A kinematic description of the temporal characteristics of jaw motion for early chewing: preliminary findings

The test of masticating and swallowing solids (ToMaSS): An investigation of applicability and clinical utility in children with orofacial myofunctional disorders

BACKGROUND

Orofacial myofunctional disorders (OMD) are often associated with limitations of oral ingestion of solid food. The Test of Masticating and Swallowing Solids (ToMaSS) is a simple diagnostic tool to assess and quantify oropharyngeal efficiency while eating a standardised cracker.

OBJECTIVES

The objective of this study was to investigate the applicability and clinical utility of the ToMaSS in children with OMD.

METHODS

In this case-control study, data were collected from 18 children between 4 and 11 years with confirmed OMD. Inter-rater reliability and age effects on the ToMaSS parameters were investigated and the specific performance profile of the OMD children was identified.

RESULTS

Inter-rater reliability was excellent for the ToMaSS parameters 'bites' (ICC = .999), 'masticatory cycles' (ICC = .961), 'time'(ICC≧ .999) and good for 'number of swallows' (ICC = .810). 'Masticatory cycles' and 'time' decreased as a function of age with a significant difference in the 'number of masticatory cycles' between the youngest (4-6 years) and oldest (10-14 years) participants (p = .006, Z = -2.739). Deviations from normative data in at least one of the four ToMaSS parameters were found in 90% of the OMD children with 'bites', and 'masticatory cycles' predominantly corresponding to the performances expected in typically-developing children in younger age groups.

CONCLUSIONS

The ToMaSS is a reliable diagnostic instrument and clinically useful to detect limited efficiency of oral solid bolus intake and specific impairments in chewing function and duration of food intake in children with OMD. Our data suggest that OMD is associated with delayed development of efficient solid bolus preparation.

Chewing skills in two and three year old children: Gender and age comparisons on an adapted version of the test of mastication and swallowing (TOMASS-C)

PURPOSE

Few assessment tools objectively measure chewing skills in the paediatric population. There is a need for assessment tools that use consistent foods so comparisons can be made between typically developing children and children with paediatric feeding disorders, and to measure the efficacy of treatment. The Test of Masticating and Swallowing Solids for adults (TOMASS) and children (TOMASS-C) are assessments that use a cracker as a consistent measure to assess chewing skills. Normative data exist for children over 4 years, however, no data are available for younger children. This study investigated age and gender-related differences in mastication skills in typically developing children aged 2-3 years when eating a cracker.

METHOD

Thirty participants aged 2;0-3;10 were assessed using an adapted version of the TOMASS-C. Participants were required to eat a single Arnott's Salada cracker, and the number of bites, masticatory cycles, swallows, and duration of time to finish the cracker were measured.

RESULT

Two-year-old children used more masticatory cycles and took longer to finish the cracker than 3-year-old children. There were no significant effects of age on the number of swallows and number of bites, and no significant differences between boys and girls.

CONCLUSION

This study provides preliminary normative data for chewing skills in children aged 2 and 3 years and confirms that the TOMASS-C is sensitive to developmental changes in mastication within this younger age range. These results expand our understanding of oral motor and chewing development in children.

Oromotor skills in autism spectrum disorder: A scoping review

Oromotor functioning plays a foundational role in spoken communication and feeding, two areas of significant difficulty for many autistic individuals. However, despite years of research and established differences in gross and fine motor skills in this population, there is currently no clear consensus regarding the presence or nature of oral motor control deficits in autistic individuals. In this scoping review, we summarize research published between 1994 and 2022 to answer the following research questions: (1) What methods have been used to investigate oromotor functioning in autistic individuals? (2) Which oromotor behaviors have been investigated in this population? and (3) What conclusions can be drawn regarding oromotor skills in this population? Seven online databases were searched resulting in 107 studies meeting our inclusion criteria. Included studies varied widely in sample characteristics, behaviors analyzed, and research methodology. The large majority (81%) of included studies report a significant oromotor abnormality related to speech production, nonspeech oromotor skills, or feeding within a sample of autistic individuals based on age norms or in comparison to a control group. We examine these findings to identify trends, address methodological aspects hindering cross-study synthesis and generalization, and provide suggestions for future research.

