Anatomical features of the mandibular canal and their clinical significance - review of literature

The clinical issues related to the anatomical variation of the mandibular canal have been extensively analyzed since the 19th century. Evolving dentistry techniques and advancements in the prosthetics forced to collect detailed information about anatomical variations of the mandibular canal due to its neurovascular content. Therefore, its radiographic imaging became an essential part of the oral surgery, in order to avoid complications resulted from an accidental damage of the mandibular canal.

Trifurcation of the facial artery at the inferior border of the mandible: a case report

PURPOSE

The facial artery is known to show variations in its origin, course, termination, and branching pattern. This study aimed to present a case with trifurcation of the facial artery at the inferior border of the mandible accompanied by variable branches.

METHODS

During our routine head dissection, it was observed that a 67-year-old male cadaver had a trifurcation of the facial artery at the level of the lower border of the mandible on the left. The skin was reflected, and the subcutaneous fatty tissue and subcutaneous layers were dissected to reveal the triple facial artery.

RESULTS

The left facial artery arising from the external carotid artery entered the face with three branches as it crossed the lower border of the mandible. The three branches are the anterior, intermediate, and posterior branches. The posterior branch passed in front of the anterior border of the masseter muscle along with the facial vein and gave off muscular branches with a straight course, whereas the anterior thickest curved branch terminated by the inferior labial artery, and a tortuous intermediate branch initially gave off the superior labial artery and then terminated by the angular artery.

CONCLUSION

Understanding these variational branches of the triple facial artery and their relationships is crucial for avoiding complications in reconstructive and reparative maxillofacial, craniofacial and plastic surgery in order to mitigate the risk of damage to the facial artery during flap surgery.

Quantitative Dynamic Contrast-Enhanced MRI Identifies Radiation-Induced Vascular Damage in Patients With Advanced Osteoradionecrosis: Results of a Prospective Study

PURPOSE

We aim to characterize the quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters associated with advanced mandibular osteoradionecrosis (ORN) compared with the contralateral normal mandible.

METHODS AND MATERIALS

Patients with a diagnosis of advanced ORN after curative-intent radiation treatment of head and neck cancer were prospectively enrolled after institutional review board approval and study-specific informed consent were obtained. Quantitative maps generated with the Tofts and extended Tofts pharmacokinetic models were used for analysis. Manual segmentation of advanced ORN 3-dimensional volume was done using anatomic sequences to create ORN volumes of interest (VOIs). Subsequently, normal mandibular VOIs were segmented on the contralateral healthy mandible of similar volume and anatomic location to create control VOIs. Finally, anatomic sequences were coregistered to DCE sequences, and contours were propagated to the respective parameter maps.

RESULTS

Thirty patients were included. The median time to ORN diagnosis after completion of IMRT was 38 months (range, 6-184 months), whereas median time to ORN progression to advanced grade after initial diagnosis was 5.6 months (range, 0-128 months). There were statistically significant higher K^trans and V_e in ORN-VOIs compared with controls (0.23 vs 0.07 min^-1, and 0.34 vs 0.15; P < .0001 for both). The average relative increase of K^trans in ORN-VOIs was 3.2-fold higher than healthy mandibular control VOIs. Moreover, the corresponding rise of V_e in ORN-VOIs was 2.7-fold higher than in the controls. Using combined K^trans and V_e parameters, 27 patients (90%) had at least a 200% increase of either of the studied parameters in the ORN-VOIs compared with their healthy mandible VOIs.

CONCLUSIONS

Our results confirm that there is a quantitatively significant higher degree of leakiness in the mandibular vasculature as measured using DCE-MRI parameters of areas with advanced ORN versus healthy mandible.

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.

3-dimensional visualization of implant-tissue interface with the polyethylene glycol associated solvent system tissue clearing method

OBJECTIVES

Dental implants are major treatment options for restoring teeth loss. Biological processes at the implant-tissue interface are critical for implant osseointegration. Superior mechanical properties of the implant constitute a major challenge for traditional histological techniques. It is imperative to develop new technique to investigate the implant-tissue interface.

MATERIALS AND METHODS

Our laboratory developed the polyethylene glycol (PEG)-associated solvent system (PEGASOS) tissue clearing method. By immersing samples into various chemical substances, bones and teeth could be turned to transparent with intact internal structures and endogenous fluorescence being preserved. We combined the PEGASOS tissue clearing method with transgenic mouse line and other labelling technique to investigate the angiogenesis and osteogenesis processes occurring at the implant-bone interface.

RESULTS

Clearing treatment turned tissue highly transparent and implant could be directly visualized without sectioning. Implant, soft/hard tissues and fluorescent labels were simultaneously imaged in decalcified or non-decalcified mouse mandible samples without disturbing their interfaces. Multi-channel 3-dimensional image stacks at high resolution were acquired and quantified. The processes of angiogenesis and osteogenesis surrounding titanium or stainless steel implants were investigated.

