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.