Craniomaxillofacial Skeleton Research Articles

Association between bilateral condylar resorption and reduced volumes of the craniofacial skeleton and masticatory muscles in adult patients: A retrospective study

ObjectivesThis retrospective cohort study aimed to analyze volumes of craniomaxillofacial bone and masticatory muscles of young adults with bilateral idiopathic condylar resorption. MethodsThis was a retrospective cohort study of 84 adults with bilateral idiopathic condylar resorption (BCR) and 48 adults with normal temporal-mandibular joint (TMJ) matched for age and sex (mean age, 23.2 ± 3.6 years). The volumes of craniomaxillofacial bone and masticatory muscles, as well as intercondylar angle were measured. Unpaired t-tests and Pearson correlation tests were applied to analyze the data. Multivariable linear regression models were used to estimate the association between bilateral condylar volume and volumes of craniomaxillofacial bone and masticatory muscles adjusted for age, sex, and disc status. ResultsCompared to the control group, the BCR group displayed significant decreased volumes of craniomaxillofacial bone (p < 0.001), craniomaxillofacial bone without mandible (p < 0.001), mandible (p < 0.001), mandible without mandibular condylar process (p < 0.001), bilateral masseter muscle (p < 0.001) and bilateral temporalis muscle (p < 0.001), as well as the intercondylar angle (p < 0.001). These variables were significantly correlated to the volume of mandibular condylar process (0.5< r < 0.8; p < 0.001). By linear regression analyses, significant associations were found for the bilateral condylar volume with craniomaxillofacial bone volume and mandible bone volume. ConclusionsYoung adults with BCR displayed smaller volumes of craniomaxillofacial skeleton and masticatory muscles, and smaller intercondylar angle than the normal patients. The craniofacial musculoskeletal volume and intercondylar angle are associated with mandibular condylar process volume.

From Augmented to Virtual Reality in Plastic Surgery: Blazing the Trail to a New Frontier.

Augmented reality (AR) and virtual reality (VR)-termed mixed reality-have shown promise in the care of operative patients. Currently, AR and VR have well-known applications for craniofacial surgery, specifically in preoperative planning. However, the application of AR/VR technology to other reconstructive challenges has not been widely adopted. Thus, the purpose of this investigation is to outline the current applications of AR and VR in the operative setting. The literature pertaining to the use of AR/VR technology in the operative setting was examined. Emphasis was placed on the use of mixed reality technology in surgical subspecialities, including plastic surgery, oral and maxillofacial surgery, colorectal surgery, neurosurgery, otolaryngology, neurosurgery, and orthopaedic surgery. Presently, mixed reality is widely used in the care of patients requiring complex reconstruction of the craniomaxillofacial skeleton for pre- and intraoperative planning. For upper extremity amputees, there is evidence that VR may be efficacious in the treatment of phantom limb pain. Furthermore, VR has untapped potential as a cost-effective tool for microsurgical education and for training residents on techniques in surgical and nonsurgical aesthetic treatment. There is utility for mixed reality in breast reconstruction for preoperative planning, mapping perforators, and decreasing operative time. VR has well- documented applications in the planning of deep inferior epigastric perforator flaps by creating three-dimensional immersive simulations based on a patient's preoperative computed tomography angiogram. The benefits of AR and VR are numerous for both patients and surgeons. VR has been shown to increase surgical precision and decrease operative time. Furthermore, it is effective for patient-specific rehearsal which uses the patient's exact anatomical data to rehearse the procedure before performing it on the actual patient. Taken together, AR/VR technology can improve patient outcomes, decrease operative times, and lower the burden of care on both patients and health care institutions.

3D Printing Applications for Craniomaxillofacial Reconstruction: A Sweeping Review.

