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Lip closing pressure in disabled children: a comparison with normal children.

Lip functions play an important role in the oral stages of feeding. Lip closing is an important early motor act in food acquisition and is essential for controlling chewing and swallowing. To date, there have been few papers on the developmental aspects of lip closing strength when taking in food, especially with regard to disabled children. This investigation was designed to produce an ordinal scale of midline lip pressure measurements for a cross-sectional, age-grouped population of normal children. Developmental changes in lip pressure were then compared with those of two populations of disabled children. Pressure measurements were obtained with a strain gauge transducer that was embedded in a spoon during normal feeding. The study population consisted of 104 normal children ranging in age from 5 months to 5 years, 11 children who showed developmental delay (mean 4.5 years), and 10 children with cerebral palsy (mean 5.0 years). Lip pressure was found to increase steadily from 5 months to 3 years and to increase slightly from 3 to 5 years in the normal population. The developmentally delayed group and the cerebral palsied group produced lip pressures and coefficients of variation below those of the normal 1 to 2-year-old group.

Age Factors↗

Evaluation of lip augmentation with Gore-Tex facial implant.

Although numerous materials, including autogenous, homogeneous, and alloplastic materials, have been used for lip augmentation with varying degrees of success, no ideal one has been found to achieve a soft and long-lasting result. Gore-Tex implant has been successfully used in cardiovascular surgery. So far, it has not been used much in lip augmentation. In this study, a Gore-Tex SAM facial implant (1.8 mm in diameter) was used for lip augmentation in 23 lips of 17 female patients. In 10 consecutive lips with three segments of the implant each, a computer-assisted imaging system was used to scrutinize the results. The results have shown that the three segments of the implant enhanced the lip projection with about 0.98 mm in mean (p < 0.01) and the exposed vermillion width with about 1. 94 mm (p < 0.01) in the over 6 months follow-ups. No major complications, only some minor ones, were seen. For lip augmentation, we find that only minor changes can be achieved with three segments of the Gore-Tex facial implant. We feel that it is safe and believe it gives a permanent result which is not the case with collagen injection and usually not the case with lipofilling despite reinjections. Furthermore, we consider the implant quite expensive at present.

Adult↗

Somatosensory evoked magnetic fields following stimulation of the lip in humans.

The topography of somatosensory evoked magnetic fields (SEFs) following stimulation of the upper and lower lips was investigated in 6 normal subjects. When the lateral side of the upper lip was stimulated, P20m and its counterpart, N20m, were identified in the hemisphere contralateral to the stimulated side. The equivalent current dipoles (ECDs) of N20m-P20m were considered to be located in lip area of the primary sensory cortex (SI). Middle latency deflections (N40m-P40m, N60m-P60m, and N80m-P80m) were identified in bilateral hemispheres. Their ECDs were located in the SI in both hemispheres. Long latency deflections (P110m-N110m) were recognized in both hemispheres, and their ECDs were located inferior to the SI, in an area considered to be the secondary sensory cortex (SII). When the midline of the lip was stimulated, similar short and middle latency deflections was also identified, but SII deflections (P110m-N110m) were decreased in amplitude. When the lower lip was stimulated, the ECDs of short and middle latency deflections were located at a site in the SI inferior to or near those elicited by upper lip stimulation. The ECDs of P110m-N110m were located in an area of the SII similar to that upon stimulation of the upper lip, but their orientations were different.

Adult↗

Ethnic differences in upper lip response to incisor retraction.

INTRODUCTION: The purpose of this retrospective longitudinal study was to investigate the response of the upper lip to incisor retraction and to ascertain the effect of ethnicity on this response. METHODS: Pretreatment and posttreatment lateral cephalograms of 88 postpubertal female patients (44 black and 44 white; mean age, 18.45 years) were evaluated. The groups were matched by age and the amount of incisor retraction at incisor superius. RESULTS: Although significant pretreatment differences existed between the groups in some cephalometric measurements, analysis of the treatment changes demonstrated significant differences only in incisor inclination. Hard and soft tissue changes of the black group were more downward, whereas changes in the white group were more backward. Multivariate regression analysis showed that the horizontal response of the upper lip to hard tissue changes at subnasale and superior labial sulcus was different in whites than in blacks. At subnasale, stepwise multivariate regression analysis showed that ethnicity contributed to the upper lip response to incisor retraction and was significantly greater in the white group. CONCLUSIONS: The hard and soft tissue treatment changes of the black group were more downward, and those of the white group were more backward. Ethnic differences exist in the soft tissue response to hard tissue changes in the upper lip, and at subnasale and the superior labial sulcus; however, these response differences at superior labial sulcus can be explained by the ethnic differences in initial lip thickness and incisor inclination; they are not due in and of themselves to ethnicity. The change at prosthion was significantly correlated with the response of the upper lip at labrale superius to incisor retraction. Ethnicity added no increase to the predictability of the response. When incisor retraction was performed, the final horizontal upper lip position could be accurately and reliably predicted.

