Anatomic variations of the superficial temporal artery.

The superficial temporal artery (STA) is a terminal branch of the external carotid artery. It is commonly described as coursing posterior to the mandibular condyle and over the posterior zygomatic root (PZR) and then dividing terminally into parietal and frontal branches. However, possible variations of the main trunk of the STA have seemingly been overlooked. This study retrospectively examined the archived head tomography angiograms of 43 patients to determine the morphology and topography of the STA prior to its terminal bifurcation. In 79% of patients, the STA topography related to the mandibular condyle was bilaterally symmetrical, either retrocondylar (65.1%) or laterocondylar (13.6%). The parietal branch was sometimes absent unilaterally (16.3%) or bilaterally (9.3%). In 2/43 cases, the frontal branch of the STA was unilaterally absent. When both terminal branches were present, the bifurcation was retrocondylar or immediately above the PZR when on the PZR, or the terminal division of the STA was high above the PZR. In 88.4% of the STAs, different patterns of kinking and coiling were documented, including retrocondylar kinks (27.9%), laterocondylar kinks (20.9%), kinks placed on the PZR (81.4%) and variably oriented suprazygomatic kinks (32.6%). Five of the 86 STAs were coiled, one retrocondylar, one laterocondylar, and three other placed on the PZR. Two cases showed unilateral pseudoaneurysms of the STA, one above the PZR and the other on the temporomandibular joint. The STA is surgically important; therefore, the number of anatomical studies of the STA should increase.

Transvenous embolization of a posterior condylar canal fistula causing pulsatile tinnitus.

Dural arteriovenous fistulas of the skull base commonly present with pulsatile tinnitus. In our experience, transvenous embolization of dural arteriovenous fistulas of the skull base represents a safe and effective treatment modality due to its precision in treatment of the site of convergence of all feeding arteries and the low risk of ischemic complications. We present a case of an adult patient who presented to our institution with pulsatile tinnitus several months following a motor vehicle accident. Cerebral angiography demonstrated a dural arteriovenous fistula at the junction of the posterior condylar vein and suboccipital venous plexus supplied by branches of the vertebral artery, occipital artery, and ascending pharyngeal artery. In this operative video we demonstrate this technique and provide an in-depth discussion of our treatment decision-making process and the anatomical considerations involved in treating this lesion.

Endosteal blood supply of the mandible: anatomical study of nutrient vessels in the condylar neck accessory foramina.

PURPOSE: In the mandible, the condylar neck vascularization is commonly described as mainly periosteal; while the endosteal contribution is still debated, with very limited anatomical studies. Previous works have shown the contribution of nutrient vessels through accessory foramina and their contribution in the blood supply of other parts of the mandible. Our aim was to study the condylar neck's blood supply from nutrient foramina. METHODS: Six latex-injected heads were dissected and two hundred mandibular condyles were observed on dry mandibles searching for accessory bone foramina. RESULTS: Latex-injected dissections showed a direct condylar medular arterial supply through foramina. On dry mandibles, these foramina were most frequently observed in the pterygoid fovea in 91% of cases. However, two other accessory foramina areas were identified on the lateral and medial sides of the mandibular condylar process, confirming the vascular contribution of transverse facial and maxillary arteries. CONCLUSIONS: The maxillary artery indeed provided both endosteal and periosteal blood supply to the condylar neck, with three different branches: an intramedullary ascending artery (arising from the inferior alveolar artery), a direct nutrient branch and some pterygoid osteomuscular branches.

Arterial Vascularization of the Mandibular Condyle and Fractures of the Condyle.

BACKGROUND: Despite substantial displacements, fractures of the mandibular condyle rarely lead to necrosis. This illustrates the negligible role of the inferior alveolar artery in intraosseous supply to the condyle, and led to this systematization of its arterial vascularization. METHODS: Forty-two temporomandibular joints from nonembalmed cadaveric specimens were studied following injection of latex (n = 32) or India ink (n = 10). RESULTS: The intraosseous branches of the inferior alveolar artery that lead to the condyle were inconstant and often rudimentary. In this study, the arteries that consistently led to the condyle were the superficial temporal artery, the deep posterior temporal artery, and arterial branches leading to the lateral pterygoid muscle emanating directly from the maxillary artery. These arteries, along with the transverse facial artery and the masseteric artery (when they participated in condoyle vascularization), formed a quadrangle around the mandibular condyle. After India ink injection, the pterygoid muscle was the most strongly colored muscle, thus indicating substantial vascularization. CONCLUSIONS: Although there is a lack of consensus in the literature regarding the constancy and proportions of the arteries participating in vascularization of the condyle, the superficial temporal artery, the maxillary arterial branches leading to the lateral pterygoid muscle, and the deep posterior temporal artery were constant in this study. This study shows the important role of the lateral pterygoid in the vascularization of the condyle. In case of a fracture with substantial displacement, the vascularization emanating from the superficial temporal artery and the lower alveolar artery is ruptured or compromised.

