Double Chin Concerns after En Bloc Mandibular U-Shaped Osteotomy: Submental-Cervical Soft Tissue Changes and Anterior Belly of Digastric Muscle Assessment.

OBJECTIVE: To assess submental-cervical soft tissue changes after en bloc mandibular U-shaped osteotomy and examine alterations in the anterior belly of digastric muscle (ABDM). METHODS: A retrospective study analyzed 20 patients who underwent en bloc mandibular U-shaped osteotomy from 2018 to 2023. Preoperative (Tp) and long-term follow-up (Tf) CT data were collected for analysis, measuring mandibular volume, soft tissue thickness at menton (Mes) and cervicale (C), and ABDM parameters (length, cross-sectional area (CSA), volume, distance from centroid point to the mandibular margin). Correlation analyses were performed to investigate the connection between soft tissue thickness changes, ABDM changes, and mandibular osteotomy volume. RESULTS: Long-term follow-up revealed a significant increase in soft tissue thickness at the Mes and C points after U-shaped mandibular osteotomy, especially at the C point. The adaptive length of ABDM decreased, CSA increased, and volume decreased, but the ABDM centroid point shifted downward relative to the mandibular margin, indicating drooping protrusion. The increment of soft tissue thickness was moderately positively correlated with the amount of osteotomy, and the decrement of ABDM length and volume were slightly positively correlated with the amount of osteotomy. CONCLUSION: The degree of soft tissue relaxation after U-shaped osteotomy is related to the extent of osteotomy. Notably, the protrusion of ABDM relative to the mandibular margin affects submental-cervical contour aesthetics. Prior to U-shaped osteotomy, it is crucial to assess the soft tissue condition of the patient's lower face, and the individualized design of the osteotomy volume should be carried out cautiously and safely. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Validity and reliability of visual assessment of orofacial muscle ultrasound images using a modified Heckmatt scale.

INTRODUCTION/AIMS: Orofacial muscle ultrasound images can be evaluated quantitatively or using a visual grading system. Quantitative muscle ultrasound (QMUS) is currently the most sensitive technique to detect pathology, but can be time-consuming. The aim of this study was to investigate the validity and reliability of two visual grading systems (the original Heckmatt scale or a modified 3-point version) for the optimal grading of orofacial muscle images. METHODS: A retrospective, comparative, reliability and validity study was performed. Ultrasound images of the digastric, geniohyoid, masseter, temporalis muscles, and intrinsic muscles of the tongue of healthy participants and of patients (suspected of) having a neuromuscular disease were included. QMUS was used as the "gold standard." Two expert raters and one inexperienced rater rated all ultrasound images using both visual grading systems. RESULTS: A total of 511 ultrasound images were included. Criterion validity showed Spearman rho correlation coefficients of >0.59. Construct validity analysis showed strong to very strong associations between the visual grading systems and mastication and/or swallowing. Inter- and intrarater reliability of the original Heckmatt scale and the modified scale were good and comparable. Rater experience had a beneficial effect on the interrater reliability of both scales. DISCUSSION: Both the original Heckmatt and the modified Heckmatt scale are valid and reliable tools for the visual grading of orofacial ultrasound images. The modified Heckmatt scale, with only three grades and including an "uncertain" category, is considered easier to use in clinical practice.

Non-invasive assessment of swallowing using flexible high-density electromyography arrays.

Swallowing is a vital function that serves to safely transport food and fluid to the stomach, while simultaneously protecting our airways. Evaluation of swallowing is important for the diagnosis and rehabilitation of individuals with dysphagia, a disorder of swallowing. Flexible high-density surface electromyography (HD sEMG) arrays were designed and fabricated to span the floor of mouth and neck muscles. These arrays were applied on 6 healthy participants over duplicate recording sessions. During each recording session, participants performed three different swallowing motor tasks. The HD sEMG signals were filtered and tasks extracted. For each task, the RMS amplitude was computed, visualized, and compared. Dynamic motor coordination was evident in the filtered signals traces, with different electrode locations showing unique temporal activations. The 2D topographical maps allowed the location of different RMS intensities to be visualized, revealing qualitatively similar patterns across participants and tasks. These motor task trends were also seen within RMS quantifications. The RMS metric across all participants identified significant differences between non-effortful 3 ml and effortful 3 ml swallow tasks ( p=0.006) and there was a minimal variation of 3.1±1.9 µV RMS for repeated recording sessions by each participant. The HD-sEMG array successfully recorded differences in muscle activations during swallowing and was able to discern between two different motor tasks. The arrays offers a spatially detailed non-invasive assessment of the neuromuscular performance of swallowing. Clinical Relevance- The utility of HD-sEMG arrays for evaluation of the muscles involved in swallowing could enable diagnosis and rehabilitation of individuals with dysphagia.

