Serious Condylar Head Absorption in Children With Intracapsular Condylar Fractures Treated Operatively With Long Screws.

OBJECTIVE: This study was performed to explore bone remodelling in children with intracapsular condylar fractures after the condylar fracture fragments were fixed using long screws and to offer possible explanations about the underlying mechanism. PATIENT AND METHODS: Records of children (less than 12 y old) who sustained intracapsular condylar fractures and fixed with long screws from May 2012 to January 2015 were retrieved. Age, gender, dates of injury, admission, and discharge, mechanism of trauma, location and pattern of fracture, other mandibular fractures, treatment methods, and time of review were recorded and analyzed. Image dates of pretreatments and posttreatments, including the date of review, were also recorded. RESULTS: A total of 8 patients completed their follow-up, and all patients (n=5) who were followed up after more than 3 months showed serious resorption of the condylar head. The condylar head resorbed until the height (or articular surface) dropped and aligned with the surface of the screw. The shortest time of absorption, as shown by the computed tomography scan was 106 days, and the longest time was 171 days (average time of 141.8 d). CONCLUSIONS: Intracapsular condyle fractures in children should be managed conservatively as much as possible. However, if the height of the fracture fragments drops remarkably, open reduction and rigid internal fixation become possible choices.

Fracture fragment of the condyle determines the ramus height of the mandible in children with intracapsular condylar fractures treated conservatively.

This study aimed to explore and impart understanding of bone remodelling in children with intracapsular fractures treated conservatively. Records of children (less than 12 years), who sustained intracapsular fractures and treated conservatively, were retrieved consecutively for the period of March 2011 to February 2016. Data about age, gender, date of injury, dates of admission and discharge, mechanism of trauma, location and pattern of fracture, other mandibular fractures, treatment methods and time of review were recorded and analysed. Image dates of pre- and post-treatments, including date of review, were also recorded. A total of 22 patients complete their follow-up and show bone remodelling process. During their follow-up, all the displaced condylar fragments fused with the ramus stump at the displaced position. Regardless of the type of conservative procedure, both treatments cannot promote the spontaneous fracture reduction in patients with intracapsular condylar fractures. During follow-up, the absorption of the lateral process of the condyle after the closed treatment becomes close to the 'horizontal absorption', until the height (or articular surface) of the lateral condylar process dropped and aligned to the articular surface of the medial process. In children with intracapsular condylar fractures, the fracture fragment of the condyle determines the ramus height of the mandible. Closed treatment cannot restore the fracture fragment. If the height of the fracture fragments dropped remarkably, then open reduction and rigid internal fixation become more suitable.

Treatment of Sagittal Fracture of the Mandibular Condyle Using Resorbable-Screw Osteosynthesis.

PURPOSE: Screw osteosynthesis is advocated for the treatment of sagittal fracture of mandibular condyle (SFMC). This study aimed to explore the applicability of resorbable-screw osteosynthesis in the treatment of SFMC. METHODS: A retrospective cohort study was performed in patients with SFMC treated with resorbable-screw osteosynthesis (group A) from June 2011 through June 2021. The patients who had undergone titanium-screw osteosynthesis served as the control group (group B). The primary outcome variable was fracture healing, defined as follows: 1) normal mouth opening and restoration of pretrauma occlusion; 2) without complications or discomfort of temporomandibular joint symptoms; and 3) fracture union without abnormal reactions or bone resorption in computed tomography images. The secondary outcome variable was condylar morphological changes including radiographic imaging appearance of the condyle, mandibular ramus height (MRH), anteroposterior diameter (APD), and mediolateral diameter (MLD) of the condyle, which were assessed by comparing the computed tomography images 1 week after surgery with those of 3 months after surgery. The collected data of the outcome variables of the 2 groups were analyzed correspondingly using Student's paired t test and Student's t test. RESULTS: There were 24 patients in group A and 71 patients in group B. All the patients displayed an evident improvement in mouth opening and restored pretrauma occlusion. Few patients had complications (group A, 8.33%; group B, 9.86%) and discomfort of temporomandibular joint symptoms (group A, 16.67%; group B, 15.49%). Fracture union without abnormal reactions or bone resorption was observed during the follow-up. The radiographic evaluation revealed no significant difference in the MRH, the maximum APD, and MLD of the condyles between 1 week and 3 months after surgery in both groups. There were no significant intergroup differences in the changes in the MRH, APD, and MLD of the condyles. CONCLUSIONS: Resorbable-screw osteosynthesis is a viable option for the treatment of SFMC.

