A Quantitative Assessment of Lip Movements in Different Facial Expressions Through 3-Dimensional on 3-Dimensional Superimposition: A Cross-Sectional Study.

PURPOSE: The quantitative assessment of facial modifications from mimicry is of relevant interest for the rehabilitation of patients who can no longer produce facial expressions. This study investigated a novel application of 3-dimensional on 3-dimensional superimposition for facial mimicry. MATERIALS AND METHODS: This cross-sectional study was based on 10 men 30 to 40 years old who underwent stereophotogrammetry for neutral, happy, sad, and angry expressions. Registration of facial expressions on the neutral expression was performed. Root mean square (RMS) point-to-point distance in the labial area was calculated between each facial expression and the neutral one and was considered the main parameter for assessing facial modifications. In addition, effect size (Cohen d) was calculated to assess the effects of labial movements in relation to facial modifications. RESULTS: All participants were free from possible facial deformities, pathologies, or trauma that could affect facial mimicry. RMS values of facial areas differed significantly among facial expressions (P = .0004 by Friedman test). The widest modifications of the lips were observed in happy expressions (RMS, 4.06 mm; standard deviation [SD], 1.14 mm), with a statistically relevant difference compared with the sad (RMS, 1.42 mm; SD, 1.15 mm) and angry (RMS, 0.76 mm; SD, 0.45 mm) expressions. The effect size of labial versus total face movements was limited for happy and sad expressions and large for the angry expression. CONCLUSION: This study found that a happy expression provides wider modifications of the lips than the other facial expressions and suggests a novel procedure for assessing regional changes from mimicry.

Development of a Low-Cost, Noninvasive, Portable Visual Speech Recognition Program.

OBJECTIVES: Loss of speech following tracheostomy and laryngectomy severely limits communication to simple gestures and facial expressions that are largely ineffective. To facilitate communication in these patients, we seek to develop a low-cost, noninvasive, portable, and simple visual speech recognition program (VSRP) to convert articulatory facial movements into speech. METHODS: A Microsoft Kinect-based VSRP was developed to capture spatial coordinates of lip movements and translate them into speech. The articulatory speech movements associated with 12 sentences were used to train an artificial neural network classifier. The accuracy of the classifier was then evaluated on a separate, previously unseen set of articulatory speech movements. RESULTS: The VSRP was successfully implemented and tested in 5 subjects. It achieved an accuracy rate of 77.2% (65.0%-87.6% for the 5 speakers) on a 12-sentence data set. The mean time to classify an individual sentence was 2.03 milliseconds (1.91-2.16). CONCLUSION: We have demonstrated the feasibility of a low-cost, noninvasive, portable VSRP based on Kinect to accurately predict speech from articulation movements in clinically trivial time. This VSRP could be used as a novel communication device for aphonic patients.

A quantitative assessment of the eating capability in the elderly individuals.

Ageing process implies physiologically weakened muscles, loss of natural teeth and movement coordination, causing difficulties in the eating process. A term "eating capability" has been proposed to measure objectively how capable an elderly individual is in overall food management. Our objectives were to establish feasible methodologies of eating capability assessment, examine correlations between hand and oro-facial muscle strengths and grade elderly subjects into groups based on their eating capabilities. This study was performed with 203 elderly subjects living in the UK (n=103, 7 community centres, 2 sheltered accommodation) and Spain (n=100, 3 nursing homes, 1 community centre). Hand gripping force, finger gripping force, biting force, lip sealing pressure, tongue pressing pressure and touching sensitivity were measured for elderly subjects. Measured parameters were normalised and scored between 1 and 5, with 1 being the weakest. Subjects were then grouped into 4 groups based on their eating capability scores, being participants of cluster 1 the weakest group and 4 the strongest. Perception of oral processing difficulty was assessed by showing food images. Hand gripping force showed a strong linear correlation with tongue pressure (UK: 0.35; Spain: 0.326) and biting force (UK: 0.351; Spain: 0.427). Biting force was strongly dependent on the denture status. Elderly of the first three groups perceived food products with more hardness and/or fibrous structure as difficult to process orally. The objective measurements of various physiological factors enabled quantitative characterisation of the eating capabilities of elderly people. The observed relationship between hand and oro-facial muscle strengths provides possibility of using non-invasive hand gripping force measurement for eating capability assessment.

Assessment of human intraoral thermal sensitivity with simple devices in the clinic: implications for orofacial pain conditions.

