Randomized clinical study comparing Piezoelectric Surgery with conventional rotatory osteotomy in mandibular third molars surgeries

PurposeThe aim of this study was to evaluate the performance and to assess the postoperative sequel and quality of life after removal of impacted mandibular third molars using piezoelectric surgery compared with conventional rotatory osteotomy.Patients and methodsA single blinded, randomized, control clinical study was performed. Sixty-three patients (44 males, 19 females) who presented with bilaterally asymptomatic impacted mandibular third molars were included in this analysis. Each patient was treated, at two separate sessions approximately 4 weeks apart, with a conventional rotatory hand piece on one side of the mandible and a piezoelectric device on the contralateral side. Patients were followed up on postoperative days 1, 3, 5, 7, and 15 to rate the pain, swelling and trismus. Inferior alveolar nerve paresthesia was evaluated up to 12 months postoperatively.ResultsThe severity of the pain, trismus and swelling using the piezosurgery were significantly different from the rotary group. In both groups, pain was most intense and peaked during the first post-operative day, while swelling and trismus reached peak levels on the third postoperative day. The piezoelectric procedure resulted in a significantly longer procedural duration compared to the rotatory surgery (P < 0.001).ConclusionPiezoelectric surgery is considered a viable alternative technique compared to the conventional rotary systems and can improve a patient’s quality of life. Thus, piezoelectric surgery might be a preferred modality for patients undergoing complicated surgical extraction of impacted lower third molars.     

Does a learning curve exist for accuracy in three-dimensional planning for maxillary positioning in bimaxillary orthognathic surgery?

The purpose of this study was to investigate the influence of time, and experience, on the accuracy of maxillary repositioning in bimaxillary orthognathic surgery performed using virtual surgical planning (VSP). Patients who had undergone bimaxillary orthognathic surgery were reviewed. Maxillary position on pre- and postoperative computed tomography scans was compared. The patients were divided into groups according to the year in which VSP was performed and surgery completed. Linear distances between upper jaw reference landmarks were measured in all three planes of space to determine accuracy between the preoperative VSP and the surgical outcome at various time points. One hundred subjects met the eligibility criteria for assessment and were allocated to groups: 2013 (n = 10), 2014 (n = 17), 2015 (n = 39), 2016 (n = 20), and 2017 (n = 14). Overall, the results demonstrated improved precision in maxillary position over the years, with more accurate results in patients who underwent surgery in 2015, 2016, and 2017. Mean linear differences between planned and obtained results demonstrated more accurate results in the horizontal direction, followed by transverse and vertical directions. An overall average difference within 1 mm was observed for 51.3% of the measurements included in the sample group. Time, and surgeon experience, can influence the accuracy of maxillary positioning in bimaxillary orthognathic surgery.     

Improvement in accuracy of maxillary repositioning of Le Fort I osteotomy with Orthopilot™ Navigation System: evaluation of 30 patients

Traditional model surgery with facebow transfer is not very accurate. We aimed to demonstrate that the Orthopilot™ Navigation System improves the accuracy of maxillary repositioning during Le Fort I osteotomy. Thirty patients underwent Le Fort I osteotomy alone or associated to sagittal split osteotomy. The maxilla positioning was done in two phases. First, the maxilla was positioned with the traditional occlusal splint, the position (“without Orthopilot™”) was recorded by the Orthopilot™. In the second phase, the Orthopilot™ was used to improve positioning; and the final position (“with Orthopilot™”) was recorded, after osteosynthesis. Positioning data were compared with planned data. Positioning data with and without the Orthopilot™ were also compared. Accuracy was classified in distinct classes with three major criteria (conformity, non-conformity, failure) according to the discrepancies. Conformity rate was significantly greater with the Orthopilot™ (2 without the Orthopilot™ compared with 8 with the Orthopilot™; p = 0.01). The failure rate was significantly lower with the Orthopilot™ (18 without Orthopilot™ compared with 7 with the Orthopilot™; p = 0.002). Dispersions of discrepancies were usually lower in all directions with the Orthopilot™. Navigation reduced the risk of discrepancy without cancelling it, especially when large movements are planned. The Orthopilot™ therefore improved the accuracy of traditional occlusal splint during Le Fort I osteotomy.     