Removal of Fracture Fragments in Intracapsular Condylar Fractures: An Alternative Treatment Option.

OBJECTIVE: This study aimed to explore bone remodeling after condylar fracture fragments have been removed from patients with intracapsular condylar fractures. it also evaluated whether condyle fracture removal can be used alternatively when the authors treat patients with comminuted or small pieces of fracture or in extremely difficult operations. METHODS: Records of patients who sustained intracapsular condylar fractures and treated by removal of fragments for the period of February 2013 to September 2019 were retrieved. Data about age, gender, date of injury, dates of admission and discharge, mechanism of trauma, location and pattern of fracture, other mandibular fracture, treatment methods and time of review were recorded and analyzed. Image dates of pre- and post-treatment (including the time of review) were also recorded. RESULTS: The data of a total of 103 patients ranging from 5 to 84 years old were retrieved during this study. A total of 135 sides of condylar fragments were removed. Almost all of the patients with comminuted condyle head fracture or type A fracture presented apparent shortening of the ramus height, and none of them showed osteogenesis (or new bone formation) during their follow-up. Present study only observed osteogenesis in few patients who sustained type B/C intracapsular condylar fractures during their follow-up. The younger the patient was, the longer the follow-up time was, and the higher the possibility of new bone formation was. No correlation was found between the amount of osteogenesis and follow-up time, the amount of osteogenesis was generally small, and no patient could form a new condyle head similar to the normal (or original) condyle head. Condylar hypertrophy only occurred in children. Four patients developed temporomandibular joint ankylosis. CONCLUSIONS: Removal of fracture fragments is an alternative treatment option for patients who sustained comminuted or small pieces of fracture or in extremely difficult operations.

Maxillofacial Injuries in Pediatric Patients.

OBJECTIVE: This study aimed to evaluate and analyse the demographic characteristics and changes in maxillofacial injuries during their development in pediatric patients. METHODS: A retrospective cohort and case-control study was conducted. The sample was composed of all children (less than 10.5 years) who presented with maxillofacial injuries within a 6.5-year period (from December 2012 to April 2019). Data about age, gender, hospitalization date, mechanism of trauma, location and pattern of injuries, associated general injuries or systemic diseases, admission methods (emergency admission or not), type of anesthesia, treatment methods and hospital costs (¥) were recorded and analyzed. Data analysis included Chi-square test, Fisher exact test, and t test. Univariate and multivariate analyses were also performed. Logistic regression analysis was used to control for confounding variables. Differences at P < 0.05 were considered significant. RESULTS: A total of 643 pediatric patients were included in this study, with a boy-to-girl ratio of 1.77:1 (411 boys and 232 girls). The age range was 0.18 to 10.5 years (average of 3.23 ±â€Š1.98 years). The largest age group was patients aged 1 to 2 years (200 patients, 31.1%), followed by 2 to 3 years (139 patients, 21.6%). In the majority of patients, fall at ground level was the most common mechanism of injury (391 patients, 60.8%). In addition, 613 patients (95.3%) sustained at least maxillofacial soft-tissue injuries, while 460 (71.5%) sustained only maxillofacial soft-tissue injuries and 183 (28.5%) sustained maxillofacial fractures. Lip was the most vulnerable soft tissue to be injured (283 patients, 44.0%). Patients who sustained maxillofacial soft-tissue injuries were less prone to maxillofacial fractures than those who did not. Maxillofacial fractures were highly presented in patients with dental injuries (OR = 6.783; 95% confidence interval, 3.147-14.620; P < 0.001). Older children (> 5 years old) were at higher risk of maxillofacial fractures than younger children (≤ 5 years old, P = 0.006). The risk of maxillofacial fractures (except symphysis fractures) increased with age, especially in patients aged between 5 and 10 years. Maxillofacial soft-tissue injuries were highly distributed amongst patients aged 1 to 5 years. The number of patients who sustained only maxillofacial soft-tissue injuries gradually decreased from 2013 to 2018. Patients in emergency admission (OR = 13.375; 95% confidence interval, 1.286-139.121; P = 0.030) and treated under general anesthesia (OR = 27015.375; 95% confidence interval, 1033.046-706484.218; P < 0.001) were more prone to be treated by surgery procedure. Patients with facial fractures were less frequent to be treated by surgery procedure (OR = 0.006; 95% confidence interval, 0.000-0.575; P = 0.028); however, the mandibular symphysis (OR = 18.141; 95% confidence interval, 2.860-115.069; P = 0.002) or body fractures (OR = 71.583; 95% confidence interval, 2.358-2172.879; P = 0.014) were highly treated by surgery procedure. CONCLUSIONS: Maxillofacial fractures in pediatric patients were significantly related to age, etiology, maxillofacial soft-tissue injury, dental injury and other general injuries. Older pediatric patients were at higher risk of maxillofacial fractures (except symphysis fractures) and lower risk of maxillofacial soft-tissue injuries than younger pediatric patients. Patients in emergency admission, fractures of the symphysis or body, and treated under general anesthesia were the main reasons for surgical management.