The Rapid Screening for Somatosensory Tinnitus Tool: a Data-Driven Decision Tree Based on Specific Diagnostic Criteria.

BACKGROUND: Somatosensory or somatic tinnitus (ST) is a type of tinnitus where changes in somatosensory afference from the cervical spine or temporomandibular area alter the tinnitus perception. Very recently, the diagnostic value of a set of 16 diagnostic criteria for ST was determined. The next step in the development of easily applicable diagnostic criteria is to provide an uncomplicated model, based on the existing criteria, which can easily be used in clinical practice. OBJECTIVES: This study aims to construct an accurate decision tree, combining several diagnostic criteria, to optimize both sensitivity and specificity of ST diagnosis. DESIGN: An online survey was launched on the online forum Tinnitus Talk, managed by Tinnitus Hub in a convenience sample of participants with tinnitus. The survey included 42 questions, both on the presence of diagnostic criteria for ST and on other potentially influencing factors. A decision tree was constructed to classify participants with and without ST using the rpart package in R. Tree depth was optimized during a five-fold cross-validation. Finally, model performance was evaluated on a subset containing 20% of the original dataset. RESULTS: Data of 7981 participants were used to construct a decision tree for ST diagnosis. Four criteria were included in the final decision tree: 'Tinnitus and neck/jaw pain increase/decrease simultaneously', 'Tension in suboccipital muscles', 'Somatic modulation', and 'Bruxism'. The presented model has an accuracy of 82.2%, a sensitivity of 82.5%, and a specificity of 79%. Receiver operator characteristic curves demonstrated an area under the curve of 0.88. CONCLUSIONS: Based on a 42-item survey, a decision tree was created that was able to detect ST patients with high accuracy (82.2%) using only 4 questions. The RaSST is therefore expected to be easily implementable in clinical practice.

A multidimensional facial surface EMG analysis for objective assessment of bulbar involvement in amyotrophic lateral sclerosis.

OBJECTIVE: To develop a multidimensional facial surface electromyographic (EMG) analysis for assessing bulbar involvement in amyotrophic lateral sclerosis (ALS). METHODS: Fifty-four linear and nonlinear features were extracted from the surface EMG recordings for masseter, temporalis, and anterior belly of digastric in 13 patients with ALS and 10 healthy controls, each performed a speech task three times. The features were factor analyzed and then evaluated in terms of internal consistency, relation to functional speech outcomes, and efficacy for patient-control classification. RESULTS: Five internally consistent, interpretable factors were derived, representing the functioning of masseter, temporalis, digastric, antagonists, and agonists, respectively. These factors explained 40-43% of the variance in the functional speech outcomes and were ≥90% accurate in patient-control classification. The jaw muscle performance of individuals with ALS was characterized by (1) reduced complexity and coherence of antagonist muscle activities, and (2) increased complexity and irregularity of temporalis activity. CONCLUSIONS: Two important bulbar muscular changes were identified in ALS, related to both upper and lower motor neuron pathologies. These changes reflected (1) decreased motor unit recruitment and synchronization for jaw antagonists, and (2) a potential neuromuscular adaptation for temporalis. SIGNIFICANCE: The surface EMG-based framework shows promise as an objective bulbar assessment tool.

Surface Electromyography Study Using a Low-Cost System: Are There Neck Muscles Differences When the Passenger Is Warned during an Emergency Braking Inside an Autonomous Vehicle?

