Chin Movements Research Articles

Three-dimensional analysis of lip and chin movements during mastication with artificial nasal obstruction.

This study aimed to investigate the effects of nasal obstruction on the coordinated movement of perioral tissues during mastication using a motion capture system. Twelve healthy adult participants were instructed to chew gum only on their habitual masticatory side for 30 s, with and without nasal obstruction. Nasal obstruction was induced by blocking nasal breathing with a nose clip. Movements of the upper and lower lips, left and right corners of the mouth, and chin during gum chewing were measured using a motion capture system, and the differences between participants with and without nasal obstruction were compared. Multilevel linear model analysis was used to evaluate inter-individual and intra-individual variations in lip and chin movements, both with and without nasal obstruction. The chin chewing cycle duration was significantly longer in participants with nasal obstruction. The chewing cycle distance of the upper lip was significantly shorter in participants with nasal obstruction. The intra-individual variation in the chewing cycle distance of the chin and lips increased with nasal obstruction, whereas the inter-individual variation decreased. Nasal obstruction causes unstable yet uniform movements of the chin and lips during mastication, while also restricting upper-lip movement. Our results indicate that nasal obstruction may significantly affect mandibular and lip movements during mastication. These findings highlight the importance of nasal breathing in maintaining stable perioral movements during mastication. This study provides new insights that could inform clinical strategies for managing oral function in individuals with nasal obstruction.

Silver oxide integrated ionic polymer composite for wearable sensing and water purification

Integrating metal nanoparticles (NPs) with ionic polymer blends/composites showed immense interest for their potential in wearable sensors, soft robotic arms, flexible man-machine interfaces of biomedical devices, and water purification applications. However, conventional NPs attached ionic polymer composites exhibit limitations such as low sensitivity (ΔR/R), low total dissolved solids (TDS) reduction, and low phosphate (PO4-P) removal rate. Herein, ionic polymer composites (IPCs) using flower-shaped silver oxide (Ag2O) attached Poly (vinylidene fluoride) (PVDF)/ polyvinylpyrrolidone (PVP)/ionic liquid (IL) were designed and developed for wearable sensing and water purification. The IPCs demonstrated remarkably high ΔR/R values of 50, 10, and 3.5 corresponding to the wrist movement of 50°, finger movement of 180°, and chin movements respectively. The Ag2O-based IPC recorded a significant reduction of TDS from sewage water from 3405 ppm to 1035 ppm, elevated the dissolved oxygen (DO) levels in the sewage water from 1.2 mg/l to 6.8 mg/l, and removed approximately 87.38 % phosphate from sewage water. Due to the uniform distribution of Ag2O within pores of IPC, it demonstrated enhanced performance for wearable and wastewater treatment applications.

Japanese Syllable Estimation Using Lip and Chin Movements

The accuracy of speech recognition from image data can be improved using a lip‐reading method, even in noisy environments. In related research, lip‐reading has not focused on jaw movements. In addition, few studies have focused on Japanese syllables. Owing to the relationship between Japanese vowels and jaw movements, such movements can improve the accuracy of syllable estimations. To improve the lip‐reading method, we studied the syllable identification method in Japanese using the features of both chin and lip movements. In addition to lip movements, the chin movement features are an improved F‐measure for a syllable identification method in Japanese. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Detecting lucid dreams only by submentalis electromyography

Lucid dreams (LDs) occur when people become aware that they are dreaming. This phenomenon has a wide range of possible applications from the perspectives of psychology, training physical movements, and controlling computers while asleep, among others. However, research on LDs might lack efficiency because the standard LD verification protocol uses polysomnography (PSG), which requires an expensive apparatus and skilled staff. The standard protocol also may reduce LD-induction efficiency. The current study examines whether humans can send phasic signals through submentalis electromyography (EMG) during muscle atonia via pre-agreed chin movements (PACM). This ability would manifest both REM sleep and consciousness, which are the main features of LDs. In laboratory conditions volunteers were instructed to open their jaws three times while in an LD right after the standard verification protocol to achieve the research goal. Results: 4 of 5 volunteers proved to be in an LD using the standard protocol, and then all of them made PACM. The outcomes show that dream signals cannot be blocked in the submentalis area during muscle atonia. Also, this finding can be considered to develop a simplified, reliable LD protocol that needs only one EMG sensor. The cost of this protocol could be only a small percentage of the current protocol, making it more convenient for researchers and volunteers. It can also be used remotely by inbuilt in wearable gadgets. Considering PACM could speed up LD research and provide many discoveries and new opportunities. Also, it can be used in sleep paralysis studies.

