Labial Pressure Research Articles

Tongue and Lip Comparisons between Healthy and Nondysphagic Poststroke Individuals

Background: The lips and tongue play a substantial role in efficient clearance of food from the mouth and pharynx into the esophagus. No study has compared oral pressures between healthy individuals and poststoke individuals who report functional swallow abilities. Aim: The current study aimed to investigate the presence of differences in oral pressures between healthy individuals and poststroke individuals who report functional swallowing abilities. Design: This is a controlled matched pair study. Population: Eighteen control participants (CG) and 18 nondysphagic poststroke participants (NDSG) were enrolled into this study. Methods: The Iowa Oral Performance Instrument (IOPI) was used to measure and compare tongue strength, endurance, and functional lingual and labial pressures between sex and age-matched pairs. Results: Six paired, two-tailed t tests revealed that tongue and lip pressures were different between the 2 groups. Maximum anterior tongue pressures and posterior tongue pressures were also different, i.e., t(17) = –2.89 (p = 0.010) and t(17) = –2.85 (p = 0.011), with the CG presenting higher pressures. Right lip pressures were significantly lower in the NDSG compared to the CG, i.e., t(17) = 2.45 (p = 0.0001). Left lip pressures were significantly lower in the NDSG compared to the CG, i.e., t(17) = –5.43 (p = 0.0001). Tongue endurance, i.e., t(17) = 0.092 (p = 0.928) and saliva swallow pressures, i.e., t(17) = –0.490 (p = 0.63) were not different. Conclusion: Although poststroke participants reported functional swallowing abilities, there were differences in tongue and lip pressures but not in endurance or saliva swallow pressures. Clinical Rehabilitation Impact: Poststroke individuals without complaints of dysphagia who are not assessed may experience subclinical dysphagia that could negatively impact their nutrition and quality of life.

Variation of upper lip pressure on upper teeth during non-extraction orthodontic treatment: A prospective clinical study

The objectives of this prospective clinical study are to quantify the variation of pressure exerted by the upper lip on the upper teeth during the alignment phase and to evaluate its capacity to adapt to changes in dental position. Thirty young subjects in skeletal Class I relationship requiring non-extraction orthodontic treatment were included in this study. The pressure exerted by the upper lip on the upper central incisors and right canine were measured during rest and swallowing positions using a pressure transducer before bracket placement (T0), after bracket placement (T1), three months (T2) and six months later (T3). Maxillary intercanine width (CC), upper arch length (U) and crowding (C) were measured on stone models at T1, T2and T3to determine the existence of a correlation between the variation of lip pressure and these variables. The lip pressure significantly increased after bracket placement and remained relatively stable during the six-month period. The labial pressure on the incisors was the only variable to significantly decrease at T3, though remaining significantly higher than the starting pressure. A positive correlation was found between the variation of the inter-canine distance and the labial pressure on the canine at rest whereas a negative correlation exists between the crowding and the labial pressure on the incisors at rest. This study showed that increasing inter-canine width disrupts the muscle equilibrium and therefore is prone to relapse, whereas the upper lip can better adapt to the protrusion of upper incisors.

Lip pressure at rest and during function in 2 groups of patients with different occlusions

The influence of the forces exerted by the perioral musculature on the position of the teeth has been the object of many scientific studies. Of the forces from the soft tissues, those from the tissues in the passive resting state are believed to be more important than forces exerted on the teeth during various functions such as speech and swallowing. The aims of this study were to measure upper lip pressure at rest and during swallowing in 2 groups of patients with different occlusions and to evaluate any differences among the groups. Fifty subjects were divided into 2 groups according to occlusal and skeletal patterns: Class I and Class II. Both groups were divided into 2 subgroups according to age: young patients (9-17 years) and adult patients (18-35 years). A force-sensing resistor device (Datalog, Flexiforce low type, Biometrics Ltd, Gwent, United Kingdom) with a transducer thickness of less of 1 mm was used for the measurements. The sensor was positioned on the midline between the maxillary incisors with a thin layer of soft wax. Labial pressure measurements were made with the lips at rest and during swallowing saliva. The average resting lip pressure was 24.59 ± 2.55 g/cm(2); during swallowing, the mean pressure was 24.87 ± 2.45 g/cm(2). No significant difference was found between lip pressure at rest and at function or between the two groups with different occlusions and skeletal patterns. There was a significant correlation between lip pressure and age. In healthy patients, (1) upper lip pressure does not change at rest and during swallowing, (2) upper lip pressure was similar in the 2 groups (Class I, 24.33 g/cm(2); Class II, 24.61 g/cm(2)), and (3) lip pressure was higher in adults than in young subjects. Further studies are needed to measure the pressure of the lower lip and to evaluate whether there are differences in labial pressure between subjects with labial competence and incompetence.