Comprehensive Dental Treatment under General Anesthesia Improves Mastication Capability in Children with Early Childhood Caries-A One-Year Follow-Up Study

BACKGROUND

Using the granulometry of ready-to-swallow food boluses, this study investigated the evolution of masticatory capability of children with Early Childhood Caries (ECC) after comprehensive dental treatment under general anesthesia (GA).

METHODS

Sixteen children with ECC were assessed before and over one year after dental treatment under GA, in comparison with 12 children with a Healthy Oral State (HOS). Oral health criteria, quality of life, body mass index, and frequency of orofacial dysfunctions were recorded. Masticatory kinematic parameters and median food bolus particle size (D50) at swallowing were assessed while masticating raw carrot (CAR), cheese (CHS), and breakfast cereals (CER). The impact of posterior teeth extractions was analyzed.

RESULTS

Quality of life and orofacial functions improved after dental treatment. Chewing frequency for all three foods increased without reaching the values of children with HOS, while D50 values for CAR and CHS decreased. After one year, children with posterior teeth extractions exhibited higher D50 values for CAR and CHS than children with only conservative treatment. One third of children with ECC were overweight or obese.

CONCLUSIONS

Comprehensive dental treatment improved children's mastication, and their BMI subsequently increased. Links between mastication and nutrition should be investigated further in children.

In vitro models of gut digestion across childhood: current developments, challenges and future trends

The human digestion is a multi-step and multi-compartment process essential for human health, at the heart of many issues raised by academics, the medical world and industrials from the food, nutrition and pharma fields. In the first years of life, major dietary changes occur and are concomitant with an evolution of the whole child digestive tract anatomy and physiology, including colonization of gut microbiota. All these phenomena are influenced by child exposure to environmental compounds, such as drugs (especially antibiotics) and food pollutants, but also childhood infections. Due to obvious ethical, regulatory and technical limitations, in vivo approaches in animal and human are more and more restricted to favor complementary in vitro approaches. This review summarizes current knowledge on the evolution of child gut physiology from birth to 3 years old regarding physicochemical, mechanical and microbial parameters. Then, all the available in vitro models of the child digestive tract are described, ranging from the simplest static mono-compartmental systems to the most sophisticated dynamic and multi-compartmental models, and mimicking from the oral phase to the colon compartment. Lastly, we detail the main applications of child gut models in nutritional, pharmaceutical and microbiological studies and discuss the limitations and challenges facing this field of research.

Vowel Context Effects on Consonant Repetition in Early Words

Purpose Consonant repetitions within words are a well-attested speech error pattern in children's early speech acquisition. We investigated the role of intervening vowel context in understanding speech forms containing consonant repetitions in early words. Intrasyllabic consonant-vowel (CV) sequences within consonant-vowel-consonant (CVC) and consonant-vowel-consonant-vowel (CVCV) forms containing consonant repetitions were analyzed to evaluate whether children's lack of independent movement control for the tongue in word-level sequences might contribute to these observed speech patterns. Method Spontaneous speech data produced by 10 typically developing children learning American English were analyzed longitudinally from the onset of word use to 36 months. Overall patterns and word shape effects for nine CV combinations occurring in their CVC and CVCV word shapes that contained repeated nonadjacent consonants and the intervening vowel were analyzed. Results Three CV combinations-coronal-front vowel, labial-central vowel, and dorsal-back vowel-occurred at above-chance levels. Preference for these CV patterns was strong in CVCV but not in CVC word shapes. These CV combinations occurred frequently at all time periods analyzed for CVCV's while decreasing across time for CVC's. Conclusions Analysis of intrasyllabic patterns within word forms containing consonant repetitions revealed that consonant repetitions in many early words occurred at above-chance levels in the context of articulatorily compatible vowels. Results suggest that children's production system capacities are an important contributing principle accounting for vowel context effects within word forms containing consonant repetitions during earliest speech acquisition.

