Clinical and imaging features of intraosseous arteriovenous malformations in jaws: a 15-year experience of single centre.

Intraosseous arteriovenous malformations in jaws (j-AVMs) are rare congenital high-flow vascular anomalies with a high tendency of life-threatening haemorrhage and are regarded as one of the most dangerous haemorrhagic diseases in maxillofacial region. Pre-treatment clinical and imaging evaluations serve as the most important diagnostic modalities. A retrospective study involved 211 patients with j-AVMs from November 2003 to November 2017 was performed. The male-to-female ratio of j-AVMs was approximately 4:3. The mean age of the patients with j-AVMs is 21.86. Bleeding was the main complaint associated with j-AVMs. J-AVMs occurred in the mandible more often than in the maxilla (64.93% and 32.23%, respectively). Most j-AVMs (95.26%) occurred in the posterior teeth region. Classical imaging features of j-AVMs included: an unclear maxillary sinus with a mild ground-glass appearance (maxillary j-AVMs) and a clear oval or irregular lucency that is mostly centred on the root of the first molar (mandibular j-AVMs) on OPGs, enhancement in the cancellous bone on contrast-enhanced CTs. Other atypical features of j-AVMs were also concluded. A comprehensive diagnose system based on clinical and imaging features of j-AVMs could provide valuable reference data for clinical management of j-AVMs and help avoid improper iatrogenic trauma or delayed treatment.

Risk factors for severe cranial ischaemic complications in giant cell arteritis.

OBJECTIVES: Vision complications and a stroke represent severe cranial ischaemic complications (sCIC) associated with increased morbidity and mortality in GCA. We aimed to determine the risk factors for sCIC in GCA. METHODS: We analysed the medical records of prospectively enrolled GCA patients diagnosed between September 2011 and August 2019, and compared the clinical and laboratory characteristics of patients with and without sCIC defined as either severe vision complications (diplopia, transient vision loss, permanent partial vision field/acuity defect and permanent visual loss) or stroke. RESULTS: During the 96-month observation period, we identified 295 new GCA patients [65.4% female, median (interquartile range) age 74.7 (67.3-80.0) years]. Sixty-one (20.7%) patients developed sCIC (52 isolated severe vision complications, 5 isolated ischaemic strokes and 4 patients with both complications). In a multivariable logistic regression model jaw claudication [odds ratio (OR) 3.43 (95% CI: 1.84, 6.42), P < 0.001], smoking [OR 1.92 (95% CI: 1.01, 3.65), P = 0.046] and increasing age [OR 1.08 (95% CI: 1.04, 1.13), P < 0.001] were significantly associated with sCIC. Higher CRP [OR 0.99 (0.99-1.00), P = 0.011] decreased the risk of sCIC. When considered separately, the odds for severe vision complications increased with age and jaw claudication, and decreased with polymyalgia rheumatica, constitutional symptoms and higher CRP. Atrial fibrillation emerged as the sole independent predictor of ischaemic stroke. CONCLUSION: Increasing age, jaw claudication and smoking predicted sCIC, while higher CRP decreased the risk of sCIC in our GCA cohort.

Vasculature submucosal changes at early stages of osteonecrosis of the jaw (ONJ).

Osteonecrosis of the jaw (ONJ), a rare, but potentially severe side effect of anti-resorptive medications, presents as exposed bone in the maxillofacial region lasting for at least 8 weeks. While clinical experience and animal models concur in finding that systemic antiresorptive treatment in conjunction with local risk factors, such as tooth extraction or dental disease may lead to ONJ development, the subclinical molecular changes that precede bone exposure remain poorly understood. The identification of these changes is not only important in understanding disease pathophysiology, but could provide potential for treatment development. Here, we evaluated the early stages of ONJ utilizing a model of experimental periodontitis (EP) in mice treated with two different types of antiresorptives, targeting potential changes in vasculature, hypoxia, oxidative stress, and apoptosis. Antiresorptive treatment in animals with EP increased levels of empty osteocytic lacunae and increased ONJ prevalence compared to Veh animals. The arteriole and venule network seen around EP areas was diminished in animals treated with antiresorptives. Higher levels of vascular endothelial growth factor A (VEGF-A) and vascular cell adhesion protein-1 (VCAM-1) were observed 1-week following EP in treated animals. Finally, levels of hypoxia, oxidative stress, and apoptosis remained high in antiresorptive treated animals with EP through the duration of the experiment. Together, our data point to subclinical vasculature organizational disturbances that subsequently affect levels of hypoxia, oxidative stress, and apoptosis in the area of developing ONJ.

