Tongue

The epithelium of the secondary palate from embryonic mice (12-14 days of gestation) was enzymatically separated from the palatal mesenchyme and was cultured in association with mesenchyme from the embryonic tongue, incisor, and salivary gland. The histological differentiation of the epithelium in each type of heterotypic recombination was always palatal. Tongue mesenchyme supported full histodifferentiation of the palatal epithelium, whereas incisor mesenchyme supported only a limited histodifferentiation in the epithelium. Salivary gland mesenchyme in direct combination with palatal epithelium influenced the epithelium to become organized into a system of ducts and acini typical of glandular morphogenesis; histodifferentiation of the epithelium, however, was palatal. Salivary gland mesenchyme grown in isolation did not undergo glandular morphogenesis.

10. DC cultures were generated as described (5, 22). Immature I-A kϩ DCs grown from C3H/HeN, C3H/HeJ, and CBA/J (Jackson Labs, Bar Harbor, ME) marrow suspensions were pulsed with HEL (1 to 3 mg/ml) with or without LPS (1 to 10 ng/ml, E. coli 0111.B4) for 1 to 3 hours, washed, and chased in HEL-and LPS-free media. Similar results were obtained with DCs from each strain. DC cultures contained supernatant from mGM-CSFexpressing J558L cells (from A. Lanzavecchia, Basel Institute, Basel, Switzerland). LPS was removed from HEL (Sigma) with Kuttsuclean adsorbent (Maruha Corporation, Ibaraki, Japan). Maturation stimuli included LPS, CD40L, tumor necrosis factor-␣, or replating (22). 11. DCs were fixed with 4% (wt/vol) paraformaldehyde and washed in phosphate-buffered saline. Cells were incubated with monoclonal antibodies (mAbs) on ice as described (23). The rat mAb C4H3 was provided by R. Germain (NIH, Bethesda, MD). C4H3 was purified on protein A-Sepharose and biotinylated. Cells were labeled with biotin-conjugated mAbs (Pharmingen) to I-E k (14-4-4S) or I-A k (10-2.16) and fluorescein

and there is significant target organ specificity. The results also tend to support the concept that the anatomical components Animal models for carcinogenesis of the oral cavity are limited, although this disease is often fatal or disfiguring Introduction and its incidence in the USA is~30 000 cases/year. Shortterm whole-animal models for this disease should prove Cancer of the oral cavity represents a significant public health valuable in the investigation of factors affecting oral carciproblem, with~30 000 new cases and 8000 deaths per year nogenesis. In this study we observed that a group of oral

Receptor proteins for photoreception have been studied for several decades. More recently, putative receptors for olfaction have been isolated and characterized. In contrast, no receptors for taste have been identified yet by molecular cloning. This report describes experiments aimed at identifying a receptor responsible for the taste of monosodium glutamate (MSG). Using reverse transcriptase (IV)-PCR, we found that several ionotropic glutamate receptors are present in rat lingual tissues. However, these receptors also could be detected in lingual tissue devoid of taste buds. On the other hand, RT-PCR and RNase protection assays indicated that a G-protein-coupled metabotropic glutamate receptor, mGluR4, also is expressed in lingual tissues and is limited only to taste buds. In situ hybrid-ization demonstrated that mGluR4 is detectable in 40-70% of vallate and foliate taste buds but not in surrounding nonsensory epithelium, confirming the localization of this metabotropic receptor to gustatory cells. Expression of mGluR4 in taste buds is higher in preweaning rats compared with adult rats. This may correspond to the known higher sensitivity to the taste of MSG in juvenile rodents. Finally, behavioral studies have indicated that MSG and L-2-amino-4-phosphonobutyrate (L-AP4), a ligand for mGluR4, elicit similar tastes in rats. We conclude that mGluR4 may be a chemosensory receptor responsible, in part, for the taste of MSG.

