Skeletal and dental changes after maxillary expansion in the mixed dentition

WOS: A1997WN48800016PubMed ID: 9082855The purpose of this study was to compare skeletal and dental aspects of three different expansion methods in the mixed dentition period in sagittal, vertical, and transversal planes, treatment periods, complications, and relapse tendencies in early periods. Patients with unilateral or bilateral posterior crossbites in the mixed dentition were studied. They were divided into three groups of 10 patients in each group. The first group received treatment with removable plates for semirapid maxillary expansion; the second group with quad-helix appliances for slow maxillary expansion; and the third group with conventional fixed hyrax appliances for rapid maxillary expansion (RME). Lateral and posteroanterior cephalometric films, occlusal films, and dental casts were taken before and after expansion, and after retention with the same appliances. Cephalometric and dental cast analyses were made. Both skeletal and dental changes were observed after all three expansion methods

The Prenatal Development of the Human Nasal and Vomeral Bones

WOS: A1994NN74600006PubMed ID: 8071424The purpose of the present study was to establish normal prenatal development standards for the nasal and vomeral bones, both formed by intramembranous ossification in the membrane covering the cartilaginous nasal capsule. The study is based upon a combination of macroscopic (devisceration and radiography) and microscopic (histology) analyses on 62 normal human fetuses from spontaneous and induced abortions, ranging in gestational age from 9 to 24 weeks, representing crown-rump lengths (CRL) from 33 to 225 mm. Special attention was paid to the onset of bone formation in relation to other maturity aspects and to the growth of the bones. The very first onset of ossification of the vomeral bone is observed as two bilateral ossification centers, prior to nasal bone ossification. Later, the two bilateral ossification centers fuse caudally below the cartilaginous nasal septum, thus changing into a U-shaped bone when observed in the coronal plane. By bony apposition caudally the U-shaped vomer gradually changes into a Y-shape. The nasal bone appears as a thin bony contour ventral to the cartilaginous nasal septum in the sagittal plane, and changes gradually during growth to a wedge-shaped bone. Knowledge of the early development of the internal nose (vomeral bone) and external nose (nasal bone) is significant in understanding mid-face congenital malformations

Atlas Morphology In Relation To Craniofacial Morphology and Head Posture

WOS: A1994NK52700002PubMed ID: 8005204The associations between dimensions of the first cervical vertebra, atlas, and a representative set of craniofacial and postural variables were studied on cephalometric radiographs of a sample of 103 adult males aged 22-30 years, recorded in the natural head position (mirror.position). Atlas morphology was expressed by nine variables, linear and angular craniofacial dimensions by 27 variables, and head and cervical posture by seven variables. A pattern of low but significant correlations was found. Although the correlations were low, the study confirmed that the dimensions of the atlas vertebra reflect associations between cranio-cervical posture and craniofacial morphology. Negative correlations were found between the height of the posterior arch of atlas and the inclination of the mandible and the maxilla to the anterior cranial base. Low positive correlations between the height of the anterior arch and vertical facial dimensions reflect the general co-ordination of the vertical growth of the face and the cervical column. Moreover, the pattern of correlations between the atlanto-cranial angle and facial morphology suggests that in changes of the cranio-cervical angle, atlas follows the cervical column