Craniomaxillofacial Complex Research Articles

Comparison of the Effects of Different Palatal Morphology on Maxillary Expansion via RME and MSE: A Finite Element Analysis.

This study aims to compare and analyze the biomechanical effect and the displacement trend of RME and MSE on the maxillofacial complex under different palatal shapes by using finite element analysis. The three-dimensional model of maxillofacial complex was obtained from a computed tomography image of a person with a normal palate. Then, we modified the shape of the palate to obtain the model with a high palate. Additionally, two expander devices were considered. MSE and RME were created and four models were made: Model 1: Normal-palate craniomaxillofacial complex with RME expander; Model 2: Normal-palate craniomaxillofacial complex with MSE expander; Model 3: High-palate craniomaxillofacial complex with RME expander; Model 4: High-palate craniomaxillofacial complex with MSE expander. Then, lateral forced displacement was applied and the analysis results were obtained. The lateral displacement of the palatal suture of Model 3 is greater than that of Model 1, and the maxilla has more rotation. The crown/root ratio of Model 1 is significantly greater than that of the other three groups. Compared with Model 1, Model 3 has greater stress concentration in the superstructure of the craniomaxillofacial complex. Both of them have greater stress in the anchorage area than Model 2 and Model 4. Different shapes of the palate interfere with the effects of RME and MSE, and its influence on the stress distribution and displacement of the craniomaxillary complex when using RME is greater than MSE. The lateral displacement of the palatal suture of MSE is significantly larger than that of RME. It is more prone to tipping movement of the anchor teeth using RME under normal palate, and MSE may manage the vertical control better due to the smaller crown/root ratio than RME and intrusive movement of molars.

Finite element analysis of sagittal screw expander appliance in the treatment of anterior maxillary hypoplasia.

The skeletal anterior crossbite is a common malocclusion in clinic. However, there have been no reports on the maxillary sagittal expansion to correct the premaxillary hypoplasia, which greatly influences the facial morphology and masticatory function, using finite element analysis. In the present study, a three-dimensional finite element model of craniomaxillofacial complex with maxillary sagittal hypoplasia is constructed and the treatment for premaxillary hypoplasia by the sagittal screw expander appliance is simulated. The hypoplasia of the left premaxilla is more serious than that of the right and thus the size of the left part of premaxillary expander baseplate is designed to be larger than that of the right part and the loading is applied at 10° leftward to the sagittal plane and 30° forward and downward to the maxillary occlusal plane. The displacements or equivalent stress distributions of the maxilla, teeth and their periodontal ligaments, are analyzed under the loads of 5.0N, 10.0N, 15.0N, and 20.0N. Consequently, as the load increases, the displacements or equivalent stresses of the maxilla, teeth and their periodontal ligaments all increase. Almost the whole premaxilla markedly move forward, downward, and leftward while other areas in the craniomaxillofacial complex remain almost static or have little displacement. The equivalent stress concentration zone of the maxilla mainly occurs around and in front of the incisive foramina. The displacements of left premaxilla are generally greater than those of the right under the loading forces. The maximum equivalent stress on the teeth and their periodontal ligaments are 2.34E-02MPa and 2.98E-03MPa, respectively. Taken together, the sagittal screw expander appliance can effectively open the premaxillary suture to promote the growth of the premaxilla. An asymmetrical design of sagittal screw expander appliance achieves the asymmetric expansion of the premaxilla to correct the uneven hypoplasia and obtains the more symmetrical aesthetic presentation. This study might provide a solid basis and theoretical guidance for the clinical application of sagittal screw expander appliance in the efficient, accurate, and personalized treatment of premaxillary hypoplasia.