AIMS: To use simple thermal devices with different diameters and temperatures to investigate reliability and magnitude of human intraoral thermal sensitivity. METHODS: Sixteen healthy volunteers participated. Six thermal devices with tapered circular ends (stimulus diameter 3, 5, and 10 mm) were used. Three different temperatures (room temperature, heat, and cold) were applied with each of the three diameters, ie, nine combinations. Participants were stimulated in randomized order at nine different sites: tongue, lip, maxillary attached gingiva adjacent to the left and right central incisors (without touching the lip) and to the left and right premolars (with or without touching the lip), and the left and right cheeks extraorally. Participants rated the perceived stimulus intensity on 0-50- 100 numeric rating scales (NRS). The number of paradoxical thermal sensations was also recorded. Ten volunteers were examined twice on the same day and recalled for a second session for assessment with the 5-mm-diameter device of within- and between-session reliability (interclass correlation coefficients [ICC]). The results were analyzed using a three-way analysis of variance. RESULTS: Reliability of NRS scores ranged from poor (ICC = 0.09, with cold stimulation at the premolar region) to excellent (ICC > 0.92, with cold stimulation at the cheek or tongue). NRS values varied with stimulus diameter (P < .050), temperature (P < .001), and sites (P < .001), with significant size x site and temperature x site interactions (P < .001). The tongue was the most sensitive site (P < .001) and the gingiva was the least sensitive site (P < .050). The 10-mm-diameter device produced higher NRS scores than the 3-mm-diameter device. CONCLUSION: The reliability of intraoral thermal sensitivity recorded with the 5-mm-diameter device varied greatly between different sites. Nonetheless, with this caveat in mind, the study did document that semiquantitative assessment of intraoral thermal sensitivity is feasible and applicable for clinical studies in different intraoral pain conditions.

Assessment of mastication in healthy children and children with cerebral palsy: a validity and consistency study.

The aim of this study was to develop the Mastication Observation and Evaluation instrument for observing and assessing the chewing ability of children eating solid and lumpy foods. This study describes the process of item definition and item selection and reports the content validity, reproducibility and consistency of the instrument. In the developmental phase, 15 experienced speech therapists assessed item relevance and descriptions over three Delphi rounds. Potential items were selected based on the results from a literature review. At the initial Delphi round, 17 potential items were included. After three Delphi rounds, 14 items that regarded as providing distinctive value in assessment of mastication (consensus >75%) were included in the Mastication Observation and Evaluation instrument. To test item reproducibility and consistency, two experts and five students evaluated video recordings of 20 children (10 children with cerebral palsy aged 29-65 months and 10 healthy children aged 11-42 months) eating bread and a biscuit. Reproducibility was estimated by means of the intraclass correlation coefficient (ICC). With the exception of one item concerning chewing duration, all items showed good to excellent intra-observer agreement (ICC students: 0.73-1.0). With the exception of chewing duration and number of swallows, inter-observer agreement was fair to excellent for all items (ICC experts: 0.68-1.0 and ICC students: 0.42-1.0). Results indicate that this tool is a feasible instrument and could be used in clinical practice after further research is completed on the reliability of the tool.

The distributed lambda (λ) model (DLM): a 3-D, finite-element muscle model based on Feldman's λ model; assessment of orofacial gestures.

PURPOSE: The authors aimed to design a distributed lambda model (DLM), which is well adapted to implement three-dimensional (3-D), finite-element descriptions of muscles. METHOD: A muscle element model was designed. Its stress-strain relationships included the active force-length characteristics of the λ model along the muscle fibers, together with the passive properties of muscle tissues in the 3-D space. The muscle element was first assessed using simple geometrical representations of muscles in the form of rectangular bars. It was then included in a 3-D face model, and its impact on lip protrusion was compared with the impact of a Hill-type muscle model. RESULTS: The force-length characteristic associated with the muscle elements matched well with the invariant characteristics of the λ model. The impact of the passive properties was assessed. Isometric force variation and isotonic displacements were modeled. The comparison with a Hill-type model revealed strong similarities in terms of global stress and strain. CONCLUSION: The DLM accounted for the characteristics of the λ model. Biomechanically, no clear differences were found between the DLM and a Hill-type model. Accurate evaluations of the λ model, based on the comparison between data and simulations, are now possible with 3-D biomechanical descriptions of the speech articulators because of the DLM.

Validated assessment scales for the lower face.

