional composite resins for intraoral appliances

The use of dental acrylics and composite resins in veterinary dentistry has become widespread. However their use is not without potential complications. All acrylics and composite resins produce an exothermic reaction during the polymerization process. The aim of the current study was to evaluate thermal conduction during the polymerization reaction of each material to offer clinical guidelines when choosing a material with particular consideration for the significant volumes typically used. Results showed that methylmethacrylate based resins generated a significantly higher degree of heat during polymerization. Bis-acryl based composite resins generated a significantly lower degree of heat during polymerization, making them the material of choice to potentially minimize thermal injury to the dentin-pulp complex. It is the responsibility of the clinician to become aware of all materials available, and to have an understanding of their properties to guide them in making sound clinical judgments.

Prevalence and nature of dentoalveolar injuries among patients with maxillofacial fractures

OBJECTIVE

Although not previously reported, experience suggests that dentoalveolar injury is -common among patients with maxillofacial fractures. The objective of this study was to evaluate and describe the prevalence and nature of dentoalveolar injuries in patients identified with maxillofacial fractures.

METHODS

Medical records of 43 dogs and cats diagnosed with maxillofacial fractures between 2005 and 2012 were reviewed to identify patients with concurrent dentoalveolar injury. Medical records of patients with dentoalveolar injury were abstracted for the following information: signalment (including sex, age and skull type), mechanism of maxillofacial trauma, location and number of maxillofacial fractures, dentoalveolar injury type and location and the number of dentoalveolar injury per patient. Statistical evaluation was performed to determine associations between signalment, mechanism of trauma, location and number of maxillofacial fractures and the prevalence and nature of concurrent dentoalveolar injury.

RESULTS

Dentoalveolar injuries are common among patients with maxillofacial trauma. Age and mechanism of trauma are significant predictors of the presence of dentoalveolar injuries in patients with maxillofacial trauma.

CONCLUSIONS AND CLINICAL RELEVANCE

The findings of this study serve to encourage veterinarians to fully assess the oral cavity in patients with maxillofacial fractures as dentoalveolar injuries are common and can be predicted by age and mechanism of trauma.

Use of an Autogenous Cortical Graft in Combination with Guided Tissue Regeneration for Treatment of an Infrabony Defect

Infrabony periodontal defects are common findings encountered during complete oral examinations. Treatment options for infrabony lesions are aimed at meeting client demands as well as patient needs. Deciding on how to treat these lesions depends on the nature and degree of disease present as well as having the materials available to improve the chances of achieving the greatest clinical success. Bone grafting of an infrabony defect of the left mandibular first molar tooth of a dog using an autogenous cortical graft harvested with a reusable bone grafter in combination with guided tissue regeneration is described.