Ultrasound for management of pediatric nasal fractures

BACKGROUND

Nasal bone fractures are common in children but can be challenging to diagnose accurately in the first days due to swelling and tenderness. While X-rays and computed tomography have limitations, ultrasound may be a radiation-free and cost-effective alternative for diagnosing and treating nasal fractures.

METHODS

A prospective cohort study at a tertiary referral hospital between 2021-2023. Children who had sustained nasal trauma were included. A radiologist and a non-radiologist blindly reviewed ultrasound scans, and the results were compared to the physical examination performed by a senior otolaryngologist. If closed reduction was necessary, ultrasound was employed during the procedure. The primary outcome was the assessment of nasal fractures in children using ultrasound; Secondary outcomes included success rates for closed reduction and test reliability.

RESULTS

Of the 50 children (mean age: 11 years, interquartile range: 6-15 years, 36 [72%] males), 22 (44%) were clinically diagnosed with a nasal fracture. Interobserver reliability for nasal fracture by ultrasound was 92%, with a Cohen's kappa coefficient of k=0.91. The sensitivity and specificity of ultrasound in detecting nasal fractures were 90% and 89%, respectively, with positive and negative predictive values of 86% and 93%, respectively. Closed reduction was performed on 18 children, with (n=11) or without (n=7) ultrasound, with the former showing better alignment results (82% vs. 71%).

CONCLUSIONS

Ultrasound has a high negative predictive value in identifying nasal fractures in children with swollen noses during presentation. This enables to avoid further unnecessary referrals and interventions. Ultrasound-guided closed reduction of nasal fractures demonstrates improved outcomes; however, further large-scale randomized studies are required to validate our findings.

Analysis of Nasal Bone Fractures: A 17-year Study of 3785 Patients

In our previous study, we classified nasal bone fractures into 6 types based on computed tomography and the patterns of the nasal bone fractures (NBF) in 503 patients treated between 1998 and 2004. In the present study, we analyzed 3785 patients treated between 2005 and 2021. The age, sex, etiology, associated injuries, pattern of fractures, and treatments were reviewed, and radiographic studies were analyzed. The highest incidence was in the age group of 10 to 19 years (N=870, 23.0%), followed by 20 to 29 years (N=792, 20.9%) and 30 to 39 years (N=635, 16.8%). The most common causes of injury were slip or fall-down (42.3%), violence (24.3%), sports (19.2%), traffic accidents (8.9%), and work-related (5.3%). Most of the patients had tenderness (96.1%) and swelling (78.8%). Other findings were depression (27.1%) and nasal deviation (25.8%). Crepitus was heard in only 0.4% of the patients. The patterns of the NBFs classified by computed tomography findings were type IIA (unilateral simple fracture with displacement/without telescoping, 1283 cases, 33.9%), IIB (bilateral simple fracture with displacement/without telescoping, 786 cases, 20.8%), IIAs (unilateral simple fracture with septal fracture and displacement/without telescoping, 566 cases, 14.9%), IIBs (bilateral simple fracture with septal fracture and displacement/without telescoping 530 cases, 14.0%), I (simple fracture without displacement, 522 cases, 13.8%), and III (comminuted with telescoping or depression, 98 cases, 2.6%). In most of the cases (3,666, 96.9%), closed reduction was performed. The present analysis is one of the largest data sets on NBF in Korea, which could provide reference values for diagnosing and managing nasal bone fractures.

Factors predicting oral and maxillofacial fractures after falling and factors predicting the duration of treatment

BACKGROUND/AIM

The first objective of this study was to identify predictive factors for oral and maxillofacial fractures at the initial response to the patient. The second objective was to determine the factors influencing the incidence of treatment duration of more than 1 month using the information shown in the medical record.

MATERIALS AND METHODS

Hospital records from 2011 to 2019 were reviewed to identify patients who had sustained oral and maxillofacial injuries by falling or falling from a height. Patterns and types of oral and maxillofacial injury, injury severity, and background of the injury were collected from the hospital records. The variables independently associated with a treatment duration of more than 1 month were determined by logistic regression analysis.

RESULTS

In total, 282 patients (150 men, 132 women; median age, 17.5 years) were selected for analysis. Maxillofacial fractures were observed in 20.9% of patients (59/282); among these, mandibular fractures were the most common (47/59). Logistic regression analysis showed that age (odds ratio [OR], 1.026), nighttime occurrence (OR, 2.192), and upper face injury (OR, 20.704) were independent predictive factors for having a maxillofacial fracture. Additionally, the number of injured teeth (OR, 1.515) and the use of intermaxillary fixation (OR, 16.091) were independent predictors of treatment duration of more than 1 month.

CONCLUSIONS

These results may be useful in the initial management of maxillofacial injuries in terms of better-informing patients injured by falling their expected treatment duration and managing the psychological impacts of a long treatment duration.

Trends in maxillofacial fractures in Otago-Southland, New Zealand: 2009 to 2020

AIMS

Fractures to the maxillofacial region can have a serious impact on quality of life. The over-representation of males in the occurrence of almost all types and mechanisms of these injuries has tended to divert attention away from maxillofacial fractures in females. This study aimed to describe trends in maxillofacial trauma in a New Zealand tertiary trauma centre over a 12 year period, with a particular focus on gender differences.

METHOD

A retrospective audit was undertaken of records for maxillofacial fracture cases referred to Dunedin Hospital and Southland Hospital Maxillofacial Units during the period January 2009 to December 2020. Information on age, gender and ethnicity, aetiology, alcohol and/or drug involvement, fracture type, and management was obtained from the Southern District Health Board - Health Connect South Network.

RESULTS

Over the observation period, 1,561 patients presented for a total of 2,480 fractures. There was an increase in the proportion of fractures arising from falls and involving the orbit, while those due to interpersonal violence (IPV) or involving the mandible fell. Additionally, the proportion of cases treated conservatively rose, while the use of surgical fixation fell. While overall just over one in five patients were female, that proportion increased from one in six in 2009-2011 to one in four in 2018-2020. Fractures among females were due mainly to falls (55.6%) and road traffic accidents (23.2%), and frequently involved the orbit (46.3%). The proportion of presentations involving people aged 50 or older also increased over time.

CONCLUSIONS

A greater proportion of women are suffering from facial fractures in the past decade than they have previously. Public health interventions for those at risk and their families are necessary. Interventions should have a focus on preventing falls and domestic violence, with a particular focus on older people and Māori/Pasifika populations. Improved and continued monitoring of these changing patterns is important for addressing the issues they present to New Zealand.

