Fourth Edition
This edition first published 2020
© 2020 John Wiley & Sons, Inc.
Edition History
© by Blackwell Munksgaard (1e, 2005)
© by Edward F. Wright (1e, 2010)
© by John Wiley & Sons, Inc. (1e, 2014)
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Library of Congress Cataloging‐in‐Publication Data
Names: Wright, Edward F., author. | Klasser, Gary D., author.
Title: Manual of temporomandibular disorders / Edward F. Wright, Gary D. Klasser.
Description: Fourth edition. | Hoboken, NJ : Wiley‐Blackwell, 2020. | Includes bibliographical references and index.
Identifiers: LCCN 2019024446| ISBN 9781119548843 (paperback) | ISBN 9781119548805 (adobe pdf) | ISBN 9781119548812 (epub)
Subjects: | MESH: Temporomandibular Joint Disorders–therapy | Temporomandibular Joint Disorders–diagnosis
Classification: LCC RK470 | NLM WU 140.5 | DDC 617.5/22–dc23
LC record available at https://lccn.loc.gov/2019024446
Cover Design: Wiley
Cover Images: © BlurryMe/Shutterstock, © sunlight19/Shutterstock
We dedicate this book to our spouses and families, who unconditionally and unselfishly gave of themselves so that we could devote our time and energy on this book, and to all the individuals, past and present, who are advancing our scientific knowledge in the study of TMD.
We are both temporomandibular disorder (TMD) educators and clinicians with additional training in TMD. As educators we strive to provide our students with an education on various subjects that will prepare them to deliver appropriate care to their patients upon graduation. As clinicians we aim to provide our patients with quality care based upon sound scientific principles. When we were educating our students about TMD we discovered a common concern among our predoctoral students and postgraduate residents. Both groups lamented they were lacking a concise, clinically relevant, evidence‐based TMD book. Specifically, they wished for a book (i) written on the level for the average dentist or dental student/resident, (ii) focused on evidence‐based diagnosis and multidisciplinary management for the majority of TMD patients, (iii) that included guidelines on how to rule out disorders that mimic TMD and identify medical contributing factors for which patients may need to be referred, (iv) that detailed how to identify patients with complex TMD who are beyond the scope of most dentists, and (v) that focused on means and ways they could provide their patients with evidence‐based management strategies and interventions.
Therefore, we decided to produce a book to satisfy their needs as well as to the needs of general dental practitioners who wish to learn more about TMD. As such, we decided to assimilate our academic and clinical evidence‐based TMD knowledge and experiences to produce such a book. This book attempts to simplify the complexities of TMD for ease of clinical understanding and application, in addition to integrating the current scientific literature, clinical trials, and clinical experiences into an effective strategy. To the degree possible, it provides a systematic guide on how to most effectively diagnose and manage the various types of TMD patients. The book directs how the information obtained from the patient interview and clinical exam can be used to select the most cost‐effective, evidence‐based management approaches that have the greatest potential to provide long‐term symptom relief.
Those who choose to manage TMD patients must not only consider the musculoskeletal factors but also the psychosocial and neurophysiology issues related to the management of TMD. Since most readers of this text are not trained to be TMD “specialists,” the most easily understandable mechanisms that correlate to the recommended management approaches have been chosen. Occasionally, when simplified mechanisms will not sufficiently explain the phenomenon, other considerations such as psychosocial and CNS involvement are discussed. Similarly, since this is not a comprehensive reference book on TMD, it periodically warns that certain characteristics are suggestive of an uncommon disorder beyond the book's scope and recommends the reader consider referring the patient to a more knowledgeable and experienced practitioner.
To enhance the educational experience for the reader, we have provided questions that we frequently receive at the beginning of the applicable chapters, and important concepts are highlighted throughout the book. Important terms are in bold, with many listed in the glossary.