Arteriovenous Malformation of the Jaws: a Black Hole for the GDP ­ A Case Report.

We report a case of a mandibular arteriovenous malformation in a 3-year-old child, who attended our department, and have carried out a literature review. Clinical relevance: Arteriovenous malformation (AVM) is a rare condition but clinicians need to be aware of it as this lesion can have potentially life-threatening complications due to massive haemorrhage.

Nonarteritic Jaw Claudication.

A 60-year-old woman with decreased visual acuity in her right eye and right-sided jaw claudication was found to have ocular ischemic syndrome secondary to complete occlusion of the brachiocephalic artery. Although jaw claudication is often considered to be pathognomonic for giant cell arteritis, it has a broad differential diagnosis including both vascular and nonvascular conditions.

Immunohistochemical and histochemical characterization of intraosseous arteriovenous malformations of the jaws: analysis of 16 cases with emphasis on GLUT-1 immunophenotype.

OBJECTIVES: Intraosseous vascular lesions of the craniofacial region are rare and may cause diagnostic and therapeutic challenges. The purpose of this study was to characterize 16 cases of intraosseous arteriovenous malformations (AVMs) affecting the jaws. STUDY DESIGN: Immunohistochemical evaluation was performed using antibodies against α-smooth muscle actin (α-SMA), desmin, CD31, D2-40, and glucose transporter 1 (GLUT-1). Staining with elastic Verhoeff-Van Gieson and Masson trichrome histochemical stains was also performed. RESULTS: No gender predilection (female:male ratio = 1:1) was observed, with patients' mean age being 50.8 years (SD of ±13.9; range 28-71 years). Predilection for the mandible was observed (12 of 16 [75%]). Immunohistochemically, diffuse endothelial CD31 staining was noted, and α-SMA strongly highlighted smooth muscle cells and pericytes. Desmin-positive vessels were identified in 9 of 16 AVMs (56.3%). D2-40 was uniformly negative in all specimens. AVMs were negative for GLUT-1 (11 of 14 [78.6%]) except for 2 cases (2 of 14 [14.3%]) exhibiting focal limited cytoplasmic GLUT-1 immunoreactivity. One case was equivocal for GLUT-1. Masson trichrome highlighted smooth muscle cells, and elastic fibers were identified in thick-walled arteries. CONCLUSIONS: AVMs of the jaws generally lack expression of GLUT-1, similar to soft tissue vascular malformations. Clinicoradiographic features of intraosseous AVMs in the present study were consistent with the findings of previous studies, although mean age was higher.

Stent-induced flow disturbances in the ipsilateral external carotid artery following internal carotid artery stenting: a temporary cause of jaw claudication.

BACKGROUND: We hypothesize that stenting of the internal carotid artery can immediately impede blood flow to the external carotid artery by either plaque shift or stent coverage of the ostium, and thereby cause ischemic symptoms like ipsilateral jaw claudication. METHODS: Thirty-three patients with high-grade asymptomatic stenosis of the internal carotid artery who underwent endovascular treatment were examined by ultrasound of the external carotid artery and performed an exercise test by chewing chewing gum synchronously to an electronic metronome for 3 min. Tests were performed before, the day after, and 1 week after the stenting procedure. Claudication time was defined as the timespan until occurrence of pain of the masseter muscle and/or chewing dyssynchrony to the metronome for more than 15 s. Ten patients with an isolated, atherosclerotic stenosis of the external carotid artery served as controls. RESULTS: A significantly reduced claudication time (in seconds) was recorded in patients who underwent carotid artery stenting compared to baseline values; median 89 (interquartile range, IQR, 57 to 124) vs. median 180 (IQR 153 to 180; p < 0.001). By categorization of the flow velocity at the external carotid artery into faster or slower as 200 cm/sec, the effect was even accentuated. Stenting values showed improvement 1 week after but did not return to baseline levels. No respective changes were found in controls. CONCLUSION: Stenting of the internal carotid artery lead to ipsilateral flow deterioration at the external carotid artery resulting in temporary jaw claudication. This impairment attenuated over the time and was significantly reduced after 1 week.

Risk factors for severe cranial ischaemic events in patients with giant cell arteritis.

