A novel CAD/CAM composite occlusal splint for intraoperative verification in single-splint two-jaw orthognathic surgery.

BACKGROUND: Previous computer-generated splints were designed and produced without modification than the traditional occlusal splints, which did not facilitate surgeon's intraoperative judgment in the single-splint two-jaw orthognathic surgery. Modifications of the digital occlusal splint can be achieved using computer-aided design and computer-aided manufacturing (CAD/CAM) software. This study reported the design, clinical application and validation of a novel CAD/CAM occlusal splint. METHODS: The maxillary and mandibular segments were fixed into the final occlusal splint and moved to the planned position according to the 3-dimensional simulation. The composite occlusal splint has 4 orthogonal bars to facilitate intraoperative assessment of the dental and skeletal midline, facial soft tissue midline, occlusal plane, upper tooth show, facial symmetry and facial bone position. To validate the surgical outcome, 5 parameters including pitch, roll and yaw rotations, midline deviation and chin position were measured on the virtual plan and the postoperative cone-beam computed tomography images to quantify the difference. RESULTS: The results showed no significant differences in the 5 parameters between the simulation and postoperative images. The root-mean-square difference between the conventional splints and CAD/CAM surgical splint ranged from 0.18 to 0.31 mm by superimposition of the two image models. All patients were satisfied with the treatment outcomes. Overall, this novel occlusal splint is ideal for verification of the maxillomandibular position during surgery. CONCLUSION: The novel composite occlusal splint provided useful and informative check to verify the maxillomandibular complex (MMC) position and facial appearance in single-splint two-jaw orthognathic surgery.

NAM-help or burden? Intercultural evaluation of parental stress caused by nasoalveolar molding: a retrospective multi-center study.

OBJECTIVES: Nasoalveolar molding (NAM) was developed to facilitate easier treatment and better outcomes for cleft lip and palate (CLP) patients. The aim of this study was to investigate the parental burden and possible intercultural differences of this treatment modality, which is often argued to burden parents to an extraordinary amount. MATERIALS AND METHODS: Standardized questionnaires (available in English, Mandarin, and German) with 15 non-specific and 14 NAM-specific items to be retrospectively answered by Likert scales by parents of unilateral CLP patients with completed NAM treatment. RESULTS: The parents of 117 patients from two treatment centers in Taiwan and Germany were included. A very high level of overall satisfaction was found in both countries with significant intercultural differences in prenatal parent information, feeding problems, dealing with 3rd party's perception, and experienced personal effort. CONCLUSION: NAM is an effective treatment tool for children's CLP deformities and their caregivers in overcoming the feeling of helplessness. Intercultural differences may be due to infrastructural reasons, cultural attitudes and habits, or different public medical education. CLINICAL RELEVANCE: In addition to facilitating easier surgical treatment, NAM can be seen as a powerful coping strategy for parents dealing with a CLP deformity of their child and does not seem to burden them extraordinarily.

Fat Grafting in Patients With Extensive Unilateral Facial Deficiency: Three-Dimensional Computer-Assisted Planning, Implementation, and Outcome Assessment.

PURPOSE: Autologous fat injection is a widely used, simple, and less invasive technique to correct volume deficiency. This study developed a treatment method by using a 3-dimensional (3D) simulation to plan and implement fat injection in patients with an extensive facial deficiency and then validated the accuracy of the method and treatment outcomes. METHODS: Seven patients with a large unilateral facial deficiency receiving autologous fat grafts between 2015 and 2017 were recruited. One patient received repeated treatment. Furthermore, 3D surgical simulation was used to measure the difference between the mirrored image and lesion side. An extra 20% to 30% of fat graft was added. A color map was provided, and contour lines 2 mm deep marked the location of the fat injection. Outcome assessments were then performed, and a 3D symmetry index was defined using the contour lines on the facial surface. RESULTS: No significant difference was noted between the predicted volume and postoperative fat graft retention (35.7 ± 7.4 and 31.6 ± 9.7 mL, respectively; P = 0.176). A comparison of preoperative (79.5% ± 4.3%) and postoperative (89.0% ± 3.3%) 3D symmetry indexes indicated significantly improved facial symmetry (P = 0.018). Patient-reported outcomes of satisfaction on FACE-Q questionnaires yielded an average score of 62.73, higher than the control score (59.83). CONCLUSIONS: By using the proposed method, we could predict the required fat graft volume; moreover, the contoured map aided accurate surgical implementation. Thus, this method is useful for planning and guiding fat grafting treatment in patients with major unilateral facial deficiency.

