| The mortality rate of trauma is only lower than cardiovascular disease, respiratory disease and cancer. Trauma is also the first cause of death of the population under the age of40. The famous American surgical specialists Watt had wittily said:"Nothing is certain in life except death and taxes, then trauma is the third thing of the life we can not escape". The trauma has a close relationship with modern social civilization.The threat of oral and maxillofacial trauma to life is not so direct and serious as the heart, brain, liver, lung, kidney and other organ injuries. However, facial is of the main part of the language and emotional expression, trauma to this area aroused great inconvenience and even obstacles to the patients social activities and interpersonal communication, can also cause serious damage to the patients psychological with time. Characteristics of maxillofacial trauma are highly related to the development of country and social-economics. Maxillofacial trauma has been aroused more and more attention by scholars from various countries of the world, but most of them were descriptive study, lack of the scientific, systematic and in-depth analysis.Problems found in clinical research, sometimes need basic research to further explain. Tissue healing and repair of post-traumatic are considered as the concentration and reproduction of the process of development and regeneration. Over the past decades, wound repair and tissue regeneration have made a lot of progress due to the contribution of molecular and deveopment biology to trauma medicine, but so far, many of the fundamental problems in wound repair has not been fully resolved. Condyle as the development center in face, possesed the highest risk of fracture or trauma, resulting in developmental disorders and facial deformities. The treatment of condylar fractures is also highly controversial. Therefore, research about the regulatory role of nell-1gene in the development of condylar process would give us inspiration to the clinical and basic research of maxillofacial trauma.The present study included two parts. First part:The epidemiological research of maxillofacial fractures in our department; Second part:Nell-1expression and regulatory mechanism in the development of condylar and systemic cartilage.Part I:Maxillofacial Trauma in Wuhan, China:a retrospective studyPurpose: 1. To assess the changes in the etiology, incidence, and pattern of maxillofacial fractures during2different study periods in our department.2. To evaluate and compare the incidence, pattern and demographic characteristics of maxillofacial fractures between women and men in China.3. To evaluate and compare the demographic characteristics of maxillofacial fractures between children and adolescents.4. To evaluate the relationship between trauma etiologies and anatomic sites of mandibular fractures.5. To analyze and evaluate the correlation between dental injuries and the pattern of maxillofacial fractures. The correlation with age, gender, trauma mechanism and type of maxillofacial fracture was also investigated.6. To investigate the occurrence and patterns of dental trauma in patients with single mandibular fracture and to evaluate the relationships between dental injury and fracture site of mandible.7. To retrospectively investigate the aetiology, pattern, and treatment of mandibular mandibular fractures in our department over the past22years.Patients and Methods:1. In this retrospective study, patients treated for maxillofacial fractures at our department from January2000to December2009were included. Data regarding patients age, sex, etiology of fracture, time of injury, site of fracture, and pattern of fracture were collected and grouped chronologically into two5-year periods:2000to2004(period1) and2005to2009(period2); the results of the study during these periodswere analyzed and compared.2. The information and data were collected based on case history, clinical, and radiographic findings for each patient from2000to2009. Data analysis included Chi-Square test, Fisher exact test, t-test. P less than.05was considered significant.3. The sample was composed of all children (less than12years) and adolescents (between13and18years old) who presented with maxillofacial fractures during a10-year period (2000-2009). The age, gender, time of injury, mechanism of trauma, location and pattern of fracture, associated injuries, and treatment methods were recorded and analyzed. Data analysis included Chi-Square test, Fisher exact test, p less than0.05was considered significant.4. The sample was composed