The purpose of the current study was to evaluate the effect of alcohol on the proliferative activity of epithelial cells in the lingual mucosa of mice by means of silver-staining nucleolar organizer region (AgNOR) count and area measurements. Forty-eight CF1 mice were separated into three groups. The test groups were submitted to topical exposure to, or intake of, 40% (volume/volume) ethyl alcohol. Biopsy specimens were collected from the middle third of the dorsal tongue at 0, 6, and 12 months, and samples were stained according to the AgNOR technique. Mean number and mean area of AgNOR per nucleus were calculated for 50 basal layer cells and 50 intermediate layer cells. Increases in mean number and mean area of AgNOR per nucleus in intermediate cells were observed at 12 months in the alcohol intake group (P Ͻ .05). Results showed that intake of 40% alcohol increased epithelial cell proliferation in the dorsal surface of lingual mucosa. Ć

Infant feeding problems are extremely common during breastfeeding establishment. To objectively assess infant sucking, consistent methods to analyze ultrasound images of the infant's oral cavity are required. We developed and assessed the reliability of an extensive ultrasound measurement protocol by measuring nipple diameter and placement. Midline submental ultrasound scans of 30 term breastfed infants were analyzed by two raters. Nipple diameter, nipple hard-soft palate junction distance and tongue hard-soft palate junction distance were measured on two frames: tongue-up and tongue-down. No evidence of measurement bias was found between raters and inter-rater agreement and consistency scores were high. The changes in nipple diameter and placement were consistent with previous descriptions; however, the diameter of the nipple was not consistent in either position. This method provides objective measurements representative of tongue movement, and further investigation is required to ensure usefulness when examining sucking difficulties. (

Glossokinetic potentials (GKPs) are electric potential responses generated by tongue movement. In this study, we use these GKPs to automatically detect and estimate tongue positions, and develop a tongue-machine interface. We show that a specific configuration of electrode placement yields discriminative GKPs that vary depending on the direction of the tongue. We develop a linear model to determine the direction of tongue from GKPs, where we seek linear features that are robust to a baseline drift problem by maximizing the ratio of intertask covariance to intersession covariance. We apply our method to the task of wheelchair control, developing a tongue-machine interface for wheelchair control, referred to as tongue-rudder. A teeth clenching detection system, using electromyography, was also implemented in the system in order to assign teeth clenching as the stop command. Experiments on off-line cursor control and online wheelchair control confirm the unique advantages of our method, such as: 1) noninvasiveness, 2) fine controllability, and 3) ability to integrate with other EEGbased interface systems.

In Australia, initial exclusive breastfeeding rates are 80%, reducing to 14% at 6 months. One factor that contributes to early breastfeeding cessation is infant tongue-tie, a congenital abnormality occurring in 2.8-10.7% of infants, in which a thickened, tightened or shortened frenulum is present. Tongue-tie is linked to breastfeeding difficulties, speech and dental problems. It may prevent the baby from taking enough breast tissue into its mouth to form a teat and the mother may experience painful, bleeding nipples and frequent feeding with poor infant weight gain; these problems may contribute to early breastfeeding cessation. This review of research literature analyses the evidence regarding tongue-tie to determine if appropriate intervention can reduce its impact on breastfeeding cessation, concluding that, for most infants, frenotomy offers the best chance of improved and continued breastfeeding. Furthermore, studies have demonstrated that the procedure does not lead to complic...

Protrusion and retraction of the tongue are essential components of such orofacial behaviors as mastication, respiration, and swallowing. Stimulation of the medial branch of the hypoglossal nerve yields tongue protrusion, while stimulation of the lateral branch yields tongue retraction in rat. We exploited the transsynaptic transport capabilities of pseudorabies virus to determine specific circuits that innervate protruder and retractor muscles of the rat tongue. Each group of muscles is innervated by distinct populations of hypoglossal motoneurons: caudal ventral and ventrolateral motoneurons form the largest proportion of those innervating protruders, whereas rostra1 dorsal motoneurons innervate retractors. Our primary finding was differential innervation of protruder and retractor motoneurons by premotoneurons in the lateral tegmental field: premotoneurons innervating protruder motoneurons were more ventral and ventromedial than those innervating retractor motoneurons. In addition, protruder motoneurons received projections from the ipsilateral lateral parabrachial nucleus but not spinal trigeminal nucleus or medial and ventral subnuclei of the solitary tract; the converse was true for retractor motoneurons. These results suggest segregation of functional networks that control hypoglossal motoneurons. The dorsal medulla, in or around the solitary tract, contains neurons specific to retractor motoneurons, and the region ventrolateral to the hypoglossal nucleus contains circuitry specific to protruder motoneurons. Common innervation of medial and lateral branch motoneurons is provided by premotoneurons in the raphe and gigantocellular reticular formation of the medial medulla. The midline medullary nuclei with diverse projections may coordinate complex behavior or modulate general motoneuron excitability, whereas the lateral reticular formation, with anatomically discrete projections, may control motoneurons that contribute to distinct orofacial behaviors. G 1~~5 Wilep-Liss, Inc.

