Objective To analyze the effects of different traction sites and directions on the maxilla and upper dentition when using clear aligners combined with protraction for the treatment of maxillary deficiency.Methods A three-dimensional(3D)finite element model including the zygomaticomaxillary complex,maxillary dentition,and clear aligners was constructed.The models were divided into Group 1(traction hook at the distal of the lateral incisor)and Group 2(traction hook at the distal of the canine).Each group was analyzed under four loading conditions with protraction angles of 0°,10°,20°,and 30° relative to the occlusal plane.A unilateral protraction force of 500 g was applied.The differences in stress distribution and displacement of the maxillary bone and dentition under different loading conditions were analyzed.Results When the protraction angle was 30°,both groups showed forward and downward displacement of the maxilla,while other angles resulted in counterclockwise rotation.Under the same protraction direction,the total displacement of the maxilla and displacements in all directions in Group 2 were greater than those in Group 1.The upper central incisors in Group 1 showed lingual displacement,which increased with the protraction angle.The maxillary dentition in Group 2 showed forward displacement,with the minimum total and sagittal displacements at a protraction angle of 30°.Stress concentration was mainly observed in the zygomaticomaxillary suture and anterior alveolar bone regions in both groups,decreasing as the protraction angle increased.Conclusions Clear aligners combined with protraction can be applied to skeletal Class Ⅲ patients with mild maxillary deficiency.When the protraction site is located at the distal of the canine with a 30° downward and forward angle to the occlusal plane,the maxilla can achieve ideal forward and downward displacement with the minimum labial movement of the upper anterior teeth.

Objective To analyze the effects of different traction sites and directions on the maxilla and upper dentition when using clear aligners combined with protraction for the treatment of maxillary deficiency.Methods A three-dimensional(3D)finite element model including the zygomaticomaxillary complex,maxillary dentition,and clear aligners was constructed.The models were divided into Group 1(traction hook at the distal of the lateral incisor)and Group 2(traction hook at the distal of the canine).Each group was analyzed under four loading conditions with protraction angles of 0°,10°,20°,and 30° relative to the occlusal plane.A unilateral protraction force of 500 g was applied.The differences in stress distribution and displacement of the maxillary bone and dentition under different loading conditions were analyzed.Results When the protraction angle was 30°,both groups showed forward and downward displacement of the maxilla,while other angles resulted in counterclockwise rotation.Under the same protraction direction,the total displacement of the maxilla and displacements in all directions in Group 2 were greater than those in Group 1.The upper central incisors in Group 1 showed lingual displacement,which increased with the protraction angle.The maxillary dentition in Group 2 showed forward displacement,with the minimum total and sagittal displacements at a protraction angle of 30°.Stress concentration was mainly observed in the zygomaticomaxillary suture and anterior alveolar bone regions in both groups,decreasing as the protraction angle increased.Conclusions Clear aligners combined with protraction can be applied to skeletal Class Ⅲ patients with mild maxillary deficiency.When the protraction site is located at the distal of the canine with a 30° downward and forward angle to the occlusal plane,the maxilla can achieve ideal forward and downward displacement with the minimum labial movement of the upper anterior teeth.

Objective: To examine the accuracy of computer-aided intraoperative navigation (Ci-Navi) in bimaxillary orthognathic surgery by comparing preoperative planning and postoperative outcome. Methods: The study comprised 45 patients with congenital dentomaxillofacial deformities who were scheduled to undergo bimaxillary orthognathic surgery. Virtual bimaxillary orthognathic surgery was simulated using Mimics software. Intraoperatively, a Le Fort I osteotomy of the maxilla was performed using osteotomy guide plates. After the Le Fort I osteotomy and bilateral sagittal split ramus osteotomy of the mandible, the mobilized maxilla and the distal mandibular segment were fixed using an occlusal splint, forming the maxillomandibular complex (MMC). Realtime Ci-Navi was used to lead the MMC in the designated direction. Osteoplasty of the inferior border of the mandible was performed using Ci-Navi when facial symmetry and skeletal harmony were of concern. Linear and angular distinctions between preoperative planning and postoperative outcomes were calculated. Results: The mean linear difference was 0.79 mm (maxilla: 0.62 mm, mandible: 0.88 mm) and the overall mean angular difference was 1.20°. The observed difference in the upper incisor point to the Frankfort horizontal plane, midfacial sagittal plane, and coronal plane was < 1 mm in 40 cases. Conclusions This study demonstrates the role of Ci-Navi in the accurate positioning of bone segments during bimaxillary orthognathic surgery. Ci-Navi was found to be a reliable method for the accurate transfer of the surgical plan during an operation.