We are proud to state this is the fourth edition of this book. The material contained herein has certainly been expanded and enhanced from the various previous editions as we have embraced the explosion of scientific knowledge in this particular field of dentistry. We sincerely hope this easily‐read textbook will be used to facilitate your TMD evaluations and therapies and ultimately assist you in providing your patients with the best scientifically‐based care possible.
Don’t forget to visit the companion website for this book:
www.wiley.com/go/wright/manual 
There you will find valuable material designed to enhance your learning, including:
Scan this QR code to visit the companion website
The cardinal signs and symptoms for temporomandibular disorder (TMD) are pain in the masseter muscle, temporomandibular joint (TMJ), and/or temporalis muscle regions; mouth‐opening limitation; and TMJ sounds. TMD pain is by far the most common reason patients seek care [1, 2].
TMD is the second most common musculoskeletal pain, with low back pain being the first. It is most often reported in individuals between the ages of 20 and 40. Approximately 33% of the population has at least one TMD symptom, and 3.6–7% of the population has TMD with sufficient severity to cause patients to seek care [2–5].
TMD symptoms generally fluctuate over time and correlate significantly with masticatory muscle tension, tooth clenching, grinding, and other oral parafunctional behaviors. TMD symptoms are also significantly associated with an increase in psychosocial factors, for example, worry, stress, irritation, frustration, and depression [6–8]. Furthermore, TMD patients with poor psychosocial adaptation have significantly greater symptom improvement when the dentist’s TMD therapy is combined with cognitive‐behavioral intervention [2, 9].
TMD can cause other symptoms that are beyond the masticatory musculoskeletal system, for example, tooth pain, nonotologic otalgia (ear pain that is not caused by the ear), dizziness, tinnitus, and neck pain. TMD can contribute to migraine and tension headaches, muscle pain in the region, and many other pain complaints [10].
Women request therapy more often than do men, providing a female–male patient ratio between 3 : 1 and 9 : 1 [2]. Additionally, TMD symptoms are less likely to resolve for women than for men [6, 7]. Many hypotheses attempt to account for the gender difference, but the underlying reason remains unclear [11].
Knowledge about TMD has grown throughout the ages. In general, management philosophies have evolved from a mechanistic dental approach to a biopsychosocial medical model with the integration of neuroscience literature. This is comparable to the management philosophies of other joint and muscle conditions in the body [3, 12, 13].
Beneficial occlusal appliance therapy and TMJ disc‐recapturing surgery were reported as early as the 1800s [12, 14]. The understanding of the importance to harmonize the occlusion for the health of the masticatory muscles and TMJs developed as the skills to reconstruct natural teeth advanced. As enthusiasm grew for obtaining optimum health, comfort, and function, the popularity of equilibrating the natural dentition also developed [12, 15].
In the 1930s, Dr. James Costen, an otolaryngologist, brought TMD into the awareness of physicians and dentists, and readers may still find TMD occasionally referred to as Costen’s syndrome. Dr. Costen reported that TMD pain and secondary otologic symptoms could be reduced with alterations of the occlusion [16].
Since TMD is a multifactorial disorder (having many etiologic factors), many therapies have a positive impact on any one patient’s symptoms. Throughout much of the 1900s, many beneficial therapies were independently identified. Physicians, physical therapists, chiropractors, massage therapists, and others treating the muscles and/or cervical region reported positive responses in treating TMD symptoms. Psychologists working with relaxation, stress management, cognitive‐behavioral therapy, and other psychological aspects reported beneficial effects with their therapies. Orthodontists, prosthodontists, and general dentists working with the occlusion also observed the positive impact that occlusal changes provided for TMD symptoms.
Surgeons reported positive benefits from many different TMJ surgical approaches. Many forms of occlusal appliance were tried and advocated, from which studies reveal there is similar efficacy for different appliance forms. Medications as well as self‐management strategies used for other muscles and joints in the body were also shown to improve TMD symptoms. During this observational period, TMD therapies were primarily based on testimonials and clinical opinions, according to a practitioner’s favorite causation hypothesis rather than scientific studies [12].
