Diagnostic Accuracy of a Temporomandibular Disorder Pain Screener in Patients Seeking Endodontic Treatment for Tooth Pain.

INTRODUCTION: This study assessed the accuracy of a TMD Pain Screener questionnaire in identifying patients with temporomandibular disorder (TMD) pain among those seeking endodontic treatment for tooth pain. It also investigated whether the screener accuracy could be improved by adding questions regarding putative predictors of TMD status. METHODS: One hundred patients seeking endodontic treatment for tooth pain were enrolled. Participants completed the 6-question TMD Pain Screener before treatment. A board-certified orofacial pain specialist/endodontic resident conducted endodontic and TMD examinations using validated Diagnostic Criteria for TMD (DC/TMD). The sensitivity (Se), specificity (Sp), and positive/negative predictive values (PPVs/NPVs) were calculated for the 6-question and 3-question versions of the TMD Pain Screener. Logistic regression and receiver operating characteristic curve (AUROC) analyses were performed to determine the screening accuracy. RESULTS: At the screening threshold of ≥3, TMD Pain Screener's sensitivity was 0.85, specificity 0.52, PPV 0.68, and NPV 0.75 for the 6-question version and 0.64, 0.65, 0.69, and 0.61, respectively, for the 3-question version. The AUROC was 0.71 (95% CL: 0.61, 0.82) and 0.60 (95% CL: 0.48, 0.71) for full and short versions, respectively. Adding a rating of current pain intensity of the chief complaint to the screener improved the AUROC to 0.81 (95% CL: 0.72, 0.89) and 0.77 (95% CL: 0.67, 0.86) for full and short versions, respectively, signifying useful overall accuracy. CONCLUSIONS: The 6-question TMD Pain Screener, combined with the patient's rating of current pain intensity of the chief complaint, could be recommended for use in endodontic patients with tooth pain for detecting painful TMD.

Dental-dedicated MRI, a novel approach for dentomaxillofacial diagnostic imaging: technical specifications and feasibility.

MRI is a noninvasive, ionizing radiation-free imaging modality that has become an indispensable medical diagnostic method. The literature suggests MRI as a potential diagnostic modality in dentomaxillofacial radiology. However, current MRI equipment is designed for medical imaging (eg, brain and body imaging), with general-purpose use in radiology. Hence, it appears expensive for dentists to purchase and maintain, besides being complex to operate. In recent years, MRI has entered some areas of dentistry and has reached a point in which it can be provided following a tailored approach. This technical report introduces a dental-dedicated MRI (ddMRI) system, describing how MRI can be adapted to fit dentomaxillofacial radiology through the appropriate choice of field strength, dental radiofrequency surface coil, and pulse sequences. Also, this technical report illustrates the possible application and feasibility of the suggested ddMRI system in some relevant diagnostic tasks in dentistry. Based on the presented cases, it is fair to consider the suggested ddMRI system as a feasible approach to introducing MRI to dentists and dentomaxillofacial radiology specialists. Further studies are needed to clarify the diagnostic accuracy of ddMRI considering the various diagnostic tasks relevant to the practice of dentistry.

Constructing the brief diagnostic criteria for temporomandibular disorders (bDC/TMD) for field testing.

BACKGROUND: Despite advances in temporomandibular disorders' (TMDs) diagnosis, the diagnostic process continues to be problematic in non-specialist settings. OBJECTIVE: To complete a Delphi process to shorten the Diagnostic Criteria for TMD (DC/TMD) to a brief DC/TMD (bDC/TMD) for expedient clinical diagnosis and initial management. METHODS: An international Delphi panel was created with 23 clinicians representing major specialities, general dentistry and related fields. The process comprised a full day workshop, seven virtual meetings, six rounds of electronic discussion and finally an open consultation at a virtual international symposium. RESULTS: Within the physical axis (Axis 1), the self-report Symptom Questionnaire of the DC/TMD did not require shortening from 14 items for the bDC/TMD. The compulsory use of the TMD pain screener was removed reducing the total number of Axis 1 items by 18%. The DC/TMD Axis 1 10-section examination protocol (25 movements, up to 12 sets of bilateral palpations) was reduced to four sections in the bDC/TMD protocol involving three movements and three sets of palpations. Axis I then resulted in two groups of diagnoses: painful TMD (inclusive of secondary headache), and common joint-related TMD with functional implications. The psychosocial axis (Axis 2) was shortened to an ultra-brief 11 item assessment. CONCLUSION: The bDC/TMD represents a substantially reduced and likely expedited method to establish (grouping) diagnoses in TMDs. This may provide greater utility for settings requiring less granular diagnoses for the implementation of initial treatment, for example non-specialist general dental practice.

