Books

Impacted teeth can be a challenging scenario in orthodontic patients asking for ‘invisible’ treatments. Skeletal anchorage can help clinicians to overcome the limitations of aligners, making possible more predictable and efficient clinical protocols. This case report describes a ‘canine-first’ approach and the relative workflow for the orthodontic management of impacted teeth with aligners and skeletal anchorage. The approach could be very effective in adult patients who present with impacted teeth and request aesthetic orthodontic treatment options. Receipt of manuscript: 28.04.2022, Acceptance: 15.05.2022 Keywords: impacted canine, aligner, skeletal anchorage

Aims: To investigate how trait anxiety and stress jointly affect the sensory and jaw motor responses to a tonic orofacial nociceptive stimulus. Methods: Orthodontic separators were placed between the first molars in 45 adults with low (n = 14), intermediate (n = 17), and high (n = 14) trait anxiety. Tooth pain, occlusal discomfort, tooth clenching (as a jaw motor behavior), and situational stress were measured three times a day for 5 days using visual analog scales. Mixed-effects regression models were used to evaluate the sensory and motor outcome measures. Results: Pain, discomfort, and frequency of tooth-clenching trajectories were affected by trait anxiety (P = .007, P < .001, and P = .055, respectively) and stress (P < .001, P < .001, and P = .044, respectively). Individuals with high anxiety reported their highest pain (17.7 ± 2.9 mm) and discomfort (35.2 ± 4.1 mm) 24 hours earlier than those with low anxiety (pain: 15.9 ± 2.6 mm, discomfort: 28.8 ± 3.7 mm). Tooth clenching decreased progressively in response to the stimulus (P < .001). Conclusion: A tonic orofacial nociceptive stimulus triggers an avoidance jaw motor behavior. Both trait anxiety and situational stress heighten the sensory response to such a stimulus, but weakly affect the motor response to it. Keywords: anxiety, bruxism, masticatory muscles, occlusion, pain, sensory thresholds

Aims: To evaluate the short-term effects of a standardized first-line noninvasive approach (FL-A) including counseling and self-management strategies on pain, masticatory muscle tenderness, and awake bruxism in women with chronic temporomandibular disorder myalgia (mTMD) and to test whether patients' trait anxiety predicted their response to treatment. Methods: FL-A was administered to 14 women with chronic mTMD (mean age ± SD = 33.8 ± 11.1 years; 8 with Graded Chronic Pain Scale [GCPS] grade I and 6 with grade II). Its effects on facial pain, masticatory muscle tenderness, and spontaneous awake bruxism episodes were evaluated using questionnaires, surface electromyography, and quantitative sensory testing. General linear models were used to test FL-A efficacy after 1 (T1) and 2 (T2) months. Results: FL-A reduced pain (from baseline [T0] to T2, P = .010), the frequency of awake bruxism episodes (T0 to T1, P = .024), and their intensity by about 30% (T0 to T1, P < .001). Pressure pain thresholds at the masticatory muscle locations increased significantly from T0 to T2 (P < .001). Patients' trait anxiety decreased significantly from T0 to T2 (P = .030). Trait anxiety measured at baseline was not correlated with relative changes in pain (T0 to T2, P = .248). Conclusion: In the short term, FL-A reduces facial pain, masticatory muscle tenderness, and awake bruxism in women with chronic mTMD with low disability. A conservative management strategy should be prioritized for the initial management of these patients. Keywords: bruxism, facial pain, masseter, temporalis, temporomandibular disorders

Aim: To investigate whether an international consensus exists among TMD experts regarding indications, performance, follow-up, and effectiveness of jaw exercises. Materials and Methods: A questionnaire with 31 statements regarding jaw exercises was constructed. 14 international experts with some geographic dispersion were asked to participate in this Delphi study, and all accepted. The experts were asked to respond to the statements according to a 5-item verbal Likert scale that ranged from "strongly agree" to "strongly disagree." The experts could also leave free-text comments, which was encouraged. After the first round, the experts received a compilation of the other experts' earlier responses. Some statements were then rephrased and divided to clarify the essence of the statement. Subsequently, the experts were then asked to answer the questionnaire (32 statements) again for the second round. Consensus was set to 80% agreement or disagreement. Results: There is consensus among TMD experts that jaw exercises are effective and can be recommended to patients with myalgia in the jaw muscles, restricted mouth opening capacity due to hyperactivity in the jaw closing muscles, and disc displacement without reduction. The patients should always be instructed in an individualized jaw exercise program and also receive both verbal advice and written information about the treatment modality. Conclusion: This Delphi study showed that there is an international consensus among TMD experts that jaw exercises are an effective treatment and can be recommended to patients with TMD pain and disturbed jaw function. (Original article published in J Oral Facial Pain Headache 2019; 33:389–398. doi: 10.11607/ofph.2359) Keywords: Delphi technique, dentistry, jaw exercises, orofacial pain, physical treatment