Deaths and serious injuries caused by traffic accidents is a concerning public health problem. However, the problem can be mitigated by the Autonomous Emergency Braking (AEB) system, which can avoid the impact. The market penetration of AEB is exponentially growing, and non-impact situations are expected to become more frequent. Thus, new injury patterns must be analysed, and the neck is particularly sensitive to sudden acceleration changes. Abrupt braking would be enough to be a potential risk for cervical spine injury. There is controversy about whether or not there are differences in cervical behaviour depending on whether passengers are relaxed or contract their muscles before the imminent accident. In the present manuscript, 18 volunteers were subjected to two different levels of awareness during an emergency braking test. Cervical muscles (sternocleidomastoid and trapezius) were analysed by the sEMG signal captured by means of a low-cost system. The differences observed in the muscle response according to gender and age were notable when passengers are warned. Gender differences were more significant in the post-braking phase. When passengers were relaxed, subjects older than 35 registered higher sEMG values. Meanwhile, when passengers contract their muscles, subjects who were younger than or equal to 35 years old experienced an increment in the values of the sEMG signals.

Echo-intensity, fatty infiltration, and morphology ultrasound imaging assessment in healthy and whiplash associated disorders populations: an observational study.

BACKGROUND: Although changes in muscle morphology and quality in deep neck flexors seem to be clear in patients with whiplash-associated disorders (WAD), evidence for deep neck extensors is heterogeneous. In addition, most studies have used magnetic resonance imaging or computer tomography, which is not available for regular practice. OBJECTIVES: To assess differences in deep neck extensors morphology and quality between patients with WAD and controls with ultrasound imaging (US) and to assess the association of imaging findings with clinical features. METHODS: One hundred and sixty brightness-mode images at C4/C5 level were acquired in 41 patients with WAD and 39 pain-free controls. Muscle morphology and quality characteristics of the cervical multifidus (CM) and short rotators (SR), clinical pain features and pressure pain thresholds (PPT) were assessed in a blinded design. RESULTS: Between-groups differences in both CM and SR were observed for fatty infiltration percentage (mean: 4.9%; P < 0.001; mean: 3.5%; P < 0.05, respectively) and mean EI (mean: 4.1; P < 0.001; mean: 3.2; P < 0.05, respectively): patients exhibited higher fatty infiltration than controls. The intensity of neck pain was negatively associated with multifidus CSA and perimeter (P < 0.001); symptoms duration was negatively associated with CM morphology (P < 0.001), CM mean EI (P < 0.05) and SR morphology (P < 0.05); pain-related disability was associated with CM morphology (P < 0.001) and SR mean EI (P < 0.05); and PPTs was associated with CM mean EI (P < 0.01) and FI (p < 0.05) and SR morphology (P < 0.001). No significant effect of gender was found in any analysis. CONCLUSION: US assessment of deep cervical extensors revealed greater fatty infiltration, but no differences in muscle morphology, between WAD patients and pain-free controls.

Assessment of potential strain injury to rectus capitis posterior minor muscles during whiplash type distortions of the cervical spine.

CONTEXT: Whiplash type injuries resulting from a rear end motor vehicle accident (REMVA) are thought to be caused by excessive loading and displacement of structural components of the cervical spine. On impact, the seat propels the driver's torso forward relative to the head, resulting in forced flexion of the occipitoatlantal (OA) joint, accompanied by forced stretching of the rectus capitis posterior minor (RCPm) muscles. Flexion of the OA joint and stretching of the RCPm muscles continues to increase until the vehicle's headrest strikes the back of the driver's head. It is known that externally applied forces that attempt to move the OA joint beyond its anatomic barrier can result in fracture, dislocation, or soft tissue damage to its structural components. However, the magnitude of headrest backset, defined as the distance between the driver's head and the vehicle's headrest, that would result in RCPm muscles being stretched to a length that would put them at risk for a muscle strain injury is unknown. OBJECTIVES: To quantify the relationships among flexion of the OA joint, RCPm muscle stretch, and backset, and to quantify the biomechanical response of RCPm muscles to increasing levels of axial load due to stretching. METHODS: Unembalmed head and neck specimens from three White females aged 85, 63, and 70 years were obtained from the Anatomical Services Division at the University of Maryland. Donors had provided written consent allowing use of their body for research purposes. Using an analytic model of the OA joint, the relationships between flexion of the OA joint and RCPm muscle stretch as a function of backset were estimated. RCPm muscles were removed from the cadavers and forcibly stretched using a servomechanism controlled hydraulic testing machine to quantify the load/displacement properties. After testing, the tissues were sectioned, mounted, and stained using Masson's trichrome to selectively stain muscle fibers red and collagen blue. RESULTS: Forced flexion of the OA joint was seen to be directly related to the magnitude of headrest backset. For values of backset greater than 7.2 cm, biomechanical testing of the RCPm muscles revealed that strain injuries ranged from the tearing of a few muscle fibers to complete rupture of the muscle and separation of the tendon at the posterior process of C1. CONCLUSIONS: Results showed that headrest backset at the time of vehicle impact is an important factor in estimating the risk of muscle strain injury to RCPm muscles. Muscle strain injury would be expected to impact the functional relationship between the RCPm muscles and the pain sensitive spinal dura. Physicians should be alert to the possibility that cervicogenic pain patients who have experienced whiplash associated with REMVA may show clinically relevant structural damage to the RCPm muscles on MRI.

