RESUMEN
OBJECTIVE: To evaluate the influence of vermilion height on the assessment of lip attractiveness by Japanese and Korean orthodontists and orthodontic patients. MATERIALS AND METHODS: Vermilion heights were modified by increasing or decreasing the vermilion height in 1.0-mm increments from -3.0 mm to 3.0 mm with reference to an average vermilion height. Participants ranged from 15 to 29 years of age and comprised 29 Japanese and 25 Korean orthodontists and 96 Japanese and 72 Korean orthodontic patients. They all rated the attractiveness of seven images with altered vermilion height using a visual analog scale. RESULTS: Across the participant groups, there were significant differences in the median esthetic scores for the seven vermilion height levels tested. The Japanese and Korean raters assigned the highest scores to the average vermilion height and assigned the lowest scores to the +3-mm increased vermilion height. The ranges of vermilion height preferred by orthodontists were found to be within the ranges preferred by orthodontic patients when evaluating the preferences in lip esthetics by country. CONCLUSIONS: We conclude that the -1-mm to +1-mm range for the average vermilion height is considered attractive for lips for both Japanese and Korean people.
Asunto(s)
Actitud Frente a la Salud , Estética , Labio/anatomía & histología , Ortodoncia Correctiva , Ortodoncia , Adolescente , Adulto , Actitud del Personal de Salud , Femenino , Humanos , Japón , Masculino , Fotograbar/métodos , República de Corea , Escala Visual Analógica , Adulto JovenRESUMEN
OBJECTIVE: To evaluate the effects of sliding velocity on friction, particularly at extremely low sliding velocity approximating orthodontic tooth movement. MATERIALS AND METHODS: Stainless-steel (SS) 0.022-inch preadjusted brackets and 0.016- and 0.016×0.022-inch SS wires and superelastic nickel-titanium 0.016×0.022-inch wires were used for this test. The wire was secured in a SS preadjusted bracket with an elastomeric module. One end of the wire was pulled upward 1.5 mm at a speed of 5.0×10(-7), 1.0×10(-5), 1.0×10(-4), 1.0×10(-3), 1.0×10(-2), and 1.0×10(-1) mm/s by the micrometer. The measurements were conducted 10 times and averaged. Tukey-Kramer tests were used to compare the mean differences of each testing measurement among the different sliding velocities. RESULTS: The frictional forces tended to increase as the sliding velocity decreased. The mean frictional force for 5.0×10(-7) mm/s sliding velocity (approximating orthodontic tooth movement) was 106.8 cN in 0.016×0.022-inch SS wires, almost double the 1.0×10(-1) mm/s sliding velocity. CONCLUSION: The effects of sliding velocity cannot be ignored when we estimate frictional forces in clinical orthodontics.
Asunto(s)
Técnicas de Movimiento Dental/métodos , Diente/fisiología , Fenómenos Biomecánicos , Aleaciones Dentales/química , Elasticidad , Elastómeros/química , Fricción , Humanos , Movimiento , Níquel/química , Diseño de Aparato Ortodóncico , Soportes Ortodóncicos , Alambres para Ortodoncia , Acero Inoxidable/química , Estrés Mecánico , Titanio/química , Técnicas de Movimiento Dental/instrumentaciónRESUMEN
STATEMENT OF PROBLEM: The perception of a pleasing smile may differ between the countries in Asia or may be converging on a more internationally pleasing one. PURPOSE: The aim of this study was to evaluate the influence of vertical positions of anterior teeth on smile esthetics as assessed by Japanese and Korean orthodontists as well as by orthodontic patients. MATERIALS AND METHODS: A standard composite smile was constructed from different females' intraoral and extraoral photographs. Vertical positions of anterior teeth were modified digitally in 1-mm increments, from 5 mm upper lip coverage of the incisors to 5 mm gingival exposure. Using a visual analog scale, 41 Japanese orthodontists and 96 Japanese orthodontic patients, 25 Korean orthodontists, and 72 Korean orthodontic patients rated the attractiveness of 11 smiles with altered gingival displays. RESULTS: Overall, the Japanese and Korean raters assigned similar esthetic scores between the corresponding groups. The male orthodontic patients assigned higher scores to the smiles with upper lip coverage of the teeth than the corresponding females did in both countries. The female patients assigned clinically significant higher scores to the smiles from 2 mm upper lip coverage of the teeth to 0 mm gingival exposure in both countries. CONCLUSIONS: In both countries, the orthodontists and the female patients shared the similar preference in the smile evaluation of vertical positions of anterior teeth, whereas the male orthodontic patients were more tolerant of upper lip coverage of the anterior teeth than the orthodontists and the female patients. CLINICAL SIGNIFICANCE: This study proposes 0 mm to 2 mm of upper lip coverage of the teeth as a threshold of acceptability for esthetic smile evaluations in female orthodontic patients. For male orthodontic patients, the paper proposes negative gingival display as a threshold of acceptability for esthetic smile evaluations.