Adolescent↗

Early establishment of lesion-insensitive mature barrelettes corresponding to upper lip vibrissae in developing mice.

Vibrissae are tactile sense organs on the face of non-human mammals, and build up topographical representations in the brainstem trigeminal sensory nucleus called barrelettes. In the present study, we examined postnatal development of barrelettes corresponding to upper lip vibrissae by cytochrome oxidase (CO) histochemistry. At nuclear regions corresponding to upper lip vibrissae, a few segregated barrelettes first appeared at postnatal day 2 (P2), and segregation became clear for most upper lip barrelettes at P4. Compared with major barrelettes corresponding to mystacial vibrissae on the snout, the development of segregated pattern formation for upper lip barrelettes was retarded by 1-2 days. When vibrissa-related patterns were examined 5 days after infraorbital nerve transection, upper lip barrelettes became obscure in all mice lesioned at P1 and P2. Lesion-insensitive upper lip barrelettes first emerged in a few mice lesioned at P3 (33%), and the percentage attained 100% at P6. This temporal transition from lesion-sensitive to lesion-insensitive barrelettes was 3 days ahead of mystacial barrelettes. Therefore, upper lip barrelettes achieve rapid development within a narrow time frame during the first postnatal week. The early and rapid establishment of lesion-insensitive, mature barrelettes can be interpreted as suggesting the importance of oral sensory function in neonatal life.

Aging↗

Perioral forces and dental changes resulting from mandibular lip bumper treatment.

This prospective study compares pretreatment and posttreatment forces produced by a lip bumper on the mandibular first molars and determines the dental effects of this appliance after 1 year of treatment. Twenty-five patients, ages 10 to 17 years, received fixed 0.045-inch passive stainless steel lip bumpers positioned at the level of the gingival margin, 2 mm from the labial surface of the teeth as the only form of treatment in the mandibular arch. At the end of 1 year, cephalometric radiographs and dental casts were taken, and lower lip forces remeasured during rest, speech, and swallowing. Lip force measurements were performed using specially designed strain gauges mounted bilaterally in the lip bumper tubes. Measurements of lip forces made before and after treatment were compared to explore the changes, if any, due to muscle adaptation to the appliance. Dental changes were measured from casts and cephalometric radiographs. Correlation analyses were performed to determine whether a relationship existed between initial force levels and resulting tooth movement. Pretreatment and posttreatment forces did not demonstrate a statistically significant difference. On the other hand, measurement of the dental casts revealed a significant increase in arch length caused by incisor proclination and protrusion, combined with molar distalization. The arch width significantly increased at the canines, first and second premolars, and first molars. The amount of force exerted by the lower lip on the molars was not correlated to the degree of tooth movement recorded in this sample.

Adaptation, Physiological↗

Sucking efficiency of early orthopaedic plate and teats in infants with cleft lip and palate.

Intraoral negative pressure during bottle feeding with two kinds of teats (a regular Nuk and a cleft Nuk) was measured in 7 infants with cleft lip and palate, 8 infants with cleft palate, 2 infants with cleft lip, 4 infants with operated cleft lip and palate and 7 normal infants. Infants with cleft lip and palate or cleft palate were unable to generate negative pressure before cleft lip and palate closure. The presence or absence of an early orthopaedic plate did not make any difference. In infants with unoperated cleft lip and with operated cleft lip and palate, peak negative pressure during feeding differed little from that of normal infants.

Bottle Feeding↗

Epidemiology of cancer of the lip in The Netherlands.

Descriptive epidemiological data of new cases of squamous cell carcinoma of the vermilion border of the lip in the Netherlands from 1989-94 inclusive are presented. Lip cancer represented 0.47 and 0.09% of all new malignancies in males and females, respectively. The lower lip was the most frequently affected site. The majority of the lip cancers were diagnosed in tumour stage I. The median age at diagnosis in males was 68 years, 5 years less than in females. The overall male-to-female ratio was 5.7. Age-adjusted incidence rates in males and females were 2.2 and 0.3 per 100,000 (ESR), respectively. The cumulative lifetime risk for developing lip cancer was 0.15 for males and 0.03 for females. Mortality/incidence ratios in males and females were 0.05 and 0.07, respectively. Differences in lip cancer incidence were observed between an urban and a rural area. There was a positive association between the occurrence of lip cancer and rural residence; rate ratios were 3.3 among males and 3.5 among females.