How does bone thickness affect the split pattern of sagittal ramus osteotomy?

This study examined the influence of bone thickness on the split pattern of sagittal ramus osteotomy at 62 sites using Dolphin 3D software. Four measurements of thickness were obtained from the preoperative computed tomography scans: measurement A was made 1.5 mm above the lingula, using the coronal and sagittal planes; measurement B was made at the same height as measurement A and 1 mm from the anterior border of the ramus; measurement C was obtained 5 mm distal to the last molar and 5 mm below the upper border of the mandible; measurement D was made in the area between the first and second molars, 6 mm above the mandibular border. Three-dimensional postoperative images were used to classify the split pattern into types, based on the classification of Plooij et al. The data were analyzed using the Kruskal–Wallis test, followed by Dunn post-hoc test. Thirty-five sagittal splits were type I, one was type II, 19 were type III, and seven were type IV. Type I presented the greatest thickness, whereas type IV presented the lowest. There was a statistically significant difference in thickness only for measurement A, when types I and IV were compared. The results indicate that thinner mandibular rami are more prone to bad splits.     

Evaluation of border movement of the mandible before and after orthognathic surgery using a kinesiograph

PurposeThe purpose of this study was to examine the changes in the mandibular border movement between class II and class III jaw deformity patients before and after orthognathic surgery, by using the same device.Subjectsand Methods: Eighty one patients (28 in class II and 53 in class III) who underwent sagittal split ramus osteotomy (SSRO) with Le Fort I osteotomy using absorbable plate fixation and 27 controls with normal occlusion were enrolled. Mandibular border movement (observed using a kinesiograph) was recorded with a mandibular movement measure system (K7) before surgery, and at 6 months and 1 year after surgery. Time-course changes of 5 components of the mandibular border movement (MVO: Maximum vertical opening, CO to MAP: Maximum antero-posterior movement from centric occlusion, MLDL: maximum lateral deviation left, MLDR: maximum lateral deviation right, CO to MO: centric occlusion to maximum opening) were compared between classes II, III and controls statistically. The relationship between lateral cephalometric measurements and the components of mandibular border movement was also examined.ResultsThere was a significant difference in CO to MAP (P = 0.0025) and CO to MO (P < 0.0001) between class II and class III in the time-course change.In class III, mean and standard deviation of MVO were 44.5 ± 6.7 mm before surgery and 39.8 ± 6.8 mm after 1 year. Mean and standard deviation of CO to MAP were 25.2 ± 6.8 mm before surgery and 21.5 ± 7.9 mm after 1 year. Mean and standard deviation of CO to MO were 53.4 ± 9.0 mm before surgery and 47.3 ± 8.4 mm after 1 year.In class II, mean and standard deviation of MVO were 38.8 ± 5.8 mm before surgery and 36.2 ± 7.4 mm after 1 year. Mean and standard deviation of CO to MAP were 18.0 ± 6.3 mm before surgery and 17.8 ± 7.4 mm after 1 year. Mean and standard deviation of CO to MO were 43.1 ± 7.5 mm before surgery and 39.6 ± 10.5 mm after 1 year.In MVO, CO to MAP and CO to MO, the values after 1 year did not significantly reach the pre-operative values in class III (P = 0.0001, P = 0.0007 and P < 0.0001), although there was no significant difference between pre-operation and after 1 year in class II.In CO to MO, class II (mean and standard deviation 39.6 ± 10.5 mm) and class III (mean and standard deviation 47.3 ± 8.4 mm) still remained smaller values than control (mean and standard deviation 52.7 ± 9.2 mm) after 1 year (P < 0.0001 and P = 0.0095).ConclusionThis study suggests that bi-maxillary surgery can have more influence on the reduction in the range of mandibular border movement including vertical or antero-posterior motion than lateral deviation motion, in both groups. The difference in the time-course change in the mandibular border movement between the groups might depend more on the mandibular length than on the movement direction of the mandible by surgery such as advancement or setback.     

