With the rapid development of augmented reality, the surgical navigation based on augmented reality technology improved gradually, especially in the field of maxillofacial surgery, where real-time and accurate positioning is required. This article reviewed the structures of augmented reality surgical navigation system, its clinical applications in the field of maxillofacial surgery and its deficiencies, in order to provide benefits to the further research of augmented reality surgical navigation.

With the rapid development of augmented reality, the surgical navigation based on augmented reality technology improved gradually, especially in the field of maxillofacial surgery, where real-time and accurate positioning is required. This article reviewed the structures of augmented reality surgical navigation system, its clinical applications in the field of maxillofacial surgery and its deficiencies, in order to provide benefits to the further research of augmented reality surgical navigation.

Distraction osteogenesis has been widely used to correct in craniosynostosis in craniofacial surgery since the end of last century because of its advantages such as minimal surgical trauma, short operation time and stable postoperative effect. There are many kinds of distraction osteogenesis procedures for the treatment of craniosynostosis. In order to facilitate patients and surgeons to understand the advantages and disadvantages of these surgical procedures and choose appropriate treatment strategies, the authors reviewed operations of distraction osteogenesis by using internal or external device, and the spring-assisted distraction osteogenesis. Author also evaluated its complications, advantages and disadvantages of these procedures.

Distraction osteogenesis has been widely used to correct in craniosynostosis in craniofacial surgery since the end of last century because of its advantages such as minimal surgical trauma, short operation time and stable postoperative effect. There are many kinds of distraction osteogenesis procedures for the treatment of craniosynostosis. In order to facilitate patients and surgeons to understand the advantages and disadvantages of these surgical procedures and choose appropriate treatment strategies, the authors reviewed operations of distraction osteogenesis by using internal or external device, and the spring-assisted distraction osteogenesis. Author also evaluated its complications, advantages and disadvantages of these procedures.

Objective: To evaluate the consistency between prostate biopsy and postoperative pathological grade, analyze the influencing factors that may lead to upgrade or downgrade, and to establish a prediction model. Methods: The clinical data of biopsy GS3+ 3=6(GR1, 330 cases) and GS3+ 4=7(GR2, 340 cases) patients from January 2013 to December 2018 in the first affiliated hospital, College of Medicine of Zhejiang university were retrospectively analyzed. The median age was 67 years old(ranging 35 to 100 years old). The median BMI was 23.74 kg/m²(ranging 16.22-38.74 kg/m²). The Median tPSA was 10.266 ng/ml(ranging 0.017-147.575 ng/ml). The median prostate volume was 29.43 ml(5.92-187.20 ml). The median PSAD was 0.34 (ranging 0.01-4.02). The median percentage of positive puncture cores was 0.25 (ranging 0.08-1.00). There were 161 patients in clinical stage ≤T_1c, 344 patients in T_2a-T_2c and 165 patients in clinical stage ≥T₃. 670 cases all accepted the radical prostatectomy. Consistency of prostate biopsy and radical prostatectomy Gleason grade was recorded. If the postoperative Gleason grade was higher than that in biopsy, it was defined as upgrade. Otherwise, it was defined as downgrade. Multivariate logistic regression model was used to evaluate the influencing factors leading to upgrades in GR1 patients or downgrades in GR2 patients. Nomograms were drawn based on the models with AUC and Horsmer-Lemeshaw test conducted to test the discrimination and calibration of the models. Results: Among the 670 patients included, 165 cases (50.0% of GR1) upgrades and 27 cases (7.9% of GR2) downgrades. PSAD≥0.25(OR=3.015) and clinical stage≥T_2b(OR=7.185)were independent influencing factors for the upgrade in GR1 patients, while PSAD<0.15(OR=4.208) and clinical stage≤T_1c(OR=4.530) were independent influencing factors for downgrade. The nomograms were drawn with the above variables. The AUC of the model (0.781 for GR1 group, 0.741 for GR2 group) and the hosmer-remeshaw test results (P=0.993 for GR1 group, P=0.234 for GR2 group) show that the nomograms have good discrimination and calibration. Conclusions PSAD and clinical stage are independent influencing factors for the upgrade or downgrade. Nomograms may provide help for clinicians to judge the accuracy of prostate biopsy. However, the nomograms still needs to be verified in clinical practice

Objective To measure the change of facial volume maintenance rate after autologous fat grafted for repaired progressive facial hemiatrophy by using three-dimensional digital technology.Methods 3D scanner was used to acquire facial data in 10 patients with progressive facial hemiatrophy before operation;Mimics 17.0 software was used to reconstruce patients' facial 3D model and to calculate the volume of facial tissue defect;autologous fat was grafted to repair facial deformity.The facial volume maintenance rate was calculated in all the patients 3 months and 6 months after operation.Results We had performed facial 3D data acquisition and facial repaired with autologus fat grafted in 10 patients;patients' facial morphology was improved.The mean facial volume maintenance rate was (35.80±3.44)％ in 3 months and (27.82±3.80)％ 6 months after surgery.Conclusions The mean facial volume maintenance rate in postoperative 3 months is inferior to that in 6 months in single autologous fat grafted for repairing progressive facial hemiatrophy.