Restoration of Ramus Height in Child Patients With Extracapsular Condylar Fractures: Is This Mission Almost Impossible to Accomplish?

OBJECTIVE: This study aimed to assess whether ramus height is restored in children with extracapsular condylar fractures treated by conservative or surgery procedures. METHODS: The sample consisted of 35 children (collected consecutively) less than 12 years old who presented with extracapsular condylar fractures and treated within an 8-year period (June 2011 to April 2019). Data on the age, gender, date of injury, mechanism of trauma, location and pattern of mandibular condylar fracture, associated injuries and treatment methods were recorded and analyzed. Ramus height restoration is the main evaluation indicator during the follow-up period. RESULTS: Within the 8-year record retrieval, the 35 children sustained 41 extracapsular condylar fractures. For the sample size, 10 (24.4%) and 31 (75.6%) had condylar neck and base fractures, respectively. Deviation and green-stick fracture were the predominant types in condylar neck and base fractures, accounting for more than 3 quarters (31, 75.6%). The majority (33, 80.5%) of patients were treated with nonsurgical treatment, and 8 (19.5%) were treated by open reduction and internal fixation (ORIF). During the follow-up period (1-1419 days, average time of 110.6 days), only 1 patient (with bilateral extracapsular condylar fractures) had their ramus height restored (follow-up period, 256 days). Most members of the ORIF group (5 of 8, 62.5%) postoperatively showed bended ramus (deviated angularly/fragment angulation). CONCLUSION: Conservative treatment could hardly restore the ramus height of children with extracapsular condylar fractures. Anatomically or totally restoring the ramus height is difficult even with the surgical treatment of ORIF; however, surgical treatment of ORIF can substantially restore the ramus height for dislocated fractures or seriously displaced fractures.

Extracapsular Condylar Fractures Treated Conservatively in Children: Mechanism of Bone Remodelling.

