Feline dental radiography and radiology: A primer

Evaluation of Dental and Oral Pathologies of 36 Captive Lions (Panthera leo) and Tigers (Panthera tigris)

The documented increase in the occurrence of dental diseases in captive big cats over the past decades has necessitated the need to target dental medical research accordingly. The aim of this study was the systematic evaluation of dental and oral pathologies of lions and tigers which included intraoral dental radiography. Thirty-six animals of both sexes, ranging in age from nine months to 18 years, predominantly in circus husbandry, served as the basis of the present study, and their dental health status was investigated. The preliminary report and history, adspection of the awake animal, and examination under anesthesia provided important information. Eight animals were specifically presented for oral examination because of known dental disease. The remaining 28 animals were anesthetized for other medically necessary procedures, and each animal's oral and dental health status was also evaluated while under anesthesia. In the 28 animals that underwent routine oral cavity examination, pathological changes that had not previously been noticed were found in two-thirds of the animals (19/28). One-quarter of all the animals (9/36) had no abnormal oral cavity findings. Dentoalveolar trauma such as tooth fractures and abrasion (24/36) were diagnosed most frequently. The results highlight the importance of regular oral examinations in big cats. Furthermore, the results suggest that there is a relationship between husbandry conditions and the incidence of dentoalveolar trauma in captive big cats.

Recasting the gold standard - part I of II: delineating healthcare options across a continuum of care

AIM

This is the first part of a two-part series on spectrum of care that encourages practitioners to embrace a non-binary approach to healthcare delivery. When care is not framed as all-or-none, either/or or best versus lesser, the provider and client can agree to diagnostic and/or treatment plans that individualize the practice of veterinary medicine. Care is tailored to the patient along a continuum of acceptable options. Care may also be intentionally incremental, with plans to reassess the patient and revise case management as needed.

RELEVANCE

Acknowledgment and ultimately acceptance that patient care journeys can be distinct, yet equitably appropriate, offers providers the flexibility to adapt case management competently and confidently to the patient based upon contextualized circumstances including client needs, wants and expectations for healthcare outcomes. Thinking outside the box to recast the historic gold standard with a continuum of care strategically offers feline practitioners a means by which they can overcome barriers to healthcare delivery.

SERIES OUTLINE

This first article introduces spectrum of care as an appropriate approach to case management and broadens its definition beyond cost of care. Part II explores communication strategies that enhance veterinary professionals' delivery of spectrum of care through open exchange of relationship-centered dialogue.

Mandibular fracture repair techniques in cats: a dentist's perspective

PRACTICAL RELEVANCE

Feline head trauma injuries are common in general practice, often resulting in mandibular fracture. An understanding of the recent advances in the field of mandibular fracture repair will facilitate evidence-based decision-making in clinical practice.

CLINICAL CHALLENGES

Feline maxillofacial and oral anatomy brings unique challenges in comparison with dogs. It has been commonplace to adapt techniques and equipment that are better suited to other body regions or are species-inappropriate for use in feline maxillofacial surgery, and this has traditionally resulted in high morbidity.

AIMS

This review presents an overview of the diagnosis of, and decison-making for, maxillofacial trauma in cats, specifically with reference to the feline mandible. The challenges associated with the management of these injuries are presented. Techniques for repair that can be employed in general practice, as well as more advanced surgical options, are discussed, as well as the indications for invasive vs non-invasive management. Underutilised methods involving composite dental materials and their versatility for the repair of mandibular fractures in cats, and miniplates for caudal mandibular fractures in cats, are specifically covered, as well as other recent advances in the field, including three-dimensional printing and custom-printed implants.

EVIDENCE BASE

Management of feline facial fractures is an often neglected topic, with very few published studies choosing to focus on head trauma outcomes in cats. Where available, however, this review draws on the published literature, as well as the authors' own clinical experience.