[Skull and skull base injuries in children and adolescents : Results of a monocentric analysis]

BACKGROUND

The present study comprises a retrospective analysis of skull, skull base, and midface fractures in children, to provide clinical orientation for their management. To date, only few data are available on these injuries in this patient group.

METHODS

Data from inpatient cases diagnosed with a midface, skull, or skull base fracture in the Children's Hospital Auf der Bult from 2015 to 2020 were evaluated. Age, gender, fracture mechanism, diagnosis, treatment, and possible complications were analyzed. Data of 224 children were grouped into 107 cases with nose fractures, 104 cases with skull fractures, 9 patients with temporal bone fractures, 4 patients with rhinobasal fractures, and 2 cases with fractures of the orbital floor.

RESULTS

Among patients with nose fractures, the average age was 10.9 years (64% males), among patients with skull fractures 1.0 year (64% males), and in children with skull base fractures 6.0 years (85% males). Falls were the most frequent genesis (63%), followed by car accidents, collisions (25%), and violence (10%). Patients with skull fractures underwent sonography in 94% of cases; in 87% the fracture was verified. Patients with nose fractures underwent x‑ray in 92% of cases, or sonography only in 8%; 95% of patients with nose fractures underwent operative repositioning. Typical fracture signs (i.e., hemotympanum, ophthalmic symptoms) or signs of central nervous system involvement (i.e., nausea, amnesia) occurred in 12 of 13 children with skull base fractures, and CT was performed in all these cases (none of whom developed a cerebrospinal fluid leak).

CONCLUSION

The imaging modality should be selected based on the clinically suspected diagnosis and the course. Most fractures can be sufficiently treated without any permanent sequelae, except for nose fractures, which frequently require operative repositioning.

In vivo evaluation of interactions between biphasic calcium phosphate (BCP)-niobium pentoxide (Nb2O5) nanocomposite and tissues using a rat critical-size calvarial defect model

Natural or synthetic biomaterials are increasingly being used to support bone tissue repair or substitution. The combination of natural calcium phosphates with biocompatible alloys is an important route towards the development of new biomaterials with bioperformance and mechanical responses to mimic those of human bones. This article evaluated the structural, physical, mechanical and biological properties of a new mechanical improved nanocomposite elaborated by association of fish biphasic calcium phosphate (BCP) and niobium pentoxide (Nb₂O₅). The nanocomposite (Nb-BCP) and the pure BCP, used as a positive control, were obtained by powder metallurgy. The density, porosity and microhardness were measured. The structural analysis was determined by X-ray diffraction (XRD) and the biological properties were studied in histological sections of critical size calvaria defects in rats, 7, 15, 30, 45 and 60 days after implantation of disks of both materials. Morphological description was made after scanning electron microscopy (SEM) and optical microscopy analysis. After sintering, the Nb-BCP nanocomposite presented four crystalline phases: 34.36% calcium niobate (CaNb₂O₆), 21.68% phosphorus niobium oxide (PNb₉O₂₅), 42.55% β-tricalcium phosphate (Ca₃(PO₄)₂) and 1.31% of niobium pentoxide (Nb₂O₅) and exhibited increases of 17% in density, 66% in Vickers microhardness and 180% in compressive strength compared to pure BCP. In vivo study, showed biocompatibility, bioactivity and osteoconductivity similar to pure BCP. SEM showed the formation of globular accretions over the implanted nanocomposites, representing one of the stages of bone mineralization. In conclusion, the BCP and Nb₂O₅ formed a nanocomposite exhibiting characteristics that are desirable for a biomaterial, such as bioperformance, higher β-TCP percentage and improved physical and mechanical properties compared to pure BCP. These characteristics demonstrate the promise of this material for supporting bone regeneration.

Prevalence of Operated Facial Injury in the Department of Oral and Maxillofacial Surgery of a Tertiary Hospital

Introduction: Maxillofacial injury is one of the commonest causes of surgery performed by anoral and maxillofacial surgeon. Socioeconomic conditions, cultural variation, age, and genderaffect the etiology of the injury. The study is aimed to find the prevalence of facial injury that isoperated by the oral and maxillofacial surgeons in the College of Medical Sciences and TeachingHospital, Bharatpur, Chitwan, a tertiary hospital. Methods: A descriptive cross-sectional study was performed using the chart from the hospitalregistry for the patient being operated under general anesthesia from April 1, 2017, to March2019. Simple random sampling was done using computer-generated random numbers. Ethicalapproval was received from the Institutional Review Committee of the hospital. The Data forthe reason for surgery, age, age groups etiology, and tissue involvement were analyzed usingStatistical Package for the Social Sciences version 20. Results: Facial injury occupies 378 (71.59%) of the total operation performed by Oral andMaxillofacial surgeon in a tertiary hospital. Soft tissue 196 (52.85%) and facial bone fracture182 (48.15%) is distributed among the facial injuries. Young adults are commonly affected, andthe road traffic accident is the major cause of facial trauma. Conclusions: Facial injury-related surgeries are more prevalent in the tertiary hospital ofBharatpur.

[Evaluation and management of paediatric nasal fractures]

This is a review discussing evaluation and management of paediatric nasal fractures, which have been reported as one of the three most common facial bone fractures. Nasal fractures in children are usually treated with closed reduction after 3-5 days, while other injuries like septal haematoma must be treated at the initial presentation. It is important to pay careful attention to the nasal anatomy during the surgical management of paediatric nasal injuries, as disturbing the nasal growth zones can have an impact on future nasal development.

Prospective analysis of mid-facial fractures in a single-center pediatric-adolescent cohort

BACKGROUND

The complex architecture of the midface renders diagnosing and treating fractures challenging, especially for young patients who present the additional risk of suffering growth and development deficiencies, which is to be avoided at all costs.

OBJECTIVES

This study sought to characterize pediatric mid-facial fractures considering the possible complications.

METHODS

Between September 2008 and September 2018, data was collected on inpatients aged <18 years, treated for mid-facial fractures at the Halle University Hospital. Evaluated parameters were age, gender, cause and type of fracture, associated injuries, treatment, and complications.

RESULTS

In total, 31 patients were examined; 20 were boys. The most common cause of injury was road traffic accident (41.9%). Orbital floor fracture was the most common type of injury (58.1%). In 54.8% of cases, surgery was performed.

CONCLUSION

The incidence of complications associated with mid-facial fractures was low (n = 7), requiring treatment in only three cases (orthodontic, ophthalmological).