The field of craniomaxillofacial (CMF) surgery is rich in pathological diversity and broad in the ages that it treats. Moreover, the CMF skeleton is a complex confluence of sensory organs and hard and soft tissue with load-bearing demands that can change within millimeters. Computer-aided design (CAD) and additive manufacturing (AM) create extraordinary opportunities to repair the infinite array of craniomaxillofacial defects that exist because of the aforementioned circumstances. 3D printed scaffolds have the potential to serve as a comparable if not superior alternative to the "gold standard" autologous graft. In vitro and in vivo studies continue to investigate the optimal 3D printed scaffold design and composition to foster bone regeneration that is suited to the unique biological and mechanical environment of each CMF defect. Furthermore, 3D printed fixation devices serve as a patient-specific alternative to those that are available off-the-shelf with an opportunity to reduce operative time and optimize fit. Similar benefits have been found to apply to 3D printed anatomical models and surgical guides for preoperative or intraoperative use. Creation and implementation of these devices requires extensive preclinical and clinical research, novel manufacturing capabilities, and strict regulatory oversight. Researchers, manufacturers, CMF surgeons, and the United States Food and Drug Administration (FDA) are working in tandem to further the development of such technology within their respective domains, all with a mutual goal to deliver safe, effective, cost-efficient, and patient-specific CMF care. This manuscript reviews FDA regulatory status, 3D printing techniques, biomaterials, and sterilization procedures suitable for 3D printed devices of the craniomaxillofacial skeleton. It also seeks to discuss recent clinical applications, economic feasibility, and future directions of this novel technology. By reviewing the current state of 3D printing in CMF surgery, we hope to gain a better understanding of its impact and in turn identify opportunities to further the development of patient-specific surgical care.

Cost Burden of Rigid Internal Fixation in Craniomaxillofacial Trauma Care in Low‐ and Middle‐Income Countries

AbstractFractures of the craniomaxillofacial (CMF) skeleton cause significant morbidity and mortality in low‐ and middle‐income countries (LMICs). Despite this, quality CMF trauma care is lacking for the majority of the world's population. There is a paucity of literature describing the costs of standard‐of‐care open reduction internal fixation (ORIF) for CMF fractures in LMICs. We consider the cost of a six‐hole plate with six screws (SHPS), standard materials used in ORIF for CMF fractures, as a percentage of gross domestic product (GDP) per capita to ascertain the cost burden to patients. Hospital pricing catalog data at 14 LMIC institutions were queried. On average, the SHPS cost represented 10.2% of the GDP per capita in sampled LMICs. We highlight manufacturing costs, import taxes, and lack of subsidized health care as factors contributing to the significant cost burden of ORIF in these areas. Future work should characterize additional financial and socioeconomic barriers to optimal CMF care.

Artificial Intelligence-Based Modeling Can Predict Face Shape Based on Underlying Craniomaxillofacial Bone.

Reconstructing facial deformities is often challenging due to the complex 3-dimensional (3D) anatomy of the craniomaxillofacial skeleton and overlying soft tissue structures. Bilateral injuries cannot benefit from mirroring techniques and as such preinjury information (eg, 2D pictures or 3D imaging) may be utilized to determine or estimate the desired 3D face shape. When patient-specific information is not available, other options such as statistical shape models may be employed; however, these models require registration to a consistent orientation which may be challenging. Artificial intelligence (AI) has been used to identify facial features and generate highly realistic simulated faces. As such, it was hypothesized that AI can be used to predict 3D face shape by learning its relationship with the underlying bone surface anatomy in a subject-specific manner. An automated image processing and AI modeling workflow using a modified 3D UNet was generated to estimate 3D face shape using the underlying bone geometry and additional metadata (eg, body mass index and age) obtained from 5 publicly available computed tomography imaging datasets. Visually, the trained models provided a reasonable prediction of the contour and geometry of the facial tissues. The pipeline achieved a validation dice=0.89 when trained on the combined 5 datasets, with the highest dice=0.925 achieved with the single HNSCC dataset. Estimated predefect facial geometry may ultimately be used to aid preoperative craniomaxillofacial surgical planning, providing geometries for intraoperative templates, guides, navigation, molds, and forming tools. Automated face shape prediction may additionally be useful in forensic studies to aid in the identification of unknown skull remains.

Patient-specific distractors for customized mandibular distraction osteogenesis to relieve upper airway obstruction in infants with Pierre Robin sequence

The purpose of this article is to report the author’s technique for using patient-specific distractors for customized distraction osteogenesis of the mandible in patients with Pierre Robin sequence and upper airway obstruction. The advantages of virtual planning and patient-specific plates in other aspects of craniomaxillofacial surgery, such as orthognathic and reconstructive surgery, have been reported previously. Similar to patient-specific plates, the theorized advantages of patient-specific distractors in infants with Robin sequence and upper airway obstruction include increased accuracy, decreased operating time, and less morbidity to vital anatomic structures such as the inferior alveolar nerve and developing tooth buds. This technique is novel in using patient-specific distractors in the craniomaxillofacial skeleton.