Asunto(s)
Actitud Frente a la Salud , Diente Canino/anatomía & histología , Estética Dental , Incisivo/anatomía & histología , Sonrisa , Adolescente , Adulto , Actitud del Personal de Salud , Actitud Frente a la Salud/etnología , Odontólogos/psicología , Femenino , Encía/anatomía & histología , Humanos , Japón , Labio/anatomía & histología , Masculino , Ortodoncia , Ortodoncia Correctiva/psicología , República de Corea , Factores Sexuales , Escala Visual Analógica , Adulto JovenRESUMEN
The purpose of this study was to evaluate the effects of orthodontic treatment, involving the extraction of four premolars, on vermilion height and lip area. Twenty-eight female patients (mean 21.9 ± 3.1 years) who were diagnosed with bimaxillary protrusion were selected for this study to be treated by extraction of four premolars. The control group consisted of 28 female volunteers (mean 25.0 ± 3.0 years) with Angle Class I normal occlusion. Frontal photographs of the patients were taken both before and after the orthodontic treatment in resting position. Thirty-five landmarks on the upper and lower lips were identified for the measurements of vermilion height and lip area. Lateral cephalograms were taken before and after active orthodontic treatment, and linear and angular measurements were performed. The mean pre-treatment values of vermilion height and lip area were significantly greater in the treatment group than those of the control group and decreased significantly after the orthodontic treatment towards the values in the control group. There were no significant differences in the vermilion height and lip area between the post-treatment and the control groups, except for lower lip area values. Significant correlations found between the changes in incisor position and the changes in vermilion height were few in number for the upper lip but greater in number for the lower lip. Thus, the results of this study show that bimaxillary protrusion cases can be treated by the extraction of four premolars to produce an aesthetic improvement in frontal facial features.
Asunto(s)
Diente Premolar/cirugía , Estética Dental , Incisivo/cirugía , Maloclusión Clase I de Angle/cirugía , Sobremordida/cirugía , Extracción Dental , Adolescente , Adulto , Cefalometría , Cara , Femenino , Humanos , Labio , Adulto JovenRESUMEN
OBJECTIVE: The purpose of this study was to evaluate the effects of four premolar extractions and orthodontic treatment on changes to the lips and vermilion height during a posed smile. METHODS: Fifteen female patients who were diagnosed with bimaxillary protrusion and treated with four premolar extractions were selected. The control group consisted of 25 female volunteers with a normal occlusion. Frontal photographs of the patients during a posed smile were taken before and after orthodontic treatment. Thirty-five landmarks on the upper and lower lips were identified and used to generate measurements of lip area and vermilion height. Linear and angular cephalometric measurements were also obtained. RESULTS: The mean values for vermilion height and lip form before orthodontic treatment were significantly larger in the treatment group compared with those of the control group. Following treatment, values significantly decreased to the extent that there was no significant difference in the vermilion height and lip form between the post-treatment and control groups. Only three and four significant correlations were found between the changes in incisor position and changes in vermilion height and lip area for the upper and lower lips, respectively. CONCLUSIONS: The vermilion height and lip area in patients with bimaxillary protrusion approached comparative and normal values as a result of four premolar extractions and orthodontic retraction.