CONCLUSIONS

Both titanium and stainless steel implants support angiogenesis at comparable levels. Successful osseointegration and calcium precipitation occurred only surrounding titanium, but not stainless steel implants. PEGASOS tissue clearing method provides a novel approach for investigating the interface between implants and hard tissue.

Cephalometric studies of the mandible, its masticatory muscles and vasculature of growing Göttingen Minipigs-A comparative anatomical study to refine experimental mandibular surgery

Over many decades, the Göttingen Minipig has been used as a large animal model in experimental surgical research of the mandible. Recently several authors have raised concerns over the use of the Göttingen Minipig in this research area, observing problems with post-operative wound healing and loosening implants. To reduce these complications during and after surgery and to improve animal welfare in mandibular surgery research, the present study elucidated how comparable the mandible of minipigs is to that of humans and whether these complications could be caused by specific anatomical characteristics of the minipigs' mandible, its masticatory muscles and associated vasculature. Twenty-two mandibular cephalometric parameters were measured on CT scans of Göttingen Minipigs aged between 12 and 21 months. Ultimately, we compared this data with human data reported in the scientific literature. In addition, image segmentation was used to determine the masticatory muscle morphology and the configuration of the mandibular blood vessels. Compared to data of humans, significant differences in the mandibular anatomy of minipigs were found. Of the 22 parameters measured only four were found to be highly comparable, whilst the others were not. The 3D examinations of the minipigs vasculature showed a very prominent deep facial vein directly medial to the mandibular ramus and potentially interfering with the sectional plane of mandibular distraction osteogenesis. Damage to this vessel could result in inaccessible bleeding. The findings of this study suggest that Göttingen Minipigs are not ideal animal models for experimental mandibular surgery research. Nevertheless if these minipigs are used the authors recommend that radiographic techniques, such as computed tomography, be used in the specific planning procedures for the mandibular surgical experiments. In addition, it is advisable to choose suitable age groups and customize implants based on the mandibular dimensions reported in this study.

Bone mineralization and vascularization in bisphosphonate-related osteonecrosis of the jaw: an experimental study in the rat

OBJECTIVES

Pathogenesis of bisphosphonate-related osteonecrosis of the jaws (BRONJ) is not fully explained. An antiangiogenic effect of bisphosphonates (BPs) or an altered bone quality have been advocated. The aims of the present study were to analyze alveolar mandibular vascularization and bone quality in rats with BRONJ.

MATERIALS AND METHODS

Thirty-eight Sprague-Dawley rats were randomized into two groups: zoledronic acid (ZA), n = 27, and control (CTRL) n = 11. The ZA group received a weekly IV injection of ZA (100 μg/kg) during 10 weeks. The CTRL group received saline. After 6 weeks, extraction of the right mandibular molars was performed. Rats were sacrificed after 14 weeks. Microtomography characterized bone lesions and vascularization after injection of a radio-opaque material. Raman microspectroscopy evaluated bone mineralization.

RESULTS

Fifty-five percent of ZA rats presented bone exposure and signs of BRONJ. None sign was found at the left hemimandible in the ZA group and in the CTRL group. Vascular density appeared significantly increased in the right hemimandibles of the CTRL group compared to the left hemimandibles. Vascularization was reduced in the ZA group. A significantly increased of the mineral-to-amide ratio was found in the alveolar bone of ZA rats by Raman microspectroscopy.

CONCLUSIONS

In a rat model of BRONJ, microtomography evidenced osteonecrosis in BRONJ. Raman spectroscopy showed an increased mineralization. Vascularization after tooth extraction was impaired by ZA.

CLINICAL RELEVANCE

Prolonged BP administration caused an increase in the mineralization and a quantitative reduction of the vascularization in the alveolar bone; both factors might be involved concomitantly in the BRONJ pathophysiology.

Mandibular AV Malformation: A Rare Cause of Massive Bleeding from Mouth Managed with Multiple Vessel Embolization

An arteriovenous malformation (AVM) is a site of abnormal connectivity between arteries and veins. Arteriovenous malformations of jaw are extremely rare conditions that can result in disastrous complications, if handled carelessly. Although various treatment modalities have been advocated in the literature, there seems to be no complete consensus on a suitable treatment in these cases. We describe a case of mandibular AVM, who presented with massive bleeding from mouth and each time, embolization of one vessel was done, it recruited new vessel.

Analysis of the blood supply to the post-fracture edentulous mandible: study by colour Doppler sonography

PURPOSE

This study assessed the arterial blood supply to the mandible of edentulous patients treated for mandibular fractures using colour Doppler ultrasound.

METHODS

The blood supply of edentulous patients surgically treated for mandibular fractures (group A) and edentulous fracture-free individuals (group B) was assessed. Only the fractured sides were evaluated in the first group (N = 17), whereas each side was evaluated in the second group (N = 20). The arterial flow of six sites was assessed. The systolic-peak maximum velocity (SPV), final diastolic velocity (FDV), resistive index (RI), pulsatility index (PI), acceleration and flow direction of each artery were obtained. Additionally, the presence of local vascular obstructive factors was evaluated. The differences between groups were analysed using the Kruskal-Wallis test, which was complemented by the Mann-Whitney test, for correlations between the degree of alveolar atrophy and the study factors (p < 0.050).