Objective: To present a new method for correction of prominent malar complex via intraoral approach by double support technique osteotomy which can provide a stable support. Methods: According to the anatomical characteristics of malar complex and relevant masseter muscle, we designed a malar reduction technique including anterior and posterior support. The reduction procedure entailed an L-shaped osteotomy ofthemalarbody and oblique osteotomy of malar arch. On the basis of prominence degree, bone fragment was moved inward and upward to form double support, which could reduce malar and zygomatic arch effectively. Results: A total of 76 patients subjected to double support technique for malar reduction between January 2015 and January 2017 were retrospectively reviewed.The follow-up period ranged from 10 to 12 months. All patients were satisfied with aesthetic outcomes without major complications, such as facial nerve damage or bone ununion. Conclusions Double support technique is an effective method to correct malar prominence andreduce the zygomatic complex which can prevent saggy cheek and bony malunion.

Objective To find a method to repair nasal deformity of Tessier 3 cleft.Methods Five Tessier 3 cleft patients were treated from June 2010 to June 2015 in our department.Nasolabial groove flap or nasolabial groove flap accompanied by offside ala nasi groove flap were performed to correct the nasal deformity according to the defect of the ala.Results Two cases were treated with simple nasolabial groove glap,and 3 cases were treated with nasolabial groove flap accompanied by offside ala nasi groove flap.All the flaps survived with incisions of donor sites healed primarily.The color,texture and thickness of the flaps were similar to those of recipient sites after 1 year follow up.The scar in donor site was concealed and not obvious.The results showed good healing and good appearance,and the symmetry between the nostrils also seemed to be acceptable.Conclusions Nasolabial groove flap and nasolabial groove flap accompanied by offside ala nasi groove flap are good methods to correct nasal deformity of Tessier 3 cleft.The offside ala can be reduced at the same time and the symmetry between the nostrils can be achieved more easily.The operation is easily performed,the scar is acceptable and the results are good.

Objective To explore the dosimetric characteristics of single photon emission computed tomography(SPECT)combined with bone marrow sparing intensity modulated radiotherapy in patients with cervical cancer.Methods Twenty patients with cervical cancer after hysterectomy were performed on 99Tc thiocolloid SPECT bone marrow imaging to determine the active bone marrow in the pelvis.SPECT image combined with the simulation CT was used as the primary planning data set.Two plans for bone marrow sparing modulated radiotherapy were generated according to the bone marrow volume defined by SPECT and outline of the pelvis(SPECT-IMRT planning and BMS-IMRT planning).Furthermore,the target section and the dosimetric distribution in organs at risk(bone marrow,small intestine,rectum and bladder)in the two plannings were compared.The prescribed dose to the PTV was 45 Gy.Results The volume of the bone marrow in SPECT-IMRT planning and BMS-IMRT planning was(238.15 ±36.82)and(1 100.61 ±109.92)cm3,respectively(t＝33.273,P＜0.05).The average bone marrow volume of SPECT-IMRT planning in high-dose radiation region(V30,V40and V45)was decreased by 6.9％,5.7％and 2.6％respectively compared with BMS-IMRT planning(t ＝3.540,3.4261,3.448,P＜0.05),but there was no statistical significant difference between the two plannings in the dose volume of low-dose radiation(V10and V20,P＞0.05).The PTV coverage rate and exposure dose of other organs at risk(small intestine,rectum and bladder)in the two plannings were not significantly different(P＞0.05).Conclusions SPECT bone marrow imaging could clearly show the range of active bone marrow on CT scan images.Compared with BMS-IMRT,SPECT-IMRT could further reduce the dose volume of high-dose radiation(V30,V40and V45).Yet the clinical significance of this advantage also needs to be confirmed by large-scale clinical studies.

Objective To discuss the correlation between initial malar reduction procedures and the method of revision procedures and the personalized treatment strategies for the second deformity of postoperative prominent malar complex.Methods From January 2003 to December 2017,27 patients underwent personalized revision surgery of malar reduction according to the different second deformity of malar complex.The surgical technique included the double support malar reduction technique,orthotopic malar osteotomy technique,malar bone grinding surgery,and autogenous bone transplantation.Results A total of 27 patients subjected to revision surgery for malar reduction between November 2006 and December 2017 were retrospectively reviewed.22 patients were satisfied with aesthetic outcomes after the first revision procedure,while 5 patients were satisfied after 2 or 3 procedures follow-up for 10 to 12 months.Conclusions The incidence of complications after malar reduction is related to the first surgical method.According to the unsatisfactory results,it can be repaired individually to obtain a better clinical repair effect.