Intra-socket application of medical-grade honey after tooth extraction attenuates inflammation and promotes healing in cats

OBJECTIVES

Dental diseases are a major problem in cats and often necessitate tooth extraction. Medical-grade honey (MGH) has antimicrobial and wound-healing properties, and therefore the aim of this study was to investigate whether intra-socket application improved healing after tooth extraction. It was postulated that applying MGH would reduce inflammation, improve the viability of the surgical flap and enhance healing following tooth extraction.

METHODS

A prospective randomised controlled trial was performed in client-owned cats undergoing bilateral tooth extractions of the same element of the canine or (pre)molar tooth. A split-mouth design was used in which every animal served as its own control. After surgical extraction of the elements, the sockets on one side were filled with an MGH-based ointment (L-Mesitran Soft), whereas the contralateral side received no treatment (control). A mucoperiosteal flap was used on both sides, and simple interrupted monofilament sutures were placed. No antimicrobial drugs were administered. Clinical parameters (inflammation/redness, flap viability and wound healing) were subjectively analysed on days 3 and 7 post-extraction by a veterinarian blinded to the treatment.

RESULTS

Twenty-one cats were included. MGH significantly decreased signs of inflammation (P <0.01), improved mucoperiosteal flap viability (P <0.01) and promoted wound healing (P = 0.01), at both time points. MGH was easy to apply and there were no adverse events.

CONCLUSIONS AND RELEVANCE

Intra-socket application of MGH after tooth extraction positively affects the surgical wound, as it reduces redness, improves flap viability and enhances wound healing. Applying MGH represents a potent adjuvant therapy to support intra-oral wound healing after tooth extraction.

A Standard Method for Intraoral Dental Radiography With Dental Photo-Stimulative Phosphor (PSP) Plates in Big Cats

In recent years, dentistry has steadily gained more prominence in veterinary medicine, including exotic and wild animal medicine. It is known that dental diseases are among the most common diseases in captured big cats. However, so far, there is no standardized method for dental radiography in these animals. Therefore, this study aimed to develop a standardized procedure for the systematic radiographic examination of the teeth in big cats. In total, 34 big cats, including 21 lions and 13 tigers, of different ages were examined. Animals that needed treatment for known dental diseases and those that had to be anesthetized for other medically necessary procedures and dental health status examinations were included. Intraoral dental radiographs were captured with digital imaging plates designed for intraoral dental radiography in horses. Based on the intraoral dental radiography procedures used in domestic cats, both the bisecting angle technique and parallel technique were used. A hemisphere model originally developed for horses was used to describe the path and position of the x-ray beam as accurately as possible. The results demonstrated that it was possible to completely image all the teeth of big cat dentition on seven radiographs using the described method. This method can be used to acquire high-quality intraoral dental radiographs in big cats, aiding in the quick and reliable diagnosis of dental diseases.

The Cat Mandible (II): Manipulation of the Jaw, with a New Prosthesis Proposal, to Avoid Iatrogenic Complications

Simple Summary

The small size of the feline mandible makes its manipulation difficult when fixing dislocations of the temporomandibular joint or mandibular fractures. In both cases, non-invasive techniques should be considered first. When not possible, fracture repair with internal fixation using bone plates would be the best option. Simple jaw fractures should be repaired first, and caudal to rostral. In addition, a ventral approach makes the bone fragments exposure and its manipulation easier. However, the cat mandible has little space to safely place the bone plate screws without damaging the tooth roots and/or the mandibular blood and nervous supply. As a consequence, we propose a conceptual model of a mandibular prosthesis that would provide biomechanical stabilization, avoiding any unintended (iatrogenic) damage to those structures. The improvement of imaging techniques and a patient-specific prosthesis made of full biocompatible material are part of the future trends to improve patients’ recovery.

