Dentists' Awareness of Physical Therapy in the Treatment of Temporomandibular Disorders: A Preliminary Study

Background Physical therapy (PT) has been shown to be one of the most effective conservative treatments for temporomandibular disorders (TMD). Not all dentists are aware of the importance of the collaboration with physical therapists in the treatment of TMD pain. Objectives To determine the awareness of dentists in Florida about the importance of PT for TMD pain and to create awareness related to collaborations. Methods An online questionnaire was used. A contact list of dentists was obtained from the Florida Dental Association. The overall awareness and information on patient referral were presented per dentist specialty. Results A total of 256 dentists completed the survey. Prior to the survey, 41% of the dentists reported not aware that PTs can treat TMD patients. Oral surgeons and orthodontists were more aware about PT compared to other specialties. After the survey, 81% of the dentists were more likely to refer their TMD patients to PT, and 80% were interested to know more about the benefits of collaborations. Conclusion This study shows the lack of dentists' awareness in Florida about the benefits of PT for TMD treatment. This study increased the awareness of the surveyed dentists in Florida about the benefit from a multidisciplinary approach.


Introduction
e temporomandibular joint (TMJ) is part of the musculoskeletal system responsible for mandibular function which includes mastication, phonation, and deglutition [1]. Temporomandibular disorders (TMD) are de ned as a musculoskeletal disorder a ecting the TMJ, the masticatory muscles, and associated structures including dental occlusion and the cervical spine [2,3]. TMD are the most common chronic orofacial pain condition, and it can signi cantly a ect the patient's quality of life by diminishing the individual's ability to work and interact in social environment [3].
Approximately 10% of the population has pain in the TMJ [4], and 3.6%-7% of the population will seek treatment due to the severity of their symptoms [3,5]. TMD signs and symptoms may include local pain in the TMJ and/or masticatory muscles, limited mouth movements, TMJ sounds, and headaches [5][6][7]. Cervical spine disorders were shown to be associated with TMD pain 70% of the time [7][8][9][10][11].
e di erent types of TMD are classi ed based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) [12]. TMD can be acute or chronic, simple or complex with persistent and associated cognitive, psychosocial, and behavioral factors [12]. A multidisciplinary approach is particularly important for successful treatment of chronic TMD cases [13]. Treatment of TMD pain may involve dentists, physical therapists (PTs), speech pathologists, physicians, and psychologists. An ideal treatment option would be the one that is least invasive and most coste ective, while considering the TMD associated factors such as parafunctional habits, poor posture, widespread pain, poor sleep, and depression [3].
Physical therapy (PT) is one of the most e ective conservative treatments for TMD pain [14]. PT is among other noninvasive therapies including behavioral therapy and occlusal appliances that were shown to improve patients with TMD [15]. e most important contribution by PTs is the identi cation of the musculoskeletal components that contribute to the symptoms of the patient [7]. Because the TMJs are part of the musculoskeletal system, PTs can treat TMJ-related pain with similar interventions as they would in most other body joints. PT includes a large number of modalities to treat TMD pain secondary to in ammation, masticatory muscle pain, TMJ hypo/hypermobility, disc displacement, bruxism, and brous adhesion [7]. Based on systematic reviews [16,17], manual therapy, jaw exercises, and postural reeducation were shown to be e ective to reduce pain and improve mobility/function in TMD patients.
More collaboration between dentists and PTs for the management of TMD pain is needed so as to improve the treatment outcomes of these patients. Not all dentists are aware of the importance of involving PTs in the treatment of TMD pain. e awareness of dentists from Florida about PT's role for TMD treatment is unknown. erefore, the primary objective of this research was to determine the current level of awareness of dentists in Florida about the importance of PT and the collaboration with PTs in the treatment of TMD. e secondary objective was to increase the awareness level of dentists regarding the importance of PT and the bene ts of the collaboration between dentists and PTs in TMD treatment to potentially increase collaborations between dentists and PTs in the treatment of TMD for best outcomes.

Study Design.
is was a cross-sectional descriptive study approved by the Institutional Research Board from Florida International University (IRB-14-0205).

Participants.
Dentists in Florida with an active dental license and members of the Florida Dental Association were contacted. A contact list of dentists was obtained from the Florida Dental Association. e dentists were contacted by an email, which included a statement of the study objectives and a link to the online survey. By completing and submitting the survey, the dentists were informed that they were consenting to participate in the study. e dentists were informed that no identi able information will be published or released and that participation is voluntary. All data were con dentially analyzed. In addition, they were informed that they will receive no compensation for participating in the study. However, an educational brochure with information related to PT for treating TMD pain was available to them upon completion of the survey. A reminder email was sent 3 times every 2 weeks from the initial recruitment email.

