[Application value of whole exon sequencing and immune related indicators in the precision treatment of oral squamous cell carcinoma].

OBJECTIVE: To explore the significance and feasibility of whole exon sequencing and immune related indexes in personalized precision treatment of oral squamous cell carcinoma (OSCC). METHODS: We retrospectively screened the patients who underwent surgery for oral cancer in Peking University Hospital of Stomatology and underwent genetic and immune biomarkers tests between January 2021 and June 2022. Combined with the clinicopathological characteristics of patients, potential targeted drugs and immunotherapy drugs were screened to evaluate the possibility of gene testing benefiting OSCC. The main evaluation indicators included the number of gene mutations, combined positive score (CPS), tumor mutation burden (TMB), microsatellite sequence status and human leukocyte antigen B (HLA-B) locus. Excel was used for statistical analysis. RESULTS: A total of 10 patients were enrolled and 9 were included in this study, including 6 males and 3 females, with an average age of (55.44±9.59) years. The tumor location was buccal (5 cases), tongue (3 cases) and gingival (1 case). The results of genetic testing showed that 3 (33.3%) patients had no gene mutations in the tumor tissue, 5 (55.6%) patients had unique TP53 gene mutations, and 1 (11.1%) patient had TP53 and CHEK1 mutations. However, no drugs were available for targeted therapy of the mutated genes. The genetic tumor gene testing results showed that no genetic tumor gene was found in all the patients, suggesting that OSCC had a low possibi-lity of hereditary tumor. In terms of immune efficacy related markers, CPS test results showed that 8 patients had CPS≥1. TMB detection results showed that the median value of TMB value was 0.72 mutations/Mb, and the range was 0 to 4.32 mutations/Mb. The negative and positive control results of microsatellite sequence status were consistent, indicating that all the tumor tissues detected were microsatellite stability. The results of HLA-B detection showed that only one patient had B62 gene mutation, suggesting that the B44 and B62 related genotypes of HLA-B in OSCC tissue samples were low. CONCLUSION: The present results do not support the wide application and promotion of genetic testing and immune related indexes in OSCC.

[Category of facial symmetry perception after maxillary reconstruction using anterolateral thigh flap].

OBJECTIVE: To preliminarily establish a category of facial symmetry perception after maxillary reconstruction using anterolateral thigh flap (ALTF) by the methods of stereophotogrammetry and subjective assessment. METHODS: The patients underwent maxillectomy due to neoplasms invasion, and all the maxillary defects were reconstructed using ALTF.Three-dimensional (3D) photographs were captured from the patients with a stereophotogrammatrical camera set-up.In the Geomagic software, the mirror image was created by reflecting along an arbitrary plane outside of the face.After the registration, the postoperative side on the original 3D photograph was segmented into 6 areas.The 3D change of the facial soft-tissue was measured using surface-based color map.Twenty laypeople took part in the study as observers, and they were asked to rate the 3D photographs using 5 point Likert-type scale according to their own aesthetic standard.The soft tissue asymmetry was graded according to the score.The collected data were subjected to statistical analysis using the SPSS 24.0 software. RESULTS: In the study, 44 subjects were recruited (21 males and 23 females, age range from 19 to 79 years).The soft-tissue symmetry was graded into three levels according to the subjective scores.The grade Ⅰ was basically symmetrical.The grade Ⅱ was slightly asymmetrical.The grade Ⅲ was obviously asymmetrical.Statistically significant differences were found in the suborbital (P < 0.05) and zygomatic (P < 0.05) areas when comparing all grades of soft-tissue asymmetry, and in the buccal (P < 0.05) and superiolabial (P < 0.05) areas when comparing grades Ⅰ and Ⅲ.The extent of maxillary defect had significant impact on the symmetry of the midface soft-tissue after maxillary reconstruction. CONCLUSION: Varying extent maxillectomy would result in varying degrees of asymmetry, and cause different grades of symmetry perception even if they had been reconstructed using ALTF.The higher the grade, the worse the symmetry of facial soft-tissue.Suborbital and zygomatic areas were important aesthetic units that affected the facial symmetry perception, followed by buccal and superiolabial areas.The clinicians should pay attention to the soft-tissue support in these areas when reconstructing the maxillary defect, especially large defect with orbital floor involved.

[Postoperative position change of fibular bone after reconstruction of maxillary defect using free fibular flap].