What factors affect the attachment of the inferior alveolar nerve to the buccal plate following sagittal split osteotomy?

PurposeThis study aimed to assess the factors that can possibly affect the positioning of the inferior alveolar nerve (IAN) in the proximal or distal segment following sagittal split osteotomy (SSO).Materials and methodsThis was a prospective cohort study. The patients were assigned according to the position of the IAN: the IAN was attached to the buccal plate in group 1 (27 SSOs), while it was in the distal segment in group 2 (83 SSOs).ResultsThe mean of the buccolingual thickness of the proximal segment at the vertical cut of the osteotomy (BLTP) was 5.0 ± 0.62 mm in group 1 and 4.16 ± 0.72 mm in group 2. The mean of the distance between the IAN and the external cortical bone at the distal of the second molar before the osteotomy (IANB) was 0.5 ± 0.24 mm in group 1 and 1.24 ± 0.45 mm in group 2. There were significant differences for the mean BLTP and IANB between the two groups (P = 0.001).ConclusionIt seems that the thickness of the buccal plate of the proximal segment, the distance from the IAN to the external cortical bone, the osteotomy technique, and the presence or absence of impacted third molars may be associated with the positioning of the IAN following SSO.     

体感诱发电位对强直性脊柱炎胸腰椎后凸矫形术中体位性臂丛神经损伤的监测作用

目的:探讨体感诱发电位(somatosensory evoked potentials,SEP)对强直性脊柱炎(ankylosing spondylitis,AS)胸腰椎后凸畸形患者经椎弓根椎体截骨术(pedicle subtraction osteotomy,PSO)中体位性臂丛神经损伤的监测作用。方法:选取2013年10月~2014年6月行单节段PSO治疗并有完整术中SEP监测数据及术前、术后临床资料的AS胸腰椎后凸畸形患者28例,其中男27例,女1例。术中均行双上肢正中神经SEP监测,SEP阳性改变标准为波幅降低超过50%和/或潜伏期延长超过10%。结果:PSO术中闭合截骨面复位后,上肢正中神经SEP监测及时发现了3例体位性单侧臂丛神经损伤,SEP波幅降低分别为100%、65%及90%。经体位垫调整后5min,2例SEP波幅降低分别为100%及65%的患者上肢正中神经SEP恢复正常,术后未出现臂丛神经损伤症状;SEP波幅降低90%的患者虽经体位调节,SEP波幅稍有好转,但仍降低70%,术后出现单侧上肢疼痛、乏力的臂丛神经损伤症状,经康复训练及药物治疗后3个月神经功能完全恢复。术中无手术操作引起的神经系统并发症。结论:术中双上肢正中神经SEP监测能及时发现AS胸腰椎后凸畸形PSO术中体位性臂丛神经损伤,经及时处理能有效减轻臂丛神经损伤程度。     

尺骨成角延长截骨治疗儿童陈旧性孟氏骨折

目的探讨应用尺骨截骨后成角延长钢板内固定术治疗儿童陈旧性孟氏骨折的疗效。方法对12例陈旧性孟氏骨折患儿(病程45 d~18个月)行手术截骨矫正内固定治疗。结果患儿均获随访,时间10~18个月。根据Mackay疗效评定标准:优11例,良1例。结论尺骨截骨成角延长治疗儿童陈旧性孟氏骨折,通过手术矫正尺骨畸形无需重建环状韧带,能够恢复正常的肱桡关节关系,改善关节功能。