Computed tomography/magnetic resonance imaging for mandibular boundary invasion of oral squamous cell carcinoma assessment.

BACKGROUND: The range of mandibular invasion by a tumour needs to be determined accurately to minimize unnecessary damage to the mandible. This study aimed to compare tumour boundary lines on computed tomography/magnetic resonance (CT/MR) images with those from pathological findings during the preoperative assessment of mandibular invasion by oral squamous cell carcinoma (OSCC). By comparing the methods, the potential of CT/MR for this application could be further elucidated. METHODS: Eight patients with OSCC were imaged with CT/MR, mandibular specimens were collected, and the material site was measured. Haematoxylin-eosin staining was used for histopathological assessment. The presence and boundaries of bone invasion were evaluated. The CT/MR and histopathological boundaries of bone invasion were delineated and merged to compare and calculate the deviation of CT/MR and histopathological boundaries using the Fréchet distance. RESULTS: The mean Fréchet distance between the CT and pathological tumour boundaries was 2.69 mm (standard error 0.46 mm), with a minimum of 1.18 mm, maximum of 3.64 mm, median of 3.10 mm, and 95% confidence interval of 1.40-3.97 mm. The mean Fréchet distance between the tumour boundaries on the MR and pathological images was 3.07 mm (standard error 0.56 mm), with a minimum of 1.53 mm, maximum of 4.74 mm, median of 2.90 mm, and 95% confidence interval of 1.53-4.61 mm. CONCLUSIONS: CT/MR imaging can provide an effective preoperative assessment of mandibular invasion of OSCC. Pathology images can be positioned on CT/MR scans with the help of computer software to improve the accuracy of the findings. The introduction of the Fréchet distance to compare tumour boundary lines is conducive to computer image diagnosis of tumour invasion of jaw boundaries.

A composite oral hygiene score and the risk of oral cancer and its subtypes: a large-scale propensity score-based study.

OBJECTIVE: This study aimed to investigate the potential relationship between oral hygiene and the risk of oral cancer and its subtypes after controlling the effects of several confounding factors. MATERIALS AND METHODS: A large-scale case-control study was conducted from January 2010 to August 2019, recruiting a total of 1,288 oral cancer cases with newly diagnosed and 4,234 healthy controls. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were utilized to minimize confounding effects. Conditional logistic regression was used to evaluate the effects of oral hygiene indicators on oral cancer. RESULTS: A composite oral hygiene score was developed based on five indicators selected based on PSM and IPTW analysis (including tooth loss, dentures wearing, the frequency of tooth brushing, regular dental visits, and recurrent dental ulcer). Participants with a higher score, compared with their lower counterparts, showed a 49% increased risk (the odds ratio (OR) was 1.49 (95% confidence interval (CI): 1.26-1.75). A similar association pattern was found following IPTW analyses (OR = 1.32; 95% CI: 1.22-1.42). Of note, the adverse effects of poor oral hygiene were more evident among the sites of gingival and buccal (PSM analysis: 2.03-fold and 2.68-fold increased risk; IPTW analysis: 1.57-fold and 2.07-fold increased risk, respectively). Additionally, a greater positive association was observed between poor oral hygiene and oral squamous cell carcinoma, compared with other pathological types. CONCLUSION: This study establishes a composite oral hygiene score and provides supportive evidence of poor oral hygiene associated with a higher risk of oral cancer, particularly in the gingival and buccal mucosa sites and in the squamous cell carcinoma. CLINICAL RELEVANCE: The data highlights the importance of improving poor oral hygiene habits, which has public health implications for the prevention of oral cancer.

Analysis of Maxillofacial Fractures Based on the Etiology in Southeast China: A 10-Year, Multi-Center Study.