Customized Three-Dimensional Printing Spacers for Bone Positioning in Orthognathic Surgery for Correction and Prevention of Facial Asymmetry.

Orthognathic surgery is a powerful tool for correction of facial asymmetry and malocclusion. The goal is to achieve good dental function and facial aesthetics. Three-dimensional simulation is used for surgical planning, and bone gaps could be created to achieve facial balance. In this study, customized "spacers" were made using computer-aided design and three-dimensional printing for guides for use during surgery. With the final three-dimensional plan, the skull images were exported to 3-Matic software, where spacers were designed according to the bone gaps. Three-dimensionally-printed spacers were made and used to facilitate positioning and fixation. Consecutive patients with facial asymmetry were recruited in this prospective study. The postoperative outcome was assessed using a visual analogue scale and the three-dimensional facial surface area discrepancy index for subjective and objective evaluation. There were 12 patients and a total of 19 spacers for the Le Fort I and mandibular ramus segments. The spacers worked nicely during the bone fixation process. Mean preoperative and postoperative visual analogue scale scores were 4.83 and 7.14, with a statistically significant improvement for facial symmetry (p = 0.018). Mean preoperative and postoperative facial surface area discrepancy index was 0.95 and 0.98, and the correction of asymmetry was significant (p = 0.009). There were no related surgical complications. All patients were satisfied with the correction of facial asymmetry and malocclusion. The custom-made, three-dimensionally-printed spacers help to achieve surgical precision to correct and prevent facial asymmetry in orthognathic surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

Higher Dose of Dexamethasone Does Not Further Reduce Facial Swelling After Orthognathic Surgery: A Randomized Controlled Trial Using 3-Dimensional Photogrammetry.

PURPOSE: The objective of this prospective, double-blind, randomized clinical trial was to compare the effect of 2 dexamethasone dosages on reducing facial swelling after orthognathic surgery through 3-dimensional (3D) photogrammetry. PATIENTS AND METHODS: Patients were classified into group 1 (control group) and group 2 (study group), depending on the administered dexamethasone dosage (5 and 15 mg, respectively). Three-dimensional images were recorded at 5 time points: preoperative (T0) and postoperative at 48 ± 6 hours (T1), 1 week (T2), 1 month (T3), and 6 months (T4). A preliminary study was performed on 5 patients, in whom 3D images were captured at 24, 36, 48, and 60 hours postoperatively to record serial changes in facial swelling. Facial swelling at T1, T2, and T3 and the reduction in swelling at T2 and T3 compared with that at the baseline (T4) were calculated. Possible complications, namely, adrenal suppression, wound dehiscence, wound infection, and postoperative nausea and vomiting were evaluated. RESULTS: In total, 68 patients were enrolled, of whom 25 patients in group 1 and 31 patients in group 2 were eligible for final evaluation. No significant differences were found between the 2 groups at any period. On average, the swelling subsided by 86% at 1 month after the orthognathic surgery. Facial swelling peaked approximately 48 hours after the surgery. The incidence of nausea and vomiting did not differ significantly between the groups. CONCLUSIONS: The effect of 5 and 15 mg of dexamethasone on facial swelling reduction as well as on nausea and vomiting after orthognathic surgery was not significantly different.