RESUMEN
The nonapeptides oxytocin and vasopressin have been implicated in a variety of social behaviors. In zebra finches, oxytocin antagonists decrease pairing in both sexes, and pairing, in turn, increases expression of both mesotocin (the avian homologue of oxytocin) and vasotocin (the avian homologue of vasopressin). Increases in mesotocin and vasotocin mRNA are correlated with the amount of directed singing by males. Thus, in the present study, we examined the hypothesis that activation of cells containing nonapeptide receptors in song-related regions (ventral tegmental area, lateral septum, and medial preoptic nucleus) would also be correlated with directed singing in males. To rule out the possibility that these regions are involved in general pairing motivation, we also included females as subjects. In the ventral tegmental area, males had higher ZENK and V1aR than females and paired animals (regardless of sex) had higher ZENK and V1aR than did unpaired animals. In the medial preoptic nucleus, paired animals had higher ZENK than did unpaired animals, and there were no sex or pairing effects in the lateral septum. Only ZENK + V1aR in the medial preoptic nucleus was correlated with singing in males. These findings suggest that pairing is associated activation of nonapeptide receptors in the ventral tegmental area and the medial preoptic nucleus, but there is only partial evidence that courtship singing accounts for these findings. (PsycINFO Database Record
Asunto(s)
Pinzones/fisiología , Antagonistas de Hormonas/farmacología , Motivación , Música , Apareamiento , Conducta Social , Agresión/fisiología , Animales , Femenino , Masculino , Oxitocina/análogos & derivados , VasotocinaRESUMEN
INTRODUCTION: During facial growth, the maxilla and mandible translate downward and forward. Although the forward displacement of the maxilla is less than that of the mandible, the interarch relationship of the teeth in the sagittal view during growth remains essentially unchanged. Interdigitation is thought to provide a compensatory (tooth movement) mechanism for maintaining the pattern of occlusion during growth: the maxillary teeth move anteriorly relative to the maxilla while the mandibular teeth move posteriorly relative to the basilar mandible. The purpose of this study was to investigate the hypothesis that the human chin develops as a result of this process. METHODS: Twenty-five untreated subjects from the Iowa Facial Growth Study with Class I normal occlusion were randomly selected based on availability of cephalograms at T1 (mean = 8.32 yr) and T2 (mean = 19.90 yr). Measurements of growth (T2 minus T1) parallel to the Frankfort horizontal (FH) for the maxilla, maxillary dentition, mandible, mandibular dentition, and pogonion (Pg) were made. RESULTS: Relative to Pg (a stable bony landmark), B-point moved posteriorly, on average 2.34 mm during growth, and bony chin development (B-point to Pg) increased concomitantly. Similarly, the mandibular and maxillary incisors moved posteriorly relative to Pg 2.53 mm and 2.76 mm, respectively. A-point, relative to Pg, moved posteriorly 4.47 mm during growth. CONCLUSIONS: Bony chin development during facial growth occurs, in part, from differential jaw growth and compensatory dentoalveolar movements.
Asunto(s)
Mentón/crecimiento & desarrollo , Mandíbula/crecimiento & desarrollo , Maxilar/crecimiento & desarrollo , Proceso Alveolar/crecimiento & desarrollo , Cefalometría , Niño , Arco Dental/crecimiento & desarrollo , Oclusión Dental , Dentición , Femenino , Estudios de Seguimiento , Humanos , Incisivo/anatomía & histología , Masculino , Mandíbula/anatomía & histología , Cóndilo Mandibular/anatomía & histología , Maxilar/anatomía & histología , Diente Molar/anatomía & histología , Hueso Nasal/anatomía & histologíaRESUMEN
INTRODUCTION: Headgears have been used to treat Class II malocclusions for over a century. The purpose of this retrospective study was to investigate the profile esthetic changes resulting from headgear use in growing Class II patients with protrusive, normal, and retrusive maxillae. METHODS: Profile silhouettes were created from pretreatment and posttreatment lateral cephalometric tracings of growing Class II patients treated with headgear followed by conventional fixed appliances. Ten patients had an initially protrusive maxilla (FH:NA, >92°), 10 had an initially normally positioned maxilla (FH:NA, 88°-92°), and 10 had an initially retrusive maxilla (FH:NA, <88°). A panel of 20 laypersons judged the profile esthetics of the randomly sorted silhouettes. Descriptive statistics, correlation analysis, and anlaysis of variance (ANOVA) with post-hoc Tukey-Kramer tests were used to ascertain differences between groups and the effects of treatment. RESULTS: A significant moderate correlation was found between initial ANB magnitude and the improvement in profile esthetic score with treatment (r = 0.49, P <0.01). No significant correlations were found between the initial anteroposterior position of the maxilla (FH:NA) and the initial, final, or change in profile esthetic scores. There were average improvements with headgear treatment in profile esthetics for all groups. CONCLUSIONS: In Class II growing patients with protrusive, normally positioned, or retrusive maxillae, headgear treatment used with fixed orthodontic appliances is effective in improving facial profile esthetics: the greater the initial ANB angle, the greater the profile esthetic improvement with treatment.
Asunto(s)
Estética Dental , Aparatos de Tracción Extraoral , Maloclusión Clase II de Angle/terapia , Maxilar/patología , Análisis de Varianza , Cefalometría/estadística & datos numéricos , Niño , Cara/anatomía & histología , Humanos , Desarrollo Maxilofacial , Prognatismo , Retrognatismo , Estudios Retrospectivos , Estadísticas no Paramétricas , Resultado del TratamientoRESUMEN
INTRODUCTION: Herbst and headgear appliances are considered effective for correcting Class II malocclusions in growing patients, although their skeletal and dental effects differ. In the literature, there is no comparison between profile esthetic outcomes with the Herbst and headgear. The purpose of this study was to provide that comparison. METHODS: Lateral cephalometric radiographs of 48 matched pairs of growing Class II Division 1 patients treated with either the Herbst appliance or headgear (both combined with fixed appliances) were used to generate pretreatment and posttreatment standardized silhouettes. The silhouettes were randomly arranged and judged by lay people and orthodontic residents using a 7-point Likert scale. Statistical analyses including nonparametric procedures and intraclass correlation were used to compare initial, final, and change profile esthetic scores for the 2 groups of subjects and agreement between evaluators. RESULTS: Both groups of subjects had significant profile improvements with treatment (P <.05), and there were no statistically significant differences between the groups in average final profile scores. Overall, there was strong agreement between the evaluations of laypersons and orthodontic residents. CONCLUSIONS: Class II Division 1 growing patients treated with either Herbst appliance or headgear (both combined with fixed appliances) will benefit from significantly improved profiles that are equally attractive.