OBJECTIVES: Cranial ischaemic events constitute a significant component in the clinical spectrum of giant cell arteritis (GCA). Our aim was to investigate whether cardiovascular risk factors, specific medications and baseline clinical features are associated with the development of severe cranial ischaemic events in GCA patients. METHODS: Retrospective analysis of GCA patients. Information collected included baseline clinical and laboratory data, comorbidities, cardiovascular risk factors and medications. GCA Patients with and without severe cranial ischaemic complications were compared. RESULTS: A total of 83 patients with GCA were included in the study. Among them, 24 (29%) patients developed severe cranial ischaemic events. Compared with patients without severe cranial ischaemic events, those with severe cranial ischaemic events had lower erythrocyte sedimentation rate (ESR) levels at diagnosis (81±17 vs. 93±21, p=0.018) and were more likely to have jaw claudication (37.5% vs. 17%, p=0.043). Rate of cardiovascular risk factors and rate of use of anti-platelets and statins were similar between the two groups. The use of ß-blockers was higher among patients with severe ischaemic events (46% vs. 20%, p=0.019). Logistic regression analysis showed that lower ESR levels (OR=0.967, 95% CI, 0.94, 0.99) and ß-blockers use (OR=4.35, 95% CI, 1.33, 14.2) predicted development of severe cranial ischaemic complications. CONCLUSIONS: The present study demonstrated that GCA patients with severe cranial ischaemic events had lower inflammatory responses and were more likely to have been treated with ß-blockers. Cardiovascular risk factors and antiplatelet therapy had no effect on the occurrence of severe cranial ischaemic events.

Oral Surgical Procedures Performed Safely in Patients With Head and Neck Arteriovenous Malformations: A Retrospective Case Series of 12 Patients.

PURPOSE: This case series describes patients with head and neck arteriovenous malformations who underwent oral and maxillofacial surgical procedures combined with interventional radiology techniques to minimize blood loss. MATERIALS AND METHODS: Twelve patients underwent femoral cerebral angiography to visualize the extent of vascular malformation. Before the surgical procedures, surgical sites were devascularized by direct injection of hemostatic or embolic agents. Direct puncture sclerotherapy at the base of surgical sites was performed using Surgiflo or n-butylcyanoacrylate glue. Surgical procedures were carried out in routine fashion. A hemostatic packing of FloSeal, Gelfoam, and Avitene was adapted to the surgical sites. RESULTS: Direct puncture sclerotherapy with Surgiflo or n-butylcyanoacrylate glue resulted in minimal blood loss intraoperatively. Local application of the FloSeal, Gelfoam, and Avitene packing sustained hemostasis and produced excellent healing postoperatively. CONCLUSION: Patients with arteriovenous malformations can safely undergo routine oral and maxillofacial surgical procedures with minimal blood loss when appropriate endovascular techniques and local hemostatic measures are used by the interventional radiologist and oral and maxillofacial surgeon.

A practical guide for diagnosis and treatment of arteriovenous malformations in the oral and maxillofacial region.

Arteriovenous malformations (AVMs) are congenital vascular malformations (CVMs) resulting from birth defects of the vasculature. It is rarely seen, only accounting for 1.5% of all vascular anomalies, and 50% of the lesions are located in the oral and maxillofacial region. Regardless of the type, AVMs may ultimately lead to significant anatomical, pathophysiological and hemodynamic consequences. Therefore, despite their relative rarity, AVMs still remain the most challenging and/or life-threatening form of vascular anomalies. Transarterial coil embolisation or ligation of feeding arteries are incorrect approaches and may result in progress of the lesion. Furthermore, such procedures would prevent future endovascular access to the lesions via the arterial route, and should be abandoned. Interventional embolisation using various sclerosants is currently the mainstay of treatment for AVMs, and elimination of the nidus (if present) is the key to success. Among various embolosclerotherapy agents, ethanol sclerotherapy produces the best long-term outcomes, with minimal complications. For more complex cases, multidisciplinary approaches and interventions may provide an excellent potential for a curative result. Based on the published literature and clinical experiences, a practical treatment guideline was established in order to provide a criterion for the management of oral and maxillofacial AVMs. This protocol will be renewed and updated to reflect cutting edge knowledge, and provide the newest treatment modalities for oral and maxillofacial AVMs.

Neurovascular disturbances after implant surgery.

With a steadily increasing impact of oral implant placement in daily practice, the number of reported surgical complications has also been growing. Recent studies reveal significant variation in the occurrence and morphology of neurovascular canal structures in the jaw bone. All those structures contain a neurovascular bundle, the diameter of which may be large enough to cause clinically significant damage. Therefore, it has become obvious that presurgical radiographic planning of jaw-bone surgery should pay attention to the neurovascular structures and their likely variations, in addition to examining many other factors, such as jaw-bone morphology and volume, bone trabecular structure and the absence of bone or tooth pathology. A critical review is accomplished to explore the potential risks for neurovascular complications after implant placement, with evidence derived from histologic, anatomic, clinical and radiologic studies. In this respect, cross-sectional imaging can often be advocated, as it is obvious that the inherent three-dimensional nature of jaw-bone anatomy may clearly benefit from a detailed spatial image analysis. Although this could initially be realized by conventional computed tomography, in current practice, dentomaxillofacial cone beam computed tomography might be used, as it offers high-quality images at low radiation dose levels and costs.