of all patients who sustained mandibular fractures during a10-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 Chi-Square test, theFisher exact test, the t test, and logistic regression analysis. P<0.05was considered significant.5. From January2000to December2009,1131patients with facial fractures were registered. Of these,473presented with associated dental injuries. The information and data collected and analyzed included:age, gender, mechanism of injury, type of facial fracture, type of dental injury, and the relationship between dental injury and facial fracture.6. From January2000to December2009,869patients with mandibular fractures were registered. Only the patients with single mandibular fracture were included. The information and data collected included age, gender, mechanism of injury, type of mandibular fracture, and type of dental injury.7. Data of patients who sustained mandibular mandibular fractures from1988to2009were recorded, including fracture etiology, pattern of mandibular fracture, time, age, sex, associated injury, patient transferred by other clinics, lag time and treatment method. Data analysis included Chi-Square test, Fisher exact test, t-test, Ridit analysis and Logistic regression analysis.Results:1. A total of1131patients sustained maxillofacial fractures:422in the first period and709in the second period. During the second period, the maleYfemale ratio increased from3.35:1to3.63:1. Road traffic accidents remained the major etiologic factor, which increased remarkably from49.3%to54.6%(P=0.085), whereas assault-related injuries decreased significantly from16.8%to12.4%(P=0.039). The proportion of patients with mandibular fractures decreased from59.6%to55.3%(P=0.037), whereas the proportion of patients with midfacial fractures increased from40.4%to44.7%(P=0.037).2. There were1,131patients (881male and250female) who sustained maxillofacial fractures, with a male-to-female ratio of3.5:1. Male patients suffered injuries most frequently during autumn (p=0.048), while females sustained more maxillofacial injuries during summer (p=0.006). Men sustained motor-related accidents (p=0.023) and assault-related accidents (p=0.036) more frequently than women, while women were more frequently injured in bicycle-related accidents (p<0.001) or falling while at ground level (p=0.001) than men. women were more frequently involved in fracture of condylar than men (p=0.028), whereas men were more prone to sustain symphsis fractures than women (p=0.037). For drivers, only men were involved (p=0.001). Male workers sustained maxillofacial fractures more frequently than female workers did (p<0.001). Children, students and company staff in female group were more prone to suffer maxillofacial fractures than males (p=0.010, p=0.004and p=0.044respectively).3. Seventy-nine children (male-to-female ratio,1.63:1) and113adolescents (male-to-female ratio,3.52:1) sustained389maxillofacial fractures. Children were more involved in falls compared to adolescents (44.3%versus23.9%, p=0.003), while adolescents sustained more assault-related injuries (13.3%versus2.5%, p=0.010) and motor-related accidents (22.1%versus8.9%, p=0.015) compared to children. Children suffered mandibular fractures proportionally higher than adolescents (93.1%versus64.5%, p<0.001). Adolescents sustained mid-facial fractures more frequently than children (35.5%versus6.9%, p<0.001). Severe facial fractures occurred more in adolescents compared to children (35.4%versus14.1%, p=0.001). Open reduction was done more in adolescents than in children (92.3%versus74.6%, p<0.001).4. Fall at ground level had a9.64-fold risk of mandibular condylar fractures (odds ratio,9.64; P G0.001). No significant relationship existed between different etiologies and symphsis fracture. All of the etiologies had a low risk to mandibular body fractures (odds radio, Gl; P G0.05). The occurrence of mandibular angle fractures was highly related to patients’age (P=0.001).5. Dental injury was sustained by473patients (41.8%), with a total of2215injured teeth. Of the2215injured teeth,1191(53.8%) were in the maxilla and1024(46.2%) in the mandible. Fall from a height had the highest risk of dental injuries (OR=4.145, P=0.002). The central incisor was the most injured tooth for both the maxilla (388,36.2%) and mandible (284,27.7%). The most common type of dental injury was avulsion (1070,47.4%). More anterior teeth in the maxilla were of crown fracture, avulsion, and intrusion than that in the mandible, whereas more anterior teeth in the mandible were of sub luxation and concussion than that in the