Aims: To investigate whether an international consensus exists among TMD experts regarding indications, performance, follow-up, and effectiveness of jaw exercises. Methods: A questionnaire with 31 statements regarding jaw exercises was constructed. Fourteen international experts with some geographic dispersion were asked to participate in this Delphi study, and all accepted. The experts were asked to respond to the statements according to a 5-item verbal Likert scale that ranged from "strongly agree" to "strongly disagree." The experts could also leave free-text comments, which was encouraged. After the first round, the experts received a compilation of the other experts' earlier responses. Some statements were then rephrased and divided to clarify the essence of the statement. Subsequently, the experts were then asked to answer the questionnaire (32 statements) again for the second round. Consensus was set to 80% agreement or disagreement. Results: There is consensus among TMD experts that jaw exercises are effective and can be recommended to patients with myalgia in the jaw muscles, restricted mouth opening capacity due to hyperactivity in the jaw closing muscles, and disc displacement without reduction. The patients should always be instructed in an individualized jaw exercise program and also receive both verbal advice and written information about the treatment modality. Conclusion: This Delphi study showed that there is an international consensus among TMD experts that jaw exercises are an effective treatment and can be recommended to patients with TMD pain and disturbed jaw function. Keywords: Delphi technique, dentistry, jaw exercises, orofacial pain, physical treatment

Aims: To determine if pressure pain thresholds (PPTs) of masticatory and neck muscles change after the application of a mandibular advancement device (MAD) in patients with obstructive sleep apnea (OSA). Methods: A prospective study was conducted in a sample of 27 OSA patients (24 males and 3 females; mean age ± standard deviation [SD]: 54.8 ± 11.8, mean apnea-hypopnea index ± SD: 23.5 ± 13.3) and 27 age- and sex-matched healthy controls. Exclusion criteria were signs and symptoms of temporomandibular disorders (TMD), metabolic diseases, and use of antidepressants, analgesics, or anti-inflammatory drugs. A calibrated examiner evaluated PPTs of seven head and neck muscles bilaterally by using a Fischer algometer. In the OSA group, PPTs were recorded immediately before the MAD application (T0), after 15 days (T1), and after 6 months (T2) of therapy; in the control group, PPTs were recorded at the same time intervals. PPT differences at baseline and over time within each group and between OSA and control groups were analyzed by Friedman and Mann-Whitney tests. Results: There were no PPT differences between groups at baseline. In the OSA group, PPTs of temporalis and masseter muscles decreased significantly at T1 compared with T0 (P .05), but no differences were found at T2. No significant PPT differences were found in the neck muscles or over time in the control group. Conclusion: MAD application induces a decrease of PPTs of masticatory muscles at the beginning of the therapy, but a physiologic adaptation occurs by 6 months. Keywords: algometer, mandibular advancement device, masticatory muscles, obstructive sleep apnea, pressure pain threshold