Asunto(s)
Diente Premolar/cirugía , Labio/patología , Maloclusión Clase I de Angle/terapia , Sonrisa , Extracción Dental/métodos , Adolescente , Adulto , Puntos Anatómicos de Referencia/patología , Cefalometría/métodos , Femenino , Humanos , Incisivo/patología , Fotograbar , Técnicas de Movimiento Dental/métodos , Adulto JovenRESUMEN
INTRODUCTION: The purpose of this study was to evaluate the influence of the size of buccal corridors on the assessment of attractive smile esthetics by Japanese and Korean orthodontists and orthodontic patients. METHODS: Buccal corridors were modified digitally from 0% to 25% compared with the inner intercommissural width. Using a visual analog scale, 41 Japanese and 25 Korean orthodontists, and 96 Japanese and 72 Korean orthodontic patients (15-29 years old) rated the attractiveness of 6 smiles with altered buccal corridors. The influence of the size of the buccal corridor on smile esthetics was assessed. RESULTS: Although there was no significant sex difference in judging the effects of buccal corridors for the Korean and Japanese orthodontists, significant sex differences were shown for the Japanese orthodontic patients. There were significant differences in the 6 levels of median esthetic scores for all groups: 0%, 5%, and 10% buccal corridors in the smiles tended to be preferred to the other smiles, to become clinically significant for all groups. The median esthetic score decreased to become clinically significant from 10% to 15% buccal corridors for all groups. CONCLUSIONS: Japanese and Korean orthodontists and orthodontic patients prefer narrow or medium buccal corridors to broad buccal corridors.
Asunto(s)
Actitud del Personal de Salud , Actitud Frente a la Salud , Estética Dental , Labio/anatomía & histología , Ortodoncia Correctiva/psicología , Ortodoncia , Sonrisa , Adolescente , Adulto , Mejilla/anatomía & histología , Arco Dental/anatomía & histología , Femenino , Humanos , Japón , Masculino , República de Corea , Factores Sexuales , Adulto JovenRESUMEN
INTRODUCTION: The purposes of this study were to assess and determine the range of a well-balanced anteroposterior lip position as evaluated by orthodontic patients from a series of varying lip positions in facial silhouettes, and whether the rater's sex and age were factors in the assessment. METHODS: The average profiles were constructed from 30 Japanese male and female subjects with normal occlusion. A series of 13 profiles was developed for males and females, respectively. The lips were protruded or retruded by 1-mm increments from the average profile. One hundred fifty Japanese orthodontic patients were asked to choose the top 3 most-favored, well-balanced profiles for each sex. RESULTS: The orthodontic patients tended to prefer a slightly retruded lip position than the average facial profile for both the male and female profiles. There was no significant difference between male and female raters in selecting the top 3 most-favored profiles. In the comparison of age groups, the over 30-year-old patients significantly preferred a more retruded lip position than did the 15- to 19-year-old and the 20- to 29-year-old patients for the female profile. CONCLUSIONS: These results suggest that, when we formulate a treatment plan, we should ask the patients about lip position before we start treatment.
Asunto(s)
Estética Dental , Labio/anatomía & histología , Ortodoncia Correctiva , Adolescente , Adulto , Factores de Edad , Actitud Frente a la Salud , Cefalometría , Mentón/anatomía & histología , Oclusión Dental , Femenino , Humanos , Japón , Masculino , Nariz/anatomía & histología , Valores de Referencia , Factores Sexuales , Adulto JovenRESUMEN
The aim of this study was to examine the effects of retraction of anterior teeth and the initial soft tissue profile variables on upper and lower lip changes in Japanese adults. Pre- and post-treatment cephalometric radiographs of 33 Japanese female adults (aged 23.0±5.0 years), with a Class II division 1 malocclusion, who had two or four first premolars extracted, were evaluated. Lateral cephalograms taken with the lips in a voluntary relaxed position were traced and compared. Nine linear and eight angular measurements were constructed for the hard tissue measurements and 16 linear and 2 angular for the soft tissue measurements. Stepwise multiple regression analysis revealed that the horizontal upper lip position could be explained by the position of the maxillary incisor cervical point and the occlusal plane to SN with a 54 percent contribution ratio, and horizontal lower lip position, maxillary incisor tip position, initial interlabial gap, and aesthetic line to the tip of lower lip with a 51 percent contribution ratio. All parameters employed explained the horizontal position of the upper and lower lip with higher than 96 percent confidence. While the horizontal positions could not be predicted by a limited number of parameters, the vertical positions of lips could be explained by three parameters with higher than 62 percent confidence. The predictability found in this study could be beneficial for orthodontists in treatment planning.
