Reliability of digital orthodontic setups.

OBJECTIVE: To evaluate the reliability of digital orthodontic setup technology by comparing it with manual setups and models cast at the end of orthodontic treatment. MATERIALS AND METHODS: Initial models, manual setups, and final models of 20 patients were used. The initial and final models, as well as the manual setups, were scanned using a 3Shape R-700 scanner, while the digital setups were fabricated based on the initial models using 3Shape OrthoAnalyzer software. Evaluation of the models based on the manual setup, digital setup, and final models of each patient was performed using the following linear measurements: intercanine widths, intermolar widths, and length of the upper and lower dental arches. RESULTS: The results disclosed that none of the measures assessed through the manual setup, digital setup, and final models showed statistically significant differences (P > .05). CONCLUSIONS: Based on these findings, it can be inferred that digital setups are as effective and accurate as manual setups and constitute a tool for diagnosing and treatment planning that can be reliably reproduced in orthodontic treatments.

How the lower face soft tissue changes after mandibular advancement or setback.

To contribute as an auxiliary tool for orthodontic and orthognathic planning and treatment, short-term changes on the lower face soft and hard tissues were investigated. All subjects presented adequate maxillary relation with the cranial base. The treatment was done by mandibular advancement in patients with skeletal class II or setback in skeletal class III, by the same oral surgeon, using the same technique, and rigid internal fixation. Lateral cephalograms were traced at the following intervals: T0--immediately before the surgical procedure, T1--6 months after surgery, and T2--1 year after surgery. The postoperative data of the lower face revealed highly significant changes for the soft tissue pogonion and lower lip, in the mandible advancement cases, whereas the underlying bone and dental structures remained constant. For the mandible setback cases, just the hard tissue pogonion variable displayed a statistically significant change.

A protocol for cranial base reference in cephalometric studies.

Establishment of the cranial base references and the coordinate system is important for measurement of events occurring on the face. The literature suggests that the horizontal axis is obtained by tracing a line in clockwise direction at seven degrees from the Sella-Nasion line, and the vertical axis is perpendicular to this former axis passing through the Sella point. However, could this standardization better represent the angle between the Sella-Nasion line and Frankfort Horizontal Plane in a Brazilian population and be employed in cephalometric studies? Thus, the present study had two purposes: to identify the cranial base inclination in adult patients presenting with intermaxillary anteroposterior skeletal disharmony and to evaluate the reliability of a protocol to reproduce the cranial base reference. Lateral cephalograms of three different times were traced: T0) onset of orthodontic treatment and immediately before the orthognathic surgery, T1) six months after surgery, and T2) one year after surgery. The results displayed a mean cranial base inclination of 7.91 degrees. Variation of the intraindividual data allowed the conclusion that the protocol proposed by utilization of an individual template of the cranial base reference was effective for the exactness of measurements in cephalometric studies.