BACKGROUND: The aim of this study was to explore the characteristics and correlation of maxillofacial fractures and concurrent injuries with different injury causes. METHODS: In this retrospective study, data were collected from patients treated for maxillofacial fractures in 3 oral and maxillofacial surgery departments in Southeast China, from January 2010 to December 2019. The information was obtained from clinical notes and surgical records using a standardized data collection form, and some causes of injuries were confirmed by telephone follow-ups and police records. These patients were divided into 7 groups according to the etiology: bicycle accident, electric bicycle accident, motorcycle accident, automobile accident, fall at ground level, fall from a height, and assault-related accident. Statistical tests were performed using R software (version 3.1.1), and all P-values were computed based on Chi-square tests and set at 0.05. RESULTS: During this 10-year retrospective study, a total of 1772 patients with definite causes were analyzed. The average age was approximately 35.04 years (9 months-94 years). All patients were treated with open reduction and rigidly internal fixation, and the average duration was approximately 6.51 days (range 0 day-50 days), that from the time of the injury to the time of treatment. Traffic accidents were identified as the main cause of maxillofacial fracture (57.62%; n = 1021 of 1772 cases). In different etiology groups, there were statistically significant differences in the distribution of age, sex, maxillofacial fracture type, and concurrent injuries (all P < 0.001). However, the main cause of maxillofacial injuries was falls (fall at ground level and fall from a height) in children, and the highest incidence of the cause of maxillofacial injuries was bicycle accident in adolescents. Compared with the other groups, zygomatic complex fracture was more common in the electric bicycle accident group, panfacial fracture was more common in the automobile accident group, and mandible fracture was more common in the other groups. CONCLUSION: The results of this study suggest that patients with maxillofacial fractures caused by different injuries had their own unique characteristics. These findings may assist us in avoiding misdiagnosis and treatment delays, and may make treatment plans faster.

The effect of formal statistical courses attitudes on learning outcomes in a cohort of undergraduate dental students.

INTRODUCTION: Whilst statistical knowledge is essential for dental students' academic or professional careers, only a few studies have measured the attitudes of these students towards statistics courses. This study aimed to investigate the attitudes of a cohort of dental students towards a formal statistical course and explore the factors that are potentially related to these attitudes. METHODS: A survey was performed amongst dental students of 2017 entry at Fujian Medical University, China. The questionnaire covers three aspects: demographic characteristics, educational background and attitudes towards formal statistics courses. RESULTS: A total of 103 dental students enrolled for the survey, and the response rate was 100.0%. 44.7% of dental students had positive attitudes towards formal statistics courses with an overall average of 25.7 (SD = 2.2, out of 30). Students' computer skills, expectations of course achievement, attention in class and learning atmosphere of the class were significantly associated with the attitudes towards formal statistics courses. Moreover, students with positive attitudes experienced a greater improvement in the statistical cognition and application ability of statistical methods after the course than those with negative/neutral attitudes. Additionally, a positive correlation was observed between students' attitudes and achievement in the examination. CONCLUSION: These results suggest that attitudes are critical to the learning effectiveness in formal statistics courses amongst undergraduate dental students. All the educators involved should monitor the students' attitudes in the teaching process and make effective interventions to improve students' attitudes towards formal statistics courses.

Orbital Apex Syndrome Causing Blindness Secondary to a Vertical Root Fracture of a Tooth.

The authors report a case of a 35-year-old man who presented with left maxillary toothache associated with left sided facial pain and a rapidly progressive loss of vision in the left eye. Clinical and radiological assessments revealed it to be an odontogenic orbital apex syndrome secondary to a vertical root fracture of a tooth. The infection was treated and controlled, postoperative follow-up showed no recurrent inflammation and the patient recovered well. However, the vision was lost permanently. Odontogenic orbital apex syndrome is a rare, aggressive disease. Once the infection spreads, it progresses rapidly, becoming a dangerous condition. To achieve better prognosis and improve survival rates, dental practitioners and oral surgeons should be aware of this distinct presentation and should have a high index of suspicion for the complication of tooth-related problems however minor they may seem.

Does Different Mandibulectomy (Marginal vs Segmental) Affect the Prognosis in Patients With Oral Squamous Cell Carcinoma?