Novel Synthesized Nanofibrous Scaffold Efficiently Delivered hBMP-2 Encoded in Adenoviral Vector to Promote Bone Regeneration

Treatment of bone defect, especially large bone defect, is still a challenge for physicians clinically. Bone morphogenetic protein 2 (BMP-2) can induce osteoblast differentiation and promote new bone formation. Recently, nanomaterials have been widely used as a carrier to hold and deliver biomolecules, like human bone morphogenetic protein 2 gene (hBMP-2) in target cells/tissues. Most nanomethods, however, need further modification in order to work more reliably in clinical applications. Therefore, in this study, we created a novel poly(lactic-co-glycolic acid [PLGA]) nanofibrous scaffold using an electrospinning technique; then, using a lyophilization process to allow nanofibrous scaffold to adsorb hBMP-2 adenoviral vector, AdCMV-hBMP2. Results indicate that the lyophilized poly(lactic-co-glycolic acid) nanofibrous scaffold/AdCMVhBMP2 can efficiently release and transduce cells in vitro and in vivo, and secrete functional hBMP-2 to promote osteogenic differentiation in vitro, and new bone generation in vivo. Importantly, the amount of newly formed bone covered >80% of the bone defect area 8 weeks post-implantation in vivo, in which the defect could not be repaired without any treatment in general. Our data demonstrate that the lyophilized PLGA nanofibrous scaffold/AdCMV-hBMP2 created herein stably and efficiently release functional viral vector to transduce local cells, resulting in secretion of hBMP-2 and promote new bone formation in vivo. Our new nanodelivery method has potential clinical application for the repair of large bone defects.

Temporomandibular Joint Regenerative Medicine

The temporomandibular joint (TMJ) is an articulation formed between the temporal bone and the mandibular condyle which is commonly affected. These affections are often so painful during fundamental oral activities that patients have lower quality of life. Limitations of therapeutics for severe TMJ diseases have led to increased interest in regenerative strategies combining stem cells, implantable scaffolds and well-targeting bioactive molecules. To succeed in functional and structural regeneration of TMJ is very challenging. Innovative strategies and biomaterials are absolutely crucial because TMJ can be considered as one of the most difficult tissues to regenerate due to its limited healing capacity, its unique histological and structural properties and the necessity for long-term prevention of its ossified or fibrous adhesions. The ideal approach for TMJ regeneration is a unique scaffold functionalized with an osteochondral molecular gradient containing a single stem cell population able to undergo osteogenic and chondrogenic differentiation such as BMSCs, ADSCs or DPSCs. The key for this complex regeneration is the functionalization with active molecules such as IGF-1, TGF-β1 or bFGF. This regeneration can be optimized by nano/micro-assisted functionalization and by spatiotemporal drug delivery systems orchestrating the 3D formation of TMJ tissues.

Occult large epidural hemorrhage in a newborn infant after in-hospital fall

Management of newborn infants fell in-hospital is especially challenging given the limited signs and symptoms of intracranial hemorrhage in this age group. We present a case of a four day old well appearing newborn infant found to have a severe epidural hemorrhage requiring emergent surgical drainage. Development of imaging protocols for newborn infants suffering in-hospital falls need to consider the potential consequences of missing actionable intracranial hemorrhage when relying on clinical observation as a management strategy.

A Festive Case Series of Emergencies, Admissions and Friendship at a Busy Oral and Maxillofacial Unit

The festive season presents oral and maxillofacial surgery (OMFS) dental core trainees (DCTs) with the challenges of managing an eclectic mix of emergencies. We present three such patients in this case series. First, Patient A, a 39-year-old homeless male who presented with a maxillary extra-oral draining sinus. Secondly, Patient B, a 38-year-old intra-venous (IV) drug user who suffered pan-facial fractures following an alcohol-fuelled assault. Finally, Patient C, a 38-year-old male who sustained a left zygomatic complex fracture a week previously, in attendance for corrective surgery. Despite the hardship, there was still festive cheer to be had by these individuals. Clinical relevance: Primary and secondary care practitioners should be aware of the advanced clinical presentation of dental and maxillofacial emergencies that occur over holiday periods.

[Nasal fractures in adults]

The risk of complications warrants treatment of most dislocated nasal fractures. Other injuries including other facial fractures and septal haematoma must be treated if present at the initial presentation. The usual treatment for a simple nasal fracture is closed reduction in local anaesthesia after five to seven days. Complicated cases require open reduction in general anaesthesia. Later revision of the deviated nose may become necessary in patients suffering from complications such as persistent nasal stenosis and/or deformity.

Nasal fractures in children and adolescents: Mechanisms of injury and efficacy of closed reduction

OBJECTIVES

To determine the most common mechanisms of traumatic nasal deformity referred to pediatric otolaryngology. To examine the efficacy of closed reduction of nasal fractures in children and adolescents based on the parents' and surgeons' ratings of post-reduction nasal symmetry.

METHODS

Case series and chart review within an urban, tertiary pediatric otolaryngology practice.

RESULTS

100 cases of traumatic nasal deformity met inclusion criteria over a 3-year study period. The mean age at presentation was 13 years (4 weeks-18 years); 55% were male and 70% were over the age of 12 years. The most common mechanism of injury was sports-related trauma (28%), followed by accidental trauma (21%), interpersonal violence (10%), motor vehicle collision (6%) and alcohol-related (2%). Of these 100 cases, 22% underwent closed reduction within a 14-day period following injury. All patients achieved symmetry in the operating room immediately following reduction. 21 of 22 post-reduction patients were assessed for nasal symmetry at the postoperative visit (7-10 days following surgery). The operating surgeon was satisfied with nasal symmetry in 43% of cases and the parent(s) satisfied in 81% of cases. Both parent and surgeon were satisfied with post-reduction symmetry 33% of the time.

CONCLUSION

The most common sources of traumatic nasal deformity in children and adolescents vary by age. In cases meriting operative intervention, parents appear to be satisfied with early postoperative results following closed reduction in approximately 80% of cases, however a result in which both parent and surgeon agree with successful re-establishment of symmetry occurs in only one-third of cases.

Spontaneous ventilation of the frontal sinus after fractures involving the frontal recess

PURPOSE

Frontal sinus fractures (FSF) have potentially catastrophic consequences due to frontal recess (FR) obstruction and proximity to the brain and orbit. Lack of follow-up and ability to predict which type of fractures predispose to complications has biased surgeons toward definitive interventions such as sinus obliteration and cranialization. These procedures carry inherent risk and may be unnecessary in a subset of patients. This study seeks to better characterize spontaneous ventilation in subjects with FSFs, including those involving the FR.