Chewing Entrains Cyclical Actions but Interferes With Discrete Actions in Children

Functional chewing patterns are achieved early in life prior to other motor skills like walking. Chewing seems to improve specific aspects of attention; however, there is limited research on chewing in dual motor tasks. This study examined relationships between chewing and secondary motor tasks in children. Sixteen typically developing children (13.1 ± 2.3 years) participated in finger tapping, simple reaction time, and walking while chewing at different speeds. The chewing rates varied when produced with a secondary motor task, especially for slow chewing and preferred chewing, and the secondary motor tasks were differentially influenced by the chewing. This relationship was not as strong as what has been reported in adults. It appears the neural oscillatory mechanisms involved in chewing and the secondary motor tasks may not be fully developed in children.

Natural food mastication capability in preschool children according to their oral condition: A preliminary study

This study investigated, for the first time, the masticatory capability of preschool children using natural foods, and the impact of an early oral health alteration (early childhood caries: ECC) on the granulometry of ready-to-swallow food boluses. Thirteen children with ECC were compared to 13 preschool children with a healthy oral condition. Oral health criteria and NOT-S scores (Nordic Orofacial dysfunction Test-Screening) were recorded. For each child, number of masticatory cycles (Nc), chewing time (Ti), and frequency (Fq = Nc/Ti) were recorded during mastication of raw carrot (CAR), cheese (CHS) and breakfast cereals (CER) samples. Food boluses were collected by stopping children at their food-dependent individual swallowing threshold (Nc), and the median food bolus particle size value (D50) was calculated. Correlations were sought between oral health and masticatory criteria. In the ECC group, mean Fq values were significantly decreased for all three foods (p ≤ .001) and mean D50 values were significantly increased (p ≤ .001) compared to the control group (i.e., D50 CAR = 4,384 μm ± 929 vs. 2,960 μm ± 627). These alterations were related to the extent of ECC. The NOT-S mean global score was significantly increased in children with ECC (2.62 ± 1.37 vs. 1 ± 0.91 in the control group, p ≤ .01), due to "Mastication and swallowing" domain impairment. This study gives granulometric normative values for three foods in preschool children and shows the impact of ECC on D50 values. The progression of children's masticatory capability after dental treatment, and the impact of such modifications of sensory input on future eating habits should be explored.

Detecting Bulbar Motor Involvement in ALS: Comparing speech and chewing tasks

Purpose: To compare two different tasks and kinematic measures in terms of their ability to detect Amyotrophic lateral sclerosis (ALS) and differences in ALS severity in order to establish potential candidate markers of bulbar decline.Method: We tracked jaw kinematics during speech and chewing to determine which is more affected by bulbar motor deterioration, based on measures of maximum speed and articulatory working space. Data were collected from 31 individuals diagnosed with ALS and 17 neurologically intact controls.Result: (1) Both sentence and chewing tasks were effective in distinguishing between the groups of individuals with ALS and controls, (2) jaw maximum speed for both chewing and speech was a more sensitive marker for bulbar dysfunction than articulatory working space, (3) the sentence task distinguished between ALS subgroups stratified by severity and (4) distinct jaw kinematic differences existed between chewing and sentence tasks. More specifically, movement speed for speech decreased with severity while movement speed for chewing increased with disease severity.Conclusion: The findings from the current investigation suggest that measures of jaw movement speed during chewing and sentence tasks are affected by bulbar deterioration, and jaw speed during a sentence task may serve as a candidate marker of bulbar disease onset and severity.

Primary Teeth Bite Marks Analysis on Various Materials: A Possible Tool in Children Health Risk Analysis and Safety Assessment

BACKGROUND

All objects put into a child's mouth could be hazardous in terms of trauma and toxic substance exposure. The aims of this study were to evaluate morphological characteristics of the primary teeth bite marks inflicted on various materials and to assess material wear using experimental model.