[Angiogenesis and condyle growth: review].

Angiogenesis plays key roles in the process of the growth of the mandibular condyle. This article reviewed the relationship between angiogenesis, condyle growth and the role that angiogenesis plays in the condyle growth and its clinical value.

Neurovascular structures of the mandibular angle and condyle: a comprehensive anatomical review.

BACKGROUND: Various surgical interventions including esthetic surgery, salivary gland excision, and open reduction of fracture have been performed in the area around the mandibular angle and condyle. This study aimed to comprehensively review the anatomy of the neurovascular structures on the angle and condyle with recent anatomic and clinical research. METHODS AND RESULTS: We provide detailed information about the branching and distributing patterns of the neurovascular structures at the mandibular angle and condyle, with reported data of measurements and proportions from previous anatomical and clinical research. Our report should serve to help practitioners gain a better understanding of the area in order or reduce potential complications during local procedures. Reckless manipulation during mandibular angle reduction could mutilate arterial branches, not only from the facial artery, but also from the external carotid artery. The transverse facial artery and superficial temporal artery could be damaged during approach and incision in the condylar area. The marginal mandibular branch of the facial nerve can be easily damaged during submandibular gland excision or facial rejuvenation treatment. The main trunk of the facial nerve and its upper and lower distinct divisions have been damaged during parotidectomy, rhytidectomy, and open reductions of condylar fractures. CONCLUSION: By revisiting the information in the present study, surgeons will be able to more accurately prevent procedure-related complications, such as iatrogenic vascular accidents on the mandibular angle and condyle, complete and partial facial palsy, gustatory sweating (Frey syndrome), and traumatic neuroma after parotidectomy.

Maxillary-fronto-temporal approach for removal of recurrent malignant infratemporal fossa tumors: Anatomical and clinical study.

PURPOSE: For recurrent malignant tumors occurring in the infratemporal fossa, it is difficult to select a proper surgical approach. We explore the efficiency of a new approach for removal of recurrent malignant tumors involving the infratemporal fossa based on the measurement on three-dimension CT, observation of six cadaveric specimens, and our surgical experience. MATERIALS AND METHODS: The distances between the surgical landmarks in the infratemporal fossa were measured using CT data to determine the safe distance. And anatomy observation was examined on 6 formalin-fixed cadaveric specimens. Data from seven patients with recurrent malignant infratemporal fossa tumors were retrospectively analyzed. RESULTS: The mean distance of the medial pterygoid plate from the zygoma was 52.12 mm. The maxillary artery can be found between the deep surface of the condyle and the sphenomandibular ligament, with mean distance of 8.25 ± 3.22 mm to the inferior border of the capsule of the temporomandibular joint. All tumors got gross resection using the maxillary-fronto-temporal approach with minor complication. CONCLUSIONS: The advantages of the new approach include adequate protection of facial nerve with extended operation field; the exposed temporal muscle could be used to fill the dead space. This technique is especially useful to remove recurrent malignant infratemporal tumors safely.

Morphological effects of mesenchymal stem cells and pulsed ultrasound on condylar growth in rats: a pilot study.

AIM: The aim of this study was to assess and describe the morphological effects of an intra-articular iniection of Mesenchymal Stem Cells (MSCs) and/or Low Intensity Pulsed Ultrasound (LIPUS) stimulation on the mandibular condyles of growing rats, using cone beam computed tomography (CBCT) and histology. METHODS: Twenty-six young (23-day-old) rats were divided into 5 groups identified as LIPUS-stimulated (20 minutes daily using 50 mW/cm2, 1MHz, 0.2 millisecond pulses), MSCs injected (1 x 10(5) cells/kg), LIPUS + MSCs, medium inlected, and untreated controls. All treatments were performed in the left temporomandibular joint of each rat (TMJs). At day 21, CBCTs were obtained for cephalometric analysis and 3D reconstructions. After animal sacrifice, left and right TMJ sections were histologically prepared and examined. The Wilcoxon sign rank test and the Kruskal-Wallis 2 test were applied for statistical comparison. RESULTS: Imaging results showed that left condyles were wider in all LIPUS-treated groups (p < 0.05), while the LIPUS-only group had a greater left sagittal condylar length. LIPUS-treated groups displayed a lower midline shift to the right (p < 0.02). No significant differences were observed in the MSC group. Bone marrow morphology and vascularity differed between the groups as LIPUS-treated groups exhibited increased vascularity in the erosive cartilage zone. CONCLUSION: It was established that LIPUS and MSC application to the TMJ region of growing rats favoured transverse condylar growth, while LIPUS application alone may enhance sagittal condylar development.The MSC injection model had little effect on sagittal condylar growth.