Pediatric Panfacial Fractures.

Pediatric panfacial trauma is a rare occurrence with poorly understood implications for the growing child. Treatment algorithms largely mirror adult panfacial protocols with notable exceptions including augmented healing and remodeling capacities that favor nonoperative management, limited exposure to avoid disruption of osseous suture and synchondroses growth centers, and creative fracture fixation techniques in the setting of an immature craniomaxillofacial skeleton. The following article provides a review of our institutional philosophy in the management of these challenges injuries with important anatomic, epidemiologic, examination, sequencing, and postoperative considerations.

Wnt/β-Catenin Signaling in Craniomaxillofacial Osteocytes.

There is a growing appreciation within the scientific community that cells exhibit regional variation. Whether the variation is attributable to differences in embryonic origin or anatomical location and mechanical loading has not been elucidated; what is clear, however, is that adult cells carry positional information that ultimately affects their functions. The purpose of this review is to highlight the functions of osteocytes in the craniomaxillofacial (CMF) skeleton as opposed to elsewhere in the body, and in doing so gain mechanistic insights into genetic conditions and chemically-induced diseases that particularly affect this region of our anatomy. In the CMF skeleton, elevated Wnt/β-catenin signaling affects not only bone mass and volume, but also mineralization of the canalicular network and osteocyte lacunae. Aberrant elevation in the Wnt/β-catenin pathway can also produce micropetrosis and osteonecrosis of CMF bone, presumably due to a disruption in the signaling network that connects osteocytes to one another, and to osteoblasts on the bone surface.

CT-Based Modeling of the Dentition for Craniomaxillofacial Surgical Planning.

Historically, the accuracy of imaging teeth by computed tomography (CT) has been suboptimal and deemed inadequate for surgical planning of orthognathic procedures. However, recent advances in CT hardware and software have significantly improved the accuracy of imaging occlusal anatomy. This technical note describes a quantitative means of evaluating the accuracy of CT-based modeling of teeth. Three-dimensional models of the dentition were created from a CT scan obtained of a craniomaxillofacial skeleton. Multiple reconstruction algorithms and modeling parameters were applied. The dentition of the same skeleton was scanned using a handheld optical scanning device to serve as the "gold standard." Semi-automated registrations of CT and optically acquired models were performed and deviation analysis was conducted. On average, the deviation of the CT model with the optical scan measured 0.19 to 0.25 mm across the various reconstruction and modeling parameters, with a mean of 0.22 mm. Computed tomography underestimated contours at cusp tips, while overestimating contours in occlusal groves. The use of bone reconstruction algorithms and decreased model smoothing resulted in more accurate models, though greater surface noise. Future studies evaluating the clinical effectiveness of CT-based occlusal splints should take this finding into account.

Pediatric Facial Fractures.

Facial trauma is common in the pediatric population with most cases involving the soft tissue or dentoalveolar structures. Although facial fractures are relatively rare in children compared with adults, they are often associated with severe injury and can cause significant morbidity and disability. Fractures of the pediatric craniomaxillofacial skeleton must be managed with consideration for psychosocial, anatomical, growth and functional differences compared with the adult population. Although conservative management is more common in children, displaced fractures that will not self-correct with compensatory growth require accurate and stable reduction to prevent fixed abnormalities in form and function.

Pharmacological Approaches and Regeneration of Bone Defects with Dental Pulp Stem Cells.