MATERIALS AND METHODS

Review of a prospectively maintained trauma database between 2009 and 2013 at a level 1 trauma center. Patients with frontal sinus fractures with follow-up imaging (>6 weeks) available were included. The medical records and imaging were reviewed for evidence of spontaneous ventilation of the frontal sinus.

RESULTS

Nineteen patients sustained frontal sinus fractures in the study period with mean imaging interval of 67.4 weeks (range, 6-188.4 weeks). Injury mechanisms included fall (32%), assault (31%), motor vehicle accident (17%), pedestrian-versus-automobile (12%), and gunshot wound (8%). 8/19 patients (42%) sustained FSFs involving the FR and 7/8 (87.5%) spontaneously ventilated by time of interval imaging. The one patient with persistent radiographic sinus opacification was associated with a naso orbital ethmoid and medial orbital blowout fracture. 6/19 patients (32%) sustained FSF sparing the FR, and all spontaneously ventilated by the time of interval imaging. 5/19 patients (26%) underwent surgical intervention.

CONCLUSIONS

An expectant, sinus-preserving approach to acute FSFs involving the FR is safe and effective. Etiology of re-ventilation failure may be due to tissue obstruction, rather than the frontal recess fracture itself.

Preparation and characterization of gelatin-hydroxyapatite composite microspheres for hard tissue repair

Gelatin-hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO3)2, NH4H2PO4 and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G-HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6-10nm and tangle into porous microspheres after blending. The cell culture indicates that G-HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G-HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G-HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS.

Evidence-Based Facial Fracture Management

With demands for an evidence-based approach to patient care, the management of facial fractures will come under increasing scrutiny because there is an overall deficiency in higher level clinical evidence. This article reviews the management of facial fractures, focusing on an evidence-based approach. It focuses on select areas of facial trauma in which there is controversy and presents randomized studies and meta-analysis to help define best practice. The article notes the many areas where the evidenced-based literature is weak and looks at the future of evidence-based facial trauma care.

Effects of polycaprolactone-based scaffolds on the blood-brain barrier and cerebral inflammation

Severe pathoanatomical and mechanical injuries compromise patient recovery and survival following penetrating brain injury (PBI). The realization that the blood-brain barrier (BBB) plays a major role in dictating post-PBI events has led to rising interests in possible therapeutic interventions through the BBB. Recently, the choroid plexus has also been suggested as a potential therapeutic target. The use of biocompatible scaffolds for the delivery of therapeutic agents, but little is known about their interaction with cerebral tissue, which has important clinical implications. Therefore, the authors have sought to investigate the effect of polycaprolactone (PCL) and PCL/tricalcium phosphate (PCL/TCP) scaffolds on the maintenance of BBB phenotype posttraumatic brain injury. Cranial defects of 3 mm depth were created in Sprague Dawley rats, and PCL and PCL/TCP scaffolds were subsequently implanted in predetermined locations for a period of 1 week and 1 month. Higher endothelial barrier antigen (EBA) expressions from PCL-based scaffold groups (p>0.05) were found, suggesting slight advantages over the sham group (no scaffold implantation). PCL/TCP scaffold group also expressed EBA to a higher degree (p>0.05) than PCL scaffolds. Importantly, higher capillary count and area as early as 1 week postimplantation suggested lowered ischemia from the PCL/TCP scaffold group as compared with PCL and sham. Evaluation of interlukin-1β expression suggested that the PCL and PCL/TCP scaffolds did not cause prolonged inflammation. BBB transport selectivity was evaluated by the expression of aquaporin-4 (AQP-4). Attenuated expression of AQP-4 in the PCL/TCP group (p<0.05) suggested that PCL/TCP scaffolds altered BBB selectivity to a lower degree as compared with sham and PCL groups, pointing to potential clinical implications in reducing cerebral edema. Taken together, the responses of PCL-based scaffolds with brain tissue suggested safety, and encourages further preclinical evaluation in PBI management with these scaffolds.

Osteoconductive property of a mechanical mixture of octacalcium phosphate and amorphous calcium phosphate

The present study was designed to investigate the extent of osteoconductive property of a mechanical mixture of octacalcium phosphate (OCP) and amorphous calcium phosphate (ACP). OCP was mixed with ACP in granules that had a diameter of 300 and 500 μm, respectively, and at 25, 50, or 75 wt %. The physicochemical characteristics and the osteoconductive properties of the mixtures were compared with OCP alone or ACP alone through implantation into rat critical-sized calvaria defects for up to 12 weeks and simulated body fluid (SBF) immersion for 2 weeks. The mixtures of OCP and ACP, in particular the OCP 25 wt % and ACP 75 wt % (O25A75), had higher radiopacity compared to ACP and OCP alone. O25A75 induced greater enhancement of bone regeneration than ACP alone at 8 weeks and that than OCP alone at 12 weeks. X-ray diffraction and Fourier transform infrared (FTIR) analyses of the retrieved mixtures showed that ACP, OCP, and O25A75 tended to convert to hydroxyapatite (HA) after the implantation, while the structure of OCP remains without complete conversion after SBF immersion. Analyses by FTIR curve fitting of the solids and the degree of supersaturation of the SBF supported the observation that the existence of ACP enhances the kinetics of the conversion. Scanning electron microscopy found that the surface of O25A75 had distinct characteristics with OCP and ACP after SBF immersion. The results suggest that the extent of the osteoconduction of OCP could be controlled by the copresence of ACP most probably through the prevailing dissolution-precipitation of the surface of ACP crystals to form HA.

Impact of newly adopted guidelines for management of children with isolated skull fracture

PURPOSE

In an effort to standardize practices and reduce unnecessary hospital resource utilization, we implemented guidelines for management of patients with isolated skull fractures (ISF). We sought to examine the impact of these guidelines.

METHODS

Patients with nondisplaced/depressed fracture of the skull vault without intracranial hemorrhage were prospectively enrolled from February 2010 to February 2014.

RESULTS

Eighty-eight patients (median age=10months) were enrolled. Fall was the most common mechanism of injury (87%). The overall admission rate was 57%, representing an 18% decrease from that reported prior to guideline implementation (2003-2008; p=0.001). Guideline criteria for admission included vomiting, abnormal neurologic exam, concern for abuse, and others. Forty-two percent of patients were admitted outside of the guideline, primarily because of young age (20%). Patients transferred from another hospital (36%) were more likely to be admitted, though the majority (63%) did not meet admission criteria. No ED-discharged patient returned for neurologic symptoms, and none reported significant ongoing symptoms on follow-up phone call.

