Prevalence and nature of dentoalveolar injuries among patients with maxillofacial fractures

Outcomes of root canal treatments with three different sealers for 120 fractured maxillary fourth premolar teeth in small-to medium-sized dogs

Introduction

Tooth fracture is one of the most common traumatic maxillofacial injuries in dogs and cats. For fractures with pulp exposure occurring in functionally important teeth, the literature indicates that root canal treatment (RCT) is an effective therapy option that may be the remedy of choice before extraction. The most commonly reported fractures in the United States involve canine teeth; however, fractures of the maxillary fourth premolars are more common in Korea, where there are many small-and medium-sized dogs. RCT mechanically and chemically removes pulp tissue and bacteria (cleaning and shaping) from the infected root canal, and obturates the root canal with filling material to restore tooth functionality without inflammation. Various techniques, instruments, and materials used in humans have been modified for application in veterinary dentistry.

Methods

This study analyzed the results of RCT of the maxillary fourth premolar in 120 small-and medium-sized dogs (weighing less than 25 kg) using three different sealers (silicone-based sealer, bioceramic sealer, and calcium hydroxide-based sealer) through a simple application of the single-cone technique.

Results

The overall success rate of RCT in maxillary fourth premolars was 90.83%, with 8.33% no evidence of failure (NEF) and 0.83% failure.

Discussion

There were no significant differences between the three different sealers. Furthermore, preexisting periapical lesion (PAL) was reconfirmed as a factor in reducing the success rate of RCT. In addition, the working length and master apical file of each root were analyzed in our study as a novel reference for endodontic veterinarians.

Tooth aspiration in two cats following maxillofacial trauma

Case series summary

Tooth aspiration is a rare occurrence in human medicine, and even more so in veterinary medicine. This report describes two cats that aspirated a tooth (one canine tooth and one premolar tooth) following maxillofacial trauma. One cat presented with dyspnoea, while the other showed no respiratory clinical signs. In both cases diagnosis was reached by obtaining routine thoracic radiographs, and successful retrieval of the teeth was achieved by bronchoscopy. Both cats recovered uneventfully.

Relevance and novel information

To our knowledge, this is the first report in the veterinary literature of tooth aspiration into the tracheobronchial tree following maxillofacial trauma. The scope of this case series is to raise awareness that tooth aspiration can occur following maxillofacial trauma and has the potential for serious complications if not diagnosed and treated promptly. Therefore, an oral examination must be performed in every maxillofacial trauma patient and missing teeth should be accounted for, even when respiratory clinical signs are not detected.

Surgical Treatment and Outcome of Acquired Midline Palate Defects in Cats

Acquired midline palate defects (PDE) affect the hard palate and/or soft palate, and result from trauma, commonly falling from a height or being hit by a motor vehicle. Additional life-threating injuries and costs associated with the treatment may delay the surgical treatment. This retrospective study describes signalment, cause, and extent of the PDE, and treatment in 25 cats. In addition, the outcome of the surgical repair is described in 19 (76%) cats. All defects were repaired within 5 days of the injury. Twenty (80%) cats were 4 years of age or younger. The most common rostral extent of the PDE was to the level of the third premolar tooth (n = 8; 32%), incisor teeth (n = 7; 28%), and fourth premolar tooth (n = 5; 20%). The soft palate laceration was present in all cases. Surgical therapy was successful in all cases with follow-up. The most common techniques used for the closure of the hard palate defect were bilateral pedicle flaps with lateral releasing incisions (n = 8; 32%), direct apposition of the oral mucosa (n = 7; 28%), bilateral pedicle flaps with lateral releasing incisions and interquadrant splinting (n = 5; 20%), and unilateral pedicle flap with one lateral releasing incision (n = 4; 16%). A tension-free closure by direct apposition of the edges was possible for the soft palate laceration. No oronasal fistulae were identified at follow-up. The only complication was malocclusion. The interquadrant splinting was most often used for PDE extending to the rostral portion of the hard palate (p < 0.05). The cats that suffered postoperative malocclusion were significantly more likely to have sustained temporomandibular joint injury, underwent CT scan, or had a feeding tube placed before discharge. The results of this retrospective study indicate that the early treatment (within 5 days) of the acquired longitudinal defects in the midline of the hard and soft palates is highly successful.