Bone defects in the craniomaxillofacial skeleton vary from small periodontal defects to extensive bone loss, which are difficult to restore and can lead to extensive damage of the surrounding structures, deformities, and limited functions. Plenty of surgical regenerative procedures have been developed to reconstruct or prevent alveolar defects, based on guided bone regeneration involving the use of autogenous bone grafts or bone substituents. However, these techniques have limitations in the restoration of morphological and functional reconstruction, thus stopping disease progression but not regenerating lost tissue. Most promising candidates for regenerative therapy of maxillofacial bone defects represent postnatal stem cells, because of their replication potential in the undifferentiated state and their ability to differentiate as well. There is an increased need for using various orofacial sources of stem cells with comparable properties to mesenchymal stem cells because they are more easily available with minimally invasive procedures. In addition to the source of MSCs, another aspect affects the regeneration outcomes. Thermal, mechanical, and chemical stimuli after surgical procedures have the ability to generate pain, usually managed with pharmacological agents, mostly nonsteroidal anti-inflammatory drugs (NSAIDs). Some studies revealed that NSAIDs have no significant cytotoxic effect on bone marrow stem cells from mice, while other studies showed regulation of osteogenic and chondrogenic marker genes in MSC cells by NSAIDs and paracetamol, but no effect was observed in connection with diclofenac use. Therefore, there is a need to focus on such pharmacotherapy, capable of affecting the characteristics and properties of implanted MSCs.

English

Reconstruction of a maxillofacial skeletal defect in the recent past has witnessed a paradigm shift in the process of treatment planning. It has now become a collaboration between the surgeon and the bioengineer to provide a customised stable reconstruction. Understanding maxillofacial skeleton from an architectural and biomechanical perspective would not only guide the surgeon in planning a reconstruction but also the bioengineer to select the biomaterial and design an ideal reconstruction. This paper intended to provide an insight into scientific concepts which needed to be considered during the designing of biomaterials for reconstruction of maxillofacial skeletal defects. Any object in the world, from a mechanical perspective is seen only as a material of varying physical and chemical (organic / inorganic) properties dwelling in a dynamic three-dimensional environment. Bone continuously has been re-modelling by adapting to the dynamic loading environment through an established force distribution pattern of equilibrium. 1 Hence, for a patient requiring reconstruction of defects of varying dimensions within the craniomaxillofacial skeleton, its architectural complexity should be seen from both the surgeon’s and bioengineer’s perspective. Such multidisciplinary approach would provide a customized comprehensive reconstructive and rehabilitative solution.

Evaluation of Postoperative Sensory and Motor Deficit Following Craniomaxillofacial Reconstruction Using Bicoronal Flap: An Evaluative Study.

Introduction:The ideal surgical approach to treat craniomaxillofacial skeleton should provide maximum exposure of the facial skeleton, ensure less potential for injury to facial structures and allow for good cosmetic result. Several designs have been described such as hemicoronal, preauricular, lateral eyebrow, and bicoronal approach. Although the bicoronal flap gives superior long-term cosmetic results, it has a few disadvantages. We conducted this study to assess neurosensory disturbances and motor deficit following craniomaxillofacial reconstruction using bicoronal flap.Materials and Methods:A prospective study was carried out in the Department of Oral and Maxillofacial Surgery, North Karnataka, India. Forty patients with craniomaxillofacial trauma requiring fixation of fracture or reconstruction were included in the study. Postoperative neurosensory evaluation is carried out at intervals of 1 week, 1 month, 3 months, and 6 months clinically using mechanoreceptive and nociceptive testing.Results:Among 40 cases, 11 (27.5%) had postoperative paraesthesia affecting the supraorbital region; 9 (22.5%) of them had return of normal sensation within 6 months and 2 (5%) patients became normal after one year. Four patients had unilateral frontalis weakness on the right side for a period of 6 months.Discussion:The bicoronal flap is a preferred approach for access to the craniofacial skeleton and orbit with minimal sensory and motor complications. However, before choosing the same, the advantage of raising such a wide flap should be weighted comparing the benefits and complications.

Conservative Treatment of Huge Fibrous Dysplasia Causing Dysfunction in the Maxilla

Abstract Fibrous dysplasia (FD) is a non-malignant condition in which normal bone and marrow are replaced by fibrous tissue and haphazardly distributed woven bone. In the craniomaxillofacial skeleton, the maxilla is more frequently affected by FD than the mandible and generally affects adjacent bones such as the sphenoid, zygomatic and the frontal bones. The aim of this case report is to present the clinical, radiological, histological findings and conservative treatment of patient diagnosed with huge FD caused dysfunction in maxilla.

Biomaterials in Craniomaxillofacial Reconstruction: Past, Present, and Future.