Different philosophies appeared, with enthusiastic nonsurgeons “recapturing” discs through occlusal appliances, whereas surgeons repositioned the discs or replaced discs with autoplastic materials. The eventual breakdown of the autoplastic materials led to heartbreaking sequelae that caused many to step back from their narrowly focused treatment regimens and recognize the multifactorial nature of TMD and the importance of conservative noninvasive evidence‐based therapies [12].
Over the last 50 years, much was learned about basic pain mechanisms and the shared neuron pool of the trigeminal spinal nucleus, other cranial nerves, and cervical nerves. This provided a better understanding of the influence that regional and widespread pain may have on TMD, the similarities between chronic TMD pain and other chronic pain disorders, and the need for chronic pain management from a psychosocial and behavioral standpoint [8, 17].
Today, a large number of potentially reversible conservative therapies are available for our TMD patients. By using the information obtained from the recommended patient interview and clinical exam, practitioners can select cost‐effective, evidence‐based therapies that have the greatest potential to provide long‐term symptom relief. The management selected often reduces a patient’s contributing factors and facilitates the patient’s natural healing capacity. This management is consistent with therapies of other orthopedic and rheumatologic disorders [2, 3, 10, 13].
We do not fully understand TMD and the mechanisms causing or sustaining it. Practitioners should bear in mind that not all TMD therapies are equally effective, and no one therapy has been shown to be best for all TMD patients. Most TMD patients can be managed successfully with reversible, conservative, noninvasive therapies by general practitioners, without using expensive, high‐tech therapies [4].
Most TMD patients who receive therapy obtain significant symptom relief, whereas patients who do not receive therapy have minimal symptom change [21].
TMD therapy is generally recommended for patients who have significant temporal headaches, preauricular pain, masseter muscle pain, TMJ catching or locking, loud TMJ noises, restricted opening, difficulty eating due to TMD, or nonotologic otalgia due to TMD.
To help your hygienists better identify patients in your practice who need your help, a recommended “Referral Criteria for Hygienists” is available on the book’s website.
Temporomandibular disorder (TMD) generally involves many structures with varying degrees of pain intensity and dysfunction. During the initial evaluation, the involved structures need to be identified and the degree to which each contributes to the patient’s symptoms need to be categorized. Additionally, the contributing factors and symptom patterns help to identify which therapies will be the most beneficial for each patient [1].
Hence, the goals of the initial examination are to identify: a patient’s primary diagnosis; secondary, tertiary, and so on, diagnoses; contributing factors; and symptom patterns.
The primary diagnosis is the diagnosis for the disorder most responsible for a patient’s chief complaint. This diagnosis can be of TMD origin (e.g. myalgia, TMJ arthralgia, or temporomandibular joint [TMJ] disc displacement without reduction with limited opening) or from a different source (e.g. pulpitis, sinusitis, or cervicogenic headache) [2].
Secondary diagnosis, tertiary diagnosis, and so on, are other TMD diagnoses that generally contribute to the TMD symptoms. Typically, the primary diagnosis will be of TMD origin (e.g. myalgia), and the secondary and tertiary diagnoses will be other TMD diagnoses (e.g. TMJ arthralgia and TMJ disc displacement with reduction) that contribute to a patient’s chief complaint. When a non‐TMD (e.g. fibromyalgia) contributes to a TMD primary diagnosis, the non‐TMD disorder is designated as a contributing factor to the TMD diagnosis and not as secondary or tertiary diagnosis [2].
During the initial exam, we also attempt to identify the perpetuating contributing factors. These are elements that perpetuate the disorder (not allowing it to resolve), for example, sleep parafunctional behaviors, gum chewing, awake clenching, stress, or neck pain [1–3]. Additionally, we attempt to identify the symptom patterns that include the period of the day in which the symptoms occur or are most intense (e.g. worse upon awaking) and the location pattern (e.g. begins in the neck and then moves to the jaw).