METHODS

Bite marks were analyzed on five materials: rubber, plastic, foil, wood, and silicone. In order to mimic children mouthing behavior an experimental setup has been designed using primary teeth placed in dentures and children's equipment specimens.

RESULTS

Deciduous teeth make visible and recognizable traces when using physiological forces on all investigated materials. The most significant material loss was revealed in silicone samples, but it has been observed in all material groups, while mouthing with incisors using higher mastication forces were identified as significant predictors for material wear. There were no significant differences between type, species, and morphological-morphometric characteristics of the bite marks which are made by incisors, canines, and molars.

CONCLUSIONS

In the range of physiological bite forces, deciduous teeth lead to wear of material from which toys are made while the analysis of bite marks in children equipment could give some information regarding the risk of trauma and exposure.

Masticatory behavior for different solid foods in preschool children according to their oral state

Gradual introduction of solid foods in early childhood takes part in the maturation of mastication. The impact of any oral state alteration on food oral processing development is poorly documented for this age group. This study investigated the masticatory behavior in 3 to 6 year-old children with or without early childhood caries (ECC) for three solid foods of different textures. Twenty-one children with healthy oral state and 23 children with severe ECC were observed during complete mastication of calibrated samples of raw carrot, cheese and breakfast cereals. Food refusals and kinematic parameters (Ti: chewing time, Nc: number of cycles and Fq: chewing frequency) were used to assess children masticatory behavior. Oral Health-related Quality of Life and orofacial dysfunctions were evaluated using, respectively the early childhood oral health impact scale (ECOHIS) and the Nordic orofacial dysfunction test screening (NOT-S). Children suffering from ECC exhibited significantly higher ECOHIS and NOT-S scores, in particular for the mastication domain. Accordingly, lower chewing frequencies values were recorded in children with ECC (i.e., carrot Fq: 1.21 ± 0.20 vs 1.35 ± 0.22, p ≤ 0.01), as well as more frequent refusals for carrots. Kinematic parameters were shown to be repeatable in all children for successive samples of the same food, and tended to vary depending on the proposed food. Some masticatory behavior regulation according to food properties could already be present in preschool children. Children with ECC developed alternative behavioral strategies to overcome feeding difficulties. Further studies should investigate food bolus properties according to oral health, as well as nutritional issues. PRACTICAL APPLICATIONS: During childhood, the way solid foods are processed in the oral cavity to be safely swallowed and then digested in available nutrients, is poorly documented. In this study, preschool children have been shown to repeatedly adapt their masticatory behavior to a given food. The collection of various food boli as recorded at the moment of swallowing could then be considered in further food bolus properties research investigations. Moreover, this study suggested that children with altered dentition modified their masticatory kinematic parameters and developed alternative strategies, including food or texture selection, to overcome their feeding difficulties. The development of a mastication evaluation protocol could help medical professionals to detect children masticatory deficiencies and then propose diet adaptations. Considering the importance of food diversity in mastication development and maturation, food industries may consider to develop a range of texture adapted foods for young children, especially designed to gradually rehabilitate the masticatory function.

Early human motor development: From variation to the ability to vary and adapt

This review summarizes early human motor development. From early fetal age motor behavior is based on spontaneous neural activity: activity of networks in the brainstem and spinal cord that is modulated by supraspinal activity. The supraspinal activity, first primarily brought about by the cortical subplate, later by the cortical plate, induces movement variation. Initially, movement variation especially serves exploration; its associated afferent information is primarily used to sculpt the developing nervous system, and less to adapt motor behavior. In the next phase, beginning at function-specific ages, movement variation starts to serve adaptation. In sucking and swallowing, this phase emerges shortly before term age. In speech, gross and fine motor development, it emerges from 3 to 4 months post-term onwards, i.e., when developmental focus in the primary sensory and motor cortices has shifted to the permanent cortical circuitries. With increasing age and increasing trial-and-error exploration, the infant improves its ability to use adaptive and efficicient forms of upright gross motor behavior, manual activities and vocalizations belonging to the native language.