Isolated rapid eye movement sleep without atonia in amyotrophic lateral sclerosis

ObjectiveThe aim of this study was to quantitatively analyze, with the most recent and advanced tools, the presence of periodic leg movements during sleep (PLMS) and/or rapid eye movement (REM) sleep without atonia (RSWA), in a group of patients with amyotrophic lateral sclerosis (ALS), and to assess their eventual correlation with the clinical severity of the disease. MethodsTwenty-nine ALS patients were enrolled (mean age 63.6 years) along with 28 age-matched “normal” controls (mean age 63.8 years). Functional impairment due to ALS was evaluated using the ALS-Functional Rating Scale-Revised (ALS-FRS) and the ALS severity scale (ALSSS). Full video polysomnographic night recordings were obtained, and PLMS were analyzed by considering their number/hour of sleep and periodicity index, the distribution of intermovement intervals, and the distribution during the night. The characteristics of the chin electromyogram (EMG) amplitude during REM sleep were analyzed by means of the automatic atonia index and the number of chin EMG activations (movements). ResultsThe ALS patients showed longer sleep latency than the controls, together with an increase in number of stage shifts, increased sleep stage 1, and decreased sleep stage 2. None of the leg PLMS parameters were different between the ALS patients and controls. The REM atonia index was significantly decreased in the ALS patients, and the number of chin movements/hour tended to increase. Both REM atonia index and number of chin movements/hour correlated significantly with the ALS-FRS; REM atonia was higher and chin movements were less in ALS patients with more preserved function (higher scores on the ALS-FRS). ConclusionAbnormal REM sleep atonia seemed to be a genuine effect of ALS pathology per se and correlated with the clinical severity of the disease. It is unclear if this might constitute the basis of a possible risk for the development of REM sleep behavior disorder or represent a form of isolated RSWA in ALS.

Aesthetic success in genioplasties procedures criteria

Maxillomandibular dysmorphia may be associated with structural chin pathologies. Three-dimensional jaws displacements have limits. Specific genioplasty is an additional surgical mean for soft tissues profile normalization. Osteotomy line is examined according an incline angle and a possible lateral extension, as chin wing technique, improves facial shape. Cephalometric set-up with R line analyzes surgical chin movements and impact of lower incisors labial inclination on lower lip and mentolabial fold after advancement genioplasty. Micro-implant anchorage is a precious help to find lower incisors good position and optimum lower occlusal plane frontal shift in asymmetric facial pattern. Orthodontics criteria are essential factors to access an aesthetic success in genioplasties procedures.

Generalised electrographic seizures presenting as perioral myoclonia

A 41-year-old man, during a neurological consultation, reported "chin twitching" over a period of a week, which was diagnosed as intermittent perioral myoclonia. With only one tonic-clonic seizure seven years before, he had mentioned several episodes of chin twitching over the years. In the clinic, there were intermittent chin movements without apparent confusion, as he was able to provide a complete history and was fully oriented with intact memory. His video-EEG showed paroxysms of polyspike and slow-wave activity, with the longest burst-free interval being 20 seconds. Discharges were maximal over the fronto-central regions, correlating with the chin myoclonus. He was able to tap his hand continuously, and remained alert. The case represents an atypical presentation of idiopathic generalised epilepsy without manifestation of absence or limb myoclonus. Although juvenile myoclonic epilepsy and other idiopathic epilepsies are rarely associated with perioral myoclonia, this sign was the principal clinical feature for this patient. Oral treatment with levetiracetam resolved his seizures.

Tongue‐mandible coupling movements during saliva swallowing

The purpose of this study was to measure the tongue and mandible positions and displacements in relation to the maxilla in the midsagittal plane to characterize the different saliva swallowing patterns by recording their kinematics. A 2D electromagnetic articulograph using four transducer coils, three attached to the upper surface of the tongue midline plus one attached to the chin anterior part allowed continuous evaluation of tongue and chin movements in twelve young adults in good general health. During 170s sequences recorded at a frequency of 100Hz, subjects were at rest, silently reading a text they had chosen. The subjects were free to swallow during the sequence. Deglutition of accumulated saliva was analysed after averaging all values obtained during successive 250ms periods. We identified three elementary swallowing patterns. Mean duration of tongue-mandible movements were 1·51±0·17s, 1·63± 0·14s and 2·00±0·08s for the first, second and third patterns respectively. In the light of other studies based on intra-oral pressure recordings, our results help to understand the tongue-mandible coupling behaviours involved in managing an in-mouth saliva bolus during the three elementary swallowing patterns identified.