OBJECTIVE: This study aims to reveal the reconstruction process in pediatric patients with extracapsular condylar fractures after conservative treatment. We clarify that the "upright" position (or "recontouring" or favorable prognosis) of condyles is not a result of the anatomical reduction of the deviated condylar processes but originates from the remodeling of the skeleton. We also explore the related mechanism. METHODS: The sample consisted of 27 pediatric patients aged less than 12 years who presented with extracapsular condylar fractures and were treated conservatively within an 8-year period (June 2011-April 2019). Data on the age, gender, date of injury, mechanism of trauma, location and pattern of mandibular condylar fracture and associated injuries and treatment methods of the patients were obtained. The process of bone remodeling in condyles was also recorded and analyzed. RESULTS: The 27 children in this study sustained 33 extracapsular condylar fractures over the 8-year period of record retrieval. Amongst these fractures, 8 (24.2%) and 25 (75.8%) were condylar neck and condylar base fractures, respectively. Deviation and green-stick fractures were the predominant types and accounted for over 3 quarters of the condylar neck and base fractures (28, 84.8%), followed by dislocation fracture (3, 9.1%), displacement fracture (1, 3.0%), and non-displaced fracture (1, 3.0%). The period of follow-up ranged from 2 days to 257 days (average, 58.78 days). Only 1 patient with bilateral extracapsular condylar fractures showed vertically reconstructed condyles, which indicates an upright position of the condylar processes. One patient showed less angulation after treatment than before treatment, 1 patient revealed greater angulation after treatment than before treatment and all other patients (20 patients) showed the same angulation pre- and post-treatment. Both patients with only extracapsular condylar fractures showed no obvious deviations in dentition and facial asymmetry after their injury and treatment. The shortest and longest times observed for bone remodeling were 33 and 256 days, respectively. Children whose condylar head remained completely or at least partly inside the glenoid fossa showed satisfactory remodeling results during follow-up. Computed tomography scan during follow-up generally showed bone regeneration in the lateral condyle articular surface and the medial portion of the ascending ramus and bone resorption in the displaced direction (ie, the medial condyle head became sharp). Condylar heads displaced completely outside of the glenoid fossa showed serious shortening of the ascending ramus, and no obvious bone remodeling was observed. Only 1 patient with bilateral extracapsular condylar fractures showed a normal contour (ie, a vertically reconstructed condyle reflecting the upright position of the condylar processes) after 8 months. CONCLUSION: Stress stimulation originating from the glenoid fossa and ascending ramus of the mandible is a prerequisite for good condylar reconstruction. Conservative treatment could be carried out if the condylar head remains completely or at least partly inside the glenoid fossa. When the condylar head is dislocated completely outside the glenoid fossa, the glenoid-condylar relationship ceases to exist, joint function is lost and the height of the ascending ramus is significantly reduced. In this case, open reduction may be suitable.

Characteristic changes of traumatic dental injuries in a teaching hospital of Wuhan under transmission control measures during the COVID-19 epidemic.

BACKGROUND/AIMS: In December 2019, a novel coronavirus emerged in Wuhan City, and a retrospective analysis is necessary to provide clinicians with the characteristics of traumatic dental injuries (TDIs) during the epidemic. The aim of this study was to evaluate the changes in the characteristics of TDIs under the transmission control measures in Wuhan City utilizing an epidemiologic investigation. MATERIALS AND METHOD: In this retrospective study, epidemiologic information, including the number of patients, gender, age, and TDI parameters such as time since injury to the clinic visit, etiology, tooth location, and the type of injury was extracted from the records of patients in the hospital from two periods: period 1 (between January 23, 2020, and April 7, 2020) and period 2 (between January 23, 2019, and April 7, 2019). The data from the two periods were compared and analyzed. RESULT: A total of 158 patients were treated for TDIs (120 in 2019 and 38 in 2020). Males were more likely to suffer from TDIs than females with a ratio of 1.5:1, both in 2020 and 2019. Other than that, there were characteristic changes in TDIs during the transmission control measures in the COVID-19 epidemic, which included the number of patients, age, time since injury to the clinic visit, etiology, tooth location and the type of TDI. CONCLUSION: The transmission control measures during the COVID-19 epidemic had a significant impact on the epidemiology and etiology of TDIs in Wuhan City.

Expert Consensus on Procedures and Operations of Navigation-guided Needle Biopsy Techniques for Skull Base Tumours.