Arteriovenous malformation of the mandible and parotid gland.

Arteriovenous malformations (AVMs) of the jaws are relatively rare, with fewer than 200 cases reported in the literature. Their real importance lies in their potential to result in exsanguination, which usually follows an unrelated treatment, such as tooth extraction, surgical intervention, puncture wound or blunt injury in involved areas, with the dentist unaware of the existence of the AVM. The present case illustrates an AVM in an 18-year-old female with swelling on the right side of the face. This case report is unique because although there was no history of bleeding episodes, thorough examination and investigation diagnosed it as high-flow vascular malformation. We ascertain the importance of dentists' awareness of the fatal outcome of these lesions and emphasize that, prior to performing any procedure, necessary investigations should always be done.

Osteochondral angiogenesis in rat mandibular condyles with osteoarthritis-like changes.

OBJECTIVE: To investigate angiogenesis at the osteochondral junction and changes in expression of pro- and anti-angiogenic factors in rat mandibular condyles with osteoarthritis-like changes. METHODS: In order to evoke osteoarthritis-like lesions in mandibular condyles, disordered occlusion was created experimentally in rats. Osteochondral vascularity was assessed histologically at 20 and 24 weeks. Protein and mRNA levels of pro-angiogenic factors including vascular endothelial growth factor (VEGF), connective tissue growth factor (CTGF) and matrix metalloproteases 9 (MMP9), and anti-angiogenic factor chondromodulin-I (CHM-I) were investigated by means of immunohistochemical staining and real-time PCR. RESULTS: Osteochondral angiogenesis was demonstrated as increased numbers of vascular channels terminating in the calcified cartilage and non-calcified cartilage in 20- and 24-week experimental groups compared with controls (all P<0.05). In the experimental groups, VEGF, CTGF and MMP9 were highly expressed in the tissues adjacent to the osteochondral junction. However, CHM-I was more expressed in the superior but not deep hypertrophic chondrocytes. Compared to their age-matched controls, the protein levels of VEGF and CTGF were higher in 20-week experimental group, and the protein and mRNA levels of CTGF, MMP-9, and CHM-I increased in the 24-week experimental group (all P<0.05). CONCLUSION: In the present rat model, osteochondral angiogenesis was observed in mandibular condyles with osteoarthritis-like changes, accompanied with local upregulation of VEGF, CTGF and MMP9. Although the increase in CHM-I may moderate pro-angiogenic factors effects in the superior cartilage, the deficiency of deep hypertrophic chondrocytes to express CHM-I may permit vascular invasion into condylar cartilage.

Vascularization of the mandibular condylar head with respect to intracapsular fractures of mandible.

BACKGROUND: Causes of mandibular condylar (condylar) head necrosis as a consequence of intracapsular mandibular fractures are still a subject of controversy. OBJECTIVES: To investigate why in some cases of intracapsular fractures condylar head necrosis occurs. MATERIAL: 58 human heads from the collection of Head and Neck Clinical Anatomy Laboratory, from the Institute of Physiology and Pathology of Hearing, Warsaw, Poland, constituted the material. STUDY: Head arterial tree injections, anatomical preparation with the use of standard set of microsurgical equipment and an operating microscope. RESULTS: The main source of condylar head vascularization is the inferior alveolar artery, supplying bone marrow of the whole mandible as well as its cortical layer. Additional arterial blood supplying comes from a various number (2-7) of branches supplying the temporomandibular joint capsule. They originate directly from the maxillary artery or from its primary branches: masseteric artery, external pterygoid artery or superficial temporal artery. Two rare variants of accessory mandibular head vascularization were encountered. The first (2 cases) was an arterial branch from the maxillary artery and the second (1 case) was a branch from the external pterygoid artery. In these cases the arterial supply of lateral part of temporomandibular joint capsule from other sources was reduced. CONCLUSION: Fractures resulting in the lateral part of the condylar head in isolation could be potentially threatened by necrosis because of poor vascularization.