Deformity and tissue loss involving the craniomaxillofacial region occurs frequently as a result of trauma, oncologic resection, or a congenital malformation. In order to maximize the patient's quality of life, reconstruction of the craniomaxillofacial skeleton must seek to restore aesthetics as well as function. Advances in diagnostic technology, surgical technique, instrumentation, and innovative biomaterials used have transformed the way reconstructive surgeons approach their patients' needs. From the advent of alloplastic reconstruction, surgeons have sought the ideal material for use in craniomaxillofacial surgery. Substances such as metals, ceramics, glasses, and more recently resorbable polymers and bioactive materials have all been utilized.While autologous bone has remained widely-favored and the gold standard, synthetic alternatives remain a necessity when autologous reconstruction is not readily available. Today, alloplastic material, autografting via microvascular tissue transfer, hormone and growth factor-induced bone formation, and computer-aided design and manufacturing of biocompatible implants represent only a fraction of a wide range of options used in the reconstruction of the craniomaxillofacial skeleton. We present a brief review of the materials used in the repair of deformities of the craniomaxillofacial skeleton as well as a look into the potential future direction of the field.

Outcomes of Intracranial Versus Subcranial Approaches to the Frontofacial Skeleton

An intracranial approach to the craniomaxillofacial skeleton can be effective for correcting complex craniofacial dystoses such as frontofacial hypoplasia, hypertelorism, and orbital dystopia. However, the significant morbidity resulting from the high complication rates has limited intracranial use. Given the need for intracranial approaches for certain clinical indications, the present study reevaluated intracranial frontofacial procedures to determine their safety and outcomes. A retrospective review was performed of all frontofacial procedures completed between 2007 and 2017 at a single institution. Patients who had undergone monobloc distraction alone or with facial bipartition, facial bipartition alone, or box osteotomy were included in the intracranial cohort. Those who had undergone Le Fort III distraction, advancement, or a combination with Le Fort I were included in the subcranial cohort. The recorded data included demographics, previous craniofacial surgery, and operative events. The complications rates were compared between the 2 cohorts. The present study included 65 patients-35 subcranial and 30 intracranial. The rates of previous craniomaxillofacial (P=.193) and intracranial (P=.340) surgery were equivalent between the 2 cohorts. Of the 30 intracranial and 35 subcranial patients, 26.7% and 34.3% experienced complications (P=.218). The intracranial patients experienced more dural tears (53.3 vs 5.7%; P<.0001); however, no significant differences were observed in cerebrospinal fluid leakage. Reintubations (n=3; 4.5%) occurred exclusively in the subcranial group. No significant differences in the major and minor complication rates were observed between the 2 cohorts. Intracranial and subcranial frontofacial procedures are associated with an equal riskof major and minor complications. Given the lack of an increase in risk, intracranial frontofacial procedures should be considered for the management of complex craniofacial dystoses.

OSTEOPATHIA STRIATA WITH CRANIAL SCLEROSIS

Background Osteopathia striata with cranial sclerosis (OSCS) is a rare x-linked genetic disorder that has variable clinical findings but specific radiographic features, which include marked sclerosis of the long bones and axial skeleton, including the skull. Linear striations, commonly seen in the long bones, are the basis for the name osteopathia striata. Maxillofacial manifestations can include a cleft palate, high palatal vault, midface hyperplasia, hypoplastic maxillary sinuses, enlarged alveolar bone processes, temporomandibular joint (TMJ) abnormalities, and dense mandibular bone with variable striations. Dental abnormalities have been poorly documented but include delayed eruption of permanent teeth, missing teeth, short roots, and microdontia. Study Design A 44-year-old male was referred to the University of Florida College of Dentistry for evaluation and treatment of temporomandibular disorder (TMD). A pantomograph was exposed to assess TMJ dysfunction related to progressive bony overgrowth of craniomaxillofacial skeleton and ankylosis, which had previously been surgically treated. His medical history was significant for OSCS, cleft lip and palate, obstructive sleep apnea, bronchitis, asthma, disk herniation, arthritis, diabetes, and chronic kidney disease. The radiographic assessment was limited because of severe sclerosis of the cranium, displayed as multiple lobulated appearances and homogeneous radiopaque entities superimposed on the maxilla, TMJs, and the sphenoid, mastoid, and temporal bones. The visualized cortical outlines of the maxilla and the mandible appeared dense, thick, and sclerotic. Discussion/Conclusions OSCS is a rare disorder. Diagnosis can often be challenging because other diseases, such as osteopetrosis, pyknodysostosis, Paget disease of bone, and other sclerosing bone dysplasias, make this difficult to diagnose. Radiologists should be aware of the specific radiographic appearance of this condition to aid in the proper diagnosis and management of these patients.