Adolescent↗

Lip curve changes in females with premolar extraction or nonextraction treatment.

Changes in lip curvature resulting from treatment have been largely ignored in orthodontic literature. The focus instead has been primarily directed at retraction of the vermilion border and changes in the nasolabial angle. This study, therefore, was designed to retrospectively analyze changes in the upper and lower lip curves associated with growth and treatment. The lateral cephalometric records of 137 female orthodontic patients were digitized. Sixty-two were treated with premolar extractions and 75 without extractions. The overall extraction group was further divided into subgroups on the basis of the chosen extraction sequence, which included extraction of 4/4, 4/5, or 5/5. Statistical analysis revealed no significant differences in changes in lip curve depth between the two overall samples, relative to either of the two reference lines. This would suggest that an appropriately selected plan, whether extraction or nonextraction, should allow treatment to be carried out without negative effects on the curvature of the lips. Calculation of correlation coefficients and regression analysis suggested that the inherent properties and morphology of the soft tissues themselves are probably the greatest determinants of lip curve behavior with treatment. The midface soft tissues appear to be less dependent on changes in the underlying hard tissues than do the lower face soft tissues. Pretreatment upper and lower incisor positions and angulations and the underlying vertical facial dimension appear to play more significant roles in the behavior of the lower lip than the upper lip.

Adolescent↗

The sequential development of jaw and lip control for speech.

Vertical displacements of the upper lip, lower lip, and jaw during speech were recorded for groups of 1-, 2-, and 6-year-olds and adults to examine if control over these articulators develops sequentially. All movement traces were amplitudeand time-normalized. The developmental course of upper lip, lower lip, and jaw control was examined by quantifying age-related changes in the similarity of each articulator's movement patterns to those produced by adult subjects and by same-age peers. In addition, differences in token-to-token stability of articulatory movement were assessed among the different age groups. The experimental findings revealed that 1- and 2-year-old children's jaw movements were significantly more adult-like than their upper and lower lip movements, which were more variable. In contrast, upper and lower lip movement patterns became more adult-like with maturation. These findings suggest that the earliest stages of speech motor development are constrained by the nonuniform development of articulatory control, with the jaw preceding the lips. The observed developmental patterns suggest that the properties of the oral motor control system significantly influence the pattern of speech sound acquisition.

Adult↗

Kinematic analysis of lip closure in stutterers' fluent speech.

An analysis of lip and jaw motion was carried out in order to evaluate previous observations on the fluent speech of stutterers and to describe possible effects of speech therapy. A strain gauge system was used to transduce lip and jaw movements during fluent repetitions of "sapapple" in adult stutterers and nonstutterers. Fifteen movement parameters were measured on lip closure for the initial /p/ sound in a group of 10 normal speakers, 10 stutterers who had no recent speech therapy, and 8 stutterers who had been through an intensive speech therapy program involving modification of speech timing. The no-therapy group and nonstutterers did not differ significantly in terms of any movement parameter. Stutterers who had been through speech therapy showed significant increases in jaw movement duration and time to peak velocity of the upper lip, lower lip, and jaw. The expected timing pattern for lip and jaw velocity peaks on lip closure (UL-LL-J) was the most frequently occurring pattern, but deviations from this pattern were observed in both stutterers and nonstutterers. The occurrence of reversals was most prevalent in the therapy group, and it was associated with increases in jaw movement duration across subjects. It is suggested that for the type of movement studied here, anomalies in stutterers' fluent speech are likely to be the result of acquired adjustments rather than properties of the speech neuromotor system that underly dysfluency.

Adult↗

Activation of lip motor units with variations in speech rate and phonetic structure.