World Small Animal Veterinary Association Global Dental Guidelines

Dental, oral, and maxillofacial diseases are some of the most common problems in small animal veterinary practice. These conditions create significant pain as well as localized and potentially systemic infection. As such, the World Small Animal Veterinary Association (WSAVA) believes that un- and under treated oral and dental diseases pose a significant animal welfare concern. Dentistry is an area of veterinary medicine which is still widely ignored and is subject to many myths and misconceptions. Effective teaching of veterinary dentistry in the veterinary school is the key to progression in this field of veterinary medicine, and to the improvement of welfare for all our patients globally. These guidelines were developed to provide veterinarians with the information required to understand best practices for dental therapy and create realistic minimum standards of care. Using the three-tiered continuing education system of WSAVA, the guidelines make global equipment and therapeutic recommendations and highlight the anaesthetic and welfare requirements for small animal patients. This document contains information on common oral and dental pathologies, diagnostic procedures (an easily implementable and repeatable scoring system for dental health, dental radiography and radiology) and treatments (periodontal therapy, extractions). Further, there are sections on anaesthesia and pain management for dental procedures, home dental care, nutritional information, and recommendations on the role of the universities in improving veterinary dentistry. A discussion of the deleterious effects of anaesthesia free dentistry (AFD) is included, as this procedure is ineffective at best and damaging at worst. Throughout the document the negative effects of undiagnosed and/or treated dental disease on the health and well-being of our patients, and how this equates to an animal welfare issue, is discussed.

Craniomaxillofacial Trauma in Dogs-Part I: Fracture Location, Morphology and Etiology

Treatment of craniomaxillofacial (CMF) trauma in dogs often requires a multidisciplinary approach and a thorough understanding of the CMF skeletal structures involved. The aim of this retrospective study was to use a large number of CT studies of dogs evaluated for CMF trauma and to describe fracture location and morphology in relation to demographic data and trauma etiology. The medical records and CT studies of 165 dogs over a 10-year period were evaluated. The skeletal location of CMF fractures as well as the severity of displacement and fragmentation of each fracture was recorded. Patient demographic data and trauma etiology were also recorded. Animal bites accounted for the majority of trauma (50%), followed by unknown trauma (15%), vehicular accidents (13%), and blunt force trauma (13%). Small dogs, <10 kg, and juveniles accounted for the majority of patients (41.8 and 25.5%, respectively). The most likely bone or region to be fractured was the maxillary bone, followed by the premolar and molar regions of the mandible. Up to 37 bones or regions were fractured in any given patient, with an average of 8.2 fractured bones or regions per dog. The most commonly fractured location varied according to trauma etiology. Specifically, vehicular accidents tended to result in more locations with a higher probability of fracture than other trauma types. A major conclusion from this study is that every bone of the CMF region was fractured in at least one case and many cases had a large number of fractured regions. Thus, the need for comprehensive assessment of the entire CMF region, preferably using CT, is underscored.

Biomechanical Testing of a Calcium Phosphate-Phosphoserine-Based Mineral-Organic Adhesive for Non-invasive Fracture Repair of Mandibular Fractures in Dogs