CONCLUSIONS

Implementation of a new guideline for management of ISF resulted in a reduction of admissions without compromising patient safety. Young age remains a common concern for practitioners despite not being a criterion for admission. Interhospital transfer may be unnecessary in many cases.

An in vivo murine model for screening cranial bone regenerative materials: testing of a novel synthetic collagen gel

Rapid and efficient animal models are needed for evaluating the effectiveness of many new candidate bone regenerative materials. We developed an in vivo model screening for calvarial bone regeneration in lipopolysaccharide (LPS)-treated mice, in which materials were overlaid on the periosteum of the calvaria in a 20 min surgery and results were detectable in 1 week. Intraperitoneal LPS injection reduced spontaneous bone formation, and local application of basic fibroblast growth factor (bFGF) increased the bone-forming activities of osteoblasts. A novel synthetic collagen gel, alkali-treated collagen (AlCol) cross-linked with trisuccinimidyl citrate (TSC), acted as a reservoir for basic substances such as bFGF. The AlCol-TSC gel in conjunction with bFGF activated osteoblast activity without the delay in osteoid maturation caused by bFGF administration alone. The AlCol-TSC gel may slow the release of bFGF to improve the imbalance between osteoid formation and bone mineralization. These findings suggest that our model is suitable for screening bone regenerative materials and that the AlCOl-TSC gel functions as a candidate reservoir for the slow release of bFGF.

Hollow hydroxyapatite microspheres: a novel bioactive and osteoconductive carrier for controlled release of bone morphogenetic protein-2 in bone regeneration

The regeneration of large bone defects is a common and significant clinical problem. Limitations associated with existing treatments such as autologous bone grafts and allografts have increased the need for synthetic bone graft substitutes. The objective of this study was to evaluate the capacity of novel hollow hydroxyapatite (HA) microspheres to serve as a carrier for controlled release of bone morphogenetic-2 (BMP2) in bone regeneration. Hollow HA microspheres (106-150 μm) with a high surface area (>100 m2 g(-1)) and a mesoporous shell wall (pore size 10-20 nm) were created using a glass conversion technique. The release of BMP2 from the microspheres into a medium composed of diluted fetal bovine serum in vitro was slow, but it occurred continuously for over 2 weeks. When implanted in rat calvarial defects for 3 or 6 weeks, the microspheres loaded with BMP2 (1 μg per defect) showed a significantly better capacity to regenerate bone than those without BMP2. The amount of new bone in the defects implanted with the BMP2-loaded microspheres was 40% and 43%, respectively, at 3 and 6 weeks, compared to 13% and 17%, respectively, for the microspheres without BMP2. Coating the BMP2-loaded microspheres with a biodegradable polymer, poly(lactic-co-glycolic acid), reduced the amount of BMP2 released in vitro and, above a certain coating thickness, significantly reduced bone regeneration in vivo. The results indicate that these hollow HA microspheres could provide a bioactive and osteoconductive carrier for growth factors in bone regeneration.

The effect of rhBMP-2 and PRP delivery by biodegradable β-tricalcium phosphate scaffolds on new bone formation in a non-through rabbit cranial defect model

This study evaluated whether the combination of biodegradable β-tricalcium phosphate (β-TCP) scaffolds with recombinant human bone morphogenetic protein-2 (rhBMP-2) or platelet-rich plasma (PRP) could accelerate bone formation and increase bone height using a rabbit non-through cranial bone defect model. Four non-through cylindrical bone defects with a diameter of 8-mm were surgically created on the cranium of rabbits. β-TCP scaffolds in the presence and absence of impregnated rhBMP-2 or PRP were placed into the defects. At 8 and 16 weeks after implantation, samples were dissected and fixed for analysis by microcomputed tomography and histology. Only defects with rhBMP-2 impregnated β-TCP scaffolds showed significantly enhanced bone formation compared to non-impregnated β-TCP scaffolds (P < 0.05). Although new bone was higher than adjacent bone at 8 weeks after implantation, vertical bone augmentation was not observed at 16 weeks after implantation, probably due to scaffold resorption occurring concurrently with new bone formation.

Comparison of temporal bone fractures in children and adults

CONCLUSION

Contrary to our expectation, that the clinical characteristics of temporal bone fracture would differ in children and adults, we found that the two groups were similar.

OBJECTIVES

Most studies of temporal bone fractures have been performed in adults. To our knowledge, no study has investigated differences in temporal bone fractures in children and adults. We therefore investigated differences in temporal bone fractures in adults and children by examining the manifestations and clinical symptoms of temporal bone fractures in pediatric patients.

METHODS

The demographic and clinical characteristics were assessed in 32 children and 186 adults with temporal bone fractures. All patients underwent computed tomography of the temporal bone.

RESULTS

Causes of fracture, gender distribution, manifestations of temporal bone fracture, and clinical symptoms were similar in adults and children (p > 0.05 each). Petrous fracture, ear fullness, dizziness, and tinnitus were significantly more frequent in adults than in children (p < 0.05 each).

Direct scaffolding of biomimetic hydroxyapatite-gelatin nanocomposites using aminosilane cross-linker for bone regeneration

Hydroxyapatite-gelatin modified siloxane (GEMOSIL) nanocomposite was developed by coating, kneading and hardening processes to provide formable scaffolding for alloplastic graft applications. The present study aims to characterize scaffolding formability and mechanical properties of GEMOSIL, and to test the in vitro and in vivo biocompatibility of GEMOSIL. Buffer Solution initiated formable paste followed by the sol-gel reaction led to a final hardened composite. Results showed the adequate coating of aminosilane, 11-19 wt%, affected the cohesiveness of the powders and the final compressive strength (69 MPa) of the composite. TGA and TEM results showed the effective aminosilane coating that preserves hydroxyapatite-gelatin nanocrystals from damage. Both GEMOSIL with and without titania increased the mineralization of preosteoblasts in vitro. Only did titania additives revealed good in vivo bone formation in rat calvarium defects. The scaffolding formability, due to cohesive bonding among GEMOSIL particles, could be further refined to fulfill the complicated scaffold processes.

Mid-facial fractures: a 5-year retrospective review in a Nigerian teaching hospital

OBJECTIVE

The aim of this study is to establish the pattern and actiology of mid-facial fractures, of patients seen and treated at the Lagos University Teaching Hospital, Lagos, Nigeria over a 5-year period.

MATERIALS AND METHODS

All cases of midfacial fractures diagnosed and treated at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital (LUTH), Lagos between January 2004 and December 2008 were reviewed. Data collected from case records of patients included age, sex, aetiology of fracture, anatomic site of fracture, associated maxillofacial fracture, types of treatment and postoperative complications.

