Video-imaging and treatment presentation: medico-legal implications and patient perception

Accuracy of three-dimensional soft tissue predictions in orthognathic surgery after Le Fort I advancement osteotomies

Prediction of postoperative facial appearance after orthognathic surgery can be used for communication, managing patients' expectations,avoiding postoperative dissatisfaction and exploring different treatment options. We have assessed the accuracy of 3dMD Vultus in predicting the final 3-dimensional soft tissue facial morphology after Le Fort I advancement osteotomy. We retrospectively studied 13 patients who were treated with a Le Fort I advancement osteotomy alone. We used routine cone-beam computed tomographic (CT) images taken immediately before and a minimum of 6 months after operation, and 3dMD Vultus to virtually reposition the preoperative maxilla and mandible in their post operative positions to generate a prediction of what the soft tissue would look like. Segmented anatomical areas of the predicted mesh were then compared with the actual soft tissue. The means of the absolute distance between the 90th percentile of the mesh points for each region were calculated, and a one-sample Student's t test was used to calculate if the difference differed significantly from 3 mm.The differences in the mean absolute distances between the actual soft tissue and the prediction were significantly below 3 mm for all segmented anatomical areas (p < 0.001), and ranged from 0.65 mm (chin) to 1.17 mm (upper lip). 3dMD Vultus produces clinically satisfactory 3-dimensional facial soft tissue predictions after Le Fort I advancement osteotomy. The mass-spring model for prediction seems to be able to predict the position of the lip and chin, but its ability to predict nasal and paranasal areas could be improved.

Surgical prediction of skeletal and soft tissue changes in Class III treatment

PURPOSE

The purpose of this study was to study the treatment outcomes and accuracy of the digital prediction using Dolphin Imaging Software and the actual postoperative outcome in subjects presenting Class III malocclusions.

MATERIALS AND METHODS

Maxillary advancement surgery was performed in group 1, and maxillary advancement was combined with mandibular setback surgery in group 2. Predictive cephalometric tracings were made using Dolphin Imaging Software.

RESULTS

Before surgery, the maxillary deficiency was significantly greater in group 1 than in group 2, and the mandibular length was significantly greater in group 2. Surgical reductions in mandibular length and angle were significantly greater 12 months after surgery than indicated by the predictive cephalometric tracings.

CONCLUSION

In groups 1 and 2, maxillary advancement surgery was performed in accordance with the Dolphin Imaging Software. The mandibular setback surgery performed was beyond the established plan, but without clinical implications. Mandibular dentoskeletal measurements showed a greater correlation with the profile than the maxillary measurements.

Soft tissue profile changes following mandibular advancement surgery: predictability and long-term outcome

The objectives of this cephalometric study were to assess long-term changes in the soft tissue profile following mandibular advancement surgery and to investigate the relationship between soft tissue and hard tissue movements. The sample consisted of 61 patients treated consecutively for mandibular retrognathism with orthodontic therapy combined with bilateral sagittal split osteotomy and rigid fixation. Lateral cephalograms were taken on 6 occasions: immediately before surgery, immediately after surgery, 2 and 6 months after surgery, and 1 and 3 years after surgery. Postsurgical changes in the upper and the lower lips and the mentolabial fold were more pronounced among low-angle cases compared with high-angle cases. In accordance with other studies, the soft tissue chin and the mentolabial fold were generally found to follow their underlying skeletal structures in a 1:1 ratio. Because of the strong influence skeletal relapse has on soft tissue profile changes, alternative ratios of soft tissue-to-hard tissue movement that accounted for mean relapse were also generated. It is suggested that if a more realistic long-term prediction of the postsurgical soft tissue profile is desirable, then ratios incorporating mean relapse should be used rather than estimates based on a 1:1 relationship.