Hard and soft tissue considerations at mini-implant insertion sites.

Various factors influence where orthodontic mini-implants will be placed. This article highlights the pertinent variables that should find consideration when planning the placement of orthodontic mini-implants.

Is the effect of mobile phone radiofrequency waves on human skin perfusion non-thermal?

OBJECTIVE: To establish whether SkBF can be modified by exposure to the radiofrequency waves emitted by a mobile phone when the latter is held against the jaw and ear. METHODS: Variations in SkBF and Tsk in adult volunteers were simultaneously recorded with a thermostatic laser Doppler system during a 20-minute "radiofrequency" exposure session and a 20-minute "sham" session. The skin microvessels' vasodilatory reserve was assessed with a heat challenge at the end of the protocol. RESULTS: During the radiofrequency exposure session, SkBF increased (vs. baseline) more than during the sham exposure session. The sessions did not differ significant in terms of the Tsk time-course response. The skin microvessels' vasodilatory ability was found to be greater during radiofrequency exposure than during sham exposure. CONCLUSIONS: Our results reveal the existence of a specific vasodilatory effect of mobile phone radiofrequency emission on skin perfusion.

Blood collection from the facial (maxillary)/musculo-cutaneous vein in true frogs (family Ranidae).

Collection of blood from amphibians, as in other classes of vertebrate animals, is essential to evaluate parameters of health, diagnose hemoparasitism, identify viral and bacterial pathogens, and measure antibodies. Various methods of blood collection have been described for amphibians. Most can be cumbersome (venipucture of femoral vein, ventral abdominal vein or lingual venus plexus) or result in pain or deleterious health consequences (cardiac puncture and toe-clipping). We describe an easy and practical technique to collect blood from frogs and toads that can be used in multiple species and is minimally invasive. The technique consists of puncturing either the facial or, less commonly, the musculo-cutaneous vein and collecting the blood with a capillary tube. These veins run dorsal and parallel to the maxillary bone and can be accessed by quick insertion and withdrawal of a needle through the skin between the upper jawline and the rostral or caudal side of the tympanum. The needle should be of 27 or 30 gauge for anurans weighing more or less than 25 g, respectively. Although the technique has been used by some amphibian researchers for years, it is little known by others and has never been fully described in a peer-reviewed publication.

Correlation between maxillofacial radiographic features and systemic severity as sickle cell disease severity predictor.

This study was conducted to investigate the relationship among radiographic features observed on panoramic radiographs of sickle cell disease patients and analyze their relationship with history of systemic severity of the disease. Panoramic radiographs of 71 subjects with sickle cell disease were evaluated for the presence of the following radiographic bony alterations: radiopaque areas, increased spacing of bony trabeculae, horizontal arrangement of bony trabeculae and corticalization of mandibular canal. History of clinical systemic severity was assessed through direct questioning about the frequency of vaso-occlusive crisis, history of stroke, clinical jaundice, femur head necrosis, and leg ulceration. Chi-square or Fisher's exact test were applied in order to analyze possible associations between radiographic features and history of complications, with p < 0.05 significance level. Increased spacing of bony trabeculae was statistically associated with absence of corticalization of mandibular canal (p < 0.01) and horizontal arrangement of bony trabeculae (p = 0.04). Statistically significant associations were demonstrated between history of clinical jaundice and presence of increased spacing of bony trabeculae (p = 0.02) and between history of stroke and presence of horizontal arrangement of bony trabeculae (p = 0.04). Based on the results of the current study, maxillofacial radiographic features may be associated with clinical parameters of systemic complications in sickle cell disease patients. The relationship between radiographic features and history of complications associated with clinical severity of sickle cell disease has not been demonstrated in the literature. Acknowledgment of such possible association may help establish prognosis and influence clinical treatment of systemic and oral complications.

[Clinical application of radiotherapy for the treatment of giant vascular malformations in oral and maxillofacial region].

OBJECTIVE: To discuss the clinical use of radiotherapy in the treatment of giant vascular malformation. METHODS: Six patients with giant vascular malformation in oral and maxillofacial region were treated by three dimensional radiation therapy in Department of Stomatology, The Second Affiliated Hospital, School of Medicne, Zhejiang University in the last ten years and the cilinical data were reviewed. The treatment results were evaluated by clinical examination and radiology. RESULTS: No complication was observed during and after the radiotherapy. All patients were satisfied with the aesthetic results. The lesions in MRI were all reduced and even disappeared. There was no sign of recurrence during the follow-up period. CONCLUSIONS: Three dimensional radiotherapy is safe and effective for oral and maxillofical vascular malformation.

