Treatment of irreducible atlantoaxial dislocation by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach.

OBJECTIVE: Investigate a novel method for treating irreducible atlantoaxial dislocation (IAAD) or with basilar invagination (BI) by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach. METHOD: From March 2015 to December 2019, 213 consecutive patients diagnosed as IAAD/BI were treated with transoral bony deformity remodeling and releasing combined with plate fixation. The main clinical symptoms include neck pain, headache, numbness of the limbs, weakness, unstable walking, inflexible hand-held objects, and sphincter dysfunction. The bony factors that impact reduction were divided into as follows: type A1 (sloping of upper facet joint in C2), type A2 (osteophyte in lateral mass joints between C1 and C2), type A3 (ball-and-socket deformity of lateral mass joint), type A4 (vertical interlocking between lateral mass joints of C1-C2), type A5 (regional bone fusion in lateral mass joints), type B1 (bony factor hindering reduction between the atlas-dens gap), type B2 (uncinate odontoid deformity), and type B3 (hypertrophic odontoid deformity). All of them were treated with bony deformity osteotomy, remodeling, and releasing techs. RESULT: The operation time was 144 [Formula: see text] 25 min with blood loss of 102 [Formula: see text] 35 ml. The average pre-operative ADI improved from 7.5 [Formula: see text] 3.2 mm pre-surgery to 2.5 [Formula: see text] 1.5 mm post-surgery (p < 0.05). The average VDI improved from 12.3 [Formula: see text] 4.8 mm pre-surgery to 3.3 [Formula: see text] 2.1 mm post-surgery (p < 0.05). The average pre-operative CMA improved from 115 [Formula: see text] 25° pre-surgery to 158 [Formula: see text] 21° post-surgery (p < 0.05); the pre-operative CAA changed from 101 [Formula: see text] 28° pre-surgery to 141 [Formula: see text] 10° post-surgery. After the operation, the clinic symptoms improved, and the JOA score improved from 9.3 [Formula: see text] 2.8 pre-operatively to 13.8 [Formula: see text] 2.5 in the sixth months of follow-up. CONCLUSION: In addition to soft tissue factors, bony obstruction was another important factor impeding atlantoaxial reduction. Transoral bony deformity osteotomy, remodeling, releasing combined with plate fixating was effective in treating IAAD/BI with bony obstruction factors.

Does trauma etiology affect the pattern of mandibular fracture?

PURPOSE: The purpose of the present study was to evaluate the relationship between trauma etiologies and anatomic sites of mandibular fractures. PATIENTS AND METHODS: The sample was composed of all patients who sustained mandibular fractures during a 10-year period (2000-2009). The patients' age and gender were recorded; the relationships between fracture etiology and pattern of mandibular fracture were also analyzed. Data analysis included the χ2 test, the Fisher exact test, the t test, and logistic regression analysis. P < 0.05 was considered significant. RESULTS: Fall at ground level had a 9.64-fold risk of mandibular condylar fractures (odds ratio, 9.64; P < 0.001). No significant relationship existed between different etiologies and symphysis fracture. All of the etiologies had a low risk to mandibular body fractures (odds radio, <1; P < 0.05). The occurrence of mandibular angle fractures was highly related to patients' age (P = 0.001). CONCLUSIONS: The pattern of mandibular fractures was highly related to patients' age and the different etiologies.

Open reduction by vestibular approach in the treatment of segmental alveolar fracture.

Fracture of the alveolar process is a common injury; the majority of alveolar fractures may be managed by closed reduction. However, some cases with severe segmental alveolar fracture cannot be reduced by close reduction, usually resulting in occlusion disturbance. This article describes open reduction by vestibular approach in the treatment of severe segmental alveolar fractures, with the aim of evaluating the prognosis. Fifteen patients with severe segmental alveolar fractures that could not be reduced by closed method were included in our case series. Open reduction by vestibular approach was performed on these patients, and the fractures were stabilized with dental arch bars or dental wires. Postoperatively, all patients achieved uneventful healing; consolidation of the fracture was confirmed clinically after 4 weeks. The technique presented is an effective treatment approach proposed for cases of severe segmental alveolar fracture that cannot be managed by closed reduction.

[The sizes of measurement files on the accuracy of electronic apex locator].

PURPOSE: To investigate the different sized measurement files on the accuracy of electronic apex locator (EAL) in vitro. METHODS: Alginate and extracted single-Ccanalled tooth were used to mimic the situation in vivo. Forty-one teeth were used. EAL Raypex 5 was applied to determine the length of the canals by 10#-40# K files. Experimental measurements and the distances (IF value) between experimental and ideal actual measurements under the same measurement environment were recorded. Paired sample F test was applied to analyze the results by using SPSS 10.0 software package. RESULTS: The results showed that at the allowance of + or - 0.5mm, the accuracy ratios were 85.4%(10#),75.6%(15#),85.4%(20#),90.2%(25#),73.2%(30#),68.3%(35#) and 63.4%(40#), respectively. While at the allowance of +0.5--1.0mm, the accuracy ratios were 87.8%(10#),87.8%(15#),90.2%(20#),97.6%(25#),97.6%(30#),97.6%(35#) and 87.8%(40#), respectively. Statistical analysis showed that there was no significant difference in accuracy between each group(P>0.05). CONCLUSION: The results suggested that it be advisable to improve the accuracy of the EAL by measuring the working length one more time with 25# K file during the preparation under this experimental environment.

[Effect of four different solutions on the accuracy of electronic apex locators].

PURPOSE: To investigate four different solutions on the accuracy of two electronic apex locators (EAL) in vitro. METHODS: 1% agar and extracted single-canaled tooth were used to mimic the situation in vivo. Forty-seven teeth were used. Two kinds of electronic apex locator, Raypex 5 and TRRY , were applied to determine the length of the canals being flooded with four different solutions. Experimental measurements and the distances(IF value) between experimental and ideal actual measurements under the same measurement environment were recorded. Paired sample t test were applied to analyze the results by using SPSS10.0 software package. RESULTS: While the canals were flooded with 0.9% NaCl, 5.25% NaOCl, human blood and 17%EDTA, the ratios of the distance within limits of +/-0.5mm were 91.5%, 91.5%, 100% and 97.8% for Raypex 5 and 95.7%, 93.5%, 93.5% and 84.8% for TRRY , respectively. There was a significant difference in accuracy between two EALs regarding blood and 17% EDTA (P<0.05). CONCLUSIONS: Both Raypex 5 and TRRY can measure root canal length accurately despite the influence of solutions under this experimental environment.

[Mandibular fracture fixed with PDLLA/nano-HA compound plates: an animal study].

OBJECTIVE: To investigate the applicability of PDLLA/nano-HA compound plates used in internal fixation of mandibular fractures. METHODS: Rabbit mandibular fracture model was used in this study. Clinical observation, the amount of callus, histological observation were studied and compared with PDLLA plates. RESULTS: All fractures were fixed rigidly. There was 1 animal experienced local inflammation and then forming fistula in the side of PDLLA plate at postoperative 2 and 3 weeks. No side-effects were found in the side of compound plates. During the early stage of bone healing, the quality of callus in the side of compound plates was apparently more than that in the other side, and histological study showed that the osteoblasts and fibroblasts were more active in the side of compound plate in the early healing stage. CONCLUSIONS: PDLLA/nano-HA compound plate has a proper degradation time. Compared with PDLLA plates, it is more effective and safer when used in mandibular fracture.