OBJECTIVE: To investigate the position change of the fibular bone after maxillary reconstruction by free fibular flap and to analyze the factors affecting the position change. METHODS: Patients who underwent maxillary reconstruction by free fibular flap in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from November 2012 to November 2016 were enrolled in this study. CT scans 1 week and 1 year postoperatively were collected and stored in DICOM format. The ProPlan CMF software was used to reconstruct the CT scans and separate the maxilla and each segment of the fibular flap. The Geomagic Control software was used to measure the long axis direction vector of each fibular segment. And the position change direction was recorded. The patients were divided into groups according to the use of the fibula or titanium plate to reconstruct the zygomaticmaxillary buttress. RESULTS: A total of 32 patients were enrolled. Among them, 21 were in the titanium plate group and 11 in the fibula bone group. The angle between the long axis of the fibular segment and the X axis in the X-Y plane was 95.65°±53.49° and 95.53°±52.77°, 1 week and 1 year postoperatively, and there was no statistical difference (P>0.05). The angle between the long axis of the fibular segment and the X axis in the X-Z plane was 96.88°±69.76° and 95.33°±67.42°, respectively, with statistical difference (P=0.0497). The angular changes of the long axis of the fibular segment in the titanium plate group and the fibular bone group were 3.23°±3.93° and 1.94°±1.78°, respectively, and the angular changes in the X-Z plane were 6.02°±9.89° and 3.27°±2.31°, respectively. There was no significant difference between the groups (P>0.05). The long axis changes of the fibular segment in the X-Y plane for reconstruction of the anterior alveolar, posterior alveolar, and buttress were 3.13°±3.78°, 2.56°±3.17°, and 5.51°±4.39°, respectively. There was a statistical difference (P = 0.023) between the posterior and buttress. In the X-Z plane, theses were 4.94°±4.75°, 5.26°±10.25°, 6.69°±6.52°, respectively. There was no statistical difference among the three groups (P>0.05). The main positional deviation directions of the titanium plate group and the fibular bone group were interior and superior sides, and there was no statistical difference between the two groups (P>0.05). CONCLUSION: One year postoperatively, the position of the free fibular flap was changed compared with 1 week postoperatively. The position of the free fibular flap was mainly changed to the interior and superior sides.

[Delayed diagnosis of oral squamous cell neoplasms at different sites].

OBJECTIVE: To investigate the diagnostic delay of patients with oral squamous cell carcinoma by self-designed questionnaire to find out the significant influencing factors, so as to identify the influencing factors of the patient's delay and the risk of oral cancer. METHODS: A total of 514 patients with primary oral squamous cell carcinoma were enrolled at Peking University School and Hospital of Stomatology from January 2014 to April 2016, including 334 men and 180 women, with a male to female ratio of 1.85:1. The youngest participant was 21 years old, with a maximum of 89 years and a median age of 57.6 years. The position of the disease according to International Classification of Diseases-10 (ICD-10) was divided into lip, buccal, gingival, retromolar, palate, floor of the mouth, tongue, and oropharynx. The age group is divided into 10 years. The level of education was divided into illiteracy, primary education level and advanced education level. Body mass index (BMI) was divided into three levels by 18 kg/m2 and 25 kg/m2. Visual analog scale (VAS) method was to evaluate the patient's preoperative pain. At the same time, the patients were examined by detailed questionnaire to understand the delay factors and delay characteristics, and use SPSS 18.0 software, analysis of variance and chi-square test to explore correlation. RESULTS: Among all patients, the proportion of patients developed in the tongue was the highest (43.3%). Delay was defined by a span of three months or longer from the onset of symptoms until treatment. The delays to diagnosis according to location were as follows (in months and in descending order): lip (6.1 months), buccal (4.1 months), floor of the mouth (3.9 months), tongue (3.6 months), oropharyngeal (2.9 months), retromolar (2.7 months), palatine (2.4 months), and gingival (2.4 months). Different sites and delayed diagnosis were statistically significant (P=0.048). There were no statistically significant differences in gender, education, pain, smoking, drinking and VAS score. CONCLUSION: The study has found that tumor positions and delay have a significant correlation. The position of the tumor is an obvious factor associated with the findings. The lip is the most likely to delay the diagnosis of oral positions. For the lip of the lesion, more than three months' obvious mass is recommended for timely treatment, while at admission, physicians should take the appropriate diagnostic method as soon as possible.

Effects of personalized oral exercises on swallowing function among patients with oral cancer after free flap transplantation: a cluster randomized controlled trial.

Dysphagia is a common complication in patients with oral cancer who have undergone free flap transplantation. The aim of this cluster randomized controlled trial was to evaluate the effect of personalized oral exercises on swallowing function in this group of patients. Eligible patients were randomly assigned to the intervention (n = 34) or control (n = 34) group. Intervention group patients received personalized oral exercises starting on day 6 after surgery. Swallowing function was evaluated on days 6 and 15, and at 1 month postoperative using the Mann Assessment of Swallowing Ability-Oral Cancer tool (MASA-OC). On day 15 and at 1 month after surgery, the total MASA-OC score (P = 0.003, P < 0.001) and the mouth opening (P = 0.001, P < 0.001) and lip seal (both P < 0.001) item scores showed a significantly greater improvement in the intervention group than in the control group. Moreover, the changes in salivation (P < 0.001) and tongue movement (P = 0.025) scores at 1 month after surgery were significantly greater in the intervention group than in the control group. There was no significant difference between the groups in the change in tongue strength scores on day 15 or at 1 month postoperative (P = 0.476, P = 0.223). Personalized oral exercises can improve swallowing function in patients with oral cancer after free flap transplantation.