Questionnaire.
A questionnaire was created using Qualtrics online survey software (Qualtrics Labs Inc., Provo, Utah). e survey was revised by 2 dentists to gather feedback for improvements. Feedback was considered and changes to the survey were implemented. e questionnaire included a total of 24 questions: 7 related to demographics, 12 on TMD patient population and referrals, and 5 related to general knowledge (Appendix 1). e online survey was estimated to take approximately 5-10 minutes to complete.

Data Analysis.
Descriptive statistics were calculated to analyze the responses. Data were presented as total number of participants (n) and frequency (%). Written information provided by some dentists was considered and presented. e overall knowledge related to PT among the respondents and information on patient referral were calculated and presented per dentist specialty.

Participants' Demographics and Characteristics.
From over 10,000 emails sent, a total of 256 dentists completed the survey (response rate of 2.5%). e mean age of the participants was 51 years with a range of 26 to 78 years, and 172 of the participants (67%) were male. Ninety-seven percent of the participants (243) had earned their professional doctoral degree, 2% [5] had earned an academic master's degree, and 0.4% [1] had earned an academic doctoral degree (PhD). Two hundred twelve participants (86%) reported practicing dentistry in a private practice setting, and most of the participants (41%) practiced for 21 to 35 years. Twenty-eight percent (65) were from South Florida District followed by West Cost District (24%) and Central Florida District (19%). e majority of the participants (73%) were general dentists followed by orthodontists (8%) and other specialties (18%), which included pediatric dentistry, TMJ and orofacial pain specialist, and neuromuscular dentistry. Table 1 shows detailed demographic and characteristics of participants.
irty-nine percent of the dentists (95) had never taken continuum education course on TMD. For those dentists reporting yes for taken courses on TMD, the courses included topics related to etiology and treatment of TMJ disorders; occlusion; bite plane therapy; TMD and occlusion; splint therapy, medication and restorative therapy; surgical and nonsurgical treatment; facial pain; myofascial pain and TMD; arthroscopic surgery, traumatic derangement; joint prosthetics and replacement; and occlusion and posture. Six dentists reported PT as part of the topic in the continuum education course taken.

TMD Patients' Information.
More than half of the dentists surveyed (57%) estimated anywhere from 1 to 15% of their patients su ered from TMD symptoms. Only 2 dentists reported not having seen these type of patients, and 17 dentists (7%) reported that more than 55% of their patients have TMD. e most common characteristics of TMD evaluated and/or treated were parafunction habits (89%), muscle tightness/tender points (75%), occlusion alterations (75%), and headaches (69%). e least common characteristics were TMJ hypermobility (26%) and TMJ degeneration (38%). Other TMD characteristics evaluated and/or treated included condyle fracture, traumatic injury, neuropathic pain, and craniocervical issues. Only 7 dentists (3%) reported never evaluating a patient with a TMJ-related problem. Methods of TMD evaluation most often used by dentists included observing jaw movements during opening/closing (86%), evaluating for dental occlusion (84%), TMJ palpation (83%), and signs of parafunctional habits (81%). Other methods reported to evaluate TMD patients included neck range of motion, radiographs, photographs, MRI, diagnostic anesthesia, biopsychosocial measurements, and surface electromyography (sEMG). Most of the patients (55%) presented a chronic condition during the initial evaluation, as opposed to the acute (25%) and subacute conditions (20%).
When asking the dentists whether or not their TMD patients also presented with neck pain, poor posture, and/or cervicogenic headache, 13%, 34%, and 32% reported never evaluating these conditions, respectively. From those who had evaluated, 76%, 58%, and 59% reported nding these conditions, respectively, present in their patients.