Additive manufacturing of biomaterials: A review

The growing field of 3D printing has undergone impressive expansion because of its flexible manufacturing technique for layer-by-layer part fabrication utilizing CAD models without the requirement for specialist machinery. 3D printing, which was first used to create pre-surgical models, has become a crucial process for creating specific patient instruments, implants, and scaffolds for applications in tissue engineering. The availability of inexpensive printers has stoked renewed interest in the use of stem cells and tailored scaffolds to promote personalized medicine. As a result, the development of printed biomaterials has significantly increased over time. A thorough analysis of current and previous developments in the creation of biomaterials and bioinks is provided in this paper. Intricate tissues, such as those present in the craniomaxillofacial complex's bone, bones, cartilage, muscles, arteries, and nerves, are frequently restored using 3D printers. Furthermore, these printers have been successfully employed in fabricating complex organs featuring intricate 3D microarchitectures, including the liver and lymphoid organs. By shedding light on the latest developments and potential avenues for further exploration, this article aims to highlight the immense potential of 3D printing in tissue engineering and personalized medicine. The ever-growing capabilities of 3D printing technology have the potential to revolutionize the medical field, opening new possibilities for tailored and highly effective treatments.

Correlation between the variation of head type and malocclusion: A Scooping Review

Aim: Examination of head type in orthodontics is pivotal. Examining the head type aims to monitor growth patterns and predict the outcome of an orthodontic treatment. Malocclusion is a disease with a complex etiology. Anomaly in the development pattern of the oral and maxillofacial region can be suspected as the etiology of malocclusion. A specific type of head will result from specific growth patterns. As a result, dental and skeletal malocclusion occurrences are linked to particular head forms. Materials and Methods: These articles’ literature sources were from various databases that described cephalic index correlation and cephalic index malocclusion. Results: A correlation is found between mesocephalic head type with skeletal and dental malocclusion class II, mesocephalic head type with skeletal and dental malocclusion class I, mesocephalic head type with skeletal malocclusion class I and dental class II, mesocephalic head type with skeletal malocclusion class I, and dental class III. Meanwhile, dolichocephalic head type correlates with dental and skeletal malocclusion class II, dolichocephalic head type with skeletal 111 class II, and dental class I, dolichocephalic head type with skeletal malocclusion class I, and dental class II. In addition, brachycephalic head type correlates to skeletal and dental malocclusion class II and the relationship between brachycephalic head type with skeletal malocclusion class III and dental class II. Class I malocclusion is associated with the mesocephalic head type because the mesocephalic head type favors balanced development of the craniomaxillofacial complex. Class II malocclusion is associated with dolichocephalic head type, selecting the face’s predominantly long morphology. Class III malocclusion is associated with brachycephalic head type, favoring the maxilla’s retrusion. Conclusion: Malocclusion classification correlates with variations in head types. Genetic and environmental variables, or possibly both, impact this disease.

Self-assembling peptide-laden electrospun scaffolds for guided mineralized tissue regeneration.

Electrospun scaffolds are a versatile biomaterial platform to mimic fibrillar structure of native tissues extracellular matrix, and facilitate the incorporation of biomolecules for regenerative therapies. Self-assembling peptide P11-4 has emerged as a promising strategy to induce mineralization; however, P11-4 application has been mostly addressed for early caries lesions repair on dental enamel. Here, to investigate P11-4's efficacy on bone regeneration, polymeric electrospun scaffolds were developed, and then distinct concentrations of P11-4 were physically adsorbed on the scaffolds. P11-4-laden and pristine (P11-4-free) electrospun scaffolds were immersed in simulated body fluid and mineral precipitation identified by SEM. Functional groups and crystalline phases were analyzed by FTIR and XRD, respectively. Cytocompatibility, mineralization, and gene expression assays were conducted using stem cells from human exfoliated deciduous teeth. To investigate P11-4-laden scaffolds potential to induce in vivo mineralization, an established rat calvaria critical-size defect model was used. We successfully synthesized nanofibrous (∼ 500nm fiber diameter) scaffolds and observed that functionalization with P11-4 did not affect the fibers' diameter. SEM images indicated mineral precipitation, while FTIR and XRD confirmed apatite-like formation and crystallization for P11-4-laden scaffolds. In addition, P11-4-laden scaffolds were cytocompatible, highly stimulated cell-mediated mineral deposition, and upregulated the expression of mineralization-related genes compared to pristine scaffolds. P11-4-laden scaffolds led to enhanced in vivo bone regeneration after 8 weeks compared to pristine PCL. Electrospun scaffolds functionalized with P11-4 are a promising strategy for inducing mineralized tissues regeneration in the craniomaxillofacial complex.