Treatment Changes of Chin Position in Class-II Division 1 Patients - A Cephalometric Study

The present study is designed to evaluate the changes of chin position in class- II division 1 growing patients, treated with Activator-headgear (ActHg) and Herbst appiiance and attempt is made to ascertain the most important determinants of AP (anteroposterior) chin position. Sample of 28 growing individuals with skeletal and dental Class II was divided in to three groups, (Activator headgear (ActHg) group 10, Herbst group 10 and a control group of 8 patients). Pre (Tl) and post (T2) growth modulation/observation standardized lateral cephalograms were traced, horizontal and vertical movements of selected landmarks were described based on Reference grid, a rectangular coordinates (X, Y). Condylar growth and true rotation of the mandible were calculated by mandibular superimpositions. Reduction in ANB was mainly due to mandibular growth with no signifïcant change in SNA value. Schudy's pogonion formula was not supported by the results. The most important determinant of anterior chin movements during growth and treatment was true rotation. Methods commonly used to correct Class II skeletal malocclusions produce no significant improvements in anteroposterior chin position. Skeletal Class II correction in growing adolescents results primarily from mandibular growth. Anteroposterior changes in chin position cannot bc accurately predicted by Schudy's pogonion formula, iustcad approximately 70% of the variability in entcroposterior movement of the chin can be explained by true rotation, horizontal and vertical condylar growth, and remodeling of the glenoid fossa.

Effects of bolus size and hardness on within-subject variability of chewing cycle kinematics

This study analysed how bolus hardness and size affect within-subject variability of chewing cycle kinematics. Two independent prospective studies were performed; both tracked chin movements using an optoelectronic recording system. Computer programs identified each subject's ten most representative cycles, and multilevel modelling procedures were used to estimate variances. One study evaluated 38 subjects who chewed 1, 2, 4 or 8 g of gum presented in random order. The second study evaluated 26 subjects who chewed approximately 2.5 g of harder (670 g) or softer (440 g) gum, also presented in random order. In terms of bolus size, the 2 g and 1 g boluses produced the least and greatest relative within-subject variability, respectively; the largest differences were found for cycle duration and excursions. Within-subject variability when chewing the harder gum was consistently greater than when chewing the softer gum, except for lateral movement towards the balancing side. Because bolus hardness and bolus size influence within-subject variability differently, they must be taken into consideration when designing experiments to study masticatory kinematics. We conclude that a 2 g bolus of soft gum should be used in studies of chewing cycle kinematics in order to reduce within-subject variability and increase statistical power.

Estimating Mandibular Motion Based on Chin Surface Targets During Speech

The movement of the jaw during speech and chewing has frequently been studied by tracking surface landmarks on the chin. However, the extent to which chin motions accurately represent those of the underlying mandible remains in question. In this investigation, the movements of a pellet attached to the incisor of the mandible were compared with those of pellets attached to different regions of the chin. Ten healthy talkers served as participants. Three speaking contexts were recorded from each participant: word, sentence, and paragraph. Chin position errors were estimated by computing the standard distance between the mandibular incisor pellet and the chin pellets. Relative to the underlying mandible, chin pellets moved with an average absolute and relative error of 0.81 mm and 7.30%, respectively. The movements of chin and mandibular pellets were tightly coupled in time. The chin tracking errors observed in this investigation are considered acceptable for descriptive studies of oromotor behavior, particularly in situations where mandibular placements are not practical (e.g., young children or edentulous adults). The observed amount of error, however, may not be tolerable for fine-grained analyses of mandibular biomechanics. Several guidelines are provided for minimizing error associated with tracking surface landmarks on the chin.

Cortical lateralization of bilateral symmetric chin movements and clinical relevance in tumor patients—A high field BOLD–FMRI study

Although unilateral lesion studies concerning the opercular part of primary motor cortex report clinically severe motor deficits (e.g. anarthria, masticatory paralysis), functional lateralization of this area has not yet been addressed in neuroimaging studies.Using BOLD–FMRI, this study provides the first quantitative evaluation of a possible cortical lateralization of symmetric chin movements (rhythmic contraction of masticatory muscles) in right-handed healthy subjects and presurgical patients suffering tumorous lesions in the opercular primary motor cortex. Data were analyzed according to “activation volume” and “activation intensity”.At group level, results showed a strong left-hemispheric dominance for chin movements in the group of healthy subjects. In contrast, patients indicated dominance of the healthy hemisphere. Here, a clinically relevant dissociation was found between “activation volume” and “activation intensity”: Although “activation volume” may be clearly lateralized to the healthy hemisphere, “activation intensity” may indicate residual functionally important tissue close to the pathological tissue. In these cases, consideration of BOLD–FMRI maps with the exclusive focus on “activation volume” may lead to erroneous presurgical conclusions.We conclude that comprehensive analyses of presurgical fMRI data may help to avoid sustained postoperative motor deficits and dysarthria in patients with lesions in the opercular part of primary motor cortex.