MRI Assessment of Swallow Muscle Activation with the Swallow Exercise Aid and with Conventional Exercises in Healthy Volunteers: An Explorative Biomechanical Study.

Swallowing muscle strength exercises are effective in restoring swallowing function. In order to perform the exercises with progressive load, the swallow exercise aid (SEA) was developed. Precise knowledge on which muscles are activated with swallowing exercises, especially with the SEA, is lacking. This knowledge would aid in optimizing the training program to target the relevant swallowing muscles, if necessary. Three healthy volunteers performed the three SEA exercises (chin tuck against resistance, jaw opening against resistance and effortful swallow) and three conventional exercises [conventional effortful swallow (cES), Shaker and Masako] in supine position inside an MRI scanner. Fast muscle functional MRI scans (generating quantitative T2-maps) were made immediately before and after the exercises. Median T2 values at rest and after exercise were compared to identify activated muscles. After the three SEA exercises, the suprahyoid, infrahyoid, sternocleidomastoid, and lateral pterygoid muscles showed significant T2 value increase. After the Shaker, the lateral pterygoid muscles did not show such an increase, but the three other muscle groups did. The cES and Masako caused no significant increase in any of these muscle groups. During conventional (Shaker) exercises, the suprahyoid, infrahyoid, and sternocleidomastoid muscles are activated. During the SEA exercises, the suprahyoid, infrahyoid, sternocleidomastoid, and lateral pterygoid muscles are activated. The findings of this explorative study further support the potential of the SEA to improve swallowing rehabilitation.

The feasibility, validity and reliability of a child friendly vestibular assessment in infants and children candidates to cochlear implant.

OBJECTIVES: The pediatric vestibular assessment has developed significantly in the past two decades, especially in terms of assessment of cochlear implant (CI) candidates. Different methods and test protocols have been applied, however without a general consensus. We present here the feasibility, validity and reliability of a child friendly vestibular testing in use at our department for the assessment of pediatric CI candidates. METHODS: The test battery consisted of head impulse test (HIT), video head impulse test (vHIT), cervical evoked myogenic potentials (cVEMP) and mini ice water caloric test (mIWC), all adapted from previous methods, mentioned in literature. We defined specific criteria for test feasibility, for test validity and test positivity (i.e. indicating vestibular insufficiency). The reliability of the whole protocol was assessed with test agreement analysis. RESULTS: Complete data from 35 children, all CI candidates, age ranging 4-79 months (67% under 2 years) and recruited over two years, were obtained. All but one child could complete at least one test with valid responses bilaterally, with the best compliance for HIT (97,1%) and least for cVEMP (68,6%). Feasibility did not appear to be affected by age or hearing loss etiology. Among the valid responses there was a substantial test agreement between HIT and vHIT, moderate agreement between vHIT/HIT and mIWC and no apparent agreement between the canal tests and cVEMP. Simple clinical guidelines were introduced to solve the tests' disagreement and to improve the protocol reliability: a) a pathological response had to be confirmed in at least two different canal tests and in at least three cVEMP trials; b) a canal/otolith disagreement was interpreted as a partial vestibular loss to be opposed to a complete vestibular insufficiency. CONCLUSIONS: The search for vestibular insufficiency in infants and young children can be attained with an opportunely adapted vestibular assessment, such the test battery proposed here. That assessment resulted easy to conduct and to interpret in a representative sample of CI candidates in preschool age, the most of whom were younger than 2 years. This method appears to particularly suit the demands of a vestibular assessment in young children CI candidates.