Effects of different force directions of intra-oral skeletally anchored maxillary protraction on craniomaxillofacial complex, in Class III malocclusion: a 3D finite element analysis.

The intra-oral skeletally anchored maxillary protraction (I-SAMP) has been found to be an effective treatment for skeletal Class III malocclusion. This in-silico study explored the influence of different force directions of intra-oral skeletally anchored Class III elastics on the changes in craniomaxillofacial complex, using finite element analysis. A 3-dimensional (3D) finite element model of the craniomaxillofacial bones including circummaxillary sutures was constructed with high biological resemblance. A 3D assembly of four miniplates was designed and fixed on the maxilla and mandible of the finite element model. The model was applied with 250g/force at the miniplates at three angulations (10°, 20°, and 30°) from the occlusal plane, to measure stress and displacement by using the ANSYS software. The zygomaticotemporal, zygomaticomaxillary, and sphenozygomatic sutures played significant roles in the forward displacement and counterclockwise rotation of maxilla and zygoma, irrespective of the angulation of load application. The displacements and rotations of the zygomatico-maxillary complex decreased gradually with an increase in the angle of load application between miniplates from 10° to 30°. The mandible showed negligible displacement, with clockwise rotation. The treatment effects of I-SAMP were corroborated, with insight of displacement patterns and sutures involved, which were lacking in the previously conducted 2D and 3D imaging studies. The prescribed angulation of skeletally anchored Class III elastics should be as low as possible, since the displacement of zygomatico-maxillary complex increases with the decrease in angulation of the elastics.

Displacement and stress distribution of the craniomaxillofacial complex under different surgical conditions: a three-dimensional finite element analysis of fracture mechanics

ObjectiveTo provide a simplified treatment strategy for patients with maxillary transverse deficiency. We investigated and compared the fracture mechanics and stress distribution of a midline palatal suture under dynamic loads during surgically-assisted rapid palatal expansion.MethodsBased on the cone-beam computed tomography (CBCT) data of a 21-year-old female volunteer, a three-dimensional model of the cranio-maxillofacial complex (including the palatal suture) was constructed. A finite element analysis model was constructed based on meshwork. After the yield strength of the palatal suture was set, an increasing expansion force (0–500 N) was applied within 140 ms to calculate the time–load curve, which mimicked nonsurgical bone expansion (model A). The same method was used to evaluate the fracture process, time and stress distribution of the palatal suture in maxillary lateral osteotomy-assisted (model B) and LeFort osteomy I (LFIO)-assisted expansion of the maxillary arch (model C).ResultsCompared with model A, the palatal suture of model B and model C showed a faster stress accumulation rate and shorter fracture time, and the fracture time of model B and model C was almost identical. Compared with model A, we discovered that model B and model C showed greater lateral extension of the maxilla, and the difference was reflected mainly in the lower part of the maxilla, and there was no difference between model B and model C in lateral extension of the maxilla.ConclusionsCompared with arch expansion using nonsurgical assistance (model A), arch expansion using maxillary lateral wall-osteotomy (model B) or LFIO had a faster rate of stress accumulation, shorter time of fracture of the palatal suture and increased lateral displacement of the maxilla. Compared with arch expansion using LFIO (model C), arch expansion using lateral osteotomy (model B) had a similar duration of palatal suture rupture and lateral maxillary extension. In view of the trauma and serious complications associated with LFIO, maxillary lateral wall-osteotomy could be considered a substitute for LFIO.

Exploring the Severity of Craniomaxillofacial Injuries From Horseback Riding.