RESULTS

The leading cause of mid-facial fractures was road traffic crashes (RTC) which occurred in 93% of highest incidence of mid-facial fractures (36.5%) occurred in the age group of 21-30 years and the lowest in the age group of 60 years and above (2.6%); with male preponderance in nearly all age groups. Female patients were significantly younger than their male counterparts (P=0.000). The most common site of mid-facial bone fractures was the zygomatic complex (n=89, 44.5%), followed by dento-alveolar (n=26, 13%), and Le fort II (n=23, 12%). Conservative management of the fractures was employed in 2.6% (n=4) of the cases while 97.4% (n=152) of the patients required surgical, intervention

CONCLUSIONS

Mid-facial fractures were most common in the 3rd decade of life; with a male-to-female ratio of 3.7: 1. Over 93% of the cases were due to road traffic crashes. Zygomatic complex was the most commonly fractured site. The fact that road traffic crashes still remain the major cause of mid-facial fracture in the studied environment is an indication that the enforcement of legislation to prevent road traffic crashes needs to be re-emphasised.

[Hospitalization of children with traumatic brain wounds in Brodposavina county]

Traumatic brain injury (TBI) is the most common cause of acquired disability and death in children. Retrospective analysis showed 350 children, 128 (36.6%) girls and 222 (63.4%) boys who were hospitalized for injury of neurocranium in a 5 year-period in Dr. Josip Bencević General Hospital in Slavonski Brod. Most of them had both contusion and commotion (46.8%), followed by just contusion of the head (12.5%) and fractures of the skull (10.5%). The haemorrhages and hemathomas were less common (epidural, subdural, SAH) (3.2%). The procedures performed showed that in almost all children X-rays had been performed (99.7%). The most commonly X-rays performed were those of the head (craniogram) and/or cervical spine, followed by CT, EEG, ultrasound and NMR. The occurence of complications was recorded in only 2% of injured children (seizure, syncopa, febrile convulsions). Analysis of treatment methods showed that in most children (89.6%) therapy was conservative. The injured children were hospitalizated mostly for 2 days (34.5%) or 3 days (32.5%), while longer hospitalization was less common. Regarding extra consultation of other specialists (besides neurosurgeons), the most commonly consulted were pediatrician, surgeon/traumatologist, specialist of ENT/maxilofacial surgery, neuropediatrician, pediatric surgeon, ophthalmologist and others. It can be said that the prognosis of TBI in children depends on the age, neurological status and kind of injury, and on the quality of care, which involves availability of neurosurgeons and other specialists.

Conservative management of transnasal intracranial injury

The purpose of this study was to explore the conservative management for an unusual case of transnasal intracranial injury. A 3-year-old female child presenting with transnasal injuries after a domestic accident whereby she apparently fell while holding a large pair of scissors, which then penetrated her left nasal cavity, piercing her nasal cavity, ethmoid sinus, and skull base. The scissors were removed from her nasal cavity. The patient had scant cerebrospinal rhinorrhea and no other additional neurologic deficits noted at the time, as well as no long-term developmental deficits. This report highlights the occurrence of this rare condition. The role of radiologic studies such as computed tomographic scans and plain films in diagnosis and management of this case is affirmed. The strategy of minimally invasive treatment of this injury can be a reasonable treatment option.

Effects of near-field ultrasound stimulation on new bone formation and osseointegration of dental titanium implants in vitro and in vivo

A near-field ultrasound stimulation system was designed for use in in vitro and in vivo trials. The intensity of ultrasound was studied to optimize the osseointegration of the dental titanium implant into the adjacent bone. MG63 osteoblast-like cells were seeded on commercial purity titanium (CP-Ti) plate, and then sonicated for 3 min/day at a frequency of 1 MHz and intensities of 0.05, 0.15 and 0.30 W/cm(2), using either pulsed or continuous ultrasound. Cells were analyzed to determine viability (inhibition of (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction) and alkaline phosphatase (ALP). Tissue culture was performed in vitro by placing a CP-Ti plate in a cultured rat neonatal calvarial defect in response to ultrasound stimulation. In the in vivo trial, screw-shaped CP-Ti implants were inserted into the metaphysis of rabbit tibia, and then stimulated by ultrasound for 10 min daily for 30 d. All samples were processed for histomorphometric evaluation and analyzed by image system. Color Doppler ultrasonography was inspected to evaluate the supply of blood flow. Pulsed ultrasound groups had higher MTT and ALP than control. Tissue culture indicated that pulsed ultrasound groups promoted cell migration and new bone regeneration more effectively than in the control. In animal study, blood flow and mature type I collagen fibers were more prevalent around titanium implants, and bone formation was accelerated in pulsed ultrasound groups. In conclusion, low-intensity pulsed ultrasound at 0.05-0.3 W/cm(2) may accelerate cell proliferation and promote the maturation of collagen fibers and support osteointegration.

Management and outcome of pediatric skull base fractures

OBJECTIVE

The management of skull base fractures in the pediatric age group continues to be a major challenge even for experienced multidisciplinary teams. This retrospective study was undertaken at a tertiary care academic hospital to evaluate the management and outcome of pediatric skull base fractures.

METHODS

Retrospective analysis covering a period of 13.5 years (from 1996 to 2009) and 63 patients (mean age 10.7 years; range 1-18 years) was performed.

RESULTS

A road traffic accident was the most frequent etiological factor (38%). The most common skull base fracture type was temporal bone fracture (64%). Longitudinal temporal fractures were observed in 45% and transversal in 23% of these patients; in 10 cases (25%) the fracture was comminuted or mixed type. A fracture involving the spheno-ethmoidal complex was the second most common type of basilar skull fracture (41%) followed by fracture through the orbital bone (35%). Forty-three percent of the patients had a concomitant intracranial injury. Early neurological deficits were diagnosed in 21 patients (33%) and 10 patients (16%) had permanent neurological deficits. One patient died after 1 week of intensive care treatment. Fifty-four patients (86%) were discharged home and 8 patients (13%) were discharged for further rehabilitation. Glasgow Coma Scale score of 8 or lower correlated with moderate to poor outcome.

CONCLUSIONS

We conclude that skull base fracture is a rare injury in childhood. Mortality is uncommon, but this trauma is commonly associated with intracranial injury. Early neurological deficits are caused by traumatic brain injury and were observed in one-third of the patients. However, only less than one-sixth suffered from permanent neurological or neuropsychiatric disorders.