Probabilistic tractography of the extracranial branches of the trigeminal nerve using diffusion tensor imaging.

PURPOSE: The peripheral course of the trigeminal nerves is complex and spans multiple bony foramen and tissue compartments throughout the face. Diffusion tensor imaging of these nerves is difficult due to the complex tissue interfaces and relatively low MR signal. The purpose of this work is to develop a method for reliable diffusion tensor imaging-based fiber tracking of the peripheral branches of the trigeminal nerve. METHODS: We prospectively acquired imaging data from six healthy adult participants with a 3.0-Tesla system, including T2-weighted short tau inversion recovery with variable flip angle (T2-STIR-SPACE) and readout segmented echo planar diffusion weighted imaging sequences. Probabilistic tractography of the ophthalmic, infraorbital, lingual, and inferior alveolar nerves was performed manually and assessed by two observers who determined whether the fiber tracts reached defined anatomical landmarks using the T2-STIR-SPACE volume. RESULTS: All nerves in all subjects were tracked beyond the trigeminal ganglion. Tracts in the inferior alveolar and ophthalmic nerve exhibited the strongest signal and most consistently reached the most distal landmark (58% and 67%, respectively). All tracts of the inferior alveolar and ophthalmic nerve extended beyond their respective third benchmarks. Tracts of the infraorbital nerve and lingual nerve were comparably lower-signal and did not consistently reach the furthest benchmarks (9% and 17%, respectively). CONCLUSION: This work demonstrates a method for consistently identifying and tracking the major nerve branches of the trigeminal nerve with diffusion tensor imaging.

An improved intraoral transverse loop coil design for high-resolution dental MRI.

PURPOSE: To improve intraoral transverse loop coil design for high-resolution dental MRI. METHODS: The transverse intraoral loop coil (tLoop) was modified (mtLoop) by overlapping the feed port conductors, bending the posterior section, introducing a parallel plate capacitor, optimizing the insulation thickness, and using it in receive-only mode. In addition, an MR-silent insulation was introduced. The performances of the mtLoop and tLoop coils were compared in terms of sensitivity, image SNR, and eddy currents using electromagnetic simulations and MRI measurements at 3T. RESULTS: The receive-only mode of the mtLoop increases the sensitivity at the apices of the roots, and the overlapped feed port design eliminated signal voids along the incisors. The bent posterior section with the parallel plate capacitor reduced the unwanted signal of the tongue by a factor of 2.3 in the selected region off interest and lowered the eddy currents by 10%. The proposed new coil provided higher SNR by elevenfold and 2.5-fold at the incisors and apices of the molar roots within the selected regions of interest, respectively, in the experiments, as well as improved comfort. Optimal insulation thickness was determined as 1 mm. With the mtLoop, a (250 µm)3 isotropic resolution of the dental arch could be realized using a UTE sequence within 2 min total acquisition time. A T2 -SPACE protocol with (350 µm)2 in-plane resolution was also demonstrated. CONCLUSION: The proposed new coil offers higher SNR at the incisors and apices of the molar roots, less unwanted signals from tongue, lower eddy currents, and improved patient comfort.

Prevalence of painful temporomandibular disorders in endodontic patients with tooth pain.