BACKGROUND: Aging in the lower face leads to lines, wrinkles, depression of the corners of the mouth, and changes in lip volume and lip shape, with increased sagging of the skin of the jawline. Refined, easy-to-use, validated, objective standards assessing the severity of these changes are required in clinical research and practice. OBJECTIVE: To establish the reliability of eight lower face scales assessing nasolabial folds, marionette lines, upper and lower lip fullness, lip wrinkles (at rest and dynamic), the oral commissure and jawline, aesthetic areas, and the lower face unit. METHODS AND MATERIALS: Four 5-point rating scales were developed to objectively assess upper and lower lip wrinkles, oral commissures, and the jawline. Twelve experts rated identical lower face photographs of 50 subjects in two separate rating cycles using eight 5-point scales. Inter- and intrarater reliability of responses was assessed. RESULTS: Interrater reliability was substantial or almost perfect for all lower face scales, aesthetic areas, and the lower face unit. Intrarater reliability was high for all scales, areas and the lower face unit. CONCLUSION: Our rating scales are reliable tools for valid and reproducible assessment of the aging process in lower face areas.

Functional MRI assessment of orofacial articulators: neural correlates of lip, jaw, larynx, and tongue movements.

Compared with complex coordinated orofacial actions, few neuroimaging studies have attempted to determine the shared and distinct neural substrates of supralaryngeal and laryngeal articulatory movements when performed independently. To determine cortical and subcortical regions associated with supralaryngeal motor control, participants produced lip, tongue and jaw movements while undergoing functional magnetic resonance imaging (fMRI). For laryngeal motor activity, participants produced the steady-state/i/vowel. A sparse temporal sampling acquisition method was used to minimize movement-related artifacts. Three main findings were observed. First, the four tasks activated a set of largely overlapping, common brain areas: the sensorimotor and premotor cortices, the right inferior frontal gyrus, the supplementary motor area, the left parietal operculum and the adjacent inferior parietal lobule, the basal ganglia and the cerebellum. Second, differences between tasks were restricted to the bilateral auditory cortices and to the left ventrolateral sensorimotor cortex, with greater signal intensity for vowel vocalization. Finally, a dorso-ventral somatotopic organization of lip, jaw, vocalic/laryngeal, and tongue movements was observed within the primary motor and somatosensory cortices using individual region-of-interest (ROI) analyses. These results provide evidence for a core neural network involved in laryngeal and supralaryngeal motor control and further refine the sensorimotor somatotopic organization of orofacial articulators.

Three-dimensional assessment of functional change following Class 3 orthognathic correction--a preliminary report.

Orthognathic surgery is a well-documented clinical procedure for patients who complain of functional and aesthetic problems related to dento-facial imbalance. The aims of treatment are to establish facial harmony, normalise function and maximise the stability of the outcome. Conventional diagnostic aids to treatment include plain film radiographs and photographs which provide a static analysis of the facial structures at a particular point in time. Functional assessment of facial movement is rarely performed but could have important implications on the stability of the surgery through post-surgical soft tissue adaptation to the new skeletal relationships. A case report is presented for which novel three-dimensional motion analysis techniques were used to assess facial movement through the surgical correction of a Class 3 malocclusion. It was found that facial movement increased for all circum-oral postures post-surgery. Future research in this field recommends collection of data from a control group to allow comparisons of facial movement between different surgical samples.

Testing orofacial abilities of children who stutter: the Movement, Articulation, Mandibular and Sensory awareness (MAMS) assessment procedure.

OBJECTIVE: The purpose of this article is to introduce a new assessment designed to measure the orofacial abilities of children who stutter (CWS), the Movement, Articulation, Mandibular and Sensory Awareness (MAMS) Orofacial Assessment. The new instrument was developed and validated to measure orofacial abilities in a comprehensive manner. DESIGN: A group of 43 CWS (mean age 13.10 years, S.D. 2.10 years) and a control group of 32 fluent children (mean age 13.4 years, S.D. 2.6 years) were tested with the new tool. It was hypothesized, that (a) the MAMS is a reliable and valid instrument to measure orofacial abilities in CWS, (b) fluent children have better orofacial abilities than CWS and (c) that the therapy outcome of CWS depend on their orofacial abilities. RESULTS: The MAMS Orofacial Assessment proved to be a valid and reliable instrument to assess orofacial abilities. Compared with their fluent peers, CWS had significantly worse orofacial abilities. CWS with better orofacial abilities had a better prognosis for therapy outcome. CONCLUSIONS: The new instrument is a reliable and valid tool to measure orofacial abilities and MAMS distinguishes CWS and controls. Orofacial abilities are one set of factors that influence therapy outcome for CWS. EDUCATIONAL OBJECTIVES: The reader will get an overview over of the literature on orofacial abilities in people who stutter and will learn about and be able to (1) describe different characteristics of orofacial abilities, (2) use the MAMS Orofacial Assessment in the diagnostic process for CWS and for research purposes, and (3) interpret the results of the MAMS to use them for therapy planning.