Morphologic features of the fetal mandibular condyle: layers, canals and microvascular pattern.

During organogenesis the mandibular condyle is divided by a fibrovascular septum, the persistence of which in the growing cartilage can lead to a bifid condyle. In this study we have evaluated the morphology of 3rd trimester human fetal temporomandibular (TMJ) specimens in order to determine the pattern of the vascular morphology associated with the layers and vascular canals (VCs) of the developing condyle (covering layers and condyle proper). Eleven human fetuses of 27-38cm crown-rump length were used for histological (hematoxylin-eosin, Van Gieson stain) and immunohistochemical evaluation (antibodies for bcl2 and CD34) and another two of 24 and 31cm, for TMJ microvasculature studies after black ink injections. With increasing fetal age, the intermediate loose lamina (LL) of the condylar proliferative layer evolves from a vascular-mesenchymal to a fibrillar pattern, via a transitory stage of a clear space that may be misdiagnosed as lower joint cavity (LJC). Within the condyle proper VCs may be present on its entire sagittal length, deepening variably towards the erosive zone and opened superiorly in the LL loose layer. Vessels of the evolving LL enter the condyle, directly or through the VCs; these vessels retract peripherally with increasing age and the intrinsic vessels of the condyle supplied from the erosive zone become prevalent. Vascular morphogenesis at the level of the LL seems comparable to that at the level of the LJC where characteristic glomeruli regress with increasing age. Lack of vascular regression and closure of central V-shaped defects of the condyle, as observed in 2/22 condyles, may represent a developmental substrate for condylar bifidism or a predisposing condition weakening the condyle, and making it more sensitive to trauma in childhood.

2-Butoxyethanol model of haemolysis and disseminated thrombosis in female rats: a preliminary study of the vascular mechanism of osteoarthritis in the temporomandibular joint.

Female rats develop haemolytic anaemia and disseminated thrombosis and infarction in multiple organs, including bone, when exposed to 2-butoxyethanol (BE). There is growing evidence that vascular occlusion of the subchondral bone may play a part in some cases of osteoarthritis. The subchondral bone is the main weight bearer as well as the source of the blood supply to the mandibular articular cartilage. Vascular occlusion is thought to be linked to sclerosis of the subchondral bone associated with disintegration of the articular cartilage. The aim of this study was to find out whether this model of haemolysis and disseminated thrombosis supports the vascular hypothesis of osteoarthritis. Six female rats were given BE orally for 4 consecutive days and the two control rats were given tap water alone. The rats were killed 26 days after the final dose. The mandibular condyles showed histological and radiological features consistent with osteoarthritis in three of the four experimental rats and in neither of the control rats. These results may support the need to explore the vascular mechanism of osteoarthritis further.

A modified far-lateral approach for large or giant meningiomas of the posterior fossa.

OBJECT: Resecting large meningiomas along the posterior fossa convexity or cerebellopontine angle (CPA) through a suboccipital approach can be challenging. Limitations include a restricted angle of view, high venous pressures, and suboptimal brain relaxation. While a far-lateral craniotomy is a viable alternative, the risks associated with condylar resection are undesirable. METHODS: The authors retrospectively evaluated a modified far-lateral approach in a consecutive series of 12 patients with large or giant posterior fossa convexity and CPA meningiomas. This approach incorporates transverse-sigmoid sinus exposure and C-1 laminectomy, but there is no condylar resection. RESULTS: Between January 2006 and February 2008, 12 patients (mean age 52 years) presented with large or giant meningiomas of the posterior fossa convexity or CPA. The mean tumor volume was 72.6 cm3 (range 8-131 cm3). Signs and symptoms at presentation included headache (in 8 patients), cranial neuropathy (in 4), and progressive hemiparesis (in 4). There were no operative complications, and the majority of patients (9) had Simpson Grade I or II resections. There were no new permanent neurological deficits following resection, although 2 patients (17%) had transient deficits. The mean modified Rankin score decreased from 2.2 preoperatively to 0.6 postoperatively. CONCLUSIONS: A modified far-lateral approach to the posterior fossa and CPA allows for safe, and often total, resection of large meningiomas with minimal morbidity. While avoiding the risks of condylar resection, this microsurgical strategy allows for greater field of view, minimal venous bleeding, and immediate access to the spinal subarachnoid space.

No signs of metabolic hyperactivity in patients with unilateral condylar hyperactivity: an in vivo positron emission tomography study.