Treatment and Referral.
e most frequent methods used to treat TMD patients (if patients are not referred) were the use of bite splints (90%), prescription medication (62%), followed by occlusion correction (58%). However, 69 dentists (30%) utilized other treatment methods including ice/heat, arthrocentesis, diet alteration, jaw and neck exercises, botox, trigger point injection, thermotherapy and cryotherapy, and soft tissue massage. Eighty-six percent (86%) reported referring TMD patients to other health care providers. Most of these dentists (70%) reported referring up to 25%. irteen percent (13%) reported referring 75-100% of their TMD patients. e health care providers to which TMD patients were most commonly referred were oral surgeons (62%), orthodontists (32%), and PTs (31%) ( Figure  1). Other providers described included TMJ/orofacial pain specialist, chiropractor, massage therapist, gnathologist, neuromuscular dentist, endocrinologist, neurologist, osteopath, and ENT. Table 2 shows the distribution of TMD patient referral per dentist specialty. e specialty that refers the most the TMD patients to PTs was oral surgeons (80% of them) followed by orthodontists (55%). e most common reasons for TMD patient referral to a PT included neck pain (43%), masticatory muscle tenderness (34%), and postural alterations (31%) (Figure 2). e most common reason for not referring a patient to PT was that they did not know about the bene ts of PT to the patient (58% of them). Other reasons reported were "lack of knowledge of a PT that treats TMJ or contact information," "insurance payment," "no formal referral system set in place," and the belief that "PT is only a temporary x" or "it is out of their skill set." In fact, 41% of all the dentists surveyed had no knowledge that PTs were capable of treating patients with TMD.

Physical erapy Awareness.
Prior to the survey, 41% of the dentists reported not aware that PTs can treat patients with TMD by, for example, reeducating jaw movements, and  Pain Research and Management restoring masticatory muscles (Table 3). In addition, 32% of the dentists reported not aware that cervical spine may be involved with masticatory region pain. Oral surgeons and orthodontists were more aware about PT for TMD management compared to other specialties (Table 3).
After asking the dentists surveyed if they are more likely to refer any of their TMD patients to a PT after participating in the survey, 184 dentists (81%) are more likely to refer to a PT by answering yes or may be. Reasons for not being likely to refer or may be are as follows: "do not know how the process is to refer it," "none have o ered services," "too speci c of treatment for PT to be helpful," "insurance issues," "not allowed to refer," "PT treatment only helps temporarily," or "do not know where to refer in my area." At the end of the survey, 80% of the dentists (180) were interested to know more about the bene ts of the collaborations with PTs to treat TMD patients. e proportion of dentists' interest on knowing more about the bene ts of the collaborations with PTs to treat TMD patients is also shown in Table 4 by dentist specialty.

