Lip and facial training improves lip-closing strength and facial morphology.

OBJECTIVE: Childhood is an important period for lip-closing strength (LCS) development, and failure to acquire LCS during childhood leads to various adverse health effects, such as mouth breathing. The purpose of this study was to examine the effectiveness of device-free lip and facial training in preschool children. DESIGN: The participants were divided into training and control groups. Both groups comprised 123 children aged 3-4 years, and only the training group received lip and facial training (i.e., opening and closing the lips and protruding the tongue) for 1 year. A two-way repeated measures analysis of variance was applied to compare the interaction effects of LCS and facial linear distance and angle by year (initial year vs. 1 year later) and group (training vs. control group). In addition, paired t-tests were used to test the changes in LCS and facial linear distance and angle after 1 year in both groups. Furthermore, the same analysis was performed in children with weak LCS in both groups (incompetent lip seal [ILS]). RESULTS: The LCS of children in the training group significantly increased after training compared with that in the control group, whether the analysis included all children or children with ILS alone. Lip and facial training for children with ILS reduced both the upper and lower lip protrusion; children with ILS without training had increased lip protrusion after 1 year. CONCLUSIONS: Lip and facial training for children with ILS effectively improved LCS and lip morphology, thereby preventing increased lip protrusion.

Incompetent lip seal affects the form of facial soft tissue in preschool children.

Objective: To examine whether incompetent lip seal (ILS) influences the form of facial soft tissue.Methods: Four hundred forty-four preschool children 3-5 years of age were selected. The images of the subjects' facial surface were obtained with a three-dimensional laser scanner. Coordinates of 16 facial landmarks were established and identified on the three-dimensional facial images, and the differences between children with (wILS) and without ILS (woILS) were measured.Results: The angle of sagittal facial convexity, excluding the nose, in 4- and 5-year-old children was significantly smaller in wILS children than in woILS children. The nasal prominence angle and the protrusion angle of lips in wILS children were significantly smaller than those in woILS children, at all ages.Conclusion: Children with ILS have anteriorly prominent subnasales and lips and flatter noses. The influence of ILS on facial form begins to appear even before 3 years of age.

Nanostructure and physical properties of cellulose nanofiber-carbon nanotube composite films.

We studied the nanostructure and physical properties of cellulose nanofiber-multi-walled carbon nanotube (CNF-MWNT) composite films prepared via MWNT aqueous dispersion using 4-O-methyl-α-d-glucuronoxylan as a MWNT dispersion aid. The composite film had high electrical conductivity (1.05S/cm), good mechanical properties (Young's modulus: 10.1GPa, tensile strength: 173.4MPa) and a low coefficient of thermal expansion (7ppm/K). FE-SEM imaging showed that the carbon nanotubes dispersed homogeneously and made reinforcing networks in the matrix of cellulose nanofibers. Improvement in the physical properties of cellulose nanofiber film by adding MWNTs is due to this composite structure.

Morphological differences of facial soft tissue contours from child to adult of Japanese males: a three-dimensional cross-sectional study.

OBJECTIVE: To evaluate morphological differences of the facial soft tissue surface between male Japanese adults and children. DESIGN: 20 adult Japanese males (average age 28 years) and 20 Japanese boys (average age 5.5 years) with normal occlusion were selected for this study. The images of the subjects' facial surface were obtained with a 3-D laser scanner. To evaluate the three-dimensional morphological differences of the facial soft tissue, we transformed the coordinates of 16 facial landmarks to a new reference plane and compared the adults' and children's facial form drawn to the same scale in the same coordinate system. RESULTS: The morphological difference ratio of the lower facial area was higher than in the upper facial area, and the nose and lower face changed more forward than downward. The morphological difference ratio of the mid face width was smaller than other areas. CONCLUSION: Our study suggests that the morphological facial soft tissue differences between Japanese adults and children are more forward and downward than laterally, manifesting in a facial form of adults that is deeper and narrow.

A reproducibility method to test lip-closing strength in preschool children.

This cross-sectional study tested the reproducibility of a simple button-pulling system for measuring lip-closing strength in normal preschool children and compared their strength to that of normal adults. The sample consisted of 348 preschool children and 123 adults. Lip-closing strength was measured by inserting a button, fastened to a piece of string, into the vestibule between the incisors and lips with minimal mouth opening. The string was attached to a digital tension gauge and was pulled parallel to the floor. Maximum tension, with three repetitions, was recorded at the instant that the button was pulled out of the mouth. Multilevel statistical models were used to evaluate any differences in contractive muscle strength between age groups and between the genders. The strength in children increased significantly from three years to five years (p<0.01). Gender-related differences were found in adults but not in preschool children. Inter-individual variation at each age was larger than intra-individual variation. Measurement of lip-closing strength by button pulling is highly reproducible in children and has potential clinical and research applications.