The purpose of this study was to describe the activation characteristics of lip-muscle single motor units in relation to speech rate and phonetic structure. Repeated experiments were carried out on three adult subjects from whom recordings of lower lip EMG and two-dimensional displacement were obtained. Single motor unit recordings were obtained from the orbicularis oris inferior (OOI), depressor labii inferior (DLI), and mentalis (MENT) muscles. Subjects' tasks involved repeating CV syllables at 1 to 4 syllables per second (syl/sec). The distribution of interspike intervals and corresponding firing rates were obtained on 11 motor units. The firing rates of OOI and MENT motor units increased as syllable rate changed from 1 to 3 syl/sec, but firing rates tended to be equivalent at 3 and 4 syl/sec. DLI and tonic motor units showed little or no modulation in their firing rates with speech rate. Firing rate data and related observations on lip movement and EMG spike count levels suggest that distinct neuromechanical processes control lip movements at low and high speech rates. Both kinematic and EMG data support the expectation that phonetic structure has its greatest effects on lip opening compared to lip closing movements in CV syllables. OOI and MENT activation levels tended to be highest for /p/ productions compared to /w/ and /f/. This may be related to the requirements for complete lip closure and elevated levels of intraoral pressure for production of /p/.

Adult↗

Treatment of upper lip wrinkles: a comparison of 950 microsec dwell time carbon dioxide laser with unoccluded Baker's phenol chemical peel.

BACKGROUND: The high energy, pulsed, or computer-scanned continuous wave carbon dioxide laser (CO2 laser) has gained popularity as a wrinkle treatment because of its minimal thermal injury and precise control of tissue vaporization depth. Chemical peels such as phenol have also been effective in treating facial wrinkles. This is, to our knowledge, the first study comparing the use of CO2 laser to phenol for treatment of wrinkles on the upper lip. OBJECTIVE: To compare the effectiveness and side effect profile of the 950 microsec dwell time CO2 laser to that of unoccluded Baker's phenol chemical peel in the treatment of upper lip wrinkles. METHODS: Twenty female subjects with moderate to severe upper lip wrinkles were randomly treated with Baker's phenol on one side of the upper lip and the 950 microsec dwell time CO2 laser on the other side. RESULTS: The average upper lip laser-treated wrinkle score (0 = none to 5 = severe) decreased from 4.30+/-0.20 before treatment to 1.11+/-0.28 at 6 months after treatment. The average upper lip phenol-treated wrinkle score decreased from 4.20+/-0.20 to 0.47+/-0.12. The degree in which the wrinkle score improved after phenol treatment compared with that after laser treatment was statistically significant (p<0.03). CONCLUSION: Treatment of upper lip wrinkles with Baker's phenol resulted in greater improvement than treatment with the 950 microsec dwell time CO2 laser.

Aged↗

Treatment of upper lip wrinkles: a comparison of the 950 microsec dwell time carbon dioxide laser to manual tumescent dermabrasion.

BACKGROUND: High-energy pulsed or computer-scanned continuous-wave carbon dioxide (CO2) laser resurfacing has gained popularity as a wrinkle treatment because of its minimal thermal injury and precise control of tissue vaporization depth. Manual tumescent dermabrasion has also been effective for treating facial wrinkles. This is, to our knowledge, the first study comparing the use of CO2 laser to manual tumescent dermabrasion for the treatment of wrinkles on the upper lip. OBJECTIVE: To compare prospectively the clinical efficacy of the 950 microsec dwell time CO2 laser to that of manual tumescent dermabrasion in the treatment of upper lip wrinkles. METHODS: Twenty female subjects with moderate to severe upper lip wrinkles were randomly treated with the 950 microsec dwell time CO2 laser on one side of the upper lip and manual tumescent dermabrasion on the other. RESULTS: The average upper lip laser-treated wrinkle score (0 = none to 5 = severe) decreased from 4.3 +/- 0.2 before treatment to 1.8 +/- 0.3 at 6 months after treatment. The average upper lip dermabrasion-treated wrinkle score decreased from 4.4 +/- 0.2 to 1.5 +/- 0.3. The degree to which the wrinkle score improved after laser treatment compared with that after dermabrasion was not statistically significant (P =.216). CONCLUSION: Manual tumescent dermabrasion and 950 microsec dwell time CO2 laser resurfacing are equally effective for the treatment of upper lip wrinkles.

Aged↗

The use of second-intention healing for partial-thickness Mohs defects involving the vermilion and/or mucosal surfaces of the lip.

BACKGROUND: Partial-thickness defects involving the vermilion and mucosa of the lip are difficult to repair surgically. OBJECTIVE: The purpose of this study was to evaluate the cosmetic and functional effectiveness of second-intention healing in the repair of partial-thickness defects confined predominantly to the vermilion and mucosa of the lip. METHODS: Thirteen patients with squamous cell carcinoma of the lip underwent Mohs micrographic surgery, which resulted in partial-thickness defects predominantly confined to the vermilion and/or mucosa of the lip. All defects were allowed to heal by secondary intention. RESULTS: Twelve patients had good to excellent cosmetic results, and functional impairment was not noted in any of the patients. One patient whose defect extended to the cutaneous portion of the lip had deformation of the vermilion border. CONCLUSIONS: Second-intention healing yields good to excellent cosmetic and functional results for the repair of partial-thickness defects involving the vermilion and/or mucosa of the lip. Defects involving more than 2 mm of the cutaneous lip or defects extending deeper than the superficial portion of the orbicularis oris muscle may result in cosmetic or functional deformity or both if allowed to heal secondarily.