Bone resorption after maxillary reconstruction with the vascularized free iliac flap.

The aim of this study was to evaluate the resorption of the iliac bone after maxillary reconstruction with a vascularized free iliac flap. Twenty-seven patients with maxillary defects who underwent maxillary reconstruction with the vascularized free iliac flap between January 2017 and January 2021 were included. Computed tomography (CT) images taken at 1 week, approximately 6 months, and 1 year after the surgery were used for evaluation. The total iliac bone thickness and height, cortical bone thickness, and cancellous bone density were measured in the CT images. Compared with 1 week after the surgery, the total thickness and height of the iliac bone were reduced significantly 1 year after the surgery, and the cortical bone thickness and cancellous bone density were reduced significantly at 6 months and 1 year after the surgery. Compared with 6 months after the surgery, cancellous bone density was reduced significantly 1 year after the surgery. In conclusion, during the first year after maxillary reconstruction with a vascularized free iliac flap, there was significant resorption of iliac bone, including the total iliac bone thickness and height, the cortical bone thickness, and the cancellous bone density.

Accurate occlusion-driven maxillary reconstruction with deep circumflex iliac artery flap using computer-assisted techniques and intraoral anastomosis: a case series.

The aim of this study was to evaluate the feasibility and accuracy of occlusion-driven maxillary reconstruction with the deep circumflex iliac artery (DCIA) flap, using computer-assisted design and manufacturing (CAD/CAM) technology and intraoral anastomosis. The data of 11 patients who underwent occlusion-driven maxillary reconstruction with this method between December 2018 and December 2020 in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology were reviewed retrospectively. Postoperative complications and functional and aesthetic outcomes were recorded. The accuracy of the postoperative restoration was assessed using Geomagic Control 2014. Reconstruction was successful in nine patients; all were satisfied with their aesthetic and functional outcomes. One patient underwent extraoral anastomosis after failure of intraoral anastomosis. In another patient, the DCIA flap had to be removed after the operation because of flap failure. Among the 10 patients with DCIA flap success, colour map analysis showed a mean deviation of 0.40 ± 0.08 mm between the preoperative and postoperative craniomaxillary models. Thus, occlusion-driven maxillary reconstruction with the DCIA flap, using CAD/CAM technology and intraoral anastomosis, appears to be a feasible and accurate method for the repair of maxillary defects.

Non-vascularised fibular bone graft after vascular crisis: compensation for the failure of vascularised fibular free flaps.

After reconstruction of a segmental mandibular defect with a fibular free flap, a vascular crisis can be detected clinically and a "no-flow" phenomenon found during re-exploration. Traditional methods used to solve this include removal of the failed flap and delayed mandibular reconstruction, or restoration of the defect with a functional reconstruction plate or contralateral fibular free flap. Our aim therefore was to investigate under what circumstances it is feasible to use a non-vascularised fibular bone graft (NVFB) as a free bone graft after the failure of a vascularised fibular free flap. From 1 January 2010-31 December 2014, 10 patients who had NVFB after failure of a fibular free flap were included in the study. All patients were treated at the Peking University School and Hospital of Stomatology. NVFB were preserved successfully without infection in all 10 cases, and follow-up imaging showed that it had incorporated well with the residual mandible, the basic function and facial aesthetics of which were maintained. In conclusion we have identified that by precise selection of patients, detailed preoperative planning, and meticulous postoperative care, NVFB can be used as a "rescue" technique after failure of a fibular free flap, and can successfully restore the segmental mandibular defect and facial contour.

Surgical navigation-assisted mandibular reconstruction with fibula flaps.

The mandible has an important role in appearance and function. The aim of this study was to describe and evaluate surgical navigation-assisted mandibular reconstruction with the fibula flap. Patients recruited into the study had a custom dental splint fabricated to maintain the mandible in a fixed position. Later, the computed tomography (CT) scan, preoperative design, and operation on the mandible were done in the same position. At 1 week after surgery, a CT scan was done to evaluate the repeatability between the preoperative design and the postoperative result. Twenty patients were enrolled in this study. Good repeatability between the postoperative CT and the preoperative design was found. The repeatability between the preoperative plan and postoperative outcome was 79.1 ± 8.6% at within 1mm, 87.1 ± 6.7% at within 2mm, and 91.9 ± 5.4% at within 3mm. From this study, it can be concluded that surgical navigation techniques can precisely transfer the preoperative design to the operation in mandible reconstruction with a fibula flap. This will assist the surgeon in achieving good cosmetic and functional outcomes.