Deep tissue massage, strengthening and stretching exercises, and a combination of both compared with advice to stay active for subacute or persistent non-specific neck pain: A cost-effectiveness analysis of the Stockholm Neck trial (STONE).

OBJECTIVE: To evaluate the cost-effectiveness of deep tissue massage ('massage'), strengthening and stretching exercises ('exercises') or a combination of both ('combined therapy') in comparison with advice to stay active ('advice') for subacute and persistent neck pain, from a societal perspective. METHODS: We conducted a cost-effectiveness analysis alongside a four-arm randomized controlled trial of 619 participants followed-up for one year. Health-related quality of life was measured using EQ-5D-3L and costs were calculated from baseline to one year. The interventions were ranked according to quality adjusted life years (QALYs) in a cost-consequence analysis. Thereafter, an incremental cost per QALY was calculated. RESULTS: In the cost-consequence analysis, in comparison with advice, exercises resulted in higher QALY gains, and massage and the combined therapy were more costly and less beneficial. Exercises may be a cost-effective treatment compared with advice to stay active if society is willing to pay 17 640 EUR per QALY. However, differences in QALY gains were minimal; on average, participants in the massage group, spent a year in a state of health valued at 0.88, exercises: 0.89, combined therapy: 0.88 and, advice: 0.88. CONCLUSIONS: Exercises are cost-effective compared to advice given that the societal willingness to pay is above 17 640 EUR per year in full health gained. Massage and a combined therapy are not cost-effective. While exercise appeared to have the best cost/benefit profile, even this treatment had only a modest benefit and treatment innovation is needed. Advice to stay active remains as a good therapeutic alternative from an economical perspective.

Assessment of Masticatory and Cervical Muscles' Thickness by Ultrasonography in Patients with Facial Asymmetry.

OBJECTIVE: The aim of this study was to determine the relationship between the thickness of masticatory and cervical muscles (temporalis, masseter and sternocleidomastoid) and facial asymmetries in young patients. METHODS: 21 subjects were selected, through a detailed anamnesis and clinical examination, in order to assess the normality of oral tissues, the presence of normal occlusion, the absence of alteration in tooth dimensions and of congenital or developmental anomalies of lips, mouth or face. RESULTS: The present investigation showed that temporalis, masseter and sternocleidomastoid muscles in untreated and growing individuals with facial asymmetries are thinner on the omolateral side when compared with controlateral normal side, but in the untreated one this value is more statistically significantly. CONCLUSIONS: In conclusion, the cervical muscle's thickness resulted increased in young patients Ultrasound is beginning to be recognized to have potential use in dentistry as a safe, noninvasive, comfortable and cost-effective adjunct to diagnosis by producing high-resolution images more easily than magnetic resonance (MRI) and computed tomography (CT) (27-kubo).

Measurement properties of instruments for assessment of cervical spine function in infants with torticollis: a systematic review.