Asunto(s)
Incisivo/patología , Labio/patología , Técnicas de Movimiento Dental/métodos , Adolescente , Diente Premolar/cirugía , Cefalometría/métodos , Mentón/patología , Estética Dental , Femenino , Humanos , Japón , Maloclusión Clase II de Angle/terapia , Mandíbula/patología , Maxilar/patología , Hueso Nasal/patología , Métodos de Anclaje en Ortodoncia/instrumentación , Silla Turca/patología , Extracción Seriada , Técnicas de Movimiento Dental/instrumentación , Dimensión Vertical , Adulto JovenRESUMEN
The aim of this study was to evaluate the influence of the amount of gingival display on smile aesthetics as assessed by Japanese orthodontists and dental students. A coloured photograph of a smiling female, displaying the first molar to first molar, whose upper lip was tangent to the upper gingival margin of the upper central incisors (zero point), was constructed from different subjects. Gingival displays were modified by moving the teeth within the lip frame in 1 mm increments, from -5 to 5. Using a visual analogue scale (VAS), 31 Japanese orthodontists and 55 Japanese dental students rated the attractiveness of the 11 smiles with altered gingival display. There was no significant difference when judging the effects of the gingival display on the smile attractiveness between the male and the female raters for both the orthodontists and dental students. Kruskal-Wallis tests revealed significant differences in the median aesthetic scores for both the orthodontists and dental students. For the orthodontists, the median aesthetic score increased gradually from -5 to 0 mm and then decreased from 0 to 5 mm. In particular, it decreased to become clinically significant (15 per cent VAS difference) from 0 to 3 mm. For the dental students, the median aesthetic score increased gradually from -5 to -2 mm and then decreased from -2 to 5 mm. The dental students were less tolerant of a more 'gummy' smile than the orthodontists.
Asunto(s)
Actitud del Personal de Salud , Estética Dental , Encía/anatomía & histología , Sonrisa , Adulto , Pueblo Asiatico , Odontólogos , Femenino , Humanos , Japón , Masculino , Fotografía Dental , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Estudiantes de Odontología , Adulto JovenRESUMEN
AIM: To compare the kinetic frictional force of a conventional plastic preadjusted bracket with thermoplastic low-friction module ligation and a self-ligating bracket. MATERIALS AND METHODS: The testing model consisted of four 0.022-inch conventional plastic preadjusted brackets; four 0.022-inch self-ligating brackets for the first premolar, canine, and lateral and central incisors; and a 0.014-inch superelastic nickel-titanium and a 0.019 × 0.025-inch stainless steel wire. The brackets were either aligned for both wires or out of line by 0.5, 1.0, 1.5, and 2.0 mm for only the 0.014-inch superelastic wire. The wires were pulled for 3.0 mm at a speed of 0.1 mm per second. Unpaired t tests were used to compare the mean differences of the measurements between the two bracket systems with both wires. RESULTS: No significant difference in the kinetic frictional force between the two bracket systems and the two wires were found for the 0.014-inch superelastic wire at 0-mm deflection. CONCLUSION: Both bracket systems demonstrate low friction, which is beneficial for effective orthodontic tooth movement with light forces.
Asunto(s)
Materiales Dentales/química , Diseño de Aparato Ortodóncico , Soportes Ortodóncicos , Plásticos/química , Diente Premolar/patología , Diente Canino/patología , Aleaciones Dentales/química , Elasticidad , Fricción , Humanos , Incisivo/patología , Níquel/química , Alambres para Ortodoncia , Acero Inoxidable/química , Estrés Mecánico , Propiedades de Superficie , Titanio/química , Técnicas de Movimiento Dental/instrumentaciónRESUMEN
OBJECTIVE: To test the hypothesis that the amount of buccal corridor has no influence on smile evaluations of Japanese orthodontists and dental students. MATERIALS AND METHODS: One photograph of a smiling female, displaying first molar to first molar, was constructed. Buccal corridors were modified digitally in 5% increments, from 0% to 25% buccal corridor compared with the inner commissural width. Using a visual analog scale (VAS), 32 Japanese orthodontists and 55 Japanese dental students rated the attractiveness of six smiles with altered buccal corridors. The Wilcoxon rank-sum test was conducted to compare the distributions of the median scores between the male and female raters for each of the rater groups. Differences in the median esthetic scores were analyzed using the Kruskal-Wallis test. We used 15% VAS difference to determine the clinical significance of the esthetic scores. RESULTS: There was no significant difference in judging the effects of buccal corridors on the smile attractiveness between the male and female raters for both the orthodontists and dental students. There were significant differences in the median esthetic scores for both the orthodontists and dental students. The median esthetic score decreased to become clinically significant from 10% to 25% buccal corridor for both the orthodontists and dental students. CONCLUSIONS: The hypothesis was rejected. Both the orthodontists and dental students preferred broader smiles to medium or narrow smiles.