Pi 'i-iodoniol 1995'i-iodoniol : 22: 923-928. © Munksgaard. 1995 Ahsrraci. Staining ofleelh and mucous membranes is a well-known side-effect with chiorhexidine mouthrinses in which dietary chrotnogcns play an important role. The purpose of (his study was to detertnine whether a co-polymer antiadhcsivc agent would prevent staining by a low concentration chiorhexidine solution. Additionally, the possibility thai an essential oil/phenolic rinse product may cause staining was investigated. The rinses studied were the anti-adhesive alone and combined with 0.02'-'^. chiorhexidine and the essential oil/phenolie rinse. These were positioned against a positive control rinse, 0.2"/u chiorhexidine. and a negative control rinse, water. Tlie study was a single blind 5-trealment. randomised Latin square cross-over design, incorporating balance for carry-over effects. 15 volunteers participated and on Day 1 of each study period were rendered stain free by scaling and polishing of the teelh. Oral hygiene was suspended and 8x per day subjects rinsed under stipervision. firstly with the allocated formulation and then with 10 ml of warm black tea. On Day 4. tooth and tongue staining was scored by area and intensity (colour). A washout period of at least 3'/2 days was permitted between treatment periods when oral hygiene was resumed. Before ihe study and during washouts, volunteers practised tongue brushing. Tooth and tongue staining was significantly increased with 0.2% chiorhexidine compared to the essential oil/phenolic rinse which in turn was significantly increased compared to the other 3 rinses. The antiadhesive,'chlorhexidine rinse produced no more staining than the anti-adhesive or water rinse. However, the parallel plaque regrowth study suggests this inhibition of staining resulted from the vitiation of the chiorhexidine activity by the antiadhcsive. The methodology would appear a simple and quick way of assessing the propensity of mouthrinses to cause extrinsic staining.

Instrumental bitterness assessment of traditional Chinese herbal medicine (TCM) preparations was addressed in this study. Three different approaches were evaluated, high-performance liquid chromatography coupled to UV detector (HPLC), capillary electrophoresis coupled to UV detector (CE) and a potentiometric multisensor system - electronic tongue (ET). Most studies involving HPLC and CE separations use these as selective instruments for quantification of individual substances. However we employed these techniques to provide chromatographic or electrophoretic sample profiles. These profiles are somewhat analogous to the profiles produced by the ET. Profiles from all instruments were then related to professional sensory panel evaluations using projections on latent structures (PLS) regression. It was found that all three methods allow for bitterness assessment in TCM samples in terms of human sensory panel with root mean squared errors of prediction ca. 0.9 within bitterness scale fro...

A case of an unusual caustic ingestion involving Compound W, an over the counter wart remover is presented. Chemical burns of the tongue, pharnyx and larnyx developed. The active ingredient in this preparation: salicylic acid in a flexible collodion vehicle produces caustic injury through a keratolytic action, which may be enhanced by the presence of collodion. (Am J Emerg Med 1986;4:554-555) Most caustic ingestions involve either strong acids or bases, both of whose pathophysiology has been well studied and described. We report here the case of an unusual ingestion (Compound W®, involving a keratolytic, salicylic acid, in a collodion vehicle as the caustic agent.

Introduction: Our objective was to evaluate the nasal passage (NP) and oropharyngeal (OP) volumes of patients with different dentofacial skeletal patterns. Methods: The study sample consisted of 140 patients (70 boys, 70 girls), divided into 3 groups as Class I (1 #ANB #3), Class II (ANB .3), and Class III (ANB \1), and then further divided into 4 groups as SNA angle $80 , SNA angle \80 , SNB angle $78 , and SNB angle \78 to evaluate how the positional changes in the maxilla and the mandible affect the OP and NP variables. Differences between groups were determined by using the Kruskal-Wallis test.

Effect evaluation of a supervised versus non-supervised implementation of an oral health care guideline in nursing homes: a cluster randomised controlled clinical trial Objective: To compare a supervised versus a non-supervised implementation of an oral health care guideline in Flanders (Belgium). Background: The key factor in realising good oral health is daily oral hygiene care. In 2007, the Dutch guideline 'Oral health care in care homes for elderly people' was developed to improve oral health of institutionalised elderly. Materials and Methods: A random sample of 12 nursing homes was randomly allocated to the intervention or the control group. Representative samples of 30 residents in each home were monitored during a 6-month study period. The intervention included a supervised implementation of the guideline. Results: At the 6-month follow-up, only a small but statistically significant (p = 0.002) beneficial effect (0.32) of the intervention was observed for denture plaque after adjustment for baseline value and the random effect of the institution. In the linear mixed regression models, including a random institution effect, difference in denture plaque level was no longer statistically significant at the 5% level. Conclusion: Only denture hygiene has been improved by the supervised implementation, although with lower benefits than presumed. Factors on institutional level, difficult to assess quantitatively, may play an important role in the final result.

