A cone-beam computed tomography triple scan procedure to obtain a three-dimensional augmented virtual skull model appropriate for orthognathic surgery planning.

The aim of this study was to present a new approach to acquire a three-dimensional virtual skull model appropriate for orthognathic surgery planning without the use of plaster dental models and without deformation of the facial soft-tissue mask. A "triple" cone-beam computed tomography (CBCT) scan procedure with triple voxel-based rigid registration was evaluated and validated on 10 orthognathic patients. First, the patient was scanned vertically with a wax bite wafer in place (CBCT scan No1).

Nasal profile changes after maxillary impaction and advancement surgery.

Purpose: The profile changes in the nasal tip and columello-labial region that occur after maxillary advancement and impaction surgery were measured to test the hypothesis that a subspinal osteotomy would induce less nasal tip change and would result in a more acute columello-labial angle than a conventional Le Fort I-type osteotomy.

Patients And Methods: The lateral cephalograms of 2 matched groups of 23 advancement/impaction cases with and without subspinal osteotomy were analyzed electronically.

Results: There was no difference in nasal tip elevation and change in nasal tip projection between the 2 groups.

Performance degradation of the coherent averaging technique by a molding effect.

In coherent averaging, we show that when temporal alignment is performed by matched filtering, the SNR improvement may reach a stable limit after a certain number of averaged events. The source of this degradation lies in the noise that can be contained in the template of the matched filter. This effect depends on the SNR and the morphology of the signal and it can be reduced by a multipass averaging procedure or by a template updating technique.

Monitoring the specific activities of dopamine and its metabolites in striatum and olfactory tubercle after intravenous administration of l-[(3)H]tyrosine: Complex relations, indicating more than two compartments.

It is still a matter of debate whether in dopaminergic nerve endings dopamine (DA) is present in different functional and/or metabolic compartments. To investigate this, DA metabolism was studied in vivo by measuring the specific activity of DA and its metabolites after intravenous administration of l-[3,5-(3)H]tyrosine (200 ?Ci/rat) to freely moving animals. The incorporation of (3)H into DA and metabolites was determined in striatum and olfactory tubercle at 5, 10, 20, 40, 60 and 80 min after [(3)H]tyrosine administration.