5 Hours of CE Credit
This course module provides foundational knowledge needed to evaluate horses with temporomandibular joint and hyoid apparatus disorders. Content includes topographic features, review of muscle of mastication, and detailed descriptions of specific articular features of the temporomandibular joint and hyoid apparatus. Biomechanical insights into mandibular movement during mastication, hyoid movements, and the effects of dental occlusion on pain and dysfunction of the equine head are provided. Pathological descriptions include material on temporomandibular joint pain and the pathogenesis of temporohyoid osteoarthropathy. Physical examination skills include observations of static and dynamic behaviors and the role of active and passive joint motion in identifying sources of pain and discomfort localized to the equine head. Treatment options include discussion of conservative approaches for managing temporomandibular joint pain and dysfunction in horses.
Section 1 Functional Anatomy of the Head
Learning objectives
Upon completion of this course content, the student will be able to:
- Readily identify palpable boney landmarks of the head
- Localize the superficial muscles of the head and describe their relative functions in horses
- Describe the basic innervation patterns of nerves that provide sensory and motor functions to the superficial structures of the head
- Discuss the function of the hyoid apparatus and the role of the associated hyoid articulations
- Describe the unique articular features of the temporomandibular joint in horses
- Evaluate the occlusal surfaces of the dental arcade in horses
- Discuss the effects of dentition on the temporomandibular joint
Clips
- Introduction
- Skull
- Temporomandibular joint
- Hyoid apparatus
- Muscles of the head
- Cervical muscles to the head
- Vasculature and innervation of the head
Section 2 Spinal Biomechanics: Temporomandibular Joint & Hyoid Apparatus
Learning objectives
Upon completion of this course content, the student will be able to:
- Describe the movement patterns of the mandible during mastication
- List the muscles that contribute to mandibular motion and explain their relative roles during mouth opening and closing
- Predict the effect of the dental occlusive surfaces on active and passive mandibular motion
- Describe the role of the hyoid apparatus in respiration, swallowing, and vocalization
- Discuss the intent for using of tongue ties and their reported biomechanical effects in horses
- Evaluate the potential helpful and harmful effects of tack on the head and mandible
Clips
- Introduction
- Temporomandibular joint biomechanics
- Dental morphology
- Dental influences on mandibular motion
- Bit and bridle biomechanics
Section 3 Pathology of the Head Region
Learning objectives
Upon completion of this course content, the student will be able to:
- Describe disorders affecting the temporomandibular joint and hyoid apparatus
- Provide a diagnostic approach for assessing masticatory muscle disorders
- Discuss the role of pain, stiffness, and soft tissue swelling associated with temporomandibular joint osteoarthritis
- Explain the pathogenesis of temporohyoid osteoarthropathy
- Provide a diagnostic approach for identifying facial nerve paralysis
- Describe the pathogenesis of vestibular deficits associated with temporohyoid osteoarthropathy
- Discuss the role otitis in the possible development of temporohyoid osteoarthropathy
- Describe the clinical effects of dental overgrowth, malocclusion, and altered occlusal surfaces
- Discuss how dental disorders relate to mandibular mobility
- Explain the pathogenesis of basilar skull fractures
Clips
- Introduction
- Myositis
- Temporomandibular joint pathology
- Dental disorders and temporomandibular joint
- Temporohyoid osteoarthropathy
- Otitis
- Basilar skull fractures
Section 4 Evaluation of the Head Region
Learning objectives
Upon completion of this course content, the student will be able to:
- Outline the functional features of the head in horses
- Discuss the purpose and clinical value of static and dynamic observation of behaviors and functions localized to the head
- Describe a structured approach for evaluating temporomandibular joint pain and dysfunction
- Explain the clinical relevance and differences in active and passive joint motion of the temporomandibular joint and hyoid apparatus
- Describe the clinical features of temporohyoid osteoarthropathy