One of the foci of Martin Donner's work was the neural control of swallowing. This present investigation continues that work by examining oropharyngeal swallowing in 8 patients identified with a single, small, left-basal ganglion/internal capsule infarction and 8 agematched normal subjects. Stroke patients were assessed with a bedside clinical and radiographic swallowing assessment, and normal subjects received only the radiographic study. Results revealed disagreement between the bedside and radiographic assessments in one of the 8 stroke patients. Stroke and normal subjects differed significantly on some swallow measures on various bolus viscosities, but behaved the same as normal subjects on a number of measures. Differences in swallowing in the stroke subjects were not enough to prevent them from eating orally. The significant differences seen in the basal ganglia/internal capsule stroke subjects may result from damage to the sensorimotor pathways between the cortex and brainstem. These differences emphasize the importance of cortical input to the brainstem swallowing center in maintaining the systematic modulations characteristic of normal swallowing physiology.

In Southern Africa, human body parts are sometimes used for medicinal (muti) purposes. The human body is seen as being very powerful. Although ritual killing for this purpose is not common, some cases have been reported. This paper reports on an unusual muti murder, where the remains of two individuals were found in a medicine man's house. Three pots were found, two of which were constructed around human skulls. Various objects, such as coins, bullets, stones, human and animal bones were found inside the pots. They were decorated with beadwork, whistles, skin bangles, etc. Osteological analysis revealed that the human remains probably belonged to a young, white adult male individual, and a juvenile individual of Negroid descent. All associated objects probably have ritual significance, and some of these are discussed.

The aim of this study was to examine the prevalence of C. albicans in the oral cavities and root canals of children. Twenty healthy and caries-free children and 13 children with caries, were screened. Imprint samples and sterile paper points were used to obtain the samples from oral cavities and root canals respectively. The production of germ tubes and the development of chlamydospores identified yeast cultures. Sixty-nine percent of children with caries and 5% of caries-free children were found to be Candida carriers. The difference in candidal prevalence between two groups was significant (p < 0.05). Sixty-one point five percent of children were positive for Candida in the root canal. Since, increase in the C. albicans in the oral cavity provides a potential source of the fungus particularly when resistance falls below a certain threshold, attention to strategies for the reduction of this pervasive and persistent pathogen becomes important. Therefore, reduction of caries and o...

AbstractThis study applied submental ultrasonography (SUS) to measure changes in dysphagic stroke patients' tongue thickness and hyoid bone displacement when swallowing 5 mL of water and correlated the results with the severity of clinical dysphagia. We included 60 stroke patients (30 tube-feeding-dependent and 30 on regular oral intake) and 30 healthy controls. An additional 10 healthy people were recruited to assess the reliability of SUS. Measurements of hyoid bone displacement using videofluoroscopic swallowing study (VFSS) and SUS were compared for 12 stroke patients to assess the correlation between the two methods. Changes in tongue thickness and hyoid bone displacement were significantly less in the tube-feeding group. Those with a tongue thickness change of less than 1.0 cm and hyoid bone displacement of less than 1.5 cm were likely to be tube-feeding. SUS showed good intra-rater/inter-rater reliability and correlated well with VFSS measurement. SUS can be an adjunct assessment tool of swallowing. (

OBJECTIVES: To determine the effects of an 8-week progressive lingual resistance exercise program on swallowing in older individuals, the most ''at risk'' group for dysphagia. DESIGN: Prospective cohort intervention study. SETTING: Subjects were recruited from the community at large. PARTICIPANTS: Ten healthy men and women aged 70 to 89. INTERVENTION: Each subject performed an 8-week lingual resistance exercise program consisting of compressing an air-filled bulb between the tongue and hard palate. MEASUREMENTS: At baseline and Week 8, each subject completed a videofluoroscopic swallowing evaluation for kinematic and bolus flow assessment of swallowing. Swallowing pressures and isometric pressures were collected at baseline and Weeks 2, 4, and 6. Four of the subjects also underwent oral magnetic resonance imaging (MRI) to measure lingual volume. RESULTS: All subjects significantly increased their isometric and swallowing pressures. All subjects who had the MRI demonstrated increased lingual volume of an average of 5.1%. CONCLUSION: The findings indicate that lingual resistance exercise is promising not only for preventing dysphagia due to sarcopenia, but also as a treatment strategy for patients with lingual weakness and swallowing disability due to frailty or other age-related conditions. The potential effect of lingual exercise on reducing dysphagiarelated comorbidities (pneumonia, malnutrition, and dehydration) and healthcare costs while improving quality of life is encouraging.