Lip-closing function of elderly people during ingestion: Comparison with young adults

In this study the relationship between the functional vertical labial pressure and aging during ingestion in the elderly is examined. The subjects were 84 community-dwelling elderly (mean: 79.4 years old), 109 elderly needing long term care (mean: 81.3 years old), and 59 healthy young adults (mean: 32.0 years old) as control. Labial pressure was measured with a pressure sensor embedded in acrylic plate. There was no correlation between age and labial pressure or the coefficient of variation of labial pressure during ingestion. In people with a history of “choking on food”, labial pressure was, however, significantly lower (p<0.01) than people without a history of “choking on food”, while the coefficient of variation of labial pressure was significantly higher (p<0.05). Poor labial pressure and movement were noted in subjects who experienced “choking on food”, suggesting that lip-closing function also plays an important role in the pharyngeal stage of feeding/swallowing. On the other hand, the coefficient of variation of labial pressure during ingestion was not changed in the elderly group in comparison to the control group. These results showed that skilled movement of lip-closing might be compensated by labial pressure. Labial pressure and skilled movement were, however, decreased in the elderly needing care because of “choking on food.”

Measuring Intraoral Pressure: Adaptation of a Dental Appliance Allows Measurement During Function

This article introduces a new way of recording intraoral pressures from a range of locations within the oral cavity. To measure pressure flow dynamics during swallowing, we fitted eight miniature pressure transducers capable of measuring absolute pressures to a chrome-cobalt palatal appliance with a labial bow. Unlike previous devices, our design provides a rigid, custom-fitted platform for the simultaneous recording of pressures at eight locations within the oral cavity during function. We placed an anterior pair of gauges to measure lingual and labial contact against the left central incisor tooth, and two pairs of gauges to measure pressure contributions of the lateral tongue margin and cheeks on the canine and first molar teeth. Finally, lingual pressure on the midline of the palate was measured by two gauges, one at the position of the premolars and one on the posterior boundary of the hard palate. We then recorded intraoral pressures in five adult volunteers seated in an upright position and asked to swallow 10 ml of water. Labial pressures on the canine rose rapidly from a resting level of 10 kPa to 33 kPa, while pressure profiles from the labial aspects of the incisor and first molar teeth followed a negative pattern, peaking at -12 kPa for the incisor and -15 kPa for the molar sensor. Pressure profiles recorded from the palatal aspects of the first molar and the canine appeared to be similar, but the former fell to -13 kPa before rising to 9 kPa, and the canine pressure rapidly increased to 22 kPa before returning to its resting level of 4 kPa. The pressure profile of the palatal aspect of the central incisor was strikingly different; at the start of the swallow, pressure dropped precipitously to -20 kPa, before slowly rising to 10 kPa. It then followed the general pattern of the other two sensors, before peaking again at 10 kPa and then returning to a resting level of 4 kPa. We also showed that there were significant negative pressures in the mouth during function, and that pressure profiles varied markedly between individuals.

要介護状態と口唇機能の関連

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. 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. 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). 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.

Muscular forces exerted on the normal deciduous dentition.