Discussion
is was the rst study evaluating the awareness of dentists in Florida about the importance of the multidisciplinary approach with PT for the management of TMD pain using an online questionnaire. Information about TMD patients treated by dentists, TMD patient referral, and their interest to know more about PT for the management of TMD pain is described. However, the results of this study should be interpreted with caution because the response rate was very low, and therefore the generalizability of the ndings is questionable. However, this preliminary study presents relevant information regarding the current level of awareness among the participants and can help further increase the level of collaboration between PTs and dentists in the treatment of TMD. From the 88 of surveyed dentists who had never referred a TMD patient to a PT, 65 of them (74%) were not aware of the bene ts of PT in treating TMD patients. Perhaps, the referral to PTs would be greater if more dentists were aware of PTfor TMD patients. In fact, after this survey, 81% of the dentists are more likely to refer a TMD patient to PT. Other studies should investigate if the referral is actually happening in Florida. According to a dentist author in his  article with a PT colleague [2], 50% of all his patients are referred to PT. Based on the TMD patients' characteristics reported by the dentists in our survey, it appears that most of them could be referred to PT for further treatment. Approximately 1/3 of dentists surveyed do not evaluate their TMD patients for poor head and neck posture and the presence of cervicogenic headaches. Also, 13% of dentists do not evaluate for the presence of neck pain. As previous researches show correlation between TMD pain and the presence of cervical spine disorders including neck pain and poor posture [7,[9][10][11], dentists should be aware of these disorders in their patients in order to possibly refer the patients to PTs for further treatment and collaboration. On the other hand, PTs should be also aware of any possible toothrelated pain or dental occlusion problems related to TMD during their evaluation in order to possibly refer the patient to the dentist. For example, if parafunction habits are common in patients with TMD, a dental splint may be fabricated by the dentist. At the same time, PTs can deprogram the masticatory muscles with soft tissue massage and intraoral mobilizations before the exercises. TMD patients will have better treatment outcomes if both dentists and PTs work together [2]. In a randomized control trial, patients who received a combination of dental splint therapy with PT had greater gains in mouth range of motion than splint therapy alone [18]. e health care providers to which TMD patients were most commonly referred to were oral surgeons (62%). Oral surgeons were the health care providers who refer the most the TMD patients to PTs. Table 4 shows that almost 70% of general dentists refer patients to oral surgeons. It seems that TMD patients are mostly referred to PT for postsurgery treatment. Studies indicate that PT has a positive e ect in relieving pain and restoring TMJ function after surgery [19,20]. However, if applicable, TMD patients should be referred to PT before a nonconservative treatment such as surgery is considered. In addition, in the cases where surgery is needed, PT should be considered as a presurgical treatment in order to prepare the patients for surgery. e bene ts of the surgery may be increased if PT is done before surgery. Gladly, 55% of the orthodonticts refer TMD patients to PT.
A lack of dentists' awareness about the bene ts of PT for the treatment of TMD patients leads to less patient referral and collaborations with PT. In fact, the most common reason for not referring a patient to a PT was the lack of awareness of PT bene ts (58%). More awareness related to the relationship between cervical spine and orofacial symptoms is needed as 32% of the dentists were not aware. For instance, cervical spine postural reeducation is recommended for TMD patients in addition to manual therapy and jaw exercises [16]. PT is considered an integral part of TMD treatments [13]. Physical therapy, as well as behavioral therapy and occlusal appliances help to improve patients with TMD [15]. erefore, according to the authors of this study, information on the role of PT on TMD treatment should be part of seminars and lectures in the curriculum of Dentistry Programs to inform them on the importance of interdisciplinary treatment of TMD patients.
From the dentists' awareness about the bene ts of PT for the management of TMD patients prior to the survey (146 dentists), 62 (43%) are more likely to refer patients to PTs after participating in the survey. But 58% of them said may be or are not likely to refer (31% and 27%, resp.). erefore, the fact that some dentists are aware about the bene ts of PTdoes not mean that the referral is happening. One of the possible reasons for the low rate of referral of patients with TMD to PTs is the lack of available PTs with expertise in treating TMD because not all PTs are trained and con dent about providing care to TMD patients. e number of PTs with specialized training and advanced education in the area of TMD such as PTs certi ed by the Physical erapy Board of Craniofacial and Cervical erapeutics (many of them members of American Academy of Orofacial Pain) represents a small fraction of the American Physical erapy Association (APTA). erefore, more education related to TMJ, TMD, and the multidisciplinary approach between dentists and PTs in the pain management of TMD patients should be also reinforced in all PT Programs. Interestingly, one comment received by a dentist was that there is a need to also educate the PTs regarding collaborations.
A study with PTs about their knowledge to treat TMD patients should be conducted. eir capabilities to collaborate with dentists should be also measured. If more PTs are capable of treating these patients the likelihood of dentists to refer their patients may increase. Information related to should be part of the curriculum of all PT programs.
TMD can be complex because patients may present different conditions including arthralgia, myalgia, myofascial pain, disc displacement disorders, degenerative joint disease, and headache attributed to TMD among other classi cations [12]. In addition, other associated factors may be present such as generalized pain, sleep disturbances, and depression. erefore, diagnosis and treatment of these patients is  challenging [12], and a multidisciplinary team is recommended to treat TMD. However, not all disciplines are necessarily needed for treating all cases of TMD. Patients' symptoms should be considered to decide which professionals need to be involved.

Study
Limitations. From over 10,000 contacted dentists, only 2.4% of them responded to the survey. e authors believe that not all email addresses were updated in the list provided and that could have a ected the amount of responses received. In order to maximize participation, the survey was made to be short (5-10 minutes to complete). In addition, a brochure with information about PT treatment was available upon participation. Other strategies to increase participation should be considered in future studies. is study included dentists from the State of Florida only. Future studies should include larger sample (higher response rate) by not only including dentists from other states, but also including more dentists from the other specialties. e majority of the dentists who responded the survey were general dentists (73%). Results may not be generalizable when data were analyzed by specialty. erefore, the results should be interpreted with caution; future studies with higher response rates and including di erent dental specialties are needed.

Conclusion
According to this survey, a large percentage of the dentists that completed the survey were not aware of the bene ts of PT in treating TMD pain. is study helped to increase the awareness level of the surveyed dentists in Florida about the importance of physical therapy and the bene t from the multidisciplinary approach with PT to their patients. Most of the dentists surveyed (80%) were interested to know more about the bene ts of the collaborations with PTs to treat TMD patients. is is important as the increased awareness of dentists about the importance of physical therapy and the interest to know more about the bene ts may increase collaborations between dentists and PTs in the treatment of TMD patients in Florida. TMD patients are more likely to be bene ted from those collaborations. Future studies should investigate if collaborations between dentists and PTs are increasing and if TMD patients treatment bene t from those collaborations.