Skull base surgery is an interdisciplinary subject. The anatomical structures in the skull base related to oral and maxillofacial surgery include the parapharyngeal space, the pterygopalatine fossa and the infratemporal space. This operative area is one of the most challenging surgical areas in oral and maxillofacial surgery due to its deep site, complex anatomy and high risk. Obtaining pathological information of the tumour preoperatively may help surgeons optimise their treatment plan. Needle biopsy is one of the major minimally invasive techniques that allows preoperative pathological results to be obtained. The navigation technology, which is developing rapidly nowadays, provides a reliable assistance for deep tissue biopsy surgery. Experts from the Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association formulated an expert consensus on the procedures and operations of navigation-guided needle biopsy techniques for skull base tumours, so as to standardise and promote the application and operation of navigation-guided needle biopsy for skull base tumours.

Expert Consensus for the Treatment Algorithm for Navigationassisted Reconstruction of Maxillofacial Deformities.

Deformities of the maxillofacial region following trauma and ablative surgery are devastating and not uncommon. Reconstruction of such defects is a surgically challenging procedure. Conventionally, reconstruction of dental arch defects lacks preoperative customised planning and relies heavily on the surgeon experience to ensure optimum surgical outcomes. The restoration of the dental arch shape and function has taken precedence after an extensive tumour resection surgery, especially in the current age of technological advancement. Thus, personalised and accurate reconstruction of dental arch defects has become a new goal. Computer-assisted surgery, especially navigation-assisted surgery, has gained popularity of late, in reconstructing deformities and restoring facial symmetry, appearance and function in the maxillofacial region. This technology provides a clearer three-dimensional visualisation of the area of interest and its relationship with the adjacent vital structures. Together with preoperative virtual surgical planning, it allows more specific and accurate osteotomies, thus reducing the ischemia and total operating times substantially. The risk of complications is also minimised whilst improving the final surgical outcomes. The use of the intraoperative navigation system and other computer-assisted surgical techniques during surgery can significantly improve the precision of the reconstruction of dental arch deformities, and achieve personalised and functional reconstructive goals while enhancing the quality of life of patients postoperatively. The Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association provides the present professional perspective and treatment protocol for navigation-guided reconstruction of dental arch defects, to allow standardisation of the technique while promoting its application among oral and maxillofacial surgeons.

Expert Consensus on Navigation-guided Unilateral Delayed Zygomatic Fracture Reconstruction Techniques.

The zygoma is located in the medial and lateral parts of the face, supporting the midfacial contour. The forward projection of the zygoma and the zygomatic arch often expose them to injury. Fractures of the zygoma can lead to the displacement of the zygoma and the zygomatic arch, causing facial collapse deformity. For delayed zygomatic fractures, the loss of normal anatomical landmarks caused by the malunion of the fracture lines and remodelling of the bony contour makes it difficult to determine the correct positions of the zygomatic bones. In such cases, ideal and steady outcomes with satisfactory midface symmetry have been difficult to obtain using traditional surgical methods. Nowadays, the application of digital surgical software and surgical navigation helps surgeons to perform accurate preoperative simulations to obtain ideal three-dimensional virtual surgical plans and achieve accurate reduction by intraoperative navigation systems, which increase the accuracy and predictability of fracture reduction outcomes. Experts from the Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association have fully discussed and formulated an expert consensus on navigation-guided unilateral delayed zygomatic fracture reconstruction techniques to standardise the clinical operation procedures and promote the application.

Expert Consensus on Navigation-guided Unilateral Orbital Fracture and Orbital Floor Reconstruction Techniques.

Orbital fracture and orbital floor reconstruction surgery is characterised by limited surgical exposure and high risks. Before the advent of digital technology, the design and implementation of the surgical scheme for orbital floor reconstruction surgery mainly depended on the intuitive understanding of imaging and the clinical experience of surgeons, with strong unpredictability and experience dependence. Surgical navigation systems with real-time positioning and imaging functions, when used in orbital reconstruction surgery, can detect the real-time intraoperative position, avoid risks, and assist in locating the reconstruction position to ensure the accuracy of orbital reconstruction, with the help of a preoperative surgical plan. Many studies have confirmed its effect. Unilateral orbital fracture and orbital floor reconstruction surgery is one of the earliest and most widely used surgical techniques in maxillofacial surgery. Experts from the Society of Oral and Maxillofacial Surgery, Chinese Stomatological Association have fully discussed and formulated this expert consensus on navigation-guided unilateral orbital fracture and orbital floor reconstruction techniques to standardise the clinical surgical procedures and promote its application.