The aim of this study was to systematically review the measurement properties of instruments which assess cervical spine function in infants with torticollis. Electronic searches were performed in MEDLINE, CINAHL, Embase, Web of Science and the Cochrane Library, combining three constructs ('torticollis', 'cervical spine assessment' and 'measurement properties'). Two reviewers independently rated the methodological quality and the quality of measurement properties of identified articles, using both the COSMIN (COnsensus-based Standards for the selection of health status Measurement INstruments) checklist and quality criteria for measurement properties. Five studies, using six instruments, met the inclusion criteria and were analysed. Included instruments were the goniometer, electronic pendular goniometer, protractor, still photography, Muscle Function Scale and a range of motion limitation scale. All studies assessed reliability, and one study also assessed content validity and hypothesis testing. The methodological quality of the studies varied from poor to excellent according to the COSMIN checklist. Two instruments were found to have good measurement properties from high-quality studies: still photography for the assessment of habitual head tilt in supine and the Muscle Function Scale for the assessment of side-flexor muscle function in lateral head righting.Conclusion: This systematic review identified two reliable tools for the assessment of cervical spine function in infants with torticollis. Further research is required to assess the measurement properties of tools already described in the literature and to develop further tools for use in this population. What is known? • A thorough assessment of the infant presenting with torticollis is essential, in order to correctly diagnose, rule out 'red flags' and manage appropriately • Assessment tools need to have robust measurement properties in order to be of value for clinical practice and research What is new? • This systematic review identified two valid and reliable tools for the assessment of cervical spine function in infants with torticollis • Further research is required to assess the measurement properties of tools already described in the literature and to develop further tools for use in infants with torticollis.

Assessment of range and quality of neck movement using a smartphone-based application.

This study had the objective of measuring the validity of using a smartphone-based application to measure range of motion (ROM) and quality of movement (QOM) of neck motion by comparing it with 3D-motion capture analysis. METHODS: Thirty healthy volunteers participated in this cross-sectional study. A helmet fitted with markers for motion capture analysis and a smartphone were fastened to the head of the participants. The smartphone recorded data using a beta version of Balancy (MEDEI, Denmark). Assessments of full active movement in transverse and sagittal planes were performed. Recordings were made simultaneously with the camera system and the smartphone. ROM and jerkiness were compared with a repeated measures ANOVA and a Pearson product moment was calculated to compare the outcomes from the different applications. Bland-Altman plots were generated to determine the levels of agreement. RESULTS: No difference was found between modalities when comparing measurements of jerkiness or ROM. An excellent Pearson product moment was found for the outcomes of the two modalities for ROM (Pearson's r: 0.83 - 0.96) and jerkiness (Pearson's r: 0.86 - 0.95). The Bland-Altman plot revealed a systemic offset where the phone consistently measured higher values for ROM and lower values for jerkiness. CONCLUSIONS: This study demonstrated that a smartphone-based application can be used to accurately measure ROM and jerkiness during neck movements. These results indicate the utility of using a smartphone-based application to assess neck movement in humans. The findings have implications for assessment of neck movement in research and clinical practice.

Intrarater and Inter-rater Reliability of Maximal Voluntary Neck Muscle Strength Assessment Using a Handheld Dynamometer in Women With Headache and Healthy Women.

OBJECTIVE: This study aimed to determine the inter-rater and intrarater reliability, agreement, and minimal detectable change (MDC) of the neck muscle strength test using a handheld dynamometer in healthy women and women with headaches. METHODS: Neck muscle strength in maximal voluntary contraction was measured using the Lafayette Manual Muscle Testing attached to a nonelastic belt in 25 women with migraines and in 25 healthy women. Three repetitions of flexion, extension, and lateral flexion were performed. The tests were performed by 2 examiners on the same day, with a 10-minute interval, and by 1 examiner, with a 1-week interval. The reliability was verified by the intraclass correlation coefficient, the agreement determined by standard error measurement, and the MDC calculated. RESULTS: The protocol exhibited moderate to excellent intrarater and inter-rater reliabilities in both groups (intraclass correlation coefficientrange, 0.53-0.90). The standard error measurement ranged from 0.43 to 1.81 and the MDC from 1.49 up to 4.61. CONCLUSION: Quantification of neck muscle strength using the handheld dynamometer with an attached nonelastic belt exhibited moderate to excellent intra- and inter-rater reliability in women with and without migraines. Moreover, the standard error measurement and MDC were proven to be useful in the interpretation of data and in guiding clinical decisions.

The Geniohyoid Muscle Directly Affects Masticatory Function: Evaluation with Decision-Tree Analysis.

PURPOSE: To clarify the effect of geniohyoid (GH) muscle morphology and related function on masticatory ability using a decision-tree analysis. MATERIALS AND METHODS: A total of 103 participants were enrolled. A cross-sectional area (CSA) of the GH muscle, neck circumference, body mass index, tongue pressure, jaw opening strength, and masticatory ability score were measured. The CSA of the GH muscle was selected as an independent variable for the first layer of the decision tree, with masticatory score as the dependent variable. RESULTS AND CONCLUSION: These data suggest that the CSA of the GH muscle may have a large impact on the masticatory ability score when evaluating masticatory ability.