Clinical anatomy of the maxillary artery.

The Maxillary artery is a component of the terminal branch of external carotid artery and distributes the blood flow to upper and lower jawbones and to the deep facial portions. It is thus considered to be a blood vessel which supports both hard and soft tissues in the maxillofacial region. The maxillary artery is important for bleeding control during operation or superselective intra-arterial chemotherapy for head and neck cancers. The diagnosis and treatment for diseases appearing in the maxillary artery-dominating region are routinely performed based on image findings such as CT, MRI and angiography. However, validations of anatomical knowledge regarding the Maxillary artery to be used as a basis of image diagnosis are not yet adequate. In the present study, therefore, the running pattern of maxillary artery as well as the type of each branching pattern was observed by using 28 sides from 15 Japanese cadavers. In addition, we also took measurements of the distance between the bifurcation and the origin of the maxillary artery and the inner diameter of vessels. These findings thus obtained could contribute to knowledge of improved accuracy of image diagnosis as an index for embolization and for knowledge of an adequate superselective intra-arterial chemotherapy.

Role of the rs6822844 gene polymorphism at the IL2-IL21 region in biopsy-proven giant cell arteritis.

OBJECTIVES: To assess the influence of the interleukin (IL)2-IL21 rs6822844 G/T polymorphism in the susceptibility to biopsy-proven giant cell arteritis (GCA) and in the clinical spectrum of manifestations of this vasculitis. METHODS: Two hundred and seventy-two biopsy-proven GCA patients were included in this study. DNA from patients and matched controls (n=791) was obtained from peripheral blood. Samples were genotyped for the rs6822844 polymorphism using a predesigned TaqMan allele discrimination assay and by polymerase chain reaction amplification. RESULTS: No significant differences in the allele and genotype frequencies between biopsy-proven GCA patients and controls were observed. However, the stratification of GCA patients disclosed some differences according to gender and ischemic manifestations of the disease. In this regard, the frequency of the minor allele T was increased in males (14.8%) compared to females (8.4%) (odds ratio-OR:1.89 (95% confidence interval-CI: 1.09-3.28); p=0.02; Bonferroni adjustment p=0.12). Also, minor allele T frequency was increased in GCA patients with severe ischemic complications (12.8%) compared to those without severe ischemic complications (7.7%) (OR:1.72 (95% CI: 0.97-3.05); p=0.05; Bonferroni adjustment p=0.30), and specifically in patients with jaw claudication (13.7% versus 8.2% in those without jaw claudication; OR:1.76 (95% CI: 1.02-3.04); p=0.04; Bonferroni adjustment p=0.24). CONCLUSIONS: IL2-IL21 rs6822844 polymorphism does not appear to be a genetic risk factor for susceptibility to biopsy-proven GCA. However, this gene polymorphism may contribute to the different phenotypic expression of this vasculitis, in particular in the development of ischemic complications of the disease.

An experimental study of bisphosphonate-induced jaws osteonecrosis in Sprague-Dawley rats.

OBJECTIVE: Patients undergoing treatment with bisphosphonates may develop jaw lesions consisting mainly of bone necrosis. The present study describes a model of maxillary osteonecrosis in Sprague-Dawley rats, applying bisphosphonates and examines the changes occurring after tooth extraction. MATERIAL AND METHODS: A total 200 animals were included in a randomized prospective study involving the following groups: group I (control, 20 rats without drug treatment), group II (60 animals administered dexamethasone 1 mg/kg/day for 7, 14 and 21 days, in subgroups of 20 animals each), group III (60 animals administered pamidronate daily at a dose of 3 mg/kg) and group IV (60 animals administered pamidronate and dexamethasone). In all groups, molar extraction was carried out on the right upper maxillary or mandibular side 8, 15 and 22 days after the start of dosing. The rats were killed 14 and 28 days after extraction in all groups. RESULTS: A total of 18 cases of osteonecrosis were recorded in the group administered pamidronate and dexamethasone. Osteonecrosis affected the upper maxilla in 10 cases and the mandible in eight cases, and was circumscribed to the extraction zone in all cases. Osteonecrosis was not seen in any of the other groups. CONCLUSIONS: The administration of pamidronate and dexamethasone in rats subjected to molar extraction increases the risk of osteonecrosis.