This study evaluated the distributing characteristic of the forces exerting on the normal deciduous dentition and the relationship between the muscular forces, sex, and oral function. The pressure measurements were made with a computer-aided perioral force-measuring system designed by the authors. The forces were measured when the subject's head position was in a state of natural head position and oral function was at rest or with swallowing. The results indicated that the forces from lips, cheeks, and tongue at rest were about 37-208 N/m2, whereas the pressure during swallowing was about 1009-1679 N/m2. At rest, the pressure from lips and cheeks was higher than that from tongue (P < .05), whereas during swallowing, the lingual pressure was statistically larger (P < .001). A significant correlation existed between the muscular pressure and sex. When at rest, the boy's force from cheeks was higher than that of the girl's (P < .05) but during swallowing the boy's labial pressure was statistically higher than that of the girl's (P < .01). It was concluded that (1) the deciduous teeth are not in a state of absolute balance between external and internal forces, (2) the distributing manner and unbalanced mode of the forces are different with the different oral functions, (3) the lingual side of the mandibular anterior teeth endures great differences during oral functions and it may account for high incidence of malocclusion in this segment, and (4) a statistical difference between muscular forces and sex exists.

The relationship between labial pressure during swallowing and maximum labial pressure

The relationship between labial pressure during swallowing and maximum labial pressure

Morphologic determinants in the etiology of class III malocclusions: A review

Morphospatial disharmony of the craniomaxillary and mandibular complexes may yield apparent mandibular prognathism, but Class III malocclusions can exist with any number of aberrations of the craniofacial complex. Deficient orthocephalization of the cranial base allied with a smaller anterior cranial base component has been implicated in the etiology of Class III malocclusions. Whereas the more acute cranial base angle may affect the articulation of the condyles resulting in their forward displacement, the reduction in anterior cranial size may affect the position of the maxilla. As well, intrinsic skeletal elements of the maxillary complex may be responsible for maxillary hypoplasia that may exacerbate the anterior crossbite seen in the Class III condition. Conversely, with an orthognathic maxilla, condylar hyperplasia and anterior positioning of the condyles at the temporo-mandibular joint may produce an anterior crossbite. Aside from the skeletal components, soft tissue matrices, particularly labial pressure from the circumoral musculature, may influence the final outcome of craniofacial growth of a child skeletally predisposed to Class III conditions. Indeed, as some Asian ethnic groups demonstrate an increased prevalence of Class III malocclusions, it is likely that the skeletal components and soft tissues matrices are genetically determined. Presumably, the co-morphologies of the craniomaxillary and mandibular complexes are likely dependent upon candidate genes that undergo gene-environmental interactions to yield Class III malocclusions. The identification of such genes is a desirable step in unraveling the complexity of Class III malocclusions. With this knowledge, the clinician may elect an early course of dentofacial orthopedic and orthodontic treatments aimed at preventing the development of Class III malocclusions. Clin. Anat. 12:382–405, 1999. © 1999 Wiley-Liss, Inc.

Morphologic determinants in the etiology of class III malocclusions: a review.

Morphospatial disharmony of the craniomaxillary and mandibular complexes may yield apparent mandibular prognathism, but Class III malocclusions can exist with any number of aberrations of the craniofacial complex. Deficient orthocephalization of the cranial base allied with a smaller anterior cranial base component has been implicated in the etiology of Class III malocclusions. Whereas the more acute cranial base angle may affect the articulation of the condyles resulting in their forward displacement, the reduction in anterior cranial size may affect the position of the maxilla. As well, intrinsic skeletal elements of the maxillary complex may be responsible for maxillary hypoplasia that may exacerbate the anterior crossbite seen in the Class III condition. Conversely, with an orthognathic maxilla, condylar hyperplasia and anterior positioning of the condyles at the temporo-mandibular joint may produce an anterior crossbite. Aside from the skeletal components, soft tissue matrices, particularly labial pressure from the circumoral musculature, may influence the final outcome of craniofacial growth of a child skeletally predisposed to Class III conditions. Indeed, as some Asian ethnic groups demonstrate an increased prevalence of Class III malocclusions, it is likely that the skeletal components and soft tissues matrices are genetically determined. Presumably, the co-morphologies of the craniomaxillary and mandibular complexes are likely dependent upon candidate genes that undergo gene-environmental interactions to yield Class III malocclusions. The identification of such genes is a desirable step in unraveling the complexity of Class III malocclusions. With this knowledge, the clinician may elect an early course of dentofacial orthopedic and orthodontic treatments aimed at preventing the development of Class III malocclusions.