maxilla. Dental injuries were more prone to occur in patients who sustained only symphysis fractures (OR=2.817, P<0.001), only0.236-fold risk in patients who sustained only mandible angle fracture (P<0.001).6. Single mandibular fractures were sustained in294(33.8%) patients. Of these,43.5%(128patients) presented with associated dental injuries (509injured teeth). The patients’ male/female ratio was2.46:1(91males and37females). Patients in30-39year age group possessed the highest risk of suffering dental injuries (odds ratio=2.004, P=0.014). Road traffic accidents were the most common mechanism of injury (54,42.2%). Lower-anterior were more often injured in patients with symphsis fracture (P<0.001), and patients with condylar fractures more frequently sustained upper-posterior injury (P<0.001). Lower-posterior injury was mostly found in patients with mandibular body fracture (P<0.001) or angle fracture (P<0.001). Dental injuries were more prone to occur in patients who sustained only symphsis fractures (odds ratio=3.283, P<0.001), and the risk was only0.193-fold in patients who sustained only mandible angle fractures (odds ratio=0.193, P<0.001).7. The sample was composed of549patients (749condyalr fractures),404male and145female (male:female=2.79:1), with a mean age of30.1214.44years. Road traffic accidents were the most common cause (248,45.2%). Condylar head fractures were significantly related to a fall at ground level (p<0.001). A fall from a height had a3.19-fold risk of bilateral condyalr fractures (odds ratio,3.19;95%confidence interval,1.33to7.65; p＜0.010). A majority of the condyalr fractures (693,92.5%)were treated by a surgical procedure. Condylar head were mostly removed (95.0%, p<0.001), condylar neck and condylar base fracturesweremost frequently treated by open reduction and internal fixation with miniplates (74.4%, p<0.001). Most of the dislocated condyalr fractures were treated by open surgery (96.5%, p<0.026).Conclusions:1. The changing pattern of maxillofacial fractures in our center is correlated to the socioeconomic status, population mobility, and etiologic factors. Strict enforcement of traffic laws and regulations is still a focal factor in attaining appreciable reduction in maxillofacial fractures associated with road traffic accidents. 2. The incidence, pattern and demographic characteristics of maxillofacial fractures in female patients are significantly different from male patients.3. The incidence and pattern of maxillofacial fractures in children were remarkably different from that in adolescents. Preventive measures and treatment plan should be designed with differences between the two groups in mind.4. The pattern of mandibular fractures was highly related to patients age and the different etiologies.5. The occurrence of dental injuries is significantly related to the pattern and position of the maxillofacial fractures.6. The occurrence and type of dental injury were significantly related to the fracture site of mandible.7. The anatomic position and uni/bilateral pattern of mandibular condylar fractures were positively related to situations when considerable force is involved. Open condylar surgery was based on the level of fracture and degree of displacement or dislocation.Part Ⅱ Expression of nell-1during the development of condyle and the cartilage in whole bodyObjective:To explore the temporal and spatial expression of NELL-1in the development of mandibular condylar and systemic cartilage in whole body. Methods: The pregnant mice (E12, E14, E16, El8); neonatal mice (2days,1week,2weeks, four weeks, six weeks, eight weeks). The detection sites was the cartilage area (condylar process, ribs, vertebrae, femur). Detection methods including RT-PCR and immunohistochemical staining method (IHC). Results:Two days after the newborn mice, NELL-1almost expressed in full thickness of the condylar cartilage, especially obvious in the proliferation layer and the pre-hypertrophic chondrocytes layer. NELL-1is expressed mainly in the cell nucleus; NELL-1expressed obviously in the costal cartilage, including the germinal layer, the proliferation layer and the hypertrophic chondrocytes. NELL-1was also found to express in vertebral cartilage; the femur cartilage showed no significant NELL-1expression. Conclusion:NELL-1expressed on the mandibular condyle and systemic cartilage in whole body except the femur cartilage. Further study should be carried out to explore the regulation mechanism of nell-1on the development of condylar process and systemic cartilage. |
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