BACKGROUND: Pain from temporomandibular disorders (TMDs) may mimic endodontic pain, but its prevalence in endodontic patients is unknown. OBJECTIVES: This cross-sectional study investigated the prevalence of painful TMDs in patients presenting for endodontic treatment of a painful tooth. Contribution of TMD pain to the chief complaint and characteristics associated with TMD prevalence were also assessed. METHODS: Patients reporting tooth pain in the 30 days before attending university clinics for nonsurgical root canal treatment or retreatment were enrolled. Before endodontic treatment, they completed questionnaires and a board-certified orofacial pain specialist/endodontic resident diagnosed TMD using published Diagnostic Criteria for TMD. Log-binomial regression models estimated prevalence ratios to quantify associations with patient characteristics. RESULTS: Among 100 patients enrolled, prevalence of painful TMDs was 54%. In 26% of patients, TMD pain was unrelated to endodontic pain; in 20%, TMD contributed to their chief pain complaint; and in 8%, TMD was a sole aetiology for pain. TMD prevalence was associated with greater intensity, frequency and duration of the chief pain complaint; pain in more than one tooth; tenderness to tooth percussion and palpation; a diagnosis of symptomatic apical periodontitis; pain medication use; and psychological distress. CONCLUSION: A majority of patients with tooth pain seeking endodontic treatment had painful TMDs; one quarter had TMD as a component or sole cause of their pain. TMD prevalence was associated with more severe symptoms and signs of tooth pain and with psychological factors. The high frequency of TMD comorbidity warrants consideration in management of endodontic patients with history of toothache.

How dental teams can help patients with temporomandibular disorders receive general dental care: An International Delphi process.

BACKGROUND: Many patients with temporomandibular disorders (TMD) find it difficult to undergo dental care due to challenges caused by their condition, previous temporomandibular joint surgery or invasive dental procedures, and the impact of comorbid conditions. Managing routine dental care for some patients with TMD can be seen as challenging by some dental practitioners. OBJECTIVE: The objective of this study was to work with patients experiencing TMD and clinicians to co-produce recommendations aimed at helping general dentists to provide routine dental care for patients with TMD. METHODS: A modified Delphi process was used to co-produce recommendations. Six patients experiencing TMD, patient advocates and seven clinicians took part, including international TMD clinicians. Two meetings were held with patient participants, mediated by a trained facilitator. Recommendations suggested by patient participants were distributed to clinicians who were asked to add additional suggestions, but not to modify patients' recommendations unless to aid clarity. Additional themes were identified from the existing literature, and the recommendations were then reviewed by the International Network for Orofacial Pain and Related Disorders Methodology (INfORM) consortium. RESULTS: Recommendations were given to support patients before, during and after dental treatment. Participants identified specific and practical recommendations to help patients with TMD receive routine dental care, but also emphasised the need for professionals to listen sensitively to patients' concerns and work with patients in an empathetic and non-judgmental way. CONCLUSION: These recommendations, co-developed with patients experiencing TMD, should help dental professionals to provide supportive general dental care for patients with TMD.

Sensitivity and Specificity of MRI versus CBCT to Detect Vertical Root Fractures Using MicroCT as a Reference Standard.

INTRODUCTION: Vertical root fracture (VRF) in root-canal-treated teeth frequently results in tooth loss, partly because VRFs are difficult to diagnose and when detected the fracture is often beyond the point of preservation with surgical intervention. Nonionizing magnetic resonance imaging (MRI) has demonstrated the ability to detect small VRFs, but it is unknown how its diagnostic capabilities compare with the current imaging standard for VRF detection, cone-beam computed tomography (CBCT). This investigation aimed to compare the sensitivity and specificity between MRI and CBCT for detecting VRF, using micro-computed tomography (microCT) as a reference. METHODS: A total of 120 extracted human tooth roots were root canal treated using common techniques, and VRFs were mechanically induced in a proportion. Samples were imaged using MRI, CBCT, and microCT. Axial MRI and CBCT images were examined by 3 board-certified endodontists, who evaluated VRF status (yes/no) and gave a confidence assessment for that decision, from which a receiver operating characteristic curve was generated. Intra- and inter-rater reliability were calculated, sensitivity and specificity, and area under the curve. RESULTS: Intra-rater reliability was 0.29-0.48 for MRI and 0.30-0.44 for CBCT. Inter-rater reliability for MRI was 0.37 and for CBCT 0.49. Sensitivity was 0.66 (95% confidence interval [CI], 0.53-0.78) and 0.58 (95% CI, 0.45-0.70), and specificity 0.72 (95% CI, 0.58-0.83) and 0.87 (95% CI, 0.75-0.95) for MRI and CBCT, respectively. Area under the curve was 0.74 (95% CI, 0.65-0.83) for MRI and 0.75 (95% CI, 0.66-0.84) for CBCT. CONCLUSIONS: There was no significant difference in sensitivity or specificity between MRI and CBCT in detecting VRF, despite the early-stage development of MRI.