Fractures of the posterior wall of the frontal sinus: non-surgical management and complications

BACKGROUND

treatment of frontal sinus fractures remains controversial. If the posterior wall is fractured and there is cerebrospinal fluid leak, treatment seeks to restore the integrity of the dura and isolate the intracranial contents through the obliteration of the nasofrontal duct and cranialization. Another group supports nonoperative management CSF leakage is produced. The purpose is to avoid complications of meningitis, fistula and late sequelae. The difficulty lies in predicting which patients will develop complications. The aim of this study is to identify complications in patients with posterior wall fracture of the frontal sinus treated nonsurgically.

METHODS

an observational, cross-sectional, retrospective study was conducted with 20 patients with posterior wall fractures of the frontal sinus treated nonsurgically at the Hospital de Traumatología y Ortopedia Lomas Verdes, Service of Maxillofacial Surgery from January 2007 to October 2009.

RESULTS

twenty patients with posterior wall fractures of the frontal sinus were included. There were 17 males and 3 females. Fractures were divided into groups according to their degree of movement and presence of cerebrospinal fluid fistula. Postoperative complications were cerebrospinal fluid fistula and frontal abscess.

CONCLUSIONS

nonsurgical treatment has proven to be an option, although not free from complications, the most common being CSF fistula and abscess. Future comparative studies should be carried out to define therapeutic strategies usibg clinical monitoring and long-term imaging.

Nasal fractures: patient satisfaction following closed reduction

AIM

Nasal fractures are commonly treated by primary closed reduction. However, studies suggest this produces unacceptable functional and aesthetic results. Many patients require revision surgery. We aimed to assess patient satisfaction following closed reduction of nasal fractures.

METHODS

Retrospective chart review of patients with nasal fractures treated by closed reduction at the Wellington Regional Plastic, Maxillofacial and Burns Unit, New Zealand over a 2-year period was undertaken. Digital manipulation under general anaesthetic was performed. Patients were followed-up by telephone with a structured interview.

RESULTS

Of 116 consecutive patients, 74 (65%) were successfully contacted. 65 (88%) were satisfied with functional outcome, and 64 (86%) with aesthetic outcome. Of the 34 patients reporting incomplete correction, 12 (35%) would consider revision surgery.

CONCLUSION

Patients treated with closed reduction of nasal fracture performed under general anaesthetic with digital manipulation reported high levels of satisfaction with functional and aesthetic outcomes. Revision rate is low.

In situ tissue engineering of canine skull with guided bone regeneration

CONCLUSION

Calcium alginate (CA) membrane prevents excessive fibrous tissue intrusion and/or dislocation of a bone scaffold. However, CA membrane did not always accelerate cranial bone regeneration.

OBJECTIVE

We previously reported skull regeneration using a bone substitute material (BSM), which consisted of collagen-coated beta-tricalcium phosphate and autologous bone fragments, and bone marrow-derived stromal cells (BSCs). However, excessive fibrous tissue intrusion or dislocation of the BSM occasionally interrupted bone regeneration. To avoid such problems, we examined CA membrane, which is useful for guided bone regeneration (GBR), to investigate whether this material maintains the bone regenerative space.

MATERIALS AND METHODS

Bone defects (2x2 cm) were created in the skulls of 12 adult beagle dogs using the same clinical procedure. Four experimental models were tested with or without BSM plus BSCs or CA membrane. In group I, the original free bone flap was replaced at the defect. In group II, after replacing the bone flap, the defect was covered with CA membrane. In group III, BSM plus BSCs were used as a gap filler. In group IV, BSM plus BSCs and CA membrane were applied. Histological examinations were performed 3 and 6 months after the operation.

RESULTS

In groups I and II, bone regeneration was not observed but fibrous tissue intrusion was prevented in group II. Bone neogenesis was more observed in group III than in group IV at 3 months (p<0.05). At 6 months, the regenerated areas were larger than those observed at 3 months, but the differences between groups III and IV were not statistically significant.

Cerebellar abscesses caused by dog bite: a case report

INTRODUCTION

Bites by house pets can be lethal or cause a series of catastrophic events with severe sequels, such as the loss of a limb or a systemic infection which may be life-endangering, especially in the case of children being bitten.

PRESENTATION

A 2-year-old girl was attacked by a dog, causing lesions at the occipital region. This was treated initially as a superficial wound that became further complicated with two cerebellar abscesses. These abscesses required neurosurgical and antimicrobial treatment, with a satisfactory outcome.

CONCLUSION

The precise and diligent evaluation of a lesion caused by an animal bite may prevent further life-endangering complications. To the best of our knowledge, there are no reports about cerebellar abscess caused by a dog bite. When cranial lesions are penetrating, an abscess must to be considered. We insist on the importance of medical evaluation and adequate treatment of such lesions.

Head injury with temporal bone fracture: one year review of case incidence, causes, clinical features and outcome

To investigate the case incidence, causes, clinical profile and outcome of temporal bone fracture complicating head trauma. A 1-year (2005) retrospective study of head injured patients presented to the Emergency Department, Hospital Tengku Ampuan Afzan, Kuantan, Pahang, Malaysia. Gender distribution, cause of injury, radiological findings and otorhinolaryngological clinical presentations were analyzed. Of 1309 patients, 61 patients were diagnosed to have temporal bone fracture (4.7%). Majority of cases were caused by motor vehicle accident (85.9%) and were predominantly male (88.5%). The right temporal bone was more frequently fractured (62.3%). Most (88.5%) were petro-mastoid fractures. Sixty-seven percent of the petrous fractures were longitudinal type. Clinical presentations mostly reported were blood rhinorrhea (36%) and blood otorrhea (32.7%). Other clinical presentations were hearing loss (9.8%), cranial nerve palsy (8.2%), cerebrospinal fluid oto-rhinorrhea (8.2%) and labyrinth concussion (6.5%). Four out of five cranial nerve palsies were facial nerve. Out of the 61 cases, 16 (26.2%) had no clinical presentation at the time of Emergency Department consultation. Thirteen (21.3%) died due to severe head injury. The case incidence of temporal bone fracture in head injured patients in our centre is 4.7%. The petro-mastoid type fracture predominates. Proper early diagnosis and management minimize complications.

Patterns and outcomes of pediatric facial fractures in the United States: a survey of the National Trauma Data Bank

BACKGROUND

Pediatric trauma involving the bones of the face is associated with severe injury and disability. Although much is known about the epidemiology of facial fractures in adults, little is known about national injury patterns and outcomes in children in the US.