PURPOSE: It is unclear whether different mandibular surgical methods affect the prognosis of patients with oral squamous cell carcinoma (OSCC). Accordingly, the authors retrospectively compared the prognosis of patients who underwent marginal mandibulectomy (MG) or segmental mandibulectomy (SG) for OSCC and aimed to determine the factors influencing prognosis. MATERIALS AND METHODS: The authors conducted a retrospective cohort study of 82 patients with OSCC who underwent mandibulectomy at their hospital from January 2001 through January 2015. All patients had a biopsy-confirmed diagnosis of OSCC adjacent to the lower mandible. The local recurrence rate and survival rate after these 2 treatment modalities were analyzed using Kaplan-Meier survival analysis. At univariate and multivariate analyses, the Cox regression model was used to screen risk factors for recurrence, including pathologic grade, pT stage, mandibular involvement, lymph node metastasis, and method of mandibulectomy. Statistical significance was considered when P values were less than .05. RESULTS: Of the 82 patients, 39 underwent MG and 43 underwent SG. According to statistical analysis, age, gender, pathologic grade, tumor stage, mandibular involvement, and lymph node metastasis were similar between the 2 groups. The 3- and 5-year local recurrence rates were not significantly different between the 2 groups (P > .05). The 3- and 5-year survival rates were not significantly different between the 2 groups (P > .05). Poorly differentiated pathologic type was the only prognostic factor for OSCC at multivariate Cox regression analysis (P = .001). CONCLUSION: The results of this study suggest that MG is safe for some evaluated patients with OSCC. Of the prognostic factors studied, MG was not associated with worse prognosis; however, poorly differentiated OSCC affected the prognosis for oral carcinoma.

Directed Bmp4 expression in neural crest cells generates a genetic model for the rare human bony syngnathia birth defect.

Congenital bony syngnathia, a rare but severe human birth defect, is characterized by bony fusion of the mandible to the maxilla. However, the genetic mechanisms underlying this birth defect are poorly understood, largely due to limitation of available animal models. Here we present evidence that transgenic expression of Bmp4 in neural crest cells causes a series of craniofacial malformations in mice, including a bony fusion between the maxilla and hypoplastic mandible, resembling the bony syngnathia syndrome in humans. In addition, the anterior portion of the palatal shelves emerged from the mandibular arch instead of the maxilla in the mutants. Gene expression assays showed an altered expression of several facial patterning genes, including Hand2, Dlx2, Msx1, Barx1, Foxc2 and Fgf8, in the maxillary and mandibular processes of the mutants, indicating mis-patterned cranial neural crest (CNC) derived cells in the facial region. However, despite of formation of cleft palate and ectopic cartilage, forced expression of a constitutively active form of BMP receptor-Ia (caBmprIa) in CNC lineage did not produce the syngnathia phenotype, suggesting a non-cell autonomous effect of the augmented BMP4 signaling. Our studies demonstrate that aberrant BMP4-mediated signaling in CNC cells leads to mis-patterned facial skeleton and congenital bony syngnathia, and suggest an implication of mutations in BMP signaling pathway in human bony syngnathia.

[Association between oral hygiene, chronic diseases, and oral squamous cell carcinoma].

OBJECTIVE: To investigate the association between oral hygiene, chronic diseases, and oral squamous cell carcinoma. METHODS: We performed a case-control study with 414 cases and 870 controls in Fujian during September 2010 to January 2015. Patients were newly diagnosed oral squamous cell carcinoma cases according to the pathologic diagnoses, control subjects were enrolled from community population. Epidemiological data were collected by in-person interviews using a standard questionnaire. The contents of the questionnaire included demography character, history of tobacco smoking and alcohol drinking, dietary habits, oral hygiene status, family history of cancer, etc. Using unconditional logistic regression analysis to estimate adjusted odds ratios (OR) and corresponding 95% confidence intervals (CI) for oral hygiene and chronic diseases. We also stratified by sex, smoking and drinking to explore possible difference in association between subgroups. RESULTS: The multivariate logistic regression analysis indicated that number of teeth (20-27 and < 20), bad prosthesis, recurrent oral ulceration were the risk factors of oral squamous cell carcinoma, the adjusted OR (95% CI) values were 2.01 (1.49-2.73), 3.51 (2.39-5.15), 2.33 (1.79-3.04), 3.96 (2.11-7.44), respectively; brushing tooth once per bay, brushing tooth more than once per day, regular oral health examination at least 5 years per time were the protective factors of oral squamous cell carcinoma, the adjusted OR (95% CI) values were 0.24 (0.13-0.43), 0.13 (0.07-0.24), 0.37 (0.26-0.53), respectively. The stratification analysis indicated that recurrent oral ulceration could increase the risk of oral squamous cell carcinoma for non-smokers and non-drinking, the adjusted OR (95% CI) value was 5.21 (2.42-11.18) and 4.71 (2.37-9.36); and a risky effect of hypertension on risk of oral squamous cell carcinoma was observed for non-smokers and non-drinking, the adjusted OR (95% CI) values were 1.70 (1.10-2.61) and 1.58 (1.07-2.34). CONCLUSIONS: Oral hygiene and chronic diseases could affect the incidence of oral squamous cell carcinoma.