Mandibular fracture repair is complicated by limited availability of bone as well as the presence of the neurovascular bundle and an abundance of tooth roots. Fractures at the location of the mandibular first molar teeth are common and it can be particularly challenging to apply stable fixation. Non-invasive fracture repair techniques utilize intraoral placement of fixation devices typically involving polymerized composites and/or interdental wiring. A novel calcium phosphate-phosphoserine–based mineral–organic adhesive was tested ex vivo to determine its effects on augmenting strength of different non-invasive fracture fixation techniques. This study both tested the use of mineral–organic adhesive for the purpose of stabilizing currently used non-invasive fracture repair constructs (intraoral composite splinting ± interdental wiring) and evaluated adhesive alone or with subperiosteally placed plates on buccal cortical bone surface. Aside from controls, not receiving an osteotomy along the mesial root of the mandibular first molar tooth, six treatment groups were tested to evaluate ultimate strength, stiffness, angular displacement, bending moment, and application time. All forms of fixation were found to be significantly weaker than control (p < 0.001). Only the control (p < 0.001) and mineral–organic adhesive and composite (P = 0.002) groups were found to be significantly stronger than wire and composite. No difference was noted in stiffness between any groups with control or wire and composite. Application times varied from the mineral–organic adhesive group (mean = 206 s) to mineral–organic adhesive and composite (mean = 1,281 s). Twenty-three fixation devices exhibited adhesive failure, 20 demonstrated cohesive failure, and 5 failed by cohesive and adhesive failure. When evaluating the ultimate strength of the fixation device groups, mineral–organic adhesive, and composite was shown to be the strongest construct. The use of resorbable bone adhesive and composite may provide a stronger fixation construct over interdental wire and composite for mandibular fracture repair in dogs.

Fracture Limits of Maxillary Fourth Premolar Teeth in Domestic Dogs Under Applied Forces

A cadaveric study was performed to investigate the external mechanical forces required to fracture maxillary fourth premolar teeth in domestic dogs and describe a clinically relevant model of chewing forces placed on functionally important teeth in which fracture patterns are consistent with those defined by the American Veterinary Dental College (AVDC). Twenty-four maxillary fourth premolar teeth were harvested from dog cadavers. Samples consisted of teeth with surrounding alveolar bone potted in polycarbonate cylinders filled with acrylic. The cylinders were held by an aluminum device at an angle of 60° with respect to the ground. An axial compression test was performed, creating a force upon the occluso-palatal aspects of the main cusps of the crowns of the teeth. The highest compressive force prior to failure was considered the maximum force sustained by the teeth. Results showed the mean maximum force (± SD) sustained by the tested teeth at the point of fracture was 1,281 N (± 403 N) at a mean impact angle (± SD) of 59.7° (± 5.2°). The most common fracture type that occurred among all samples was a complicated crown fracture (n = 12), followed by an uncomplicated crown fracture (n = 6), complicated crown-root fracture (n = 5), and uncomplicated crown-root fracture (n = 1). There was no statistically significant correlation between dog breed, age, weight, impact angle, crown height or crown diameter, and the maximum force applied at the point of fracture. The only independent variable that remained significantly associated with maximum force was the crown height to diameter ratio (p = 0.005), suggesting that a decreased ratio increases tooth fracture resistance. The methodology described herein has been successful in creating a pattern of fracture of maxillary fourth premolar teeth consistent with that defined by the AVDC under angled compression at forces within the maximum chewing capability of the average domestic dog.

Retrospective evaluation of canine and feline maxillomandibular trauma cases. Comparison of lunar cycle and seasonality with non-maxillomandibular traumatic injuries (2003-2012)

OBJECTIVES

To determine relationships between seasonality and lunar cycle and the frequency of maxillomandibular (MM) and non-maxillomandibular (non-MM) injury in canine and feline trauma patients.

METHODS

A medical records database was searched to identify all MM trauma patients (n = 67) and a random sample of non-MM trauma patients (n = 129) according to search criteria. Season of injury, moon phase, and moon luminosity were calculated for the date of injury.

RESULTS

Maxillomandibular injury occurred predominately in the spring and decreased through winter while non-MM injury occurred more frequently in the summer and fall. The difference in the frequency of MM and non-MM injuries during different seasons was not significant (p = 0.071). When comparing the amount of moon illuminated when injuries occurred during the quarters before or after the full moon, a difference (p = 0.007) was noted with a greater number of injuries occurring immediately following the full moon.

CLINICAL SIGNIFICANCE

These results may guide clinicians to closely evaluate trauma patients that are presented on emergency during a particular season or lunar phase. Based on the season at the time of injury, close evaluation for MM versus non-MM trauma may be appropriate.

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.