Asunto(s)
Mejilla/anatomía & histología , Estética Dental , Sonrisa , Adulto , Odontólogos , Femenino , Humanos , Japón , Masculino , Estudiantes de Odontología , Adulto JovenRESUMEN
OBJECTIVE: To compare frictional resistance of the plastic preadjusted brackets ligated with the low-friction ligatures with those of the conventional elastomeric ligatures. DESIGN: In vitro study. SETTING: Department of Orthodontics, Faculty of Dentistry, Kyushu University, Fukuoka, Japan. MATERIALS AND METHODS: The testing model consisted of four 0.022-inch plastic preadjusted brackets for the first premolar, the canine, the lateral incisor, and the central incisor. A superelastic nickel-titanium 0.014-inch wire and a stainless steel 0.019 x 0.025-inch wire were used for this test. The brackets were either aligned or out of line by 0.5, 1.0, 1.5 and 2.0 mm for the 0.014-inch wire and aligned for the 0.019 x 0.025-inch wire. The frictional forces in plastic preadjusted brackets with low-friction ligatures and conventional elastomeric ligatures were measured at a pulling speed of 0.1 mm/second. Welch t-tests were used to compare the mean differences of each testing measurement between the low-friction and the conventional elastomeric ligatures. RESULTS: In both use of the superelastic nickel-titanium 0.014-inch wire and the stainless steel 0.019 x 0.025-inch wire, the brackets with the low-friction ligatures showed significantly lower frictional forces than those of the conventional elastomeric ligatures in both aligned and all misaligned brackets (P < 0.0001). CONCLUSION: The study found the significantly lower frictional forces for the low-friction ligatures than those of the conventional elastomeric ligatures.
Asunto(s)
Diseño de Aparato Ortodóncico , Soportes Ortodóncicos , Aleaciones Dentales , Análisis del Estrés Dental , Elastómeros , Fricción , Humanos , Níquel , Plásticos , Acero Inoxidable , TitanioRESUMEN
AIMS: To investigate the relationship between mechanomyogram (MMG), electromyogram (EMG) and bite force during isometric contraction of the human masseter muscle. METHODS: Data were obtained from 16 healthy Japanese males (Mean age: 25.6 +/- 2.3 years). The measuring device for MMG consisted of an amorphous sensor and a small magnet. The bite force, MMG and EMG signals were recorded simultaneously during isometric contraction of the masseter muscle. The subjects were instructed to perform 0, 5, 10, 20, 30, 40, 50, and 60% maximal voluntary contractions (MVC) for 20 seconds. The average rectified value (ARV) for MMG and EMG were calculated from 1 to 5 second samples. The median frequency of the power spectrum (MFPS) for MMG and EMG were determined with the use of a fast Fourier transformation algorithm. RESULTS: The mean ARV for MMG increased up to 20% MVC and then gradually decreased at the higher force levels. The mean ARV for EMG increased with bite force in a monotonic fashion. The mean MFPS for MMG clearly increased up to 10% MVC and then gradually increased. On the other hand, the mean MFPS for EMG clearly increased up to 10% MVC, but then gradually decreased with bite force. CONCLUSION: These findings suggest that the MMG analysis combined with the EMG may be a more useful method for evaluating the status of the masseter muscle.
Asunto(s)
Fuerza de la Mordida , Contracción Isométrica/fisiología , Músculo Masetero/fisiología , Miografía/instrumentación , Adulto , Electromiografía , Humanos , Magnetismo/instrumentación , Masculino , VibraciónRESUMEN
INTRODUCTION: A consensus on the contemporary perception of beauty might have been developed between different countries because of increased worldwide access to variations in pleasing facial profiles. The objectives of this study were to determine, assess, and compare the ranges of values of the most-favored facial profiles rated by young Korean and Japanese adults. METHODS: Average profiles were constructed from the profiles of 30 Japanese men and women with normal occlusions. A series of 13 profiles each was developed for men and women. In the series, the average profile was located in the center (number 7), and the lips were protruded or retruded in 1-mm increments from the average profile. Forty-six Korean dental students and 52 Japanese dental students were asked to rate the top 3 most-favored profiles. RESULTS: Both the Korean and the Japanese dental students tended to select a slightly more retruded lip profile compared with the averages for men and women, and the tendency to prefer a more retruded lip position was evident for the women. CONCLUSIONS: These findings suggest that young Korean and Japanese adults prefer a retruded profile, even though their profiles have historically been characterized by more convex facial features.