[Influencing factors for oral-maxillofacial benign tumors: a case-control study].

OBJECTIVE: To investigate the clinical influence factors of oral-maxillofacial benign tumors. METHODS: We conducted a case-control study with 113 cases newly diagnosed primary oral-maxillofacial benign tumors and 584 cases controls from a hospital in Fujian from September 2010 to January 2015. Epidemiological data were collected by in-person interviews using a standard questionnaire. The contents of the questionnaire included demography character, history of tobacco smoking and alcohol drinking, dietary habits, oral hygiene status, family history of cancer, etc. Unconditional logistic regression was used to research the relationship between the factors and oral-maxillofacial benign tumors. RESULTS: Multivariable analysis showed that risk factors of oral-maxillofacial benign tumors included: cigarette smoking index above 1 000, passive smoking before the age of 18, age of wearing bad prosthesis between 33 to 55 years old and high blood pressure; the corresponding OR (95% CI) values were 14.63 (3.88-55.13), 2.34 (1.19-4.62), 2.35 (1.17-4.73), 3.46 (1.71-7.00), respectively; Protective factors included: regularly intake of meat above 1 time/day, fruits, health care products and vitamin tablets, brushing teeth above 1 time per day and oral examination above 5 years/time, the corresponding OR (95% CI) values were 0.22 (0.07-0.70), 0.18 (0.08-0.41), 0.32 (0.11-0.88), 0.22 (0.07-0.73), 0.28 (0.16-0.48), 0.28 (0.13-0.60), respectively. CONCLUSION: Abstinence from tobacco smoking, reduce passive smoking before the age of 18, regularly intake of meat, fruits, health care products and vitamin tablets, and oral examination at regular time might have impact on the incidence of oral-maxillofacial benign tumors to a certain extent.

Towards superior biopolymer gels by enabling interpenetrating network structures: A review on types, applications, and gelation strategies.

Gels derived from single networks of natural polymers (biopolymers) typically exhibit limited physical properties and thus have seen constrained applications in areas like food and medicine. In contrast, gels founded on a synergy of multiple biopolymers, specifically polysaccharides and proteins, with intricate interpenetrating polymer network (IPN) structures, represent a promising avenue for the creation of novel gel materials with significantly enhanced properties and combined advantages. This review begins with the scrutiny of newly devised IPN gels formed through a medley of polysaccharides and/or proteins, alongside an introduction of their practical applications in the realm of food, medicine, and environmentally friendly solutions. Finally, based on the fact that the IPN gelation process and mechanism are driven by different inducing factors entwined with a diverse amalgamation of polysaccharides and proteins, our survey underscores the potency of physical, chemical, and enzymatic triggers in orchestrating the construction of crosslinked networks within these biomacromolecules. In these mixed systems, each specific inducer aligns with distinct polysaccharides and proteins, culminating in the generation of semi-IPN or fully-IPN gels through the intricate interpenetration between single networks and polymer chains or between two networks, respectively. The resultant IPN gels stand as paragons of excellence, characterized by their homogeneity, dense network structures, superior textural properties (e.g., hardness, elasticity, adhesion, cohesion, and chewability), outstanding water-holding capacity, and heightened thermal stability, along with guaranteed biosafety (e.g., nontoxicity and biocompatibility) and biodegradability. Therefore, a judicious selection of polymer combinations allows for the development of IPN gels with customized functional properties, adept at meeting precise application requirements.

A 3-year follow-up clinical study on the preservation for vitality of involved tooth in jaw cysts through an innovative method.