The purpose of our study is to assess the severity of craniomaxillofacial injuries from horseback-riding accidents. This is a 20-year retrospective cross-sectional study of the National Electronic Injury Surveillance System. Injuries from the activity of horseback-riding were included if they occurred in the craniomaxillofacial complex. Study predictors were derived from both patient and injury characteristics. The study outcome was the presence or absence (probability) of hospital admission from the emergency department. A multiple logistic regression model was created to model the odds of admission using all significant univariate predictors. The final sample consisted of 6730 patients. The decrease in horseback riding injuries from 2000 to 2019 was significant (P = 0.042).The mean age of the sample was 27.80 years (range: 2-91 years). Gender-wise, females composed the majority of injured horseback riders (71.9%). Over two-thirds of the sample consisted of White patients (68.1%). Over three-fourths of the injuries occurred in the head (80.9%), rendering it the most frequently injured region of the craniomaxillofacial complex. The most common primary diagnoses were internal organ injury (40.2%). On univariate analysis, the admission rates were significantly associated with gender (P < 0.01), age group (P < 0.01), body part injured (P < 0.01), diagnosis (P < 0.01), location of injury (P < 0.01) and mechanism of injury (P < 0.05). Relative to young adults, children (odds ratio [OR], 1.579; 95% OR confidence interval [CI] [1.31, 1.91]; P < 0.01), adults (OR, 1.857; 95% OR CI [1.55, 2.22]; P < 0.01), and seniors (OR, 3.738; 95% OR CI [2.73, 5.12]; P < 0.01) were each independently associated with an increased odds of admission. Relative to the mouth, the head had 4.8 odds of admission (P < 0.01) and the face had 2.5 odds of admission (P < 0.01). Relative to contusions/abrasion, concussions (OR, 3.542; 95% OR CI [2.28, 5.49]; P < 0.01) and internal organ injuries (OR, 9.020; 95% OR CI [5.90, 13.79]; P < 0.01), lacerations (OR, 1.946; 95% OR CI [1.17, 3.24]; P < 0.05), and fractures (OR, 32.068; 95% OR CI [20.53, 50.09]; P < 0.01) were each independently associated with increased odds of admission relative to contusions. Direct trauma from a horse (OR, 1.422; 95% OR CI [1.06, 1.91]; P < 0.05) was associated with independently increased odds of admission relative to other injuries. Injuries that took place in a farm (OR, 1.617; 95% OR CI [1.25, 2.09]; P < 0.01) and a street (OR, 2.735; 95% OR CI [1.83, 4.09]; P < 0.01) were each independently associated with increased odds of admission. Finally, relative to females, males (OR, 1.374; 95% OR CI [1.20, 1.57]; P < 0.01) were independently associated with increased odds of admission. Many variables contribute to the chance of hospital admission from horseback riding. Fractures seem to be the leading risk factor for hospital admission, therefore, future study may look into how to reduce the incidence of fractures through the employment of more protective equipment than helmets for horseback riders.

Panfacial fractures: Prevalence, sociodemographics, and pattern of presentation in a major referral hospital in the Southern province of the Kingdom of Saudi Arabia

Background: Panfacial fractures are defined as fractures of the craniomaxillofacial complex involving bones in the lower, middle, and upper thirds of the facial skeleton. The aim of the current study is to report the prevalence, sociodemographics, and pattern of panfacial fractures in Najran, Kingdom of Saudi Arabia. Materials and Methods: This was a retrospective study of panfacial fractures seen and managed in a major referral hospital in the southern province of the Kingdom of Saudi Arabia over a 10-year period from 2008 to 2018. Data collected include demographics such as age, gender, etiological factor, and pattern of bone fracture involved in the panfacial fracture. Data were stored and analyzed using IBM SPSS Statistics for IOS Version 25 (Armonk, NY, USA: IBM Corp.). Results were presented as simple frequencies and descriptive statistics. Statistical significance was set at P ≤ 0.05. Results: A total of 1057 patients presented with maxillofacial injuries, of which 43 male patients suffered from panfacial fractures during the study period giving a prevalence rate of 4.1%. The age ranged from 16 to 45 years with mean ± standard deviation (26.6 ± 8.3) years. The age group of 21–30 years had the highest frequency of panfacial fracture, whereas the age group of 41–50 years had the least occurrence with a statistically significant difference. Most of the mandibular fractures involved the symphysis and parasymphysis (27.9% and 23.3%), respectively. In the midface, Le Fort I and II were the most common maxillary fractures. Conclusion: Inquiry into the prevalence, sociodemographics, and pattern of panfacial fractures is essential in decision-making by the attending clinicians for the patients' overall management. This study has reported a prevalence rate of 4.1% with only male preponderance.