Feeding Problems in Infants and Children: Assessment and Etiology

Feeding problems in infants and young children are common. In healthy children who are developing and growing normally, feeding problems are usually not serious and can be managed conservatively by reassuring the family and providing them with anticipatory guidance and follow-up. A majority of serious childhood feeding problems occur in children who have other medical, developmental, or behavioral problems. These are best evaluated and treated by an interprofessional team who can identify and address issues in the medical and/or developmental history, problems with oral motor control and function, problems with swallowing, and behavioral and/or sensory issues that may interfere with normal feeding.

Differing structural properties of foods affect the development of mandibular control and muscle coordination in infants and young children

The development of chewing is an essential motor skill that is continually refined throughout early childhood. From a motor control perspective, the advancement of textures is dependent upon the fit between a child's oral anatomic and motor system and food properties. The purpose of this exploratory study is to identify age-related changes in chewing motor coordination and control and to determine if these changes are associated with the differing structural properties of solid foods, as well as to explore the role of explanatory variables such as the emergence of teeth and bite force. The masticatory muscle coordination (i.e., coupling of synergistic and antagonistic muscle pairs) and control (i.e., speed, displacement, chewing rate, duration, and number of chews) of fifty children were assessed cross-sectionally at five ages: 9-, 12-, 18-, 24-, and 36-months using electromyography (EMG) and 3D optical motion capture while children ate three foods that had differing structural properties. The results of this study found that children made gains in their chewing motor control (decreased duration of chewing sequences and lateral jaw displacement) and coordination (improved jaw muscle coupling) throughout this period. The structural differences in foods also affected chewing performance at all ages. These preliminary findings suggest that some solid textures are better adapted for immature mandibular control than others and that the development of chewing is a protracted process that may be impacted by the emergence of teeth and changes to bite force.

Spatial Characteristics of Jaw Movements During Chewing in Children with Cerebral Palsy: A Pilot Study

This study compared jaw motion between children with cerebral palsy (CP) and their typically-developing (TD) peers during chewing. The jaw movements of 11 children with spastic CP (GMFCS levels II-V) all of whom were exclusively oral feeders with no reported clinical issues with feeding [mean age = 7.49 (2.30) years; 7 males, 4 females] and 11 age- and sex-matched TD peers [mean age = 7.54 (2.35) years] were recorded using optical motion capture. Participants chewed five trials of three different consistencies, including puree, mechanical soft, and solid. For each chewing sequence, the path distance (total amount of distance traveled by the jaw), average jaw speed, and working space (total 3-dimensional size of the jaw movements during chewing) were calculated. The CP group had greater path distances for mechanical soft and solids (p < 0.001) and larger working spaces (p < 0.001) than the TD group. Consistency differences were also found with path distances increasing for both groups with increased bolus consistency (p < 0.001). Puree was chewed most slowly for both groups (p = 0.05) and was associated with smaller working space than the other consistencies for both groups (p < 0.001). The TD group demonstrated slower speeds for mechanical soft as compared to solids (p = 0.05), a finding which was not observed in the CP group. The results suggest children with CP showed jaw movement differences during chewing despite being exclusive oral eaters with no reports of clinical feeding or deglutition disorders. Food consistency also influenced jaw movements in both children with CP and their TD peers.

Are There Sensitive Periods for Food Acceptance in Infancy?

PURPOSE OF REVIEW

A sensitive period in development is one in which it is easier for learning to take place; the behaviour can however still be learned at a later stage, but with more difficulty. This is in contrast to a critical period, a time at which a behaviour must be learned, and if this window of opportunity is missed, then the behaviour can never be acquired. Both might determine food acceptance in childhood.