Effect of lesion temperature on the durability of percutaneous radiofrequency rhizotomies to treat trigeminal neuralgia.

OBJECTIVE: Percutaneous radiofrequency rhizotomy is a common procedure for trigeminal neuralgia (TN) that creates thermocoagulative lesions in the trigeminal ganglion. Lesioning parameters for the procedure are left to the individual surgeon's discretion, and published guidance is primarily anecdotal. The purpose of this work was to assess the role of lesioning temperature on long-term surgical outcomes. METHODS: This was a retrospective analysis of patients who underwent percutaneous radiofrequency rhizotomy from 2009 to 2020. Patient data, including demographics, disease presentation, surgical treatment, and outcomes, were collected from medical records. The primary endpoint was the recurrence of TN pain. Univariate and multivariate Cox proportional hazards regressions were used to assess the impact of chosen covariates on pain-free survival. RESULTS: A total of 280 patients who had undergone 464 procedures were included in the analysis. Overall, roughly 80% of patients who underwent rhizotomy would have a recurrence within 10 years. Lower lesion temperature was predictive of longer periods without pain recurrence (HR 1.05, p < 0.001). The inclusion of lesion time, postoperative numbness, prior history of radiofrequency rhizotomy, surgeon, and multiple sclerosis as confounding variables did not affect the hazard ratio or the statistical significance of this finding. Postoperative numbness and the absence of multiple sclerosis were significant protective factors in the model. CONCLUSIONS: The study findings suggest that lower lesion temperatures and, separately, postoperative numbness result in improved long-term outcomes for patients with TN who undergo percutaneous radiofrequency rhizotomies. Given the limitations of retrospective analysis, the authors suggest that a prospective multisite clinical trial testing lesion temperatures would provide definitive guidance on this issue with specific recommendations about the number needed to treat and trial design.

Alveolar bone measurements in magnetic resonance imaging compared with cone beam computed tomography: a pilot, ex-vivo study.

OBJECTIVES: To compare alveolar bone height and width measurements from zero-echo-time MRI (ZTE-MRI) and cone beam CT (CBCT), in human specimens. MATERIAL AND METHODS: Twenty posterior edentulous sites in human cadaver specimens were imaged with CBCT and ZTE-MRI. Bone height and width at 1, 3, 5, 7 and 9 mm from the top of the alveolar ridge was measured by two trained observers in cross-sections of a site where an implant was to be planned. Twenty percent of the sample was measured in duplicate to assess method error and intra-observer reproducibility (ICC). The differences between CBCT and ZTE-MRI measurements were compared (t-test). RESULTS: Inter- and intra-observer reproducibility was >0.90. The method error (average between observers) for bone height was 0.45 mm and 0.39 mm, and for bone width (average) was 0.52 mm and 0.80 mm (CBCT and ZTE-MRI, respectively). The majority of the bone measurement differences were statistically insignificant, except bone width measurements at 5 mm (p ≤ .05 for both observers). Mean measurement differences were not larger than the method error. CONCLUSION: ZTE-MRI is not significantly different from CBCT when comparing measurements of alveolar bone height and width.

Minimal Detectable Width of Tooth Fractures Using Magnetic Resonance Imaging and Method to Measure.

