Relation Between Masticatory Performance and Skeletal Properties in Patients With Skeletal Class III Malocclusion.

This study aimed to measure masticatory performance (MP) using ß-carotene gummy jelly to investigate its relationship with skeletal properties in decompensated patients diagnosed with skeletal class III malocclusion. The study included 78 patients (38 men and 40 women) diagnosed with skeletal class III malocclusion without temporomandibular joint disorder and periodontal disease. MP was measured using a new masticatory measuring device and ß-carotene in the gummy jelly. Lateral and posteroanterior cephalograms were obtained, and skeletal properties (Me deviation, ANB, SNB, APDI, Wits, ODI, facial axis, body length, ramus length, SN-GoGn, anterior facial height, posterior facial height, saddle angle, articular angle, and gonial angle) were evaluated. MP differences according to age and sex and the effect of skeletal properties on MP were analyzed using multiple linear regression analysis. The MP of all patients was 3690.55±1428.77 mm², MP of the male group was 4043.05±1498.09 mm², and MP of the female group was 3355.68±1272.19 mm². Among the items investigated, the variable that affected MP was posterior facial height. Posterior facial height showed a positive correlation (P=0.022). There was no significant difference between MP and other skeletal properties (P>0.05). The severity of the hypodivergency in skeletal class III could affect MP. The relationship between facial asymmetry or skeletal relation and MP could not be explained in this study.

Reconstruction of maxillofacial bone defects using patient-specific long-lasting titanium implants.

The objective of this retrospective study is to verify the effectiveness and safety of patient-specific titanium implants on maxillofacial bones, with a long-term follow-up. Total 16 patients with various maxillofacial defects underwent reconstruction using patient-specific titanium implants. Titanium implants, manufactured by electron beam melting, selective laser sintering, or milling, were inserted into the maxilla, mandible, or zygoma. Long-term follow-up (36.7 ± 20.1 months) was conducted after the surgery. Bone fusion of the titanium implant body, postoperative infection, implant malunion, functional results, patient satisfaction, subsidence, osteolysis around the implants, and complications were recorded and analyzed at the last follow-up. Of the 28 implants, only one failed to unite with the bone; therefore, revision surgery was performed. No osteolysis or subsidence around the titanium implants nor adverse events were observed; the mean VAS score for satisfaction was 9. All patients enrolled in this trial were esthetically and functionally satisfied with their surgical results, and fixation failure and esthetic dissatisfaction complications were well resolved. Patient-specific titanium showed satisfactory outcomes when used to treat various oral and maxillofacial defects. A 3D printed titanium implant can be effectively used in the reconstruction of the zygoma and mandible instead of autogenous bone without donor site morbidity.

A Clinical Trial to Evaluate the Efficacy and Safety of 3D Printed Bioceramic Implants for the Reconstruction of Zygomatic Bone Defects.

The purpose of this study was to evaluate the clinical efficacy and safety of patient-specific additive-manufactured CaOSiO2-P2O5-B2O3 glass-ceramic (BGS-7) implants for reconstructing zygomatic bone defects at a 6-month follow-up. A prospective, single-arm, single-center, clinical trial was performed on patients with obvious zygoma defects who needed and wanted reconstruction. The primary outcome variable was a bone fusion between the implant and the bone evaluated by computed tomography (CT) at 6 months post surgery. Secondary outcomes, including implant immobilization, satisfaction assessment, osteolysis, subsidence of the BGS-7 implant, and safety, were assessed. A total of eight patients were enrolled in the study. Two patients underwent simultaneous reconstruction of the left and right malar defects using a BGS-7 3D printed implant. Cone beam CT analysis showed that bone fusion at 6 months after surgery was 100%. We observed that the average fusion rate was 76.97%. Osteolysis around 3D printed BGS-7 implants was not observed. The mean distance displacement of all 10 implants was 0.4149 mm. Our study showed no adverse event in any of the cases. The visual analog scale score for satisfaction was 9. All patients who enrolled in this trial were aesthetically and functionally satisfied with the surgical results. In conclusion, this study demonstrates the safety and promising value of patient-specific 3D printed BGS-7 implants as a novel facial bone reconstruction method.