Hybrid simulated annealing and its application to optimization of hidden Markov models for visual speech recognition.

We propose a novel stochastic optimization algorithm, hybrid simulated annealing (SA), to train hidden Markov models (HMMs) for visual speech recognition. In our algorithm, SA is combined with a local optimization operator that substitutes a better solution for the current one to improve the convergence speed and the quality of solutions. We mathematically prove that the sequence of the objective values converges in probability to the global optimum in the algorithm. The algorithm is applied to train HMMs that are used as visual speech recognizers. While the popular training method of HMMs, the expectation-maximization algorithm, achieves only local optima in the parameter space, the proposed method can perform global optimization of the parameters of HMMs and thereby obtain solutions yielding improved recognition performance. The superiority of the proposed algorithm to the conventional ones is demonstrated via isolated word recognition experiments.

Performance enhancement for audio-visual speaker identification using dynamic facial muscle model.

Science of human identification using physiological characteristics or biometry has been of great concern in security systems. However, robust multimodal identification systems based on audio-visual information has not been thoroughly investigated yet. Therefore, the aim of this work to propose a model-based feature extraction method which employs physiological characteristics of facial muscles producing lip movements. This approach adopts the intrinsic properties of muscles such as viscosity, elasticity, and mass which are extracted from the dynamic lip model. These parameters are exclusively dependent on the neuro-muscular properties of speaker; consequently, imitation of valid speakers could be reduced to a large extent. These parameters are applied to a hidden Markov model (HMM) audio-visual identification system. In this work, a combination of audio and video features has been employed by adopting a multistream pseudo-synchronized HMM training method. Noise robust audio features such as Mel-frequency cepstral coefficients (MFCC), spectral subtraction (SS), and relative spectra perceptual linear prediction (J-RASTA-PLP) have been used to evaluate the performance of the multimodal system once efficient audio feature extraction methods have been utilized. The superior performance of the proposed system is demonstrated on a large multispeaker database of continuously spoken digits, along with a sentence that is phonetically rich. To evaluate the robustness of algorithms, some experiments were performed on genetically identical twins. Furthermore, changes in speaker voice were simulated with drug inhalation tests. In 3 dB signal to noise ratio (SNR), the dynamic muscle model improved the identification rate of the audio-visual system from 91 to 98%. Results on identical twins revealed that there was an apparent improvement on the performance for the dynamic muscle model-based system, in which the identification rate of the audio-visual system was enhanced from 87 to 96%.

[Relation between the level of care needed and frailty for labial functions].

AIM: The purpose of this study was to examine whether the improvement of oral functions could prevent increase in the level of care needed in the elderly by analyzing the relationship between the level of care needed and labial functions. METHODS: The subjects were 114 elderly people who were healthy or needing care (44 men, 70 women; average age 81.3 +/- 6.3 years), all of whom maintained posterior occlusal support with their natural dentition and had no defect in front teeth. They were divided into four groups; Group 1: healthy elderly, Group 2: elderly requiring assistance or Care Category 1, Group 3: elderly requiring Care Categories 2 and 3, Group 4: elderly requiring Care Categories 4 and 5, according to the classification of certification of eligibility for long-term care by the Japanese Ministry of Health, Labor and Welfare. Water-repellent pressure sensors (PS-2KA, Kyowa Electric Co, Japan) were embedded in an acrylic plate. The device was used to measure the labial-closing pressure during 1-gram yogurt ingestion, the maximum labial pressure with effort and the reserve capacity of pressure. Drooling of food as feeding/swallowing dysfunction of the subjects was surveyed. RESULTS: 1) The mean value of labial pressure with effort was 296.4 +/- 153.9 Pa, and that of the reserve capacity of labial pressure was 209.6 +/- 152.3 Pa. They showed significant declines in accordance with the aggravation level of needing care (p < 0.01). 2) The labial pressure with effort and the reserve capacity of pressure in subjects who showed drooling of food symptom were significantly lower compared to those who showed no drooling of food symptom (p < 0.05). CONCLUSION: Labial functions declined in accordance with the increased level of care needed, and a relationship between drooling of food and labial-closing pressure was recognized. It was suggested that the improvement of labial functions might prevent increased need of care.

Speed, amplitude, and asymmetry of lip movement in voluntary puckering and blowing expressions: implications for facial assessment.

