Sex and pairing status explain variations in the activation of nonapeptide receptors in song and motivation regions.

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.

Chin development as a result of differential jaw growth.

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.

Effect of maxillary anteroposterior position on profile esthetics in headgear-treated patients.

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.

Comparison of soft-tissue profiles after treatment with headgear or Herbst appliance.

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.