INTRODUCTION: Vertical root fracture (VRF) in root canal-treated (RCT) teeth is a common cause of pain, bone resorption, and tooth loss. VRF is also difficult to diagnose and measure. Magnetic resonance imaging (MRI) has the potential to identify VRF due to beneficial partial volume averaging, without using ionizing radiation. This investigation aimed to describe the narrowest VRFs detectable based on MRI, using micro-computed tomography (microCT) as the reference standard and proposes a method using profile integrals to measure the widths of small VRFs. METHODS: VRFs were induced in 62 RCT tooth root samples. All samples were imaged in a phantom using MRI and reference imaging was obtained using microCT. The stacks of 3-dimensional axial MRIs were assessed by 3 board-certified endodontists. Evaluators determined the most coronal slice within the stack that was discernible as the extent of the VRF. This slice was measured on correlated microCT sections to determine the minimum VRF width (µm) detectable using a profile integral-based method to measure small fractures and negate the effects of the point spread function. RESULTS: Using profile integrals to measure VRF width was repeatable and resulted in estimates that were on average 1 µm smaller than known reference widths. Adjusted median VRF width detected using MRI was 45 µm (first quartile: 26 µm, third quartile: 64 µm). CONCLUSION: Using profile integrals is a valid way to estimate small VRF width. The MRI approach demonstrated ability to repeatedly detect VRFs as small as 26 µm.

The practical limits of high-quality magnetic resonance imaging for the diagnosis and classification of trigeminal neuralgia.

BACKGROUND: Neurovascular compression (NVC) has been the primary hypothesis for the underlying mechanism of classical trigeminal neuralgia (TN). However, a substantial body of literature has emerged highlighting notable exceptions to this hypothesis. The purpose of this study is to assess the reliability and diagnostic accuracy of high resolution, high contrast MRI-determined neurovascular contact for TN. METHODS: We performed a retrospective, randomized, and blinded parallel characterization of neurovascular interaction and diagnosis in a population of TN patients and controls using four expert reviewers. Performance statistics were calculated, as well as assessments for generalizability using shuffled bootstraps. RESULTS: Fair to moderate agreement (ICC: 0.32-0.68) about diagnosis between reviewers was observed using MRIs from 47 TN patients and 47 controls. On average reviewers performed no better than chance when diagnosing participants, with an accuracy of 0.57 (95% CI 0.40, 0.59) per patient. CONCLUSION: While MRI is useful in determining structural causes in secondary TN, expert reviewers do no better to only slightly better than chance with distinguishing TN with MRI, despite moderate agreement. Further, the causal role of NVC for TN is not clear, limiting the applicability of MRI to diagnose or prognosticate treatment of TN.

Identifying symptomatic trigeminal nerves from MRI in a cohort of trigeminal neuralgia patients using radiomics.

INTRODUCTION: Trigeminal neuralgia (TN) is a devastating neuropathic condition. This work tests whether radiomics features derived from MRI of the trigeminal nerve can distinguish between TN-afflicted and pain-free nerves. METHODS: 3D T1- and T2-weighted 1.5-Tesla MRI volumes were retrospectively acquired for patients undergoing stereotactic radiosurgery to treat TN. A convolutional U-net deep learning network was used to segment the trigeminal nerves from the pons to the ganglion. A total of 216 radiomics features consisting of image texture, shape, and intensity were extracted from each nerve. Within a cross-validation scheme, a random forest feature selection method was used, and a shallow neural network was trained using the selected variables to differentiate between TN-affected and non-affected nerves. Average performance over the validation sets was measured to estimate generalizability. RESULTS: A total of 134 patients (i.e., 268 nerves) were included. The top 16 performing features extracted from the masks were selected for the predictive model. The average validation accuracy was 78%. The validation AUC of the model was 0.83, and sensitivity and specificity were 0.82 and 0.76, respectively. CONCLUSION: Overall, this work suggests that radiomics features from MR imaging of the trigeminal nerves correlate with the presence of pain from TN.

Preoperative Factors Associated with Anesthesia Failure for Patients Undergoing Nonsurgical Root Canal Therapy: A National Dental Practice-Based Research Network Study.