Histological Diversity, Diagnostic Challenges, and Surgical Treatment Strategies of Fibrous Dysplasia of Upper and Mid-Thirds of the Craniomaxillofacial Complex.

Background:Owing to the overlapping clinical, radiographic and histopathological features among the diverse group of Fibro-osseous lesions, a precise and definitive diagnosis of Fibrous Dysplasia (FD) can be quite challenging. Moreover, FD itself may manifest with widely varying clinical presentations, radiographic appearances and histological pictures, depending upon the maturity of the lesion, and the relative quantum of its ‘fibrous’ and ‘osseous components’. Prompt and accurate diagnosis of Fibrous Dysplasia (FD) of the Craniomaxillofacial region is particularly important, as the condition is capable of causing considerable facial asymmetry or deformity leading even to marked disfigurement, which can have a profound psychosocial impact on the patient. Involvement of Maxillofacial bones by aggressive forms of FD, can produce serious functional debility as well, by compromising airway, breathing, vision, hearing, occlusion, mastication and mouth opening. Calvarial bone involvement can produce cranial asymmetry, and cranial base involvement can lead to persistent headaches, facial pain, numbness, and other neurological deficits owing to compression of cranial nerves.Aims and Objectives:To evaluate the importance of early and precise diagnosis, with prompt surgical management of these lesions, for a successful overall esthetic and functional outcome.Materials and Methods:A Case series of 15 patients, showcasing the principal variants of FD affecting the Craniomaxillofacial complex, namely, the Monostotic and Craniofacial forms have been described. Diversity in their Clinical, Radiographic and Histopathological presentations; their management modalities elucidating the various surgical approaches employed to access and excise these bone pathologies, have been provided along with a review of existing literature.Results:Various surgical approaches may be employed to access the lesions, depending upon their location, extent and involvement. Treatment protocols range from complete surgical excision to surgical shaving and recontouring, and must be decided upon on a case to case basis, with the aim to achieve the best possible esthetic and functional outcome with the least postoperative morbidity.Conclusion:Correlation of HPE with history, clinical features, biological behaviour, radiographic and CT appearance, laboratory findings, and intra-operative findings is imperative, so that they can be distinguished from other bony lesions and an appropriate, ideal and effective treatment modality can be instituted in time, so as to achieve the most favourable esthetic and functional outcome.

Endoscopically Assisted Modified Caldwell-Luc Approach to Enucleation of Dentigerous Cyst With Ectopic Tooth From the Maxillary Sinus

Dentigerous cysts in the craniomaxillofacial complex are a benign pathology commonly associated with ectopically placed teeth. Owing to slow and asymptomatic growth, they often attain considerable size before diagnosis that may compromise adjacent anatomical structures. Various techniques for removal of dentigerous cysts from the maxillary sinus have been described. This case report demonstrates a hybrid endoscopically assisted modification of the Caldwell-Luc approach to provide the technical advantages of both techniques.

Foreign Body Removal in the Craniomaxillofacial Complex: Indications, Techniques, and Treatment

Foreign body migration in the deep spaces of the neck is particularly concerning due to the increased risk of damage to the great vessels and nerves. In addition, migration often cannot be easily predicted as objects may travel outside the confines of anatomic fascial planes. Although patients may be asymptomatic for years prior to presentation, timely removal of foreign bodies is ideal to preclude injury to important vascular and neurological structures as well as to prevent the development of recurrent infections and foreign body reactions. The authors report two cases of removal of migrated foreign bodies that presented at their institution. In one case, they report the use of intraoperative computed tomography (CT) imaging to help locate the position of a migrating dental needle. In another, they report the retrieval of a bullet fragment six months after the initial trauma. The classic method for retrieval of foreign bodies within the craniomaxillofacial complex centered around review of static radiographic imaging and a “blind,” broad exposure of the site in an attempt to localize and retrieve the material. This often resulted in iatrogenic injuries to surrounding structures or migration of the foreign body to a location, which may cause the patient additional harm. The utilization of intraoperative CT technology and computer navigation affords the craniomaxillofacial surgeon an additional tool for retrieval of these foreign bodies, often in a manner that affords minimally invasive surgical approaches, identification of vital structures within the operative field, and decrease in overall operative time for removal. Referral to institutions, which have this technology, should be considered early in the operative care of patients who encounter retained foreign bodies in the craniomaxillofacial region.

