Are Virtually Designed 3D Printed Surgical Splints Accurate Enough for Maxillary Reposition as an Intermediate Orthognathic Surgical Guide.

Background and Aim: The accuracy of the virtually-designed 3D-printed surgical splints requires investigation for the practical use of surgical plan in the operating room. This study aimed to compare the validity of the 3D-printed and the conventional intermediate splints and evaluate the outcomes after the surgical application of the 3D-printed splint compared with the predicted values. Methods: In this study, ten patients with dentofacial deformity were recruited. Participants were analyzed by the conventional surgical planning and virtual surgical planning. The intermediate surgical splints were created by the conventional and 3D-printing methods. Maxillary movements in 3 spatial directions were measured in an articulator after the application of both splints. Correlation and agreement between the two methods were tested by intraclass correlation coefficient (ICC). After the confirmation of 3D printed splint validity for each patient, the surgery was performed using 3D printed splints. It is assumed that ideally cephalometric prediction values are going to be obtained using conventional acrylic splints (gold standard). So, as a second objective, the outcome of the surgically-applied 3D-printed splint was evaluated and compared with the predicted values and finally analyzed by the paired t-test. Results: Based on the observations, there was an excellent agreement between the virtually-designed 3D-printed and conventional intermediate surgical splints (ICC ranged between 0.83 and 0.99 for linear values). There was a good cumulative agreement of ICC greater than 0.80. Overall, the mean linear measurements were not different between conventional and 3D-printed splint on the articulator. Also, there were no significant differences between the linear and angular measurements of 2D-cephalometric prediction and postoperation values. Conclusion: The results showed cautiously the acceptable accuracy of the 3D-printed splints for several parameters in three spatial dimensions within the laboratory and clinical settings.

Management of the Cephalic Positioning of the Lower Lateral Cartilage in Modern Rhinoplasty: An Algorithmic Approach.

Cephalic positioning of lateral cruras literally means that the cartilage does not support the nasal rim. Cephalic positioning is a relatively common anatomic variant of lower lateral cartilages that shows an extremely vulnerable rhinoplasty patient. In these patients, any reductive technique, such as cephalic trimming without compensation, worsens the situation and may lead to esthetic failures and airway compromise. True cephalic malpositioning needs to be diagnosed from pseudomalpositions preoperatively. The presence of the pseudomalposition does not mean that it can be ignored. Either malposition or pseudomalposition is best diagnosed and considered in the treatment plan.