Objective: To examine the accuracy of computer-aided intraoperative navigation (Ci-Navi) in bimaxillary orthognathic surgery by comparing preoperative planning and postoperative outcome. Methods: The study comprised 45 patients with congenital dentomaxillofacial deformities who were scheduled to undergo bimaxillary orthognathic surgery. Virtual bimaxillary orthognathic surgery was simulated using Mimics software. Intraoperatively, a Le Fort I osteotomy of the maxilla was performed using osteotomy guide plates. After the Le Fort I osteotomy and bilateral sagittal split ramus osteotomy of the mandible, the mobilized maxilla and the distal mandibular segment were fixed using an occlusal splint, forming the maxillomandibular complex (MMC). Realtime Ci-Navi was used to lead the MMC in the designated direction. Osteoplasty of the inferior border of the mandible was performed using Ci-Navi when facial symmetry and skeletal harmony were of concern. Linear and angular distinctions between preoperative planning and postoperative outcomes were calculated. Results: The mean linear difference was 0.79 mm (maxilla: 0.62 mm, mandible: 0.88 mm) and the overall mean angular difference was 1.20°. The observed difference in the upper incisor point to the Frankfort horizontal plane, midfacial sagittal plane, and coronal plane was < 1 mm in 40 cases. Conclusions This study demonstrates the role of Ci-Navi in the accurate positioning of bone segments during bimaxillary orthognathic surgery. Ci-Navi was found to be a reliable method for the accurate transfer of the surgical plan during an operation.

Background: Previous studies showed controversial findings for correlation of periodontal disease and cognitive deficits. Methods: We searched systematically for studies pertaining to correlation of periodontal disease and cognitive deficits published between August 1980 and December 2019 on Web of Science and PubMed. We combined the data extracted from the included studies to determine the correlation between periodontal disease and cognitive deficits. Results: Our analysis indicated a higher risk of cognitive deficits in those with moderate to severe periodontal disease when compared to those with mild or no periodontal disease (odds ratio (OR) = 1.38 (95% confidence intervals (CI): 1.28-1.48). Subgroup analysis showed significant correlations in only case-control and cohort studies (case-control studies: OR = 1.49 (95% CI: 1.24-1.80); cohort studies: relative risk (RR) = 1.33 (95% CI: 1.22-1.45)). Subgroup analysis also indicated that moderate to severe periodontal disease was correlated to increased dementia and Alzheimer disease risks, whereas no significant correlation was found between periodontal disease and mild cognitive impairment (dementia: OR/RRs = 1.32 (95% CI: 1.22-1.44); Alzheimer disease: OR/RRs = 1.51 (95% CI: 1.20-1.90); Mild cognitive impairment: OR/RRs = 1.31 (95% CI: 0.89-1.94)). Furthermore, subgroup analysis showed significant correlations between cognitive deficits and tooth loss, periodontitis, whereas no significant correlation was found between deep periodontal pockets and cognitive deficits (tooth loss: OR/RRs = 1.57 (95% CI: 1.39- 1.77); periodontitis: OR/RRs = 1.43 (95% CI: 1.03-2.00); deep periodontal pockets: OR/RRs = 1.24 (95% CI: 0.77-2.00)). Conclusions: This review suggests a significant correlation between periodontal disease and cognitive deficits. Interventional studies for periodontal disease may be beneficial for patients with cognitive deficits