Quantitative effects of mattress types (comfortable vs. uncomfortable) on sleep quality through polysomnography and skin temperature

Information concerning the stages of sleep is one of the most important clues for determining the quality of a particular mattress. The purpose of this study was to determine the effects of mattress type on sleep quality by measuring skin temperature, by using a subjective mattress rating system, and through the use of Polysomnogram. Polysomnography involved the recording of brain waves through electroencephalography (EEG) and the generation of a video graphic record of eye movement (EOG), chin movements (EMG) and heart rhythm (ECG). Sixteen subjects were used in this study, which was a test of mattress comfort. Subjects spent 6 days and nights in the laboratory. Data was recorded for a period of 7 h for each of 3 nights. It was found that mean skin temperature, deep sleep (stage III and stage IV), sleep efficiency, wake after sleep onset (WASO), stage 1 and subjective ratings of mattress comfort were significantly affected according to mattress type. When subjects slept on “comfortable” mattresses, mean skin temperature was higher than for “uncomfortable” mattresses. Lower body skin temperature, sleep efficiency and percentage of deep sleep were higher as well. The percentages of WASO and stage 1 were lower when subjects slept on “comfortable” mattresses. Subjective ratings of sleep quality paralleled recorded sleep data.

Effect of an auditory cue on chewing cycle kinematics

This study analysed the systematic and random effects of a rhythmic auditory cue on chewing cycle kinematics. The chin movements of 25 subjects (19-35 years of age) with normal class I occlusion were recorded at 100Hz (Optotrak) Northern Digital) during two natural gum chewing (2.5 g) sequences to determine the chewing rate of each subject. Another sequence was recorded with the subjects chewing at their natural rate following an audible cue. Multilevel modeling procedures were used to evaluate differences between natural chewing with and without an audible cue. Differences were found between experimental conditions for excursions, velocities and cycle shape. When chewing with the audible cue velocities were slower and there was less excursion of the chin marker, with the exception of initial lateral movements toward the balancing side. No differences in between-subject variability were found when chewing with or without an audible cue. Within-subject variability was 44% smaller for total cycle duration and 53% smaller for total 3D excursion when chewing with the auditory cue. Chewing at one's normal rate while following an auditory cue produces more consistency in chewing cycle kinematics. This method may be applicable, with some limitations, to reduce within-subject variability in chewing cycle kinematics.

Children with multiple disabilities and minimal motor behavior using chin movements to operate microswitches to obtain environmental stimulation

In these two studies, two children with multiple disabilities and minimal motor behavior were assessed to see if they could use chin movements to operate microswitches to obtain environmental stimulation. In Study I, we applied an adapted version of a recently introduced electronic microswitch [Lancioni, G. E., O’Reilly, M. F., Singh, N. N., Sigafoos, J., Oliva, D., & Baccani, S., et al. (2004). Technological aids to promote basic developmental achievements by children with multiple disabilities: evaluating two cases. Cognitive Processing 5, 232–238]. In Study II, we set up a new microswitch detecting the chin-movement response through an optic sensor. Each study was carried out according to an ABAB sequence in which A represented baseline and B intervention phases. A 2-month post-intervention check also occurred. The data showed that both children increased the frequency of the chin response, thus increasing the level of environmental stimulation, during the intervention phases. This performance was retained at the post-intervention check. The overall suitability of this response and related microswitches as well as the need to explore other potential responses and microswitches for children with minimal motor behavior is discussed.

Influence of fMRI smoothing procedures on replicability of fine scale motor localization

Recent publications analyzing the influence of spatial smoothing on fMRI brain activation results demonstrated that smoothing may artificially combine activations from adjacent though functionally and anatomically distinct brain regions and that activation from large draining vessels may be smoothed into neighboring neuronal tissue. To investigate whether functional localizations may be artificially shifted by the smoothing procedure we performed replicability measurements. Localization centers of motor hand activations achieved during different conditions (isolated hand movements and simultaneous hand and chin movements) were compared with respect to smoothing effects. The voxel with the highest probability to represent a true positive activation was localized with a non-smoothed and a standard 4 x 4 x 6 mm smoothed correlational data analysis technique. Results show an increase of motor center aberrations between measurements by about 100% due to data smoothing indicating a statistically significant decrease in localization replicability.