INTRODUCTION: The aim of this study was to identify preoperative factors associated with local anesthesia failure. METHODS: The National Dental Practice-Based Research Network (www.NationalDentalPBRN.org) data from 534 patients who received a nonsurgical root canal treatment completed in a single appointment were included in this analysis. Three methods for defining anesthesia failure were used: definition 1, patient-reported level of numbness; definition 2, provider-reported quality of anesthesia; and definition 3, provider-reported use of supplemental anesthesia. Fifty-one preoperative factors were investigated and analyzed individually against the overall failure rate for each method, and multivariate generalized estimating equation logistic models were fit with predictors chosen using stepwise model selection to evaluate factors that may interact with each other. RESULTS: The overall anesthesia failure rates were 5%, 15%, and 30% for definitions 1, 2, and 3, respectively. Provider experience, diabetes, absence of sharp or aching pain, absence of smoking, and a fair expected outcome were associated with anesthesia failure (definition 1). Provider level of training, absence of a sinus tract, bite sensitivity, and stress making the pain worse were associated with anesthesia failure (definition 2). Provider level of training, pain provoked by stimulus, mandibular teeth, teeth with vital pulps, and pain interfering with daily activities were associated with the use of supplemental anesthesia (definition 3). CONCLUSIONS: With the range of 5%-30% of anesthesia failures, a few common factors across the models assessed were elucidated. Providers with higher levels of training had significantly fewer anesthesia failures. Patient self-reported history of diabetes and preoperative pain-related interference with daily activities were associated with more anesthesia failures. Greater severity of various tooth-related pain characteristics, as a group but not individually, accounted for more anesthesia failures.

Interexaminer Agreement in the Radiologic Identification of Apical Periodontitis/Rarefying Osteitis in the National Dental Practice-Based Research Network PREDICT Endodontic Study.

INTRODUCTION: Periapical images are routinely made in endodontics to support diagnosis and treatment decisions, but conventional imaging may not readily demonstrate inflammatory changes. This study aims to quantify disagreement in the radiologic interpretation of apical periodontitis/rarefying osteitis between 2 expert examiners and to determine if differences exist based on anatomic location. METHODS: We used 1717 pretreatment periapical images made before orthograde endodontic treatment as part of the Predicting Outcomes of Root Canal Treatment (PREDICT) study conducted within the National Dental Practice-Based Research Network. Periapical changes were assessed independently by 2 board-certified specialists, an oral and maxillofacial radiologist and an endodontist, blinded to other clinical information. If the examiners disagreed about whether a diagnosis of apical periodontitis/rarefying osteitis was justified, an adjudication was made by a third examiner. RESULTS: The overall prevalence of this radiologic diagnosis in the periapical images was 55%, and interexaminer agreement measured with the Cohen kappa statistic was calculated to be 0.56 (95% confidence interval, 0.52-0.60). Diagnostic disagreements between the 2 examiners occurred for 377 teeth (22%), with disagreements more frequent for jaw location (P = .038) and tooth type (P = .021). Differences between root number (P = .058) and jaw location and tooth groups (P = .069) were found not to be statistically significant. CONCLUSIONS: The variability of diagnostic disagreements across anatomic location and tooth type may reflect the inability of periapical images to reveal bone changes masked by the complexity and density of overlying anatomic structures, a limitation that could potentially be overcome with the use of 3-dimensional imaging.

Temporomandibular disorder-related characteristics and treatment outcomes in Oromandibular Dystonia patients in two different clinical settings: A cross-sectional study.

INTRODUCTION: Clinical presentation of oromandibular dystonia (OMD) is variable that can be further complicated by the presence of temporomandibular disorder (TMD) symptoms. We sought to evaluate variations in the clinical presentation of OMD patients, particularly TMD-related characteristics, in two clinical settings. METHODS: In a cross-sectional study design, a Web-based data collection survey was provided to eligible patients with OMD from movement disorder (MD) and oro-facial pain (OFP) clinics. The survey questionnaire was designed to collect information on demographic characteristics, clinical presentation particularly related to TMD, quality of life and treatment outcomes. Validated questionnaires were used when available such as the TMD Pain Screener, EuroQol 5-Dimensions 5-Levels (EQ-5D-5L), Jaw Functional Limitation Scale and Global Rating of Change Scale. RESULTS: Of 53 eligible patients, 31 responded to the survey for a 58% response rate. Forty-eight per cent of patients in the MD clinic and 60% of patients in the OFP clinic reported jaw pain along with involuntary movements. Of those, 90% from the MD group and 83% from the OFP group screened positive with the TMD Pain Screener at the onset of symptoms based on recall. Positive TMD Pain Screener response was observed in about 40% of patients in both clinics within 30 days of questionnaire response. No statistically significant differences were observed between two groups for any measured variables. CONCLUSION: Patients with OMD have features of TMD, irrespective of the clinical setting in which they seek and receive care. OMD patients from both clinics were similar in terms of clinical presentation, quality of life and treatment outcomes.