Objective To explore and analyze the effect of ambroxol hydrochloride combined with budesonide in treatment of children bronchial pneumonia on C-reactive protein level and WBC levels.Methods 100 cases of patients with bronchial pneumonia treated in our hospital from May 2015 to December 2016, were randomly divided into observation group and control group, 50 cases in each group.The control group were given routine treatment, while the observation group were given ambroxol hydrochloride combined with budesonide treatment on the basis of the control group,the course of treatment was 14 days.C-reactive protein and WBC levels were measured before treatment and 14 days after treatment, the Resultswere observed and statistical.ResultsThere were significant differences in the content of CRP between groups and multiple time points(F=11.50, P=0.003;F=4.78, P=0.03;F=5.45, P=0.02).The content of CRP 14 days after treatment in the observation group were significantly lower than the control group(t=14.12,P<0.05), the difference was statistically significant.There were significant differences in the WBC counts between groups and multiple time points(F=11.52, P=0.003;F=4.73, P=0.03;F=5.44, P=0.02),the difference was statistically significant.The count of WBC 14 days after treatment in the observation group after treatment were significantly lower than the control group(t=8.12, P<0.05), the difference was statistically significant.The number of cured, effective and ineffective cases in the control group was 20, 13 and 15, respectively.The observation group was 30, 15, and 5 cases, respectively.By rank sum test, the difference of the effective rate between the 2 groups was statistically significant(u=2.33, P<0.05).And the total effective rate in observation group was 90.0%, which was significantly higher than the control group(70.0%)(x2=6.25, P<0.05), the difference was statistically significant.Conclusion Ambroxol hydrochloride combined with budesonide in the treatment of bronchial pneumonia in children is effective and can effectively reduce the CRP and WBC count, so it is worth popularizing widely in clinic.

Objective To investigate the peri-nasopharyngeal invasion patterns of nasopharyngeal carcinoma (NPC) on MRI and its relationship with tumor staging. Methods One thousand five hundred and seventy-three patients with newly diagnosed NPC which were histo-pathologically proved were retrospectively studied. The MRI manifestations and invasion patterns of the NPCs were elevated according to the 2008 Tstaging system of NPC. Z test was used to analyze the rate of adjacent structures invasion in NPCs. Results The structures invaded by NPCs included pharyngobasilar fascia in 1299 cases (82. 58% ); parapharyngeal space, 1090 ( 69. 29% ); nasal cavities, 304 ( 19. 33% ); oropharynx, 49 ( 3. 12% ); carotid space,514(32. 68% ); medial pterygoid muscle, 661 (42. 02% ); lateral pterygoid muscle, 210( 13. 35% ); skull base bones, 943(59. 95% ); cranial nerves, 630(40. 05% ) and paranasal sinuses, 242 ( 15.38% ). The T-stage distribution was T1, 242 cases ( 15.38% ); T2, 288 ( 18. 31% ); T3, 410 (26. 06% ) and T4,633 (40. 24% ). Among the cases with nasal cavities invasion, 90. 46% (275/304)showed the involvement of the structures seen in T3 or T4 stage, which was found in all cases with oropharynx invasion. In addition,69. 14% (457/661) of cases with medial pterygoid muscle invasion and 92. 15% (223/242) of cases with paranasal sinuses invasion showed the involvement of structures seen in T4 stage. As for the invasion patterns of NPC, the lateral invasion of pharyngobasilar fascia was more frequent than upward invasion of skull base (Z = 14. 025, P ＜ 0. 01 ) and downward invasion of oropharynx ( Z = 45.032, P ＜ 0. 01 ), and the downward invasion of oropharynx was less frequent than upward invasion of skull base ( Z = 34. 301, P ＜ 0. 01 ) and forward invasion of nasal cavities ( Z = 14. 404, P ＜ 0. 01 ). Conclusion NPC has a predilection of lateral invasion rather than upward and downward invasion, and its upward and forward invasion are more common than downward invasion.