口唇の筋訓練による筋機能の経日的変化

Myofunctional therapy has been in use as an auxiliary means of orthodontic treatment. A number of case presentations have been made on myofunctional therapy. Not many fundamental studies however have been made to date. Six adult subjects with good occlusion without any abnormality in the oral soft tissue therefore were selected and given lip exercise for three months to make chronological examinations of the effect of muscle training. Lip exercise was done 20 times at a time by the button pull method. The exercise was done twice a day, every day, and changes in myofunctions before, during and for two months after the training were examined. For this study, lip strength against instantaneous and sustained pulling of a strung button, integrated EMG activity under the load of weights each attached to the upper and lower lips, labial and lingual pressures on the maxillary and mandibular incisors at rest were examined about every half a month. The results were as follows : 1. Lip strength against pulling of the strung button increased significantly (p<0.05). For two months after the training, no significant changes were seen. 2. EMG activity of the upper lip against loading with weights tended to decrease and showed no significant changes for two months after the training. EMG activity of the lower lip showed various changes depending on the loads but on the whole showed decrease from 0.5 to 1.5 months after the start of the training, and tended to increase gradually for two months after the training. 3. Labial pressure at rest on the mandibular incisor increased significantly (p<0.05) by the training and decreased significantly (p<0.05) for two months after the training. Labial pressure on the maxillary incisor showed great individual differences and no significant changes were seen. Lingual pressure at rest, on the other hand, decreased significantly (p<0.05) for both the maxillary and mandibular incisors and increased significantly (p<0.05) for two months after the training. On the basis of the foregoing findings, muscle training of the lips appeared to prompt increase in muscle strength and muscle pressure of the lips and adaptation of EMG activity to the load. Lip exercise therefore was considered effective for orthodontic treatment of malocclusion accompanied by abnormality in myofunction and for prevention of relapse after treatment.

Intraoral pressure measurement with telemetry system

The purpose of this study is 1) to develop a telemetry system to monitor the intraoral pressure continuously without any restriction on the daily life and 2) toinvestigate the clinical application of this system. The telemetry system consists of a battery-less intraoral unit and an external one. The electromagnetic coupling between the intraoral coil and the external one is used to supply the power to the intraoral unit and to receive the signal corresponding to the pressure of the upper central incisor region. The pressure transducer, which is 6 mm in diameter and 1 mm in thickness, is constructed from a stainless steel cantilever beam 0.08 mm thick to which the semiconductor strain gauges are cemented on both sides. The clinical application of this system is investigated on four adult subjects. The results are as follows 1) The labial pressure of the upper central incisor is 1.5 g/cm2, 10.9 g/cm2 and 5.0 g/cm2 at rest, at deglutition and during speech, respectively. 2) The lingual pressure of the same place is 4.0 g / cm2, 19.1 g/cm2 and 13.9 g / cm2 at rest, at deglutition and during speech, respectively. 3) The lingual pressure is always larger than the labial pressure in the upper central incisor region.

Intraoral pressures/incisor inclination in Classes I, II, and III: From J. Dent. Res., March, 1985

Equilibrium theory proposes that stability of teeth in the dental arch is due to a balance of forces on them. Later work was unable to demonstrate such balance. However, when head posture was considered as a variable, a balance between soft tissue pressures on the mandibular incisors was demonstrated (Wood, 198 1). The purpose of this study was to determine if mandibular incisor angulation can be predicted from intraoral pressures. Mandibular incisor angulation was measured from the cephalometric radiographs of IO Class I, 11 Class II, and IO Class III subjects. Labial and anterior lingual pressures were recorded in the mandible using the pressure transducer technique previously described. Recordings were made in natural head position and at both ? 20” of head extension and flexion. Pressures were measured during resting, swallowing, and speaking. Our results suggest the following conclusions. 1) The incisor angulation of Cluss III subjects di&ered sign$cantly from Class I and Class II subjects. 2) No significant correlation was observed between individual’s incisor angulation and labial pressures. 3) No significant correlation was observed between individual’s incisor angulation and tongue pressures. 4) The difference between anterior lingual and labial pressures resulted in no significant correlations with incisor angulation of the sample as a whole. 5) However, sign@xuzt correlations were observed when individuals were grouped by skeletal Class. 6) A majority of the highest correlations between incisor angulation and pressures were demonstrated by Class I subjects. These results suggest that incisor inclination is not solely dependent on pressures exerted by the soft tissues, although measurement over time may result in higher correlations.