Location and distribution of craniomaxillofacial fractures in 45 cats presented for the treatment of head trauma.

The aim of this retrospective study was to describe the location and distribution of craniomaxillofacial (CMF) fractures in 45 cats presented to a veterinary referral centre between 2012 and 2017. Cats with a history of head trauma, one or more CMF fractures and a pretreatment CT scan of the CMF region were included in this study. For the purpose of the study, the CMF skeleton was divided into 15 functional anatomical regions and the fracture sites were allocated to one of these functional regions. Statistical analysis was performed using R. Skull fractures were evident in 80.0% of cats, and mandibular fractures in 86.7% of cats in this study. The median number of anatomical functional regions affected was eight and there was evidence of moderate or strong correlation between fractures of different regions of the mid-face. Where fractures were recorded in the nasopharynx and orbit they were bilateral in 93.5% and 89.7%, respectively. Twenty-six (57.8%) of the cats had fractures affecting one or both temporomandibular joints, which included fractures of the mandibular fossa, condylar neck and condyle. Twenty-nine cats (64.4%) had tooth fractures and seven cats (15.6%) had significant eye injuries. Cats presenting with a single symphyseal separation or parasymphyseal fracture are very likely to have further fractures at other locations. Fractures in the nasopharynx, orbit, nose, upper jaw, intermaxillary suture and zygomatic arch regions (the 'mid-face') are likely to occur together. The pattern of distribution of mandibular fractures is not as predictable as that for maxillary fractures. CT imaging is required to achieve a complete diagnosis of the location and distribution of skull fractures in cats after head trauma.

The role of 3D printing in treating craniomaxillofacial congenital anomalies.

Craniomaxillofacial congenital anomalies comprise approximately one third of all congenital birth defects and include deformities such as alveolar clefts, craniosynostosis, and microtia. Current surgical treatments commonly require the use of autogenous graft material which are difficult to shape, limited in supply, associated with donor site morbidity and cannot grow with a maturing skeleton. Our group has demonstrated that 3D printed bio-ceramic scaffolds can generate vascularized bone within large, critical-sized defects (defects too large to heal spontaneously) of the craniomaxillofacial skeleton. Furthermore, these scaffolds are also able to function as a delivery vehicle for a new osteogenic agent with a well-established safety profile. The same 3D printers and imaging software platforms have been leveraged by our team to create sterilizable patient-specific intraoperative models for craniofacial reconstruction. For microtia repair, the current standard of care surgical guide is a two-dimensional drawing taken from the contralateral ear. Our laboratory has used 3D printers and open source software platforms to design personalized microtia surgical models. In this review, we report on the advancements in tissue engineering principles, digital imaging software platforms and 3D printing that have culminated in the application of this technology to repair large bone defects in skeletally immature transitional models and provide in-house manufactured, sterilizable patient-specific models for craniofacial reconstruction.

Dental Stem Cells Harvested from Third Molars Combined with Bioactive Glass Can Induce Signs of Bone Formation In Vitro.

ABSTRACTObjectivesThe aim of this study was to assess the interaction of a bioactive glass scaffold with cells derived from dental pulp, dental follicle and periodontal ligament.Material and MethodsImpacted third molars were surgically removed from three young donors. Cells from the dental pulp, follicle and periodontal ligament tissues were isolated and expanded. Different cell populations were characterised using specific CD markers. Expanded pulp, follicle and periodontal cells were then seeded onto bioactive glass scaffolds and cultured in osteogenic medium or basic medium. Cell attachment, viability, proliferation and alkaline phosphatase activity were assessed.ResultsThis study revealed good biocompatibility of the specific bioactive glass configuration tested and the osteogenic induction of cells derived from dental pulp, dental follicle and periodontal ligament. Osteogenic medium seemed to increase the differentiation pattern and dental pulp stem cells showed the most positive results compared to periodontal ligament and dental follicle stem cells.ConclusionsDental pulp stem cells combined with a bioactive glass scaffold and exposed to osteogenic medium in vitro represent a promising combination for future study of hard tissue regeneration in the cranio-maxillofacial skeleton.