Jaw cysts commonly affect the oral and maxillofacial region, involving adjacent tooth roots. The management of these teeth, particularly regarding root canal therapy and apicoectomy, lacks consensus. This study introduces a novel treatment concept and refined surgical approach to preserve pulp viability in teeth involved in jaw cysts. The objective was to investigate the effectiveness and potential benefits of this approach over a 36-month follow-up period. A conservative management approach prioritized vitality preservation, reserving root canal treatment and apicectomy for cases with post-operative discomfort. A comprehensive follow-up of 108 involved teeth from 36 jaw cyst cases treated with the modified method was conducted. Clinical observation, X-ray imaging, cone-beam computed tomography (CBCT), and pulp vitality testing assessed changes in cyst size, tooth color, pulp vitality, root structure, and surrounding alveolar bone. After 36 months, our modified surgical approach successfully preserved tooth vitality in 84 involved teeth. Adverse symptoms in 19 teeth, such as redness, swelling, fistula, and pain, resolved with postoperative root canal therapy. Follow-up was lost for five teeth in two cases. No cyst recurrences were observed, and in 34 cases, the bone cavity gradually disappeared, restoring normal bone density during long-term follow-up. Our modified surgical method effectively preserves tooth vitality in jaw cysts. This innovative approach has the potential to improve the management of teeth involved in jaw cysts.

The potential value of oral microbial signatures for prediction of oral squamous cell carcinoma based on machine learning algorithms.

OBJECTIVE: This study aimed to explore the potential predictive value of oral microbial signatures for oral squamous cell carcinoma (OSCC) risk based on machine learning algorithms. METHODS: The oral microbiome signatures were assessed in the unstimulated saliva samples of 80 OSCC patients and 179 healthy individuals using 16S rRNA gene sequencing. Four different machine learning classifiers were used to develop prediction models. RESULTS: Compared with control participants, OSCC patients had a higher microbial dysbiosis index (MDI, p < 0.001). Among four machine learning classifiers, random forest (RF) provided the best predictive performance, followed by the support vector machines, artificial neural networks and naive Bayes. After controlling the potential confounders using propensity score matching, the optimal RF model was further developed incorporating a minimal set of 20 bacteria genera, exhibiting better predictive performance than the MDI (AUC: 0.992 vs. 0.775, p < 0.001). CONCLUSIONS: The novel MDI and RF model developed in this study based on oral microbiome signatures may serve as noninvasive tools for predicting OSCC risk.

Phenytoin regulates osteogenic differentiation of human bone marrow stem cells by PI3K/Akt pathway.

Background: We mainly studied the mechanism by which phenytoin promotes osteogenic differentiation of human jawbone marrow stem cells. Methods: Bone marrow stem cells were extracted from jaw bone tissue debris obtained from 5 subjects undergoing implant restoration. Osteogenic and adipogenic experiments proved cells stemness, and the expression of ALP, RUNX2, and OSX were detected by qPCR and Western blot. High-throughput sequencing was used to extract differentially expressed genes, the network database predicted phenytoin drug targets, GO and KEGG enrichment combined with PPI network diagram to analyze the osteogenesis mechanism. Results: Calcium nodules and lipid droplet formation were observed in osteogenic and adipogenic experiments. The concentration of phenytoin within 100 mg/L does not produce cytotoxicity. The results of PCR and WB indicated that 50 mg/L phenytoin significantly promoted the expression of ALP and RUNX2, and 25 mg/L phenytoin significantly promoted the expression of OSX. The results of network pharmacology suggest that phenytoin promotes bone formation by up-regulating FGFR2, S1PR1, TGFB3, VCAN core proteins and activating PI3K/Akt pathway. Conclusions: Phenytoin activated the PI3K/Akt pathway to regulate the osteogenic differentiation of human jawbone marrow stem cells. https://data.mendeley.com/datasets/t3xstktt93/1.

Machine learning-based radiomics for predicting BRAF-V600E mutations in ameloblastoma.