RECENT FINDINGS

There is evidence to support the idea of a sensitive period for the introduction of tastes, a critical period for the introduction of textures and for the development of oral motor function, and a possible critical period for the introduction of new foods but only in children where there is an innate disposition to develop early and extreme disgust responses.

SUMMARY

There are both sensitive and critical periods in the acquisition of food preferences.

Can mastication in children with cerebral palsy be analyzed by clinical observation, dynamic ultrasound and 3D kinematics?

The aim of this study was to explore the feasibility of the Mastication Observation and Evaluation (MOE) instrument, dynamic ultrasound and 3D kinematic measurements to describe mastication in children with spastic cerebral palsy and typically developing children. Masticatory movements during five trials of eating a biscuit were assessed in 8 children with cerebral palsy, spastic type (mean age 9.08years) and 14 typically developing children (mean age 9.01years). Differences between trials were tested (t-test) and the mastication of individual children with cerebral palsy was analyzed. MOE scores ranged from 17 to 31 (median 24) for the children with cerebral palsy and from 28 to 32 (median 31) for the typically developing children. There was an increased chewing cycle duration, a smaller left-right and up-down tongue displacement and larger anterior mandible movements for the trials (n=40) of cerebral palsy children (p<0.000 for all comparisons) compared to the trials of typically developing children (n=70). The MOE captures differences in mastication between individual children with cerebral palsy. The MOE items 'jaw movement' and 'fluency and coordination' showed the most similarity with the objective measurements. Objective measurements of dynamic ultrasound and 3D kinematics complemented data from the MOE instrument.

Validation of Clinical Observations of Mastication in Persons with ALS

Amyotrophic lateral sclerosis (ALS) is a progressive neurological disease that can result in difficulties with mastication leading to malnutrition, choking or aspiration, and reduced quality of life. When evaluating mastication, clinicians primarily observe spatial and temporal aspects of jaw motion. The reliability and validity of clinical observations for detecting jaw movement abnormalities is unknown. The purpose of this study is to determine the reliability and validity of clinician-based ratings of chewing performance in neuro-typical controls and persons with varying degrees of chewing impairments due to ALS. Adults chewed a solid food consistency while full-face video were recorded along with jaw kinematic data using a 3D optical motion capture system. Five experienced speech-language pathologists watched the videos and rated the spatial and temporal aspects of chewing performance. The jaw kinematic data served as the gold-standard for validating the clinicians' ratings. Results showed that the clinician-based rating of temporal aspects of chewing performance had strong inter-rater reliability and correlated well with comparable kinematic measures. In contrast, the reliability of rating the spatial and spatiotemporal aspects of chewing (i.e., range of motion of the jaw, consistency of the chewing pattern) was mixed. Specifically, ratings of range of motion were at best only moderately reliable. Ratings of chewing movement consistency were reliable but only weakly correlated with comparable measures of jaw kinematics. These findings suggest that clinician ratings of temporal aspects of chewing are appropriate for clinical use, whereas ratings of the spatial and spatiotemporal aspects of chewing may not be reliable or valid.

On the Mechanics of Fatigue and Fracture in Teeth

Tooth fracture is a major concern in the field of restorative dentistry. However, knowledge of the causes for tooth fracture has developed from contributions that are largely based within the field of mechanics. The present manuscript presents a technical review of advances in understanding the fracture of teeth and the fatigue and fracture behavior of their hard tissues (i.e., dentin and enamel). The importance of evaluating the fracture resistance of these materials, and the role of applied mechanics in developing this knowledge will be reviewed. In addition, the complex microstructures of tooth tissues, their roles in resisting tooth fracture, and the importance of hydration and aging on the fracture resistance of tooth tissues will be discussed. Studies in this area are essential for increasing the success of current treatments in dentistry, as well as in facilitating the development of novel bio-inspired restorative materials for the future.