The blue-tongue lizard (Tiliqua scincoides) is a variety of large skink common throughout Australia. There are seven species of Tiliqua and all of them have long bodies, short limbs and short and robust tails. T. scincoides occurs in a wide range of habitats; its diet is omnivorous. When threatened, it opens the mouth and protrudes its characteristic large fleshy cobalt blue tongue. It is currently found as a popular species and also as a pet animal in the European countries. No data are available in literature about the morphology of the tongue of T. scincoides; therefore, the aim of the present study was to investigate by means of scanning electron microscopy and light microscopy, the anatomy of the dorsal lingual surface. Our results demonstrate the presence of a tongue tip with a smooth surface without papillae. The foretongue was characterized by a stratified epithelium with foliate-like papillae and deep interpapillar spaces in the middle part and cylindrical papillae with a flat surface in the lateral parts. All the posterior area of the tongue was characterized by more compacted papillae and the inter-papillar spaces were very narrow. Light microscopy showed the presence of melanin throughout the tongue. No taste buds were recognized on the lingual dorsal surface. Therefore, the papillae probably have a mechanical function showing an important role in the swallowing phase. The morphology of the tongue surface can be correlated to the diet and, different roles, as in other examined species, can be hypothesized for different areas.

Candida-associated denture stomatitis was demonstrated by its cultivation m 171 out of 240 patients examined with partial or total dentures, After taking smears from lesions of the oral mucosa (tongue, cheeks, palate) and the coatig~ous demure surface by cotton wool swabs and inoculating them onto Sabouraud glucose agar and CHROMagar Candtda, individual yeast species were identified by a germ tube. filamentous, and assimilation tests employing the coin-mercial kit AuxaColor. Seven Candtda species were identified

This paper presents a detailed protocol for performing the videofluorographic swallowing study (VFSS), and describes how it evolved from its antecedents. The objectives of the VFSS are both diagnostic and therapeutic. Preparing for the VFSS is described, including the equipment, food preparation, and a brief discussion of the clinical evaluation. The detailed description of the VFSS procedure covers the position of the patient, the foods presented, the views obtained, modifications of feeding and swallowing that are commonly employed, the standardized set of observations, and reporting the results. Criteria for deviating from the protocol or aborting the study are presented. The VFSS does not necessarily end when a patient aspirates. Indeed, the complete evaluation of aspiration, and the effects of maneuvers designed to reduce it, is a major purpose of the VFSS. Modifications of feeding and swallowing are tested empirically during the study. The modifications include therapeutic and compensatory techniques that may improve the safety and efficiency of swallowing. A rationale for deciding which modifications to test in a given patient is discussed. The protocol has been used successfully in more than 350 patients. It has improved the efficiency and quality of our videofluorographic examinations.

Three experimental techniques based on automatic swept-frequency network and impedance analysers were used to measure the dielectric properties of tissue in the frequency range 10 Hz to 20 GHz. The technique used in conjunction with the impedance analyser is described. Results are given for a number of human and animal tissues, at body temperature, across the frequency range, demonstrating that good agreement was achieved between measurements using the three pieces of equipment. Moreover, the measured values fall well within the body of corresponding literature data.

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 S O M A -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.

vation including premotor cortex, suggesting that the frontal activation might reflect aspects of the actionrelated meaning of action words (Martin and Chao, 2001; Olaf Hauk, Ingrid Johnsrude, and Friedemann Pulvermü ller* Medical Research Council Pulvermü ller, 1996). If so, the cortical locus of meaning Cognition and Brain Sciences Unit processing could be, in part, determined by the general 15 Chaucer Road neuroscientific principle of Hebbian learning according Cambridge, CB2 2EF

Halitosis is the offensive or disagreeable odour that may emanate from the mouth. In 80%-90% of cases, bacterial activities especially on the dorsum of the tongue are implicated. Current studies on halitosis accessed from electronic databases were appraised in the light of prevalence, impact and control of halitosis. Halitosis has a worldwide occurrence with a prevalence range of 22% to 50%. Due to the associated social and psychological effects, it should be taken seriously in all affected patients. Oral healthcare professionals ought to be well informed, because their office(s) are usually the first points of call for the affected patients.