3D Printing &amp; Pharmaceutical Manufacturing: Opportunities and Challenges

Many researchers have attempted to use computer-aided design (C.A.D) and computer-aided manufacturing (CAM) to realize a scaffold that provides a three-dimensional (3D) environment for regeneration of tissues and organs. As a result, several 3D printing technologies, including stereolithography, deposition modeling, inkjet-based printing and selective laser sintering have been developed. Because these 3D printing technologies use computers for design and fabrication, and they can fabricate 3D scaffolds as designed; as a consequence, they can be standardized. Growth of target tissues and organs requires the presence of appropriate growth factors, so fabrication of 3Dscaffold systems that release these biomolecules has been explored. A drug delivery system (D.D.S) that administrates a pharmaceutical compound to achieve a therapeutic effect in cells, animals and humans is a key technology that delivers biomolecules without side effects caused by excessive doses. 3D printing technologies and D. D. Ss have been assembled successfully, so new possibilities for improved tissue regeneration have been suggested. If the interaction between cells and scaffold system with biomolecules can be understood and controlled, and if an optimal 3D tissue regenerating environment is realized, 3D printing technologies will become an important aspect of tissue engineering research in the near future. 3D Printing promises to produce complex biomedical devices according to computer design using patient-specific anatomical data. Since its initial use as pre-surgical visualization models and tooling molds, 3D Printing has slowly evolved to create one-of-a-kind devices, implants, scaffolds for tissue engineering, diagnostic platforms, and drug delivery systems. Fuelled by the recent explosion in public interest and access to affordable printers, there is renewed interest to combine stem cells with custom 3D scaffolds for personalized regenerative medicine. Before 3D Printing can be used routinely for the regeneration of complex tissues (e.g. bone, cartilage, muscles, vessels, nerves in the craniomaxillofacial complex), and complex organs with intricate 3D microarchitecture (e.g. liver, lymphoid organs), several technological limitations must be addressed. Until recently, tablet designs had been restricted to the relatively small number of shapes that are easily achievable using traditional manufacturing methods. As 3D printing capabilities develop further, safety and regulatory concerns are addressed and the cost of the technology falls, contract manufacturers and pharmaceutical companies that experiment with these 3D printing innovations are likely to gain a competitive edge. This review compose the basics, types &amp; techniques used, advantages and disadvantages of 3D printing

Recent advances in 3D printing of biomaterials.

3D Printing promises to produce complex biomedical devices according to computer design using patient-specific anatomical data. Since its initial use as pre-surgical visualization models and tooling molds, 3D Printing has slowly evolved to create one-of-a-kind devices, implants, scaffolds for tissue engineering, diagnostic platforms, and drug delivery systems. Fueled by the recent explosion in public interest and access to affordable printers, there is renewed interest to combine stem cells with custom 3D scaffolds for personalized regenerative medicine. Before 3D Printing can be used routinely for the regeneration of complex tissues (e.g. bone, cartilage, muscles, vessels, nerves in the craniomaxillofacial complex), and complex organs with intricate 3D microarchitecture (e.g. liver, lymphoid organs), several technological limitations must be addressed. In this review, the major materials and technology advances within the last five years for each of the common 3D Printing technologies (Three Dimensional Printing, Fused Deposition Modeling, Selective Laser Sintering, Stereolithography, and 3D Plotting/Direct-Write/Bioprinting) are described. Examples are highlighted to illustrate progress of each technology in tissue engineering, and key limitations are identified to motivate future research and advance this fascinating field of advanced manufacturing.