Multitargeting the sleep-pain interaction with pharmacological approaches: A narrative review with suggestions on new avenues of investigation.

The multimorbidity formed by sleep disturbances and pain conditions is highly prevalent and has a significant impact in global health and in the socioeconomic system. Although different approaches have been directed toward its management, evidence regarding an optimal treatment is lacking, and pharmacological options are often preferred. Health professionals (e.g., pain and sleep clinicians) tend to focus on their respective expertise, targeting a single symptom with a single drug. This may increase polypharmacy and the risk of drug interactions, adverse events, and mortality. Hence, the use of medications that can directly or indirectly improve sleep, pain, and other possible accompanying conditions without exacerbating them becomes especially relevant. The objectives of this comprehensive review are to: a) describe the beneficial or deleterious effects that some commonly used medications to manage pain have on sleep and sleep disorders; and b) describe the beneficial or deleterious effects that frequently prescribed medications for sleep may have on pain. Moreover, medications targeting some specific sleep-pain interactions will be suggested and future directions for improving sleep and alleviating pain of these patients will be provided with clinical and research perspectives.

Design of an Intraoral Dipole Antenna for Dental Applications.

OBJECTIVE: In dental MRI, intraoral coils provide higher signal-to-noise ratio (SNR) than coils placed outside the mouth. This study aims to design an intraoral dipole antenna and demonstrates the feasibility of combining it with an extraoral coil. METHODS: Dipole antenna design was chosen over loop design, as it is open toward the distal; therefore, it does not restrain tongue movement. The dipole design offers also an increased depth-of-sensitivity that allows for MRI of dental roots. Different dipole antenna designs were simulated using a finite-difference-time-domain approach. Ribbon, wire, and multi-wire arms were compared. The best design was improved further by covering the ends of the dipole arms with a high-permittivity material. Phantom and in vivo measurements were conducted on a 3T clinical MRI system. RESULTS: The best transmit efficiency and homogeneity was achieved with a multi-wire curved dipole antenna with 7 wires for each arm. With an additional high-permittivity cap the transmit field inhomogeneity was further reduced from 20% to 5% along the dipole arm. When combined with extraoral flexible surface-coil, the coupling between the coils was less than -32dB and SNR was increased. CONCLUSION: Using intraoral dipole design instead of loop improves patient comfort. We demonstrated feasibility of the intraoral dipole combined with an extraoral flexible coil-array for dental MRI. Dipole antenna enabled decreasing imaging field-of-view, and reduced the prevalent signal from tongue. SIGNIFICANCE: This study highlights the advantages and the main challenges of the intraoral RF coils and describes a novel RF coil that addresses those challenges.

Personalizing Dual-Target Cortical Stimulation with Bayesian Parameter Optimization Successfully Treats Central Post-Stroke Pain: A Case Report.

Central pain disorders, such as central post-stroke pain, remain clinically challenging to treat, despite many decades of pharmacological advances and the evolution of neuromodulation. For treatment refractory cases, previous studies have highlighted some benefits of cortical stimulation. Recent advances in new targets for pain and the optimization of neuromodulation encouraged our group to develop a dual cortical target approach paired with Bayesian optimization to provide a personalized treatment. Here, we present a case report of a woman who developed left-sided facial pain after multiple thalamic strokes. All previous pharmacologic and interventional treatments failed to mitigate the pain, leaving her incapacitated due to pain and medication side effects. She subsequently underwent a single burr hole for placement of motor cortex (M1) and dorsolateral prefrontal cortex (dlPFC) paddles for stimulation with externalization. By using Bayesian optimization to find optimal stimulation parameters and stimulation sites, we were able to reduce pain from an 8.5/10 to a 0/10 during a 5-day inpatient stay, with pain staying at or below a 2/10 one-month post-procedure. We found optimal treatment to be simultaneous stimulation of M1 and dlPFC without any evidence of seizure induction. In addition, we found no worsening in cognitive performance during a working memory task with dlPFC stimulation. This personalized approach using Bayesian optimization may provide a new foundation for treating central pain and other functional disorders through systematic evaluation of stimulation parameters.