Administration, Topical↗

Predicting upper lip response to 4-piece maxillary LeFort I osteotomy.

The purpose of this retrospective study was to understand and predict the multidimensional changes in upper lip morphologic features after segmental (4-piece) maxillary Le Fort I advancement/impaction with VY closure and alar base cinch sutures. The study evaluated longitudinal lateral cephalograms of 57 patients (42 women, 15 men) 27.5 +/- 11.2 years of age before surgery. Lateral cephalograms with teeth in occlusion and lips in repose were taken 2 weeks before surgery and at least 6 months after the operation. Mean postsurgical duration was 15.5 months. The upper lip predictably moved anteriorly in a graduated fashion, from 50% (subnasale) to 90% (labrale superius) the amount of the underlying osseous anterior movement, and showed a slight lengthening (0.73 +/- 1.9 mm) from subnasale to upper lip stomion. The upper lip surface contour was also straightened as a result of the surgical movement. Multiple regression models showed that the anterior changes in the landmarks prosthion and facial surface of the upper incisor were the most important variables in predicting upper lip response. The prediction equations for horizontal movements explained 86% to 94% of the variation, with errors of the estimates that range between 1.27 mm and 1.65 mm. The models, when applied to an independent validation sample of 14 subjects, explained between 86% and 94% of the total variation. The conclusion is that upper lip response after 4-piece Le Fort I advancement/impaction (VY closure and alar base cinch suture) can be accurately predicted.

Adult↗

The effect of anterior tooth retraction on lip position of orthodontically treated adult Indonesians.

This study was conducted to determine upper and lower lip changes after orthodontic treatment of bimaxillary dental protrusion in adult Indonesians. Pretreatment and posttreatment cephalograms of 40 patients (6 males and 34 females) who required extraction of 4 premolars, were traced, superimposed, and measured. The changes of anterior tooth position (measured as the horizontal distance from the incisal tip to a constructed vertical through sella) were correlated with changes in the upper and lower lip positions with the Pearson correlation method. Significant positive correlation was found between changes of the maxillary and mandibular incisors with the changes in both the upper lip (r(U1) = 0.39, P <.05; r(L1) = 0.44, P <.01) and the lower lip (r(U1) = 0.44, P <.01; r(L1) = 0.51, P <.01) positions. By using stepwise multiple regression, it was found that for every millimeter of mandibular incisor retraction, 0.4 mm of upper lip retraction and 0.6 mm of lower lip retraction were produced. This study concluded that, for this Indonesian sample, a strong correlation exists between mandibular anterior tooth retraction and the position of both lips.

Adolescent↗

Development of the orbicularis oris muscle in normal and cleft lip and palate human fetuses using three-dimensional computer reconstruction.

As part of an ongoing study of cleft lip and palate fetal morphology, normal and dysmorphic development of the human fetal orbicularis oris muscle was studied in a cross-sectional sample of 29 human fetuses (20 "normal" and 9 cleft lip and palate) ranging in age from 8 to 21 postmenstrual weeks. The specimens were embedded in celloidin and sectioned at 20 microns, and every tenth section was stained with hematoxylin and eosin. A computer reconstruction technique was applied to produce three-dimensional representations of the orbicularis oris muscle. The orbicularis oris muscle in the normal fetal sample with discernible lip fibers (N = 15) increased symmetrically in both fiber density and complexity from 12 to 21 weeks. Metrically, muscle volume and thickness growth curves were consistent with qualitative observations. In contrast, the unilateral cleft lip and palate fetal specimens with discernible lip fibers (N = 3) exhibited a 3.5-week delay in overall muscle development, asymmetrical fiber distribution, and abnormal fiber insertions. However, quantitatively, no significant (p greater than 0.05) differences were noted in orbicularis oris muscle thickness or volume between the normal and cleft lip and palate fetal specimens through 21 weeks. Findings suggest that orbicularis muscle deficiency, noted clinically in cleft lip and palate neonates, may be a result of perinatal functional dysmorphogenesis rather than congenital mesenchymal reduction or deficiency.

Cleft Lip↗