Abduction of the condyle head leads to condylar resorption: A radiologic study in children with intracapsular fractures.

OBJECTIVE: This study aimed to explore and make an understanding of absorption existed in children with intracapsular fractures. METHODS: The sample was composed of all children (less than 12 years) who presented with intracapsular fractures within a 5-year period (January 2011 to April 2016). Data about age, gender, date of injury, dates of admission and discharge, transfer and/or referral by other clinics or local facilities, mechanism of trauma, location and pattern of fracture, associated injuries, centimeter of mouth opening, treatment methods, image date of pre- and post-treatment (including time of review), position of condylar head in pre-treatment or post-treatment, and absorption of condylar head in pre-treatment or post-treatment were recorded and analyzed. Data analysis included the Chi-Square test, the Fisher exact test, and the t-test. Logistic regression analysis was utilized to control the confounding variables. Probabilities of p less than 0.05 were considered statistically significantly different. RESULTS: In the 5 years records retrieved during this study, 93 children patients sustained a total of 140 condylar head fractures. Statistical analysis revealed that abduction of condylar process in post-treatment was highly related to the condylar absorption. Patients associated with other mandibular fractures were highly related to abduction of condylar process. Patients with condylar head fractures, the closer to the medial of the condylar process, the higher the risk of abduction of the condyle. No matter what kind of treatment method is used, it is very difficult to reverse the abduction of condylar process in children patients with intracapsular fractures efficaciously. CONCLUSION: Abduction of condylar process in post-treatment was highly related to the condylar absorption. Patients associated with other mandibular fractures were highly related to abduction of condylar process. Children patients who presented with condylar head fractures, the closer to the medial of the condylar process the higher the risk of abduction of the condyle. Neither surgery nor conservative treatment can recover the abduction of condylar process efficaciously.

Mandibular condylar fractures in children and adolescents: 5-Year retrospective cohort study.

OBJECTIVE: This study aimed to evaluate and compare the demographic characteristics of mandibular condylar fractures between children and adolescents. METHODS: The sample was composed of all children (less than 12 years) and adolescents (between 13 and 18 years old) who presented with mandibular condylar fractures within a 5-year period (January 2011 to April 2016). The age, gender, time of injury, mechanism of trauma, location and pattern of fracture, associated injuries and treatment methods were recorded and analysed. Data analysis included chi-square test and Fisher exact test. Differences at p less than 0.05 were considered significant. RESULTS: A total of 111 children and 39 adolescent patients with condylar fractures were registered and compared. More children than adolescents were involved in falls from a height (p = 0.007), but nearly no relationship was observed between the trauma aetiology and type of condylar fracture in the two patient groups. Condylar head fractures occurred most frequently in the children and adolescents, especially in the children (p < 0.05). Condylar neck fractures were more frequently observed in the adolescent patients (p < 0.001) than in the children. Green-stick fractures occurred only in the child patients (p = 0.005). The patients who fractured other sites of the mandible tended to show a decreased frequency of dislocation (condylar head was out of the glenoid fossa) (p = 0.024). Symphysis/para-symphysis fractures were highly common in the children who sustained unilateral condylar fractures, compared to adolescents (p < 0.05). The patients with bilateral condylar fractures were more frequently associated with other mandibular fractures (children, p = 0.001; adolescents, p = 0.011), especially the fracture of the mandibular body or symphysis. The children who sustained extracapsular fractures were more prone to fractures of other mandibular sites (p = 0.009), especially fracture of the symphysis/para-symphysis (p = 0.014). Intracapsular fractures in children were treated non-surgically more frequently than surgically (p < 0.001). The extracapsular fractures (mild and serious fractures) in children were also treated non-surgically more frequently (p < 0.05). CONCLUSIONS: The trauma mechanisms, incidence, pattern and treatment of condylar fractures in children substantially differ from those in adolescents. This study was conducted to enable the understanding of the differences in condylar fractures between children and adolescents. Accordingly, preventive measures and treatment plans in children or adolescents should be applied differently.