- Outline the neurologic deficits associated with temporohyoid osteoarthropathy
- Discuss the indications and specific value of different diagnostic imaging procedures of the head
Clips
- Introduction
- Static and dynamic observation of the head
- Soft tissue and bony palpation of the head
- Temporomandibular joint and hyoid mobility
- Neurologic examination of the head
- Diagnostic imaging of the head
Section 5 Treatment Options: Hyoid and Temporomandibular Joint Pain and Dysfunction
Learning objectives
Upon completion of this course content, the student will be able to:
- Describe conservative approaches for managing temporomandibular joint pain and dysfunction in horses
- Outline medical and surgical approaches for addressing temporohyoid osteoarthropathy
- Discuss the role of acupuncture in managing neurologic deficits and head shaking
- Identify primary rehabilitation issues and provide treatment options based on the specific needs of an individual horse
- Safely and effectively perform joint mobilization of the mandible and hyoid apparatus
- Discuss treatment options for managing trigeminal nerve sensitization
- Outline treatment options for correcting dental overgrowth and malocclusion
- Discuss tack-related issues that may induce pain and restrict mandibular mobility
- Outline surgical options for managing severe temporomandibular joint disease
Clips
- Introduction
- TMJ & hyoid treatment options: Literature review
- Acupuncture of the head
- Hyoid apparatus mobilization
- Medical and surgical treatment: Temporohyoid osteoarthopathy
- Mandibular mobilization: Dental-related issues
- Mandibular mobilization: Temporomandibular joint
- Medical and surgical treatment: Temporomandibular joint
Kevin K. Haussler, DVM, DC, PhD
Diplomate, American College of Veterinary Sports Medicine and Rehabilitation
Dr. Haussler obtained a Bachelor of Science in agriculture from the University of Nebraska-Lincoln in 1984. He graduated in 1988 from The Ohio State University, College of Veterinary Medicine, followed by a small animal internship at the Sacramento Animal Medical Group in 1989. Dr. Haussler was a relief veterinarian for multiple small animal practices, emergency clinics, and humane societies from 1989 to 1994, when he became interested in pursuing further specialized training in the diagnosis and management of pain and musculoskeletal disorders in animals.
He enrolled in Palmer College of Chiropractic-West, a human chiropractic program, to learn how to apply human chiropractic techniques and principles to the treatment of animals with musculoskeletal-related disorders and graduated with a Doctor of Chiropractic (DC) degree in 1993. Dr. Haussler started a veterinary chiropractic clinical practice treating horses and small animal patients in 1992.
Dr. Haussler went on to obtain a PhD in Comparative Pathology from the University of California-Davis, School of Veterinary Medicine in 1997. The focus of his PhD research was the evaluation of the anatomy, pathology, and biomechanics of the lower back and pelvis of Thoroughbred racehorses.
He then went on to complete postdoctoral training investigating equine spinal kinematics in 1999 at the College of Veterinary Medicine at Cornell University and was invited to be a Lecturer at Cornell University until 2005.  During this time, he was responsible for teaching equine anatomy, conducting biomechanical research, and initiation of a clinical Integrative Medicine Service for both the large and small animal clinics that provided chiropractic, acupuncture, and physical therapy services. Dr. Haussler’s research studies have included the evaluation of in vivo equine spinal kinematics, paraspinal muscle morphometry and histochemistry, and the initiation of equine chiropractic research assessing pain and spinal flexibility.
In 2010, Dr. Haussler was invited to be a founding member of the new specialty college, The American College of Veterinary Sports Medicine and Rehabilitation, where he has served as the Examination Committee chair, and on the Board of Director’s as secretary and president.
Currently, Dr. Haussler is an Associate Professor at the Orthopaedic Research Center in the College of Veterinary Medicine and Biomedical Sciences at Colorado State University where he has continued his research interests in objective measures of musculoskeletal pain, spinal pathology, and rehabilitation.