Asunto(s)
Belleza , Labio/anatomía & histología , Adulto , Pueblo Asiatico , Cefalometría , Estética Dental , Cara/anatomía & histología , Femenino , Humanos , MasculinoRESUMEN
OBJECTIVE: To determine whether there is an association between temporomandibular joint (TMJ) osteoarthritis/osteoarthrosis (OA) and immune system factors in a Japanese sample. MATERIALS AND METHODS: The records of 41 subjects (7 men, aged 22.0 +/- 3.8 years; 34 women, aged 24.8 +/- 6.3 years) and 41 pair-matched controls (7 men, aged 22.1 +/- 2.3 years; 34 women, aged 24.8 +/- 6.4 years) based on age and gender were reviewed. Information on medical history included local or systemic diseases, details on medication type and use, and the presence of allergies and asthma. Dental history questions referred to details regarding past oral injuries. The validity of the hypothesis, defining allergies and asthma as risk factors in OA, was tested by using a logistic regression analysis. RESULTS: The incidence of allergy was significantly higher in the TMJ OA (P = .008), with a mean odds ratio of 4.125 and a 95% confidence interval of 1.446-11.769. CONCLUSION: These results suggest that allergy may be a risk factor in association with TMJ OA in this Japanese sample.
Asunto(s)
Osteoartritis/inmunología , Trastornos de la Articulación Temporomandibular/inmunología , Adulto , Asma/diagnóstico , Estudios de Casos y Controles , Dermatitis Atópica/diagnóstico , Dermatitis por Contacto/diagnóstico , Enfermedad , Quimioterapia , Femenino , Humanos , Hipersensibilidad/diagnóstico , Japón , Masculino , Anamnesis , Boca/lesiones , Radiografía Panorámica , Rango del Movimiento Articular/fisiología , Hipersensibilidad Respiratoria/diagnóstico , Estudios Retrospectivos , Factores de RiesgoRESUMEN
AIM: To test whether there is a relationship between head and cervical posture and dentofacial morphology in patients with temporomandibular joint osteoarthritis/osteoarthrosis (OA). METHODS: The subjects consisted of 34 Japanese females with TMJ OA (aged 24.7 +/- 6.1 years). Six craniocervical angular measurements were constructed for head posture. Two angular and 6 linear measurements were constructed for the skeletal relationship, while 1 angular and 6 linear measurements were constructed for the dental relationship. Pearson correlation coefficients were calculated between head posture and dentofacial variables. RESULTS: In the skeletal relationship, increased craniocervical angulations were significantly associated with a more posterior position of the maxilla, a decreased Frankfort to mandibular plane angle, decreased mandibular length, and a decreased lower facial height. In the dental relationship, increased craniocervical angulations were significantly associated with more posterior positions of the anterior teeth to the basal bone and decreased alveolar height of the anterior-posterior teeth. CONCLUSION: The hypothesis was rejected. These results suggest that an association may exist between head and cervical posture and dentofacial morphology in patients with TMJ OA.
Asunto(s)
Cabeza/fisiopatología , Desarrollo Maxilofacial , Osteoartritis/fisiopatología , Postura , Trastornos de la Articulación Temporomandibular/fisiopatología , Adulto , Cefalometría , Femenino , Humanos , Maloclusión/fisiopatología , Cuello/fisiopatología , Estudios Retrospectivos , Adulto JovenRESUMEN
The aims of this study were to determine Japanese cephalometric norms in the antero-posterior and vertical dimension, and to test the hypothesis that there are racial differences in cephalometric measurements between Japanese and Caucasian norms. Radiographs were obtained from 25 healthy Japanese males (aged 25.1 +/- 2.7 years) and 24 healthy Japanese females (aged 23.6 +/- 1.3 years). Inclusion criteria were an ANB angle between 2 and 5 degrees, a normal occlusion with minor or no crowding, all teeth present except third molars, no previous orthodontic treatment, and no prosthetic replacement of teeth. Two angular and five linear measurements were constructed for the skeletal hard tissue analysis, one angular and six linear measurements for the dental hard tissue analysis, and two angular and seven linear measurements for the soft tissue analysis. The mean and standard deviations for the hard and soft tissue measurements were determined for each gender. Unpaired t-tests were used to determine the mean differences for each cephalometric measurement between the Japanese and the Caucasians. In the antero-posterior dimension, the Japanese subjects had a significantly more retruded chin position (P < 0.001), typically protruding mandibular incisors, and protruded lip positions compared with the Caucasian norms. In the vertical dimension, the Japanese had a significantly steeper mandibular plane (P < 0.01). The Japanese females had a significantly larger lower face height and increased dental height (P < 0.001). The results of this study suggest that these cephalometric measurements might be helpful to formulate treatment plans for Japanese patients.