Human Stem Cells for Craniomaxillofacial Reconstruction

Human stem cell research represents an exceptional opportunity for regenerative medicine and the surgical reconstruction of the craniomaxillofacial complex. The correct architecture and function of the vastly diverse tissues of this important anatomical region are critical for life supportive processes, the delivery of senses, social interaction, and aesthetics. Craniomaxillofacial tissue loss is commonly associated with inflammatory responses of the surrounding tissue, significant scarring, disfigurement, and psychological sequelae as an inevitable consequence. The in vitro production of fully functional cells for skin, muscle, cartilage, bone, and neurovascular tissue formation from human stem cells, may one day provide novel materials for the reconstructive surgeon operating on patients with both hard and soft tissue deficit due to cancer, congenital disease, or trauma. However, the clinical translation of human stem cell technology, including the application of human pluripotent stem cells (hPSCs) in novel regenerative therapies, faces several hurdles that must be solved to permit safe and effective use in patients. The basic biology of hPSCs remains to be fully elucidated and concerns of tumorigenicity need to be addressed, prior to the development of cell transplantation treatments. Furthermore, functional comparison of in vitro generated tissue to their in vivo counterparts will be necessary for confirmation of maturity and suitability for application in reconstructive surgery. Here, we provide an overview of human stem cells in disease modeling, drug screening, and therapeutics, while also discussing the application of regenerative medicine for craniomaxillofacial tissue deficit and surgical reconstruction.

Titanium implants: A removal torque study in osteopenic rabbits

Osteoporosis is a skeletal disorder characterized by low bone mass and microarchitectural deterioration of bone tissue. It may affect the craniomaxillofacial complex and result in less bone-implant contact. The objective of this study was to measure the endosseous integration of titanium implants using the removal torque test in low-mineral density experimental animal models. Thirty female New Zealand white rabbits were divided into two groups: control (n=14), sham-operated; and test (n=16), ovariectomized. All animals received 2.2 mm Χ 4.0 mm titanium implants in the right tibia, 120 days after ovariectomy or sham surgery. Animals were killed at 7 and 14 weeks of postimplant insertion, when implants were removed by reverse torque rotation using a digital torque meter. Statistical analysis used was Student's t-test. At the 7-week period, the mean torque values for the control and test groups were 11.6 Ncm and 10.4 Ncm, respectively, with no statistical significance. Implant removal torque analysis showed statistically lower values (P < 0.05) for the test group at the 14-week period (control=16.7 Ncm and test=9.7 Ncm). The results of this study indicate that hormonal privacy compromise implants biomechanical performance.

A possible pathogenesis for Alzheimer’s disease: Craniomaxillofacial dysfunction leading to localized cerebrospinal fluid stasis

In the last two decades, a voluminous amount of research from multiple disciplines has been generated for Alzheimer's disease (AD). Despite the increased knowledge and understanding of AD and the potential therapeutics that are emerging, there is still no clear understanding of the pathogenesis. Without a precise, known mechanism, current potential targets for treatment may fall short of addressing an underlying cause. Any hypothesis must not only account for pathologic findings, but also the neurologic findings. Proposed hypotheses in the past have not completely accomplished this task, and have left many research findings unexplained. As AD is considered a heterogeneous disease, it may be helpful to compare and contrast it to other heterogeneous medical conditions. It is possible that today, there is sufficient knowledge and research on AD, but insufficient integration of that information. Thus, a unifying hypothesis that attempts to integrate much of the interdisciplinary research is presented to explain AD under a new paradigm. Stasis of cerebrospinal fluid (CSF) has been previously suggested to be a factor in the etiology of AD, but it has generated little attention among researchers. Therefore, CSF is discussed in greater detail and how disruption of its flow may have adverse consequences. The following hypothesis proposes that dependent, localized cerebrospinal fluid stasis in select areas of the brain may be one way to initiate and perpetuate AD pathogenesis. In that vein, it is also proposed that craniomaxillofacial function, involving the dentition and paranasal sinuses, plays a vital role for proper CSF flow dynamics. In this way, a possible mechanical risk factor involving a compromised craniomaxillofacial complex will be described for AD. The identification of a mechanical risk factor would open a discussion for immediate, inexpensive possibilities to prevent AD.