Predicting postoperative facial swelling following impacted mandibular third molars extraction by using artificial neural networks evaluation.

Patients' postoperative facial swelling following third molars extraction may have both biological impacts and social impacts. The purpose of this study was to evaluate the accuracy of artificial neural networks in the prediction of the postoperative facial swelling following the impacted mandibular third molars extraction. The improved conjugate grads BP algorithm combining with adaptive BP algorithm and conjugate gradient BP algorithm together was used. In this neural networks model, the functional projective relationship was established among patient's personal factors, anatomy factors of third molars and factors of surgical procedure to facial swelling following impacted mandibular third molars extraction. This neural networks model was trained and tested based on the data from 400 patients, in which 300 patients were made as the training samples, and another100 patients were assigned as the test samples. The improved conjugate grads BP algorithm was able to not only avoid the problem of local minimum effectively, but also improve the networks training speed greatly. 5-fold cross-validation was used to get a better sense of the predictive accuracy of the neural network and early stopping was used to improve generalization. The accuracy of this model was 98.00% for the prediction of facial swelling following impacted mandibular third molars extraction. This artificial intelligence model is approved as an accurate method for prediction of the facial swelling following impacted mandibular third molars extraction.

Lysophosphatidic Acid Analogue rather than Lysophosphatidic Acid Promoted the Bone Formation In Vivo.

Lysophosphatidic acid (LPA), a bioactive lipid molecule, has recently emerged as physiological and pathophysiological regulator in skeletal biology. Here we evaluate the effects of LPA on bone formation in vivo in murine femoral critical defect model. Primary femoral osteoblasts were isolated and treated with osteogenic induction conditional media supplemented with 20 µM LPA or LPA analogue. Mineralized nodules were visualized by Alizarin Red S staining. Forty-five C57BL/6 mice underwent unilateral osteotomy. The femoral osteotomy gap was filled with porous scaffolds of degradable chitosan/beta-tricalcium phosphate containing PBS, LPA, or LPA analogue. 2, 5, and 10 weeks after surgery, mice were sacrificed and femurs were harvested and prepared for Micro-Computed Tomography (Micro-CT) and histological analysis. Alizarin Red S staining showed that LPA and LPA analogue significantly enhanced the mineral deposition in osteoblasts. Micro-CT 3D reconstruction images and HE staining revealed that significantly more newly formed bone in osteotomy was treated with LPA analogue when compared to control and LPA group, which was verified by histological analysis and biomechanical characterization testing. In summary, our study demonstrated that although LPA promotes mineralized matrix formation in vitro, the locally administrated LPA was not effective in promoting bone formation in vivo. And bone formation was enhanced by LPA analogue, administrated locally in vivo. LPA analogue was a potent stimulating factor for bone formation in vivo due to its excellent stability.

Clinical, retrospective case-control study on the mechanics of obstacle in mouth opening and malocclusion in patients with maxillofacial fractures.

This study aims to identify and distinguish various factors that may influence the clinical symptoms (limited mouth opening and malocclusion) in patients with maxillofacial fractures. From January 2000 to December 2009, 963 patients with maxillofacial fractures were enrolled in this statistical study to aid in evaluating the association between various risk factors and clinical symptoms. Patients with fractured posterior mandibles tended to experience serious limitation in mouth opening. Patients who sustained coronoid fractures have the highest risk of serious limitation in mouth opening (OR = 9.849), followed by arch fractures, maxilla fractures, condylar fractures, zygomatic complex fractures and symphysis fractures. Meanwhile, the combined fracture of zygomatic arch and condylar process results in normal or mild mouth opening. High risks of sustaining malocclusion are preceded by the fracture of nasal bone (OR = 3.067), mandible, condylar neck/base, combined fracture of zygomatic arch and condylar process, mandibular body, bilateral condylar, dental trauma, mandibular ramus, symphysis, mandibular angle and mid-facial. Patients who experienced serious limitation in mouth opening are treated with surgery more frequently (OR = 2.118). No relationship exists between the treatment options and the patients with malocclusion.

