Evaluation of the Accuracy of Virtual Planning in Orthognathic Surgery: A Morphometric Study.

BACKGROUND: The purpose of this study was to prospectively test the accuracy of computer-aided orthognathic surgery comparing the virtual surgical planning with the three-dimensional (3D) outcome. METHODS: Patients that underwent computer-assisted orthognathic surgery were retrospectively evaluated. The postoperative results were compared with the surgical plan, superimposing the postoperative computed tomography (CT) scan onto the virtual plan. Surface-based superimpositioning of the postoperative CT scan onto the 3D preoperative plan was carried out to visualize the discrepancy between preoperative virtual plan and postoperative 3D CT result. RESULTS: A total of 17 consecutive patients that underwent two-jaw computer-assisted orthognathic surgery were enrolled in the study.The average linear differences for selected points were <1 mm in 12 patients out of 17. In 5 patients out of 17, the average differences for selected points were <2 mm. CONCLUSIONS: An overall high degree of accuracy between the virtual plan and the postoperative result was found.

Accuracy of splint vs splintless technique for virtually planned orthognathic surgery: A voxel-based three-dimensional analysis.

PURPOSE: This study compared two transferring methods for virtually planned orthognathic surgery - the CAD/CAM intermediate splint and the customized surgical guide with fixation plates. METHODS: This was a prospective clinical study in which participants were consecutively recruited and underwent bimaxillary orthognathic surgery. They were divided into two groups based on the transferring method used. The pre- and postoperative CBCTs were aligned using voxel-based landmark-free registration, and the discrepancies for selected points were compared with the planned displacement of the virtually planned surgery. The maxilla and mandible were analyzed separately, and translation and rotation movements were considered. RESULTS: A total of 16 patients, divided into two groups of eight patients each, were included in this study. The splintless group was significantly more accurate for the translation movement along the x-axes for points A (p = 0.008; mean absolute error 0.527 ± 0.387 for the splint group and 0.137 ± 0.067 for the splintless group) and Ans (p = 0.045; mean absolute error 0.535 ± 0.446 for the splint group and 0.156 ± 0.002 for the splintless group). For the mandible there was a significant difference in accuracy along the x-axes for points B (p = 0.049; mean absolute errors 1.728 ± 1.181 and 0.697 ± 0.519 for the splint and splintless groups, respectively), LL3 (p = 0.049; mean absolute error 1.629 ± 0.912 and 0.851 ± 0.797 for the splint and splintless groups, respectively), LR3 (p = 0.049; mean absolute error 1.711 ± 0.906 and 0.844 ± 0.780 for the splint and splintless groups, respectively), with the splintless group being more accurate. For the rotation the splintless group was significantly more accurate along the y-axes (p = 0.04; mean absolute error 1.62 ± 0.78 and 0.49 ± 0.31 for the splint and splintless groups, respectively) and z-axes (p = 0.04; mean absolute error 0.63 ± 0.45 and 0.17 ± 0.05 for the splint and splintless groups, respectively) for the maxilla, while no significant difference was found for the mandible. CONCLUSIONS: Overall, the customized fixation plate system is more accurate than the intermediate CAD/CAM splint for transferring the virtual plan into the operation room.

A hydrosilver gel for plaque control in adults affected by chronic periodontitis: Effects on the 'red complex' bacterial load. A prospective longitudinal pilot study using polymerase chain reaction analysis.

In subjects affected by chronic periodontitis, the chemical control of plaque is a strategy aiming primarily at controlling infection and bacterial loading. The aim is to evaluate the bacterial loading of the so-called 'red complex' associated with a short-term use of a hydrosilver gel (HSG) by using an in vivo model in adult subjects affected by chronic periodontitis. This prospective short-term clinical trial involved 10 adult volunteers using a 15-day in vivo model. After receiving professional prophylaxis at baseline (t0), each volunteer performed daily applications of HSG at home. After 15 days (t1) from the first application, subgingival plaque samples were collected, and the bacterial loading of species belonging to the red complex was evaluated using polymerase chain reaction (PCR) analyses. The bacterial loading of the red complex showed no statistically significant difference between t0 and t1, although it tended to decrease. HSG can be used at home as an adjunct to domestic oral care because it seems a promising tool, but further studies are needed to involve a larger sample and a longer follow-up.

Use of CAD-CAM technology to improve orthognathic surgery outcomes in patients with severe obstructive sleep apnoea syndrome.

INTRODUCTION: Although multilevel surgery is the mainstay treatment for severe obstructive sleep apnoea syndrome (OSAS), bi-maxillary surgery (maxillomandibular advancement [MMA]) is the most efficacious single procedure for the expansion of the whole pharyngeal airway. MMA is an alternative to the gold standard of continuous positive airway pressure and is equivalent to tracheotomy. PATIENTS AND METHOD: Computer-aided design/computer-aided manufacturing (CAD-CAM) technology was used to virtually assess the degree of mandibular and/or maxillary advancement and rotation required to obtain adequate posterior airway space (PAS) in eight patients (seven males, one female). The mean age of the patients was 45.5 years (range, 27-51 years), and the average body mass index was 28.9 kg/m2 (range, 21.9-31.8 kg/m2). RESULTS: The study group showed significant mandibular advancement, widening of the PAS, and reduction of the apnoea hypopnea index (p < 0.0001, p < 0.0001, and p < 0.0002, respectively). Moreover, patient satisfaction scores regarding postoperative facial profile changes showed excellent compliance. CONCLUSION: This study demonstrated that bi-maxillary surgery is an efficient single surgical procedure in patients with multilevel OSAS. CAD-CAM technology aided surgeons in performing this operation precisely and enabled patients to expect specific facial profiles.