Accuracy and precision of a custom camera-based system for 2-d and 3-d motion tracking during speech and nonspeech motor tasks

PURPOSE Studying normal or disordered motor control requires accurate motion tracking of the effectors (e.g., orofacial structures). The cost of electromagnetic, optoelectronic, and ultrasound systems is prohibitive for many laboratories and limits clinical applications. For external movements (lips, jaw), video-based systems may be a viable alternative, provided that they offer high temporal resolution and submillimeter accuracy. METHOD The authors examined the accuracy and precision of 2-D and 3-D data recorded with a system that combines consumer-grade digital cameras capturing 60, 120, or 240 frames per second (fps), retro-reflective markers, commercially available computer software (APAS, Ariel Dynamics), and a custom calibration device. RESULTS Overall root-mean-square error (RMSE) across tests was 0.15 mm for static tracking and 0.26 mm for dynamic tracking, with corresponding precision (SD) values of 0.11 and 0.19 mm, respectively. The effect of frame rate varied across conditions, but, generally, accuracy was reduced at 240 fps. The effect of marker size (3- vs. 6-mm diameter) was negligible at all frame rates for both 2-D and 3-D data. CONCLUSION Motion tracking with consumer-grade digital cameras and the APAS software can achieve submillimeter accuracy at frame rates that are appropriate for kinematic analyses of lip/jaw movements for both research and clinical purposes.

Anatomical, functional, physiological and behavioural aspects of the development of mastication in early childhood

Mastication efficiency is defined as the efficiency of crushing food between the teeth and manipulating the resulting particles to form a swallowable food bolus. It is dependent on the orofacial anatomical features of the subject, the coordination of these anatomical features and the consistency of the food used during testing. Different measures have been used to indirectly quantify mastication efficiency as a function of children's age such as observations, food bolus characterisation, muscle activity measurement and jaw movement tracking. In the present review, we aim to describe the changes in the oral physiology (e.g. bone and muscle structure, teeth and soft tissues) of children and how these changes are associated with mastication abilities. We also review previous work on the effect of food consistency on children's mastication abilities and on their level of texture acceptance. The lack of reference foods and differences in testing methodologies across different studies do not allow us to draw conclusions about (1) the age at which mastication efficiency reaches maturity and (2) the effect of food consistency on the establishment of mature mastication efficiency. The effect of food consistency on the development of children's mastication efficiency has not been tested widely. However, both human and animal studies have reported the effect of food consistency on orofacial development, suggesting that a diet with harder textures enhances bone and muscle growth, which could indirectly lead to better mastication efficiency. Finally, it was also reported that (1) children are more likely to accept textures that they are able to manipulate and (2) early exposure to a range of textures facilitates the acceptance of foods of various textures later on. Recommending products well adapted to children's mastication during weaning could facilitate their acceptance of new textures and support the development of healthy eating habits.

The Need for International Terminology and Definitions for Texture-Modified Foods and Thickened Liquids Used in Dysphagia Management: Foundations of a Global Initiative

Conservative estimates suggest that dysphagia (difficulty swallowing) affects approximately 8 % of the world's population. Dysphagia is associated with malnutrition, dehydration, chest infection and potentially death. While promising treatments are being developed to improve function, the modification of food texture and liquid thickness has become a cornerstone of dysphagia management. Foods are chopped, mashed or puréed to compensate for chewing difficulties or fatigue, improve swallowing safety and avoid asphyxiation. Liquids are typically thickened to slow their speed of transit through the oral and pharyngeal phases of swallowing, to avoid aspiration of material into the airway and improve transit to the esophagus. Food texture and liquid modification for dysphagia management occurs throughout the world. However, the names, the number of levels of modification and characteristics vary within and across countries. Multiple labels increase the risk to patient safety. National standardization of terminology and definitions has been promoted as a means to improve patient safety and inter-professional communication. This article documents the need for international standardized terminology and definitions for texture-modified foods and liquids for individuals with dysphagia. Furthermore, it documents the research plan and foundations of a global initiative dedicated to this purpose.