Treatment of Sagittal Fracture of the Zygomatic Arch Root Assisted by Surgical Navigation Technology.

Sagittal fracture at the temporal root of the zygomatic arch often occurs as a part of zygomaticomaxillary fractures. The authors described the application of computer-assisted navigation in the lag screw insertion for the fixation of sagittal fracture at the temporal root of zygomatic arch. Using the presurgical planning of the computer-assisted navigation system, the trajectory of lag screw insertion was designed, and the insertion depth was calculated. In the presurgical planning, the trajectory of screw insertion was placed with an anterior inclination of 10° to 15° (mean: 12.24°), and the screw insertion depth was 9.0 to 12.0 mm (mean: 10.65 mm). In the operation, the screw insertion in the fixation of the sagittal fracture was performed under the guidance of navigation system according to the presurgical planning. The postoperative CT scan showed exact reduction and fixation of the sagittal fracture in all cases. Computer-assisted navigation is a useful tool for the lag screw insertion in the precise fixation of sagittal fracture at the temporal root of the zygomatic arch in complex zygomaticomaxillary fractures.

Risk factor analysis and idiographic features of mandibular coronoid fractures: A retrospective case-control study.

This study aimed to identify and distinguish various factors that may influence the occurrence of mandibular coronoid fractures. From January 2000 to December 2009, a total of 1131 patients with maxillofacial fractures were enrolled in this statistical study to evaluate the association between mandibular coronoid fractures and other risk factors. Among these patients, 869 had mandibular fractures, and 25 sustained a total of 25 coronoid fractures. More than half (13 of 25 patients, 52%) of the coronoid fractures in these patients were caused by motor vehicle accidents. Among these coronoid fractures, seven were associated with other mandibular fractures, and 23 (92.0%) were related to midfacial fractures. The most common site of midfacial fracture was the zygomatic arch (20 patients, 80%). Multivariate logistic regression analysis revealed that the most important influencing factor was the zygomatic arch fracture (odds ratio, 9.033; 95% confidence interval, 1.658, 49.218; p = 0.011). The majority of coronoid fracture fragments (19 of 25, 76%) were removed during operation. The most commonly used incision is hemicoronal or bicoronal approach (16 of 19, 84.2%).

AG490 suppresses interleukin-34-mediated osteoclastogenesis in mice bone marrow macrophages.

Interleukin-34 (IL-34) has been recently identified as a novel cytokine, substituting for the function of macrophage colony-stimulating factor (M-CSF), a pivotal osteoclastogenic factor involved in bone-related diseases (e.g., osteomyelitis of the jaws). However, the molecular mechanisms are not fully understood. This study aimed to explore the potential mechanism of IL-34 in receptor activator of NF-kB ligand (RANKL)-induced osteoclast formation. We found that IL-34 alone significantly maintained the survival of bone marrow macrophages (BMMs) and enhanced the expression of the osteoclast-related genes TRAP, Ctsk, and NFATc1, as well as TRAP-positive multinucleated cells combined with RANKL, which can be reversed by AG490. Conversely, AG490 did not affect the M-CSF-mediated osteoclastogenesis in the presence of RANKL. The protein expression of p-STAT3 in BMMs was enhanced by IL-34 combined with RANKL compared with RANKL alone, and AG490 inhibited the expression of p-SATA3 at protein level in the IL-34 plus RANKL group, resulting in significantly increased Smad7 expression. This study demonstrated for the first time that IL-34 may play a crucial role in RANKL-induced osteoclastogenesis by promoting the proliferation and differentiation of BMMs, stimulating p-STAT3 expression, and inhibiting the expression of Smad7 in the absence of M-CSF.