Asunto(s)
Pueblo Asiatico/estadística & datos numéricos , Cefalometría/normas , Arco Dental/anatomía & histología , Cara/anatomía & histología , Dimensión Vertical , Adulto , Cefalometría/estadística & datos numéricos , Femenino , Humanos , Incisivo/anatomía & histología , Japón , Masculino , Valores de Referencia , Reproducibilidad de los Resultados , Población Blanca/estadística & datos numéricosRESUMEN
Experimentally, temporomandibular joint (TMJ) nerve units respond to capsaicin, which is used clinically to treat TMJ pain. However, the existence of capsaicin receptors in the TMJ has not previously been clearly demonstrated. Immunohistochemical analysis has revealed the presence of transient receptor potential vanilloid subtype 1 (TRPV1) expression in the nerves and synovial lining cells of the TMJ. TRPV1-immunoreactive nerves are distributed in the synovial membrane of the joint capsule and provide branches to the joint compartment. The disc periphery is supplied by TRPV1 nerves that are mostly associated with small arterioles, and occasional nerves penetrate to the synovial lining layer. Double immunofluorescence has shown that many TRPV1-immunoreactive nerves are labeled with neuropeptide calcitonin gene-related peptide, whereas few are labeled with IB4-lectin. The results provide evidence for the presence of TRPV1 in both nerves and synovial lining cells, which might thus be involved in the mechanism of nociception and inflammation in the TMJ.
Asunto(s)
Canales Catiónicos TRPV/metabolismo , Articulación Temporomandibular/inervación , Animales , Técnica del Anticuerpo Fluorescente Indirecta , Colorantes Fluorescentes , Inmunohistoquímica , Indoles , Masculino , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
The objective of this study was to determine whether there is an association between excessive root resorption and immune system factors in a sample of Japanese orthodontic patients. The records of 60 orthodontic patients (18 males, age 17.7 +/- 5.7 years; 42 females, age 16.4 +/- 6.0 years) and 60 pair-matched controls (18 males, age 15.9 +/- 4.5 years; 42 females, age 18.5 +/- 5.2 years) based on age, sex, treatment duration, and the type of malocclusion were reviewed retrospectively. The validity of our hypothesis was tested using the logistic regression analysis. The pretreatment records revealed that the incidence of allergy and root morphology abnormality was significantly higher in the root resorption group (P = .030 and .001), with a mean odds ratio of 2.794 and 6.317 and 95% confidence interval of 1.107-7.053 and 2.043-19.537, respectively. The incidence of asthma also tended to be higher in the root resorption group. From these results, we concluded that allergy, root morphology abnormality, and asthma may be high-risk factors for the development of excessive root resorption during orthodontic tooth movement in Japanese patients.
Asunto(s)
Asma/complicaciones , Hipersensibilidad/complicaciones , Resorción Radicular/inmunología , Raíz del Diente/anomalías , Adolescente , Pueblo Asiatico , Asma/epidemiología , Métodos Epidemiológicos , Femenino , Humanos , Hipersensibilidad/epidemiología , Masculino , Ortodoncia Correctiva , Resorción Radicular/epidemiología , Raíz del Diente/inmunologíaRESUMEN
OBJECTIVES: To compare the lip positions found in two ancient Buddha statues with the lip positions in contemporary Japanese adults. METHODS: The facial profiles of Yakushi-ji temple Sho Kannon (male) and Chugu-ji temple Bodhisattva (female), generally considered to be two of the most beautiful Buddha statues in existence, were compared with the facial profiles of 30 Japanese dental students. Profiles of the statues were measured on photographs and profiles of the adults on cephalometric radiographs. The adults comprised 15 men between 22 and 26 years of age (Mean age: 23.8+/-1.3 years) and 15 women between 22 to 25 years of age (Mean age: 22.9+/-1.0 years). RESULTS: The Buddha statues had retrusive lips compared with the lip positions in contemporary Japanese adults. CONCLUSION: Flat profiles may be favoured by Japanese adults who, typically, have protrusive lips.