Aims: The original Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I diagnostic algorithms have been demonstrated to be reliable. However, the Validation Project determined that the RDC/TMD Axis I validity was below the target sensitivity of ≥ 0.70 and specificity of ≥ 0.95. Consequently, these empirical results supported the development of revised RDC/TMD Axis I diagnostic algorithms that were subsequently demonstrated to be valid for the most common pain-related TMD and for one temporomandibular joint (TMJ) intra-articular disorder. The original RDC/TMD Axis II instruments were shown to be both reliable and valid. Working from these findings and revisions, two international consensus workshops were convened, from which recommendations were obtained for the finalization of new Axis I diagnostic algorithms and new Axis II instruments. Methods: Through a series of workshops and symposia, a panel of clinical and basic science pain experts modified the revised RDC/TMD Axis I algorithms by using comprehensive searches of published TMD diagnostic literature followed by review and consensus via a formal structured process. The panel's recommendations for further revision of the Axis I diagnostic algorithms were assessed for validity by using the Validation Project's data set, and for reliability by using newly collected data from the ongoing TMJ Impact Project-the follow-up study to the Validation Project. New Axis II instruments were identified through a comprehensive search of the literature providing valid instruments that, relative to the RDC/TMD, are shorter in length, are available in the public domain, and currently are being used in medical settings. Results: The newly recommended Diagnostic Criteria for TMD (DC/TMD) Axis I protocol includes both a valid screener for detecting any pain-related TMD as well as valid diagnostic criteria for differentiating the most common pain-related TMD (sensitivity ≥ 0.86, specificity ≥ 0.98) and for one intra-articular disorder (sensitivity of 0.80 and specificity of 0.97). Diagnostic criteria for other common intra-articular disorders lack adequate validity for clinical diagnoses but can be used for screening purposes. Inter-examiner reliability for the clinical assessment associated with the validated DC/TMD criteria for pain-related TMD is excellent (kappa ≥ 0.85). Finally, a comprehensive classification system that includes both the common and less common TMD is also presented. The Axis II protocol retains selected original RDC/TMD screening instruments augmented with new instruments to assess jaw function as well as behavioral and additional psychosocial factors. The Axis II protocol is divided into screening and comprehensive selfreport instrument sets. The screening instruments' 41 questions assess pain intensity, pain-related disability, psychological distress, jaw functional limitations, and parafunctional behaviors, and a pain drawing is used to assess locations of pain. The comprehensive instruments, composed of 81 questions, assess in further detail jaw functional limitations and psychological distress as well as additional constructs of anxiety and presence of comorbid pain conditions. Conclusion: The recommended evidence-based new DC/TMD protocol is appropriate for use in both clinical and research settings. More comprehensive instruments augment short and simple screening instruments for Axis I and Axis II. These validated instruments allow for identification of patients with a range of simple to complex TMD presentations. Keywords: diagnostic criteria, diagnostic reliability, diagnostic validity, sensitivity, specificity, temporomandibular disorders

Aims: To combine empirical evidence and expert opinion in a formal consensus method in order to develop a quality-assessment tool for experimental bruxism studies in systematic reviews. Methods: Tool development comprised five steps: (1) preliminary decisions, (2) item generation, (3) face-validity assessment, (4) reliability and discriminitive validity assessment, and (5) instrument refinement. The kappa value and phi-coefficient were calculated to assess inter-observer reliability and discriminative ability, respectively. Results: Following preliminary decisions and a literature review, a list of 52 items to be considered for inclusion in the tool was compiled. Eleven experts were invited to join a Delphi panel and 10 accepted. Four Delphi rounds reduced the preliminary tool-Quality-Assessment Tool for Experimental Bruxism Studies (Qu-ATEBS)- to 8 items: study aim, study sample, control condition or group, study design, experimental bruxism task, statistics, interpretation of results, and conflict of interest statement. Consensus among the Delphi panelists yielded good face validity. Inter-observer reliability was acceptable (k = 0.77). Discriminative validity was excellent (phi coefficient 1.0; P .01). During refinement, 1 item (no. 8) was removed. Conclusion: Qu-ATEBS, the seven-item evidence-based quality assessment tool developed here for use in systematic reviews of experimental bruxism studies, exhibits face validity, excellent discriminative validity, and acceptable inter-observer reliability. Development of quality assessment tools for many other topics in the orofacial pain literature is needed and may follow the described procedure. Keywords: bruxism, Delphi technique, masticatory muscles, pain measurement

Aims: To test the hypothesis that the effects of an experimental occlusal interference differ between individuals reporting a high or low frequency of wake-time oral parafunctions. Methods: Study participants reporting very high (HFP group; n = 10) or very low (LFP group; n = 10) levels of oral parafunctions were selected by means of a questionnaire administered to 200 medical students. The selected participants wore an experimental occlusal interference in a single-blind longitudinal study, which comprised different occlusal conditions: interference free (IFC) and active occlusal interference (AIC). Assessments included clinical examination, measurements of nonfunctional tooth contacts, state and trait anxiety, and visual analog scale scores for occlusal discomfort, masticatory muscle pain, and headache. Data were analyzed by repeated measures twoway analysis of variance on ranked data, followed by calculation of within- and between-group differences using Friedman tests and Mann-Whitney tests, respectively. Results: During AIC, the frequency of nonfunctional tooth contacts significantly decreased in both groups (median [interquartile range, IQR]: in HFP from 55.3% [60.0%] to 31.1% [33.5%], P = .03; in LFP from 31.8% [32.4%] to 14.0% [22.8%], P .01), the decrease being more pronounced in LFP than in HFP (P .01). Trait anxiety was significantly higher (P = .01) in the HFP group (median, IQR = 22.5, 9.0) than in the LFP group (median, IQR = 19.0, 3.0). The interference caused more occlusal discomfort in the HFP group than in the LFP group (P = .02) and was associated with a significant increase of masticatory muscle pain (P = .05) and headache (P = .04) only in the HFP group. Conclusion: The application of an experimental occlusal interference has a different effect in individuals reporting a high or low frequency of oral parafunctions.