Abstract

The cat mandible is relatively small, and its manipulation implies the use of fixing methods and different repair techniques according to its small size to keep its biomechanical functionality intact. Attempts to fix dislocations of the temporomandibular joint should be primarily performed by non-invasive techniques (repositioning the bones and immobilisation), although when this is not possible, a surgical method should be used. Regarding mandibular fractures, these are usually concurrent with other traumatic injuries that, if serious, should be treated first. A non-invasive approach should also first be considered to fix mandibular fractures. When this is impractical, internal rigid fixation methods, such as osteosynthesis plates, should be used. However, it should be taken into account that in the cat mandible, dental roots and the mandibular canal structures occupy most of the volume of the mandibular body, a fact that makes it challenging to apply a plate with fixed screw positions without invading dental roots or neurovascular structures. Therefore, we propose a new prosthesis design that will provide acceptable rigid biomechanical stabilisation, but avoid dental root and neurovascular damage, when fixing simple mandibular body fractures. Future trends will include the use of better diagnostic imaging techniques, a patient-specific prosthesis design and the use of more biocompatible materials to minimise the patient’s recovery period and suffering.

Successful Use of MTA Fillapex as a Sealant for Feline Root Canal Therapy of 50 Canines in 37 Cats

Intentional or unintentional pulp exposure of cat canines can lead to periapical disease, osteomyelitis, and oral pain. Root canal therapy (RCT) allows the retention of cat canines with pulp exposure by removing the infected pulp and replacing it with an inert material. This study used MTA Fillapex™ as a root canal sealant with gutta percha single cone obturation in 37 cats (50 canine teeth). Roots were classified as "successful," "no evidence of failure (NEF)," or "failed" at 6-month radiographic reviews. Therapy was considered "successful" if a preoperative periapical lucency had healed or not formed after treatment and any preoperative external inflammatory root resorption (EIRR) had stabilized without progression. Therapy was categorized as "NEF" if a periapical lucency had remained the same or decreased in size but not completely resolved and any preoperative EIRR had stabilized without progression. "Failed" if a periapical lucency had occurred or increased in size posttreatment or if EIRR had developed or progressed posttreatment. Thirty-two canine teeth (64%) were classified as "successful," 14 canine teeth (28%) were classified as "NEF," and 4 canine teeth (8%) were classified as "failed". The study concluded that RCT using MTA Fillapex as a root canal sealant is a suitable endodontic treatment for fractured cat canines, especially those that are periodontally or endodontically challenged.

Neurobehavioral Disorders: The Corticolimbic System in Health and Disease

The corticolimbic system (prefrontal cortices, amygdala, and hippocampus) integrates emotion with cognition and produces a behavioral output that is flexible based on the environmental circumstances. It also modulates pain, being implicated in pathophysiology of maladaptive pain. Because of the anatomic and function overlap between corticolimbic circuitry for pain and emotion, the pathophysiology for maladaptive pain conditions is extremely complex. Addressing environmental needs and underlying triggers is more important than pharmacotherapy when dealing with feline orofacial pain syndrome or feline hyperesthesia syndrome. By contrast, autoimmune limbic encephalitis requires prompt diagnosis and management with immunosuppression and seizure control.

Tooth resorption in cats: pathophysiology and treatment options

PRACTICAL RELEVANCE

Tooth resorption is common in the domestic cat and the incidence has been reported to increase with increasing age. Cats with clinically missing teeth have also been found to be more likely to have tooth resorption. All types of teeth in the feline dentition may be affected, but lesions seem to be more common in certain teeth.

CLINICAL CHALLENGES

Tooth resorption can be difficult to detect, with cats often masking signs of oral discomfort or pain. Routine radiography is required for timely diagnosis, as clinical (visual and tactile) methods only detect late-stage lesions - that is, when they become evident in the crown. The aetiology of many tooth resorptions is not clear. A large number of lesions appear to be idiopathic and, to date, there is no known treatment that prevents the development and/or progression of this category of tooth resorption. Tooth extraction is the gold standard treatment but teeth with resorptive lesions are notoriously difficult to extract and coronal amputation is often indicated. Determining the best treatment option in an individual case again relies on radiography.

AUDIENCE

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

EVIDENCE BASE

The author draws on the published literature and her clinical experience and own research to review current thinking about the epidemiology, aetiology and pathogenesis of tooth resorptions, and to offer advice on diagnosis and treatment options.