Effects of head position on intraoral pressures in Class I and Class II adults

Variations in resting lip and tongue pressures and their relationship to alterations in head posture were investigated in subjects with Class I and Class II dental and skeletal morphology. Intraoral pressures were measured by means of transducers mounted in plastic carriers, customized for each subject from dental casts. Transducers were placed in the carriers to measure posterior lingual, anterior lingual, and labial pressures along the mandibular dentition. Ten Class I subjects and eleven Class II subjects participated. Pressures were recorded in natural head position, with 20 degrees of head extension and 20 degrees of head flexion. The Friedman two-way analysis of variance using ranked data was used to compare transducer location and head posture within skeletal classes. Anterior pressures were found to differ from posterior pressures in both classes. In Class I subjects, posterior lingual pressures were consistently different from labial pressures in all head positions. In Class II subjects, posterior lingual pressures differed from labial pressures in flexion and natural head positions, and from anterior lingual pressures in flexion and natural head positions. No increase in labial pressures with head extension was found in either Class I or Class II samples. Since every subject showed pressure changes with changes in head position, the influence of posture should be considered in studies on facial morphology and dental equilibrium.

Norms for orbicularis oris muscular strength for normal swallowing children in grades three thru six

Summary and Discussion: Subjects were used for establishing norms for labial strength. The group consisted of 114 NRSP subjects, all of whom were elementary school children in grades 3-6. The data of the 114 NRSP subjects shows the mean labial strength as being 4.45 lbs. There also appears to be some support for using the labial strength measurements as part of the diagnostic criteria for identifying the presence of reverse swallowing patterns (RSP). In addition, it is suggested that a measurement level well below the normative mean can be used successfully while a measurement of 4 lbs. and above could represent normal labial pressure. This procedure is strongly suggested in as much as most assessment presently utilized in determining the presence and/or absence of RSP have been essentially subjective observations. If the procedure mentioned herein is utilized, at least one objective measurement can be used along with the subjective observations. This writer feels that labial strength can be used along with the traditional observations for the successful diagnosis of RSP.

Simultaneous Measurements of Intraoral Pressure, Force of Labial Contact, and Labial Electromyographic Activity during Production of the Stop Consonant Cognates /p/ and /b/

Simultaneous measures of intraoral pressure, labial pressure, and labial electromyographic (EMG) activity were obtained from 18 normal adult speakers in an effort to provide descriptive data relevant to the supra-glottal characteristics of the English bilabial stops /p/ and /b/. The stops were produced in isolated nonsense syllables such that their position and the vocalic stress varied systematically. The results suggest that (1) the labial gesture for /p/ and /b/ appears to be essentially monotypic, requiring no more forceful labial contact or EMG activity for one than for the other; (2) intraoral pressure provides reliable discrimination between /p/ and /b/, irrespective of consonantal position and vocalic stress, while labial pressure and EMG activity provide relatively poor discrimination; (3) when all three variables are combined, reliable /p/-/b/ discrimination obtained when little or no vocalization follows the stop, and poor discrimination is observed when vocalization follows the stop; (4) a considerable amount of between-subject variability is evident in all three parameters; thus, caution is necessary when making assumptions based upon data of this type.

Simultaneous Measurement of Intraoral Pressure, Labial Pressure, and Labial Electromyographic Activity During Production of the Bilabial Soops /p/—/b/

Intraoral pressure, labial pressure, and labial EMG activity were obtained from 18 adult speakers to provide data relevant to the supraglottal characteristics of /p/ and /b/. Isolated nonsense syllables were used with the stop position and syllabic stress varied in a controlled manner. Results suggest that: (1) the labial gesture for /p/ and /b/ is monotypic, requiring no more forceful labial contact or EMG activity for one than for the other; (2) intraoral pressure provides good discrimination between /p/ and /b/, regardless of position or stress, while labial pressure and EMG activity provide poor discrimination; (3) with all three parameters combined, good /p/—/b/ discrimination is obtained, if essentially no vocalization follows the stop, while poor discrimination is obtained if a significant amount of vocalization follows; (4) considerable between subject variability is evident in all three parameters, emphasizing the need for caution when making generalizations from data of this type.