The context of voluntary movement during facial assessment has significant effects on the activity of facial muscles. Using automated facial analysis, we found that healthy subjects instructed to blow produced lip movements that were longer in duration and larger in amplitude than when subjects were instructed to pucker. We also determined that lip movement for puckering expressions was more asymmetric than lip movement in blowing. Differences in characteristics of lip movement were noted using facial movement analysis and were associated with the context of the movement. The impact of the instructions given for voluntary movement on the characteristics of facial movement might have important implications for assessing the capabilities and deficits of movement control in individuals with facial movement disorders. If results generalize to the clinical context, assessment of generally focused voluntary facial expressions might inadequately demonstrate the full range of facial movement capability of an individual patient.

An instrument for the non-invasive assessment of lip function during speech.

This paper describes the development of an instrument using infrared light as a non-invasive means of detecting lip opening, the extent of the opening and also the forward protrusion and backward movement of the lips during speech. The design criteria were to build a simple stand alone means of assessing lip function, which could also link to the group's commercially available Super Nasal-Oral Ratiometry System (SNORS+). SNORS+ allows objective assessment of the function and co-ordination of key articulators, with lip function previously monitored using a video camera. Synchronised tests were carried out using the new Lip Function Monitor and the video camera simultaneously, in order to verify that the signals produced related directly to the activity of the mouth. A small trial was then conducted to show that the system provides reproducible results throughout a range of 'normal' subjects. These subjects were of different gender and race to create a sample group within which there was a variety of lip sizes and face shapes. Technical aspects of the instrument and trial results are presented here. These suggest that the simple visual output and feedback of the instrument will prove useful in the assessment and management of speech disorders.

Interrater and intrarrater reliability of the exeter dysphagia assessment technique applied to healthy elderly adults.

The purpose of this study was to evaluate the inter- and intrarater reliabilities of the Exeter Dysphagia Assessment Technique in a sample of elderly adults. This procedure uses noninvasive methods to record aspects of oral motor efficiency and synchronization of respiration during swallowing with the aid of specially developed equipment. Changes in the direction of nasal air flow, time of lip or tongue/spoon contact, and the time/frequency of swallow sounds are monitored and analyzed. Seventy records were evaluated independently by three trained assessors on three consecutive occasions. Interrater reliability was found to be good to very good for five of the respiratory variables assessed and moderate for the sixth. Interrater agreement was also very good for three of the timed oropharyngeal events assessed and moderate for the fourth. Intrarater reliability was very good for the same five respiratory variables and moderate for the sixth. Intrarater agreement was also very good for three of the timed oropharyngeal events and moderate for the fourth. Repeat evaluations of these records showed that agreement between and within raters concerning the sixth respiratory variable was improved substantially when the charts were examined in an enlarged form that provided improved resolution. We conclude that the majority of variables monitored by the Exeter Dysphagia Assessment Technique can be evaluated very reliably.

Schedule for oral-motor assessment (SOMA): methods of validation.

The Schedule for Oral Motor Assessment (SOMA) was developed for the purpose of objectively rating the oral-motor skills of preverbal children, with a view to identifying areas of deficient abilities that could have clinical significance. The instrument can be administered without special equipment, by a trained observer. Oral-motor function is assessed across a range of food textures and fluids. Ratings of oral-motor skills are largely made post hoc by analysis of a videorecording of the test administration. The test-retest and interrater reliability of the instrument have been shown to be excellent. Criterion validity was investigated by means of a novel 'seeded cluster analysis' procedure in which 127 young children were assessed, most of whom were between 8 and 24 months of age. Ten percent of the sample had known abnormal oral-motor function in association with cerebral palsy (ages between 12 and 42 months). Not only was criterion validity satisfactorily established by the analysis but an abbreviated version of the SOMA--suitable for screening purposes--was developed. This has been shown to have a positive predictive validity greater than 90% and sensitivity greater than 85% for the detection of infants with clinically significant oral-motor dysfunction.

The application of quantitative perioral assessment to orthodontic case analysis and treatment planning.

Maximum tonicity of the lips can be accurately measured through the use of the pommeter. 2. Patients with significant hypertonicity of the lips whose maxillary central incisors are positioned oingualy as in Class II, Div. 2 and also in certain Class I malocclusions should be treated nonextraction and as early as possible. Torguing maxillary incisors into a more normal labial axial inclination is a form of expansion which does not detrimentally affect the position and function of the perioral muscles. In this early conservative approach not only is arch length increased but also marked improvement in the overbite is accomplished. These types of treated malocclusions should be retained until after the eruption of the second permanent molars. 3. If extraction is necessary in patients with hypertonic lip muscles it should be done as far as possible from the incisor teeth, preferably the second premolars. 4. In Class I malocclusions where maximum tonicity is in the normal range is to attempt to accommodate blocked out or rotated teeth within the framework of the perioral musculature surrounding the teeth...