Background: Ameloblastoma is a locally invasive and aggressive epithelial odontogenic neoplasm. The BRAF-V600E gene mutation is a prevalent genetic alteration found in this tumor and is considered to have a crucial role in its pathogenesis. The objective of this study is to develop and validate a radiomics-based machine learning method for the identification of BRAF-V600E gene mutations in ameloblastoma patients. Methods: In this retrospective study, data from 103 patients diagnosed with ameloblastoma who underwent BRAF-V600E mutation testing were collected. Of these patients, 72 were included in the training cohort, while 31 were included in the validation cohort. To address class imbalance, synthetic minority over-sampling technique (SMOTE) is applied in our study. Radiomics features were extracted from preprocessed CT images, and the most relevant features, including both radiomics and clinical data, were selected for analysis. Machine learning methods were utilized to construct models. The performance of these models in distinguishing between patients with and without BRAF-V600E gene mutations was evaluated using the receiver operating characteristic (ROC) curve. Results: When the analysis was based on radiomics signature, Random Forest performed better than the others, with the area under the ROC curve (AUC) of 0.87 (95%CI, 0.68-1.00). The performance of XGBoost model is slightly lower than that of Random Forest, and its AUC is 0.83 (95% CI, 0.60-1.00). The nomogram evident that among younger women, the affected region primarily lies within the mandible, and patients with larger tumor diameters exhibit a heightened risk. Additionally, patients with higher radiomics signature scores are more susceptible to the BRAF-V600E gene mutations. Conclusions: Our study presents a comprehensive radiomics-based machine learning model using five different methods to accurately detect BRAF-V600E gene mutations in patients diagnosed with ameloblastoma. The Random Forest model's high predictive performance, with AUC of 0.87, demonstrates its potential for facilitating a convenient and cost-effective way of identifying patients with the mutation without the need for invasive tumor sampling for molecular testing. This non-invasive approach has the potential to guide preoperative or postoperative drug treatment for affected individuals, thereby improving outcomes.

Associations between condylar fractures and external auditory canal fracture: A 7-year retrospective study.

The study aimed to investigate whether the incidence rate of external auditory canal (EAC) fracture varies among different clinical types of condylar fracture. A retrospective cohort study was conducted in single hospital of China. Eligible patients diagnosed with mandibular condylar fractures were retrospectively reviewed. Among all patients with condylar fractures (318 cases and 437 sides), 45 cases and 59 sides (59/437 sides, 13.5%) were found with EAC fracture, including 17(17/38, 44.7%) sides of sagittal fracture of condyle (Type I), 21(21/59, 35.6%) sides of intracapsular condylar fracture (Type II), 8 (8/306, 2.6%) sides of condylar neck fracture (Type III), and 6 (6/34, 17.7%) sides of condylar base fracture (Type IV). Type III condylar fracture had a significant lower rate of EAC fracture than all other three types (all p<0.001). Type I condylar fracture had a higher rate of EAC fracture compared to Type IV (p=0.014). The incidence rates of EAC fracture in combined Type I+Type II group (38/97, 39.2%) was significantly higher than Type III (8/306,2.6%, p<0.001) and Type IV (6/34,17.7%, p=0.002). A total of 35 sides (27 patients) with combined fractures were followed up for 6 months after treatment, among whom 11 sides (7 patients) were operated for both fractures simultaneously. Neither EAC stenosis nor hearing loss was observed. Meanwhile, for 24 non-operated ears from 20 patients, all EACs showed different degrees of stenosis. In conclusion, oral and maxillofacial surgeons should pay more attention to EAC fracture combined with condylar fracture, especially for patients diagnosed with condylar head fracture. Maxillofacial fractures should be accompanied by early treatment of EAC fractures, in order to prevent EAC stenosis, hearing loss, and other complications.

Digitally reconstructed severe trauma-induced oro-maxillofacial defects with free vascularised composite tissue flaps.

The aim of this study was to outline the characteristics of severe trauma-induced oro-maxillofacial defects and explore the application of microsurgical reconstruction of these defects by selecting appropriate free vascularised composite tissue flaps. A retrospective analysis was performed in 11 cases with severe trauma-induced oromaxillofacial defects from 2005 to 2018, All cases were reconstructed with free vascularised composite flaps using a supermicro-surgical/micro-surgical and digital technology. This study consisted of 11 patients (8 men, 3 women) with a median age (range) of 28 (6-64) years. Patients with long-standing trauma experienced severe scars and displacements. The trauma-induced oro-maxillofacial defects ranged in size from 4.0 × 5.0 cm2 to 7 × 15 cm2. Six radial forearm flaps, three fibular osteocutaneous flaps, a lateral thoracic flap, and an anterolateral thigh flap were harvested individually. All patients were treated effectively and followed up for over two years, with a 100% survival rate of these free vascularised composite tissue flaps. No uncontrollable complications occurred, and all patients were satisfied with the postoperative shape and function. The trauma-induced oro-maxillofacial defects display unique features, and microsurgical techniques play an important role in the reconstruction of shapes and function. In addition, some patients may need multi-stage surgeries to attain aesthetic refinement.

[Application of computer virtual design to assist the accuracy of socket preparation during tooth autotransplantation].