Predicting masticatory jaw movements from chin movements using multivariate linear methods

Previously, we have used bivariate correlations of maximum and minimum displacement, velocity and acceleration variables to compare masticatory chin and jaw movements (J. Prosthet. Dent. 81 (1999) 179). This previous study represented a first step in exploring the hypothesis that the chin contained useful information regarding jaw kinematics. The current study extends our understanding of the relationship between masticatory chin and jaw movements by: (1) reconstructing and evaluating a more continuous trajectory of chin and jaw movements, and (2) performing multivariate correlations comparing chin and jaw movements at discrete points along the trajectory in order to gain insight into the coupling of chin and jaw movements during a chewing cycle. Results indicated that chin and jaw movement trajectories were visually similar in the lateral, vertical, and anteroposterior axes. The adjusted R 2 results in the lateral, vertical, and anteroposterior dimensions averaged 0.74, 0.78, and 0.89, respectively. Within chewing cycles, the lowest correlations between chin and jaw movements in the lateral and vertical dimensions occurred when the jaw was relatively closed, whereas the lowest correlations between chin and jaw movements in the anteroposterior dimension occurred while the jaw was opening from a closed position. The results indicated that jaw and chin movements were qualitatively similar and that at least 74% of the variation in jaw movements could be accounted for by multivariate linear models of chin movement.

Technological aids to promote basic developmental achievements by children with multiple disabilities: evaluation of two cases

Technological aids such as microswitches may be critical to foster learning and development in children with multiple disabilities. In study I, a child with minimal motor behavior was provided with a microswitch for chin movements to assess whether he could learn to use these movements to activate environmental stimuli. In study II, a child with dystonic (difficult-to-control) behavior was provided with microswitches for two motor responses and two vocal utterances. We wanted to assess whether he could use both types of responses effectively (varying within each pair, consistent with choice performance). The results were highly encouraging with both children. In study I, there was a significant increase in the child’s responding, suggesting learning and contingency awareness. In study II, there was a significant increase in responding as well as response variation that suggested choice behavior. The importance of microswitch devices in promoting new learning/developmental objectives and improving quality of life is discussed.

Reducing within-subject variation in chewing cycle kinematics—a statistical approach

High levels of within-subject variability have limited the use of chewing cycle kinematics in the experimental and clinical context. The purpose of this study was to validate a new strategy for reducing within-subject variability in chewing cycle kinematics, based on the 10 most representative cycles from a chewing sequence. This prospective study included 25 young subjects, with normal class I occlusions. An optoelectronic recording system was used to track chin movements of subjects chewing gum (2.5 g). Computer programs provided estimates for duration and movement as well as the 3D coordinates of the chin point. The total output files were further processed for selection of 10 representative cycles based on standard scores for total duration, excursive ranges in the lateral, vertical and antero-posterior directions. Multilevel modelling procedures were used to test for significant differences. There were no significant differences in cycle duration or excursions between the estimates for all cycles versus the 10 most representative cycles. Cycle shapes were very similar. There were no statistically significant differences in between-subject variances. All within-subject variances were smaller when using data from the 10 most representative cycles. The reduction of variance was approximately 33% for total duration and 75% for total 3D excursion. The results validate the pre-processing strategy that selects the 10 most representative cycles from a sequence without altering cycle duration, excursions or shape or affecting between-subject variation but reducing within-subject variation substantially.

Enabling a person with multiple disabilities and minimal motor behaviour to control environmental stimulation with chin movements

Purpose: To assess whether a young man with multiple disabilities and minimal motor behaviour would learn to control environmental stimulation using chin movements and a mechanical microswitch. Method: The study was carried out according to an ABAB design in which A represented baseline and B intervention phases. The chin movements controlled the stimulation only during the intervention phases. A 2-month post-intervention check was conducted. Results: The man increased the frequency of his chin movements, thus increasing the level of environmental stimulation, during the intervention phases. This performance was maintained at the post-intervention check. Conclusion: The use of chin movements is a practical strategy for enabling individuals with minimal motor movements to control environmental stimulation. Future research should examine whether similar types of movements may enable some individuals to control voice-output communication devices.