The following non‐TMD examples may help you better understand how these terms are used. A patient complains to her physician about wrist pain. Through palpation of her wrist area, her physician determines the primary cause for her pain is the tenderness within the wrist joint (its diagnosis would be the primary diagnosis). Her physician also finds the muscles around the wrist are painful but less tender than the wrist joint (the muscle diagnosis would be the secondary diagnosis). The physician also knows the patient has a systemic arthritic condition, which he suspects makes her more susceptible to developing the wrist pain (a contributing factor).
By asking questions, the physician finds that this pain only occurs upon awakening and lasts half an hour; this suggests that wrist activity occurring during sleep is the major contributing factor. Her physician may decide the best initial therapy is to prescribe her a wrist splint to wear during sleep to ensure the wrist stays in a neutral position.
In a second example, the patient has the identical diagnosis and a systemic arthritic condition but has a different symptom pattern. In this example, the wrist pain consistently begins approximately half an hour after she starts using the computer and continues as long as she uses the computer, suggesting that computer use is the major contributing factor for her wrist pain.
To treat the wrist pain, her physician decides the best initial approach is to (i) refer her to a therapist to teach her about computer keyboard and mouse ergonomics, and (ii) prescribe her a nonsteroidal anti‐inflammatory drug (NSAID) short term, to provide her with temporary pain relief until her wrist responds to the computer keyboard and mouse ergonomic instructions. In both situations, the physician decides to not escalate therapy for the systemic arthritic condition because he believes the local therapies will resolve the pain complaint.
In spite of having the identical diagnoses and systemic contributor, the preferred therapy changed with different contributing factors.
The initial TMD evaluation involves interviewing the patient about his or her symptoms, potential contributing factors, and potential non‐TMD. The interview most influences the patient’s final management approach and generally brings to light concerns that the practitioner will need to evaluate during the clinical examination.
The clinical examination will help to confirm or rule out the structures involved in the patient’s complaints and other suspected disorders that may contribute to these complaints. Imaging may be appropriate, but, in our experience, it rarely changes the management approach derived from the patient interview and examination.
In the late 1980s when one of the authors was in the U.S. Air Force, an experience demonstrated that patients with TMD symptoms needed a more thorough evaluation for potential non‐TMD than what most dentists provided. A physician asked if he knew that one of the dentists who worked for him had diagnosed someone with TMD when the patient actually had meningitis. After reviewing the patient’s dental record, he found that she had been referred by the emergency room physician for possible TMD. The patient told the dentist she had been previously diagnosed with TMD, had an occlusal appliance, and believed she was having a relapse of this disorder. The dentist palpated her masticatory muscles and TMJs and found that the muscles were tight and tender to palpation. The dentist confirmed for the patient that she had TMD, gave her TMD self‐management instructions, and told her she should see her civilian dentist to have her appliance adjusted (as she was not an active‐duty military patient). At the time, it appeared to him the dentist performed an appropriate evaluation and provided an accurate diagnosis.
The emergency room record was then reviewed to obtain a better perspective of what had transpired. It was documented that the patient also told the emergency room physician that she had previously been diagnosed with TMD, had an occlusal appliance, and believed she was having a relapse of this disorder. The physician found that she had firm masticatory and cervical muscles and a fever, and referred her to the dentist for a TMD evaluation and to a neurologist. When the patient saw the neurologist, he did a spinal tap and found that she had meningitis.
This disheartening experience inspired him to research everything he could concerning disorders that mimic TMD. Lists were made of how their symptoms differed from TMD and a fairly brief list of questions was finally formulated that dentists can use to warn themselves that a patient may have a non‐TMD condition that is mimicking TMD [4]. This questionnaire has been used ever since and modified as new information became available [5–7]. This questionnaire is certainly not foolproof, but it is the best this author can formulate to alert him of potential non‐TMD disorders, contributing factors, and symptom patterns.