STUDY DESIGN

The epidemiology of facial injuries in children and adolescents (ages 0 to 18 years) was described using the National Trauma Data Bank (2001 to 2005) to examine facial fracture pattern, mechanism, and concomitant injury by age.

RESULTS

A total of 12,739 (4.6%) facial fractures were identified among 277,008 pediatric trauma patient admissions. The proportion of patients with facial fractures increased substantially with age. The most common facial fractures were mandible (32.7%), nasal (30.2%), and maxillary/zygoma (28.6%). The most common mechanisms of injury were motor vehicle collision (55.1%), violence (11.8%), and falls (8.6%). These fracture patterns and mechanisms of injury varied with age. Compared with patients without facial fractures, patients with fractures exhibited substantial injury severity, hospital lengths of stay, ICU lengths of stay, ventilator days, and hospital charges. In addition, patients with facial fractures had more severe associated injury to the head and chest and considerably higher overall mortality.

CONCLUSIONS

Causes and patterns of facial fractures vary with age. Cranial and central facial injuries are more common among toddlers and infants, and mandible injuries are more common among adolescents. Although bony craniofacial trauma is relatively uncommon among the pediatric population, it remains a substantial source of mortality, morbidity, and hospital resource use. Continued efforts toward injury prevention are warranted.

Repair of critical bone defects with injectable platelet rich plasma/bone marrow-derived stromal cells composite: experimental study in rabbits

BACKGROUND

Platelet-rich plasma (PRP) has been applied to promote bone healing and developed as a novel material for bone regeneration. This study aimed to investigate the feasibility of PRP carrier to deliver bone marrow derived stromal cells (BMSCs) and regenerate bone tissues to reconstruct critical bone defects in rabbits.

METHODS

Critical sized defect were made on eighteen rabbits' crania and treated by different composites: BMSCs/PRP (n=6); Autogenous particulate cancellous bone group (n=6) and PRP alone group (n=6). The defects were evaluated by gross observation, radiographic examination, histological examination, and mechanical examination at 12 weeks postoperatively.

RESULTS

The results showed that repair of bone defect was the least in PRP alone group, and significant new bone formation could be observed in BMSCs/PRP group and particulate cancellous bone group, radiopacity area in BMSCs/PRP group attained 76.5%, which was in the same range of that in autogenous particulate cancellous bone group (82.4% in radiopacity area), compressive strength of engineered bone in BMSCs/PRP group attained 71% of that in autogenous particulate cancellous bone group (p<0.05).

CONCLUSION

These data implicated that BMSCs delivered from PRP gel can repair bony defect in immunocompetent animals, and the tissue engineered bone in BMSCs/PRP group is comparable to autogenous particulate cancellous bone group for the repair of critical-sized bone defect.

Frontal sinus fractures: a review of trends, diagnosis, treatment, and outcomes at a level 1 trauma center in Connecticut

The purpose of this retrospective study is to document the incidence and etiology of frontal sinus fracture at a level 1 traumacenterin Connecticut, assess the variability of management within our institution, and assess the effect on outcome over a seven-year period (January 1995-March 2002). Sixty-three cases were identified. Mean age was 31 years (92% male). The most common mechanism of injury was motor vehicle accident, followed by falls. The rates of associated facial fracture and intracranial injury were 83%, and 54% respectively. Diagnostic imaging missed two fractures. This study documents significant intrainstitutional variation in surgical management across contemporaneous primary treatment teams. There was no significant difference in outcome noted based on the treating specialty of the primary team for a given fracture type. The material used for sinus obliteration had no affect on outcome. Notable complications ofcerebrospinal fluid leak and mucocele are discussed as they contribute to current management guidelines.

In vivo bone response to 3D periodic hydroxyapatite scaffolds assembled by direct ink writing

The in vivo bone response of 3D periodic hydroxyapatite (HA) scaffolds is investigated. Two groups of HA scaffolds (11 mm diameter x 3.5 mm thick) are fabricated by direct-write assembly of a concentrated HA ink. The scaffolds consist of cylindrical rods periodically arranged into four quadrants with varying separation distances between rods. In the first group, HA rods (250 microm in diameter) are patterned to create pore channels, whose areal dimensions are 250 x 250 microm(2) in quadrant 1, 250 x 500 microm(2) in quadrants 2 and 4, and 500 x 500 microm(2) in quadrant 3. In the second group, HA rods (400 microm in diameter) are patterned to create pore channels, whose areal dimensions of 500 x 500 microm(2) in quadrant 1, 500 x 750 microm(2) in quadrants 2 and 4, and 750 x 750 microm(2) in quadrant 3. Each group of scaffolds is partially densified by sintering at 1200 degrees C prior to being implanted bilaterally in trephine defects of skeletally mature New Zealand White rabbits. Their tissue response is evaluated at 8 and 16 weeks using micro-computed tomography, histology, and scanning electron microscopy. New trabecular bone is conducted rapidly and efficiently across substantial distances within these patterned 3D HA scaffolds. Our observations suggest that HA rods are first coated with a layer of new bone followed by subsequent scaffold infilling via outward and inward radial growth of the coated regions. Direct-write assembly of 3D periodic scaffolds composed of micro-porous HA rods arrayed to produce macro-pores that are size-matched to trabecular bone may represent an optimal strategy for bone repair and replacement structures.

The primacy of octacalcium phosphate collagen composites in bone regeneration

We have engineered a scaffold constructed of synthetic octacalcium phosphate (OCP) and porcine collagen sponge (OCP/Col), and reported that OCP/Col drastically enhanced bone regeneration. In this study, we investigated whether OCP/Col would enhance bone regeneration more than beta-tricalcium phosphate (beta-TCP) collagen composite (beta-TCP/Col) or hydroxyapatite (HA) collagen composite (HA/Col). Discs of OCP/Col, beta-TCP/Col, or HA/Col were implanted into critical-sized defects in rat crania and fixed at 4 or 12 weeks after implantation. The newly formed bone and the remaining granules of implants in the defect were determined by histomorphometrical analysis, and radiographic and histological examinations were performed. Statistical analysis showed that the newly formed bone by the implantation of OCP/Col was significantly more than that of beta-TCP/Col or HA/Col. In contrast, the remaining granules in OCP/Col were significantly lower than those in beta-TCP/Col or HA/Col. Bone regeneration by OCP/Col was based on secured calcified collagen and bone nucleation by OCP, whereas bone regeneration by beta-TCP/Col or HA/Col was initiated by poorly calcified collagen and osteoconductivity by beta-TCP or HA. This study showed that the implantation of OCP/Col in a rat cranial defect enhanced more bone regeneration than beta-TCP/Col and HA/Col.