PURPOSE: It was aimed to apply computer virtual design and digital surgical templates to simulate postoperative position of tooth and guide the accuracy of socket preparation during tooth autotransplantation. METHODS: The study enrolled 10 patients who underwent tooth autotransplant surgery. Cone-bean CT (CBCT) data were imported into Proplan CMF 3.0 software. The donor tooth was transferred to the recipient site according to the occlusion and space situation. A digital template was designed to guide socket preparation. Computer-aided rapid prototyping (RP) technique was used to print the surgical template and tooth model. RESULTS: With computer virtual design and digital template, it was possible to accurately guide socket preparation in recipient site. The six-month follow-up results showed the periodontal space in the radiographs was continuous and intact. There was no mobility in all cases and the probing depth of the tooth was <4 mm. The related data showed a favorable survival and success rates of the donor teeth. CONCLUSIONS: Computer virtual design can successfully simulate postoperative position in tooth autotransplantation while simplifying the surgical procedure, and enhance the accuracy of socket preparation.

[Evaluation of using Proplan virtual software in teaching of orthognathic surgery].

PURPOSE: Using Proplan virtual software to construct a virtual teaching platform for orthognathic surgery, and to explore an effective teaching model for orthognathic surgery. METHODS: One-hundred grade four students of stomatology in Fujian Medical University were divided into two groups. Traditional orthognathic surgery teaching method and Proplan virtual software teaching method were employed to teach the two groups of students, respectively. Orthognathic-surgery-related paper test was used to evaluate how the two groups of students understand orthognathic surgery; then the students were switched to the other teaching method, respectively. A follow-up questionnaire survey was conducted to further evaluate students' acceptance of the two teaching methods. Finally, a comprehensive statistical analysis was performed for students understanding of orthognathic surgery using SPSS 11.0 software package. RESULTS: According to the test scores, students in the experimental group scored higher than the control group, the difference was significant (P<0.01). The acceptance of different teaching methods displayed remarkable difference between the two groups. Token together, our finding showed that virtual model surgery teaching was an easier teaching method for students to understand and accept. CONCLUSIONS: Proplan virtual software teaching improves the teaching efficiency of orthognathic surgery and deserves further promotion.

Nomograms and risk scores for predicting the risk of oral cancer in different sexes: a large-scale case-control study.

Background: Although previous studies have explored the associations of modifiable lifestyle factors with oral cancer risk, few studies integrated these factors and established predictive tools for oral cancer risk in different sexes. Methods: Using a case-control study design, a total of 978 oral cancer cases and 2646 healthy controls were recruited in this study. Nomograms were constructed according to significant factors in multivariable logistic regression. Risk scores were calculated based on the nomograms and quantified the risk of oral cancer using restricted cubic spline. Results: Multivariate analyses demonstrated that smoking, alcohol drinking, tea, intake of fish, seafood, vegetables, fruits, teeth loss, regular dental visits and repetitive dental ulcer were independent factors for male oral cancer. Passive smoking, age at first intercourse, cooking oil fumes exposure, tea, intake of beans, vegetables, fruits, teeth loss, regular dental visits and repetitive dental ulcer were associated with female oral cancer. Then, two nomograms were developed for predicting the probability of oral cancer in men and women with the C-index of 0.768 (95% CI: 0.723-0.813) and 0.700 (95% CI: 0.635-0.765), respectively. Restricted cubic splines graphically revealed the risk of oral cancer in individuals with different risk scores. Moreover, the risk escalated continuously with the increasing number of the risk scores among both sexes. Conclusions: Combining nomograms with risk scores developed in this study could precisely predict oral cancer occurrence and provide an accurate risk assessment.

[Clinical effect of modified alveolar cleft repair with bone grafting].

PURPOSE: To evaluate the clinical effect of improved alveolar cleft repair with bone grafting. METHODS: Forty one cases with alveolar cleft treated by modified operation between 2008-2016 were included. The modified techniques were as follow: incision design, preparation of bone graft bed, bone removal and bone grafting, etc. The therapeutic effect was analyzed. RESULTS: The successful rate was 92.8%. After 6-12 months of follow-up, bone graft survived well with no obvious complications. CONCLUSIONS: Iliac bone is a good source for bone graft. Improvement of tight tension-free suture in bone bed is the key to surgical success.