PURPOSE: The purpose of this study was to assess bone growth and blood flow in the condylar region in patients with unilateral condylar hyperactivity (UCH) by use of positron emission tomography (PET). PATIENTS AND METHODS: This prospective study included 7 patients with UCH and a control group of 6 volunteers. In addition to normal clinical investigations, labeled fluoride ((18)F(-)) and oxygen 15-labeled water (H(2)(15)O) PET scans were performed. RESULTS: In control subjects the net rate of fluoride influx, representing bone metabolism, was similar for left and right condylar sides. Interestingly, this was not significantly different from the affected condyles in UCH patients. Rather, the net rate of fluoride influx on the contralateral side of UCH patients was reduced significantly compared with the affected side (P= .02) and control subjects (P= .004). The mean blood flow on the left and right condylar sides in control subjects was not significantly different. The same was true for the hyperactive and contralateral condyles of UCH patients. Blood flow in the condylar region in UCH patients was similar to that in the control group. CONCLUSIONS: There was no evidence of an abnormally high rate of bone growth in the affected condylar region in UCH patients. Instead, the rate of bone growth appeared to be reduced in the contralateral condylar region. These PET results are in contrast to the characteristic clinical picture of UCH patients and suggest the possibility of subgroups in patients with a mandibular asymmetry caused by UCH. Furthermore, no evidence of hypervascularization of the condylar region in UCH patients was found.

Relación céntrica: revisión de conceptos y técnicas para su registro. Parte I / Centric relation: concepts revision and recording techniques. Part I

La relación céntrica ha sido objeto de disparidad de criterios en la odontología durante más de un siglo. A lo largo de este trabajo, vamos a exponer diferentes métodos usados tanto para obtener el registro, como para comprobar su certeza y corroborar la posición condilar. Dado que no existe evidencia científica en el tema, en este trabajo, revisaremos los estudios experimentales que aparecen en la literatura. Los hemos divididos en dos partes, la primera relacionada con la definición de relación céntrica y la segunda parte relacionada con técnicas de registro, posición condilar y la discrepancia entre relación céntrica y oclusión céntrica (AU)

The centric relation has been controversial on dentistry during more of one century. Along of this work, we are going to expose different methods to recording as checking the accuracy and condilar position. Given that there aren’t scientific evidence, in this work, we review the researches publicated. We have divided them into two parts; the first is related with the definition of centric relation and the second part is related with recording techniques, condilar position and centric relation- centric occlusion discrepancy (AU)

A new approach to control condylar growth by regulating angiogenesis.

OBJECTIVE: To provide a comprehensive review of the mechanisms of growth of mandibular condyle, the roles of angiogenesis enhancers and inhibitors during endochondral ossification in mandibular condyle and newly developed delivery methods for local gene delivery that may represent strategies to regulate condylar growth. DESIGN: Narrative review. RESULTS: Angiogenesis is the crucial step in mandibular condylar growth for it regulates the transformation from cartilage to bone. Angiognesis enhancers, especially VEGF and FGF, play important roles in the process of new blood lumen formation and invasion. On the other hand, angiostatin and endostatin inhibit angiogenesis by targeting endothelial cells and several signal cascades. Delivery methods such as liposomes, stem cells and virus vectors have been studied. Recombinant AAV-mediated gene therapy is considered as one of the most promising strategies of condylar growth management. CONCLUSION: AAV-mediated gene therapy using VEGF or angiogenesis inhibitor will be a promising way to regulate condylar growth at an early stage.

Vascular malformation of the temporomandibular joint: report of a case and review of the literature.

The diagnosis and treatment of vascular anomalies is extremely challenging because of inconsistent terminology and classification systems, as well as nonspecific clinical and radiological findings. We report a vascular malformation that was treated successfully via resection, and reconstructed using a custom-made temporomandibular joint fossa and condylar prosthesis by TMJ Concepts. The available pertinent literature is also reviewed.

The occurrence, variations and diameter of the human condylar canal in relation to the jugular foramen.

In medical practice, especially in analysis of radiograms and computed tomography scans, it is very important to be familiar with the anatomy of the skull base, not only the normal and typical anatomical structures but also the variations and anomalies. One of the important venous foramina of the human skull is the condylar canal. This structure is described as the most stable and permanent venous emissary, with a prevalence of up to 100%. In our study, based on 100 human macerated skulls, this canal was encountered in 81% of cases. In several it was double. We have not encountered any information on this in the available literature. We found that the condylar canal in humans could be double and that the size of the external opening of this canal is not crucial in relation to the size of the jugular foramen. There was no significant correlation between the jugular foramen and the condylar canal in our specimens.