The dielectric properties of tissues have been extracted from the literature of the past five decades and presented in a graphical format. The purpose is to assess the current state of knowledge, expose the gaps there are and provide a basis for the evaluation and analysis of corresponding data from an on-going measurement programme. † Present address:

A parametric model was developed to describe the variation of dielectric properties of tissues as a function of frequency. The experimental spectrum from 10 Hz to 100 GHz was modelled with four dispersion regions. The development of the model was based on recently acquired data, complemented by data surveyed from the literature. The purpose is to enable the prediction of dielectric data that are in line with those contained in the vast body of literature on the subject. The analysis was carried out on a Microsoft Excel spreadsheet. Parameters are given for 17 tissue types.

There is relation between posture, tongue, palatal muscles, all body muscles, tension, personality, neurodivergence, personality disorders, mental illnesses, intelligence, cognition, lazyness, stress and the decisions that shape us. Short work addressing & explaining some aspects of that.

The anatomy, physiology and psychology of taste provide a glimpse into a uniquely heterogeneous sensory world; a world that is robust in its importance to flavor, redundant in its transductive heterogeneity and complexity, requisite in that feeding and hence life usually depend upon taste input, regenerative in that taste cells constantly turn over and regrow after tissue damage, and resistant to disease, loss of neural innervation and epithelial destruction. This chapter considers our current state of knowledge in anatomy, taste bud physiology, molecular biology of bitter, sweet, sour, savory and salty tastes, afferent signaling and quality coding, human perception, and pathophysiology and senescence of taste. We highlight some of the advances made in molecular biology of taste and point out areas where further research is needed ranging from taste bud development and regeneration, to within-taste bud processing, to central/perceptual coding networks for taste. Our hope is that this chapter will provide a background for greater understanding of taste physiology, perception, disease, and future sensory research.

An in vitro preparation of the dorsal epithelium of the dog tongue actively transports ions, producing a transepithelial potential difference characteristic of the ions and their concentration. Hypertonic sodium chloride solutions generally cause increased potentials and short-circuit currents and reduced resistances when placed on the mucosal surface. This hypertonic flux is eliminated by ouabain and is not found in ventral lingual epithelia. When either sodium acetate or tetramethylammonium chloride is substituted for sodium chloride in the mucosal medium, the currents are diminished but their sum at a given concentration approximates that for sodium chloride at the same concentration. This result suggests a current composed of inward sodium ion movement and outward chloride ion movement. Actively regulated potentials and currents, whether generated in the taste buds or in supporting cells, may be important in both normal chemotransduction and in taste responses evoked by currents passing through the tongue.

The aim of this prospective study was to use cone-beam computed tomography to assess the dimensional changes of the upper airway in orthodontic patients with maxillary constriction treated by rapid maxillary expansion. Methods: Fourteen orthodontic patients (mean age, 12.9 years; range, 9.7-16 years) were recruited. The patients with posterior crossbite and constricted maxilla were treated with rapid maxillary expansion as the initial part of their comprehensive orthodontic treatments. Before and after rapid maxillary expansion conebeam computed tomography scans were taken to measure the retropalatal and retroglossal airway changes in terms of volume, and sagittal and cross-sectional areas. The transverse expansions by rapid maxillary expansion were assessed between the midlingual alveolar bone plates at the maxillary first molar and first premolar levels. The measurements of the before and after rapid maxillary expansion scans were compared by using paired t tests with the Bonferroni adjustment for multiple comparisons. Results: After rapid maxillary expansion, significant and equal amounts of 4.8 mm of expansion were observed at the first molar (P 5 0.0000) and the first premolar (P 5 0.0000) levels. The width increase at the first premolar level (20.0%) was significantly greater than that at the first molar level (15.0%) (P 5 0.035). As the primary outcome variable, the cross-sectional airway measured from the posterior nasal spine to basion level was the only parameter showing a significant increase of 99.4 mm 2 (59.6%) after rapid maxillary expansion (P 5 0.0004). Conclusions: These results confirm the findings of previous studies of the effect of rapid maxillary expansion on the maxilla. Additionally, we found that only the cross-sectional area of the upper airway at the posterior nasal spine to basion level significantly gains a moderate increase after rapid maxillary expansion. (Am J Orthod Dentofacial Orthop 2013;143:462-70)