Sonographic assessment of swallowing in irradiated nasopharyngeal carcinoma patients.

OBJECTIVES/HYPOTHESIS: Ultrasonography is an emerging clinical tool to study the dysfunction of swallowing muscles. This was the first sonographic study to assess the relationship between suprahyoid muscle contraction, hyoid bone displacement, and penetration-aspiration status (PAS) during swallowing in nasopharyngeal carcinoma (NPC) patients treated with radiotherapy (RT). The study also aimed to establish reliability data for the sonographic technique described. STUDY DESIGN: Cross-sectional study. METHODS: Geniohyoid muscle contraction was quantified using brightness-mode ultrasonography in this study of 40 post-RT NPC patients. A series of physiological parameters and PAS were measured using videofluoroscopy. RESULTS: Intra- and inter-rater agreement values ranged from 0.75 to 0.96 across various sonographic measurements. Percentage increase in the cross-sectional area of the geniohyoid muscle correlated with anterior (r = 0.42, P < .05) but not superior (r = 0.27, P = .09) hyoid displacement. Anterior hyoid displacement and pharyngeal constriction ratio were significantly associated with PAS score. CONCLUSIONS: Sonographic measurement of suprahyoid muscles provides valuable information on muscle function and is potentially a useful clinical tool in swallowing assessment. Further research is needed to refine the role of this examination in dysphagia. LEVEL OF EVIDENCE: 2b. Laryngoscope, 2552-2559, 2018.

Volumetric Assessment of Swallowing Muscles: A Comparison of CT and MRI Segmentation.

PURPOSE: Recent retrospective studies have proposed a high correlation between atrophy of swallowing muscles, age, severity of dysphagia and aspiration status based on computed tomography (CT). However, ionizing radiation poses an ethical barrier to research in prospective non-patient populations. Hence, there is a need to prove the efficacy of techniques that rely on noninvasive methods and produce high-resolution soft tissue images such as magnetic resonance imaging (MRI). The objective of this study was therefore to compare the segmentation results of swallowing muscles using CT and MRI. METHODS: Retrospective study of 21 patients (median age: 46.6; gender: 11 female) who underwent CT and MRI of the head and neck region within a time frame of less than 50 days because of suspected head and neck cancer using contrast agent. CT and MR images were segmented by two blinded readers using Medical Imaging Toolkit (MITK) and both modalities were tested (with the equivalence test) regarding the segmented muscle volumes. Adjustment for multiple testing was performed using the Bonferroni test and the potential time effect of the muscle volumes and the time interval between the modalities was assessed by a spearman correlation. The study was approved by the local ethics committee. RESULTS: The median volumes for each muscle belly of the digastric muscle derived from CT were 3051 mm3 (left) and 2969 mm3 (right), and from MRI they were 3218 mm3 (left) and 3027 mm3 (right). The median volume of the geniohyoid muscle was 6580 mm3 on CT and 6648 mm3 on MRI. The interrater reliability was high for all segmented muscles. The mean time interval between the CT and MRI examinations was 34 days (IQR 25; 41). The muscle differences of each muscle between the two modalities did not reveal significant correlation to the time interval between the examinations (digastric left r = 0.003 and digastric right r = -0.008; geniohyoid muscle r = 0.075). CONCLUSION: CT-based segmentation and MRI-based segmentation of the digastric and geniohyoid muscle are equally feasible. The potential advantage of MRI for prospective studies is the absence of ionizing radiation. KEY POINTS: · CT-based segmentation and MRI-based segmentation of the swallowing muscles are equally feasible.. · The advantage of MRI is the absence of ionizing radiation.. · MRI should therefore be deployed for future prospective studies.. CITATION FORMAT: · Sporns KB, Hanning U, Schmidt R et al. Volumetric Assessment of Swallowing Muscles: A Comparison of CT and MRI Segmentation. Fortschr Röntgenstr 2018; 190: 441 - 446.