Comparison of Lip Line Cant Change After 1-Jaw and 2-Jaw Surgery.

OBJECTIVES: The purpose of this study was to compare the lip line cant (LLC) changes after 1 and 2-jaw surgery, and to evaluate the correlations of the craniofacial factors affecting LLC. METHODS: The study subjects were selected (LLC amount within 1.5-6.0°) from among the patients diagnosed with Class III malocclusion who underwent one (n = 20) or 2-jaw surgery (n = 20). Cone beam computed tomography images were obtained immediately before the operation (T1) and 6 months after the operation (T2). Preoperative and postoperative craniofacial measurements were obtained. RESULTS: The study subjects showed 3.12° LLC on average before undergoing 1-jaw surgery, and their LLC changed to 1.27° after the surgery. As for 2-jaw surgery, the subjects showed 3.38° LLC on average before the surgery and 0.98° after the surgery. LLC at pre-treatment may be more affected by a cant of the occlusal plane in the mandible than maxilla. In the comparison of the value of changes of LLC, the value of 2-jaw surgery was bigger than the value of 1-jaw surgery but the difference was statistically insignificant. LIMITATIONS: This study had a limitation in that the muscles were not considered. And the metal bracket or metal crown and bridge, however, can cause noise and blurring artifacts in CT, which can lead to a low resolution. And the limited number of the patients should be considered. CONCLUSIONS: In correlation analysis, both pre-surgery LLC and change of LLC have correlation with almost all the craniofacial measurement. Lip-line cant of patients with facial asymmetry has higher correlation with mandibular cant than with other cants. To improve the LLC, a surgical plan should be established to minimize the mandibular cant using the computer simulation as well as the maxillary cant.

Correction to: The structural changes of pharyngeal airway contributing to snoring after orthognathic surgery in skeletal class III patients.

[This corrects the article DOI: 10.1186/s40902-017-0120-6.].

The structural changes of pharyngeal airway contributing to snoring after orthognathic surgery in skeletal class III patients.

BACKGROUND: Two-jaw surgery including mandibular and maxillary backward movement procedures are commonly performed to correct class III malocclusion. Bimaxillary surgery can reposition the maxillofacial bone together with soft tissue, such as the soft palate and the tongue base. We analyzed changes of pharyngeal airway narrowing to ascertain clinical correlations with the prevalence of snoring after two-jaw surgery. METHODS: A prospective clinical study was designed including a survey on snoring and three-dimensional (3D) computed tomography (CT) in class III malocclusion subjects before and after bimaxillary surgery. We conducted an analysis on changes of the posterior pharyngeal space find out clinical correlations with the prevalence of snoring. RESULTS: Among 67 subjects, 12 subjects complained about snoring 5 weeks after the surgical correction, and examining the 12 subjects after 6 months, 6 patients complained about the snoring. The current findings demonstrated the attenuation of the largest transverse width (LTW), anteroposterior length (APL), and cross-sectional area (CSA) following bimaxillary surgery given to class III malocclusion patients, particularly at the retropalatal level. The average distance of maxillary posterior movements were measured to be relatively higher (horizontal distance 3.9 mm, vertical distance 2.6 mm) in case of new snorers. CONCLUSIONS: This study found that bimaxillary surgery could lead to the narrowing of upper airway at the retropalatal or retroglossal level as well as triggering snoring in subjects with class III malocclusion. Based on the current clinical findings, we also found that upper airway narrowing at retropalatal level may contribute to increasing the probability of snoring and that polysonography may need to be performed before orthognathic surgery in subjects with class III malocclusion.

Partially Withdrawn Nasotracheal Tube: An Alternative to the Nasal Trumpet.

After 2-jaw surgery, difficulty in breathing through the mouth and the nose is common due to nasal airway obstruction, intraoral bleeding, and sometimes maxillomandibular fixation. A partially withdrawn nasotracheal tube can be used economically with equal efficacy to the nasopharyngeal airway to provide supplemental oxygen after 2-jaw surgery.