RESULTS

There was a significant decrease in the flow of certain arteries, especially the submental (SPV, p = 0.007, PI, p = 0.022, and acceleration, p = 0.015), in the fracture group. The facial artery in both groups showed lower values related to local obstructive factors (SPV, p = 0.001, FDV, p = 0.040, and PI, p = 0.030). The submental artery flow was higher (SPV, p = 0.006, and FDV, p = 0.009) in non-atrophic individuals.

CONCLUSIONS

There was a decreased flow mainly in the submental artery, but there were no cases of major vascular injury in edentulous patients treated for mandibular fractures.

Endovascular embolization for the management of inferior alveolar artery bleeding after a third molar extraction: A case report

Removal of third molars is a common surgical procedure with low complication rates. Localized alveolar osteitis, infection, bleeding, and paresthesia are the four most common postoperative complications of third molar extraction reported in the literature. Postoperative severe hemorrhages are rare and are usually related to inferior alveolar artery damage. Although most bleeding is usually managed effectively by local compression or packing of the socket, even life-threatening complications may occur. Endovascular embolization has been rarely reported as treatment for such a complication and represents an ideal solution, with a low complication rate and excellent control of bleeding. The authors report a case of potentially life-threatening hemorrhage continuing 4 days after extraction of the mandibular right third molar, resulting in significant anemia (Hb 6.6 g/dL) and treated successfully with endovascular embolization of the inferior alveolar artery. The authors consider it important for general practitioners to know this treatment and how to manage this rare complication in the correct way, saving time if satisfactory hemostasis cannot be reached with common procedures.

Cone Beam Computed Tomography for the Dental Implant Patient

Cone beam computed tomography offers many advantages over 2-D imaging for the evaluation of potential implant sites. With the use of CBCT scans becoming more commonplace, it is important for clinicians to be knowledgeable and to use this new technology appropriately and judiciously. The purpose of this article is to describe the advantages and limitations of CBCT imaging for the presurgical and postsurgical evaluations of implant treatment and assessment of implant-related complications.

Frequency and anatomy of the retromolar canal - implications for the dental practice

The retromolar canal (RMC) is an anatomical variant of the mandibular canal. Apart from blood vessels it also contains accessory nerve fibers and is clinically important, because its presence can account for failures of mandibular block anesthesias and in rare cases, injuries of its neurovascular bundle can lead to complications such as hemorrhages and dysesthesias. The aim of this retrospective case study was to analyze the frequency and anatomy of the RMC using cone beam computed tomography (CBCT) in order to draw conclusions for the dental practice. A total of 680 CBCT scans comprising 1,340 mandibular sides were evaluated. A total of 216 RMCs (16.12%) were found. The most common appearance of the canal (39.82%) corresponded to type Al (vertical course), whereas type C (horizontal course) occurred least often (6.02%). Mean measured values were 1.03 mm (SD=0.27mm) regarding the RMC diameter, 10.19 mm (SD=2.64mm) regarding the RMC height and 15.10 mm (SD=2.83 mm) regarding the distance of the RMC to the second molar. Neither demographic factors nor the spatial resolution of the CBCT had a statistically significant impact on the frequency of the RMC. Since the present study revealed a frequency of RMCs amounting to 16.12% (corresponding approximately to every sixth retromolar area), we recommend to spare it during surgery or to consider an additional locoregional anesthesia in the retromolar region. For preoperative diagnosis the CBCT has proved suitable, offering the possibility to select the spatial resolution depending on the indication, so that radiation exposure is reduced without a decrease in validity.

Trigeminocardiac reflex by mandibular extension on rat pial microcirculation: role of nitric oxide

In the present study we have extended our previous findings about the effects of 10 minutes of passive mandibular extension in anesthetized Wistar rats. By prolonging the observation time to 3 hours, we showed that 10 minutes mandibular extension caused a significant reduction of the mean arterial blood pressure and heart rate respect to baseline values, which persisted up to 160 minutes after mandibular extension. These effects were accompanied by a characteristic biphasic response of pial arterioles: during mandibular extension, pial arterioles constricted and after mandibular extension dilated for the whole observation period. Interestingly, the administration of the opioid receptor antagonist naloxone abolished the vasoconstriction observed during mandibular extension, while the administration of N_ω-Nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, abolished the vasodilation observed after mandibular extension. Either drug did not affect the reduction of mean arterial blood pressure and heart rate induced by mandibular extension. By qRT-PCR, we also showed that neuronal nitric oxide synthase gene expression was significantly increased compared with baseline conditions during and after mandibular extension and endothelial nitric oxide synthase gene expression markedly increased at 2 hours after mandibular extension. Finally, western blotting detected a significant increase in neuronal and endothelial nitric oxide synthase protein expression. In conclusion mandibular extension caused complex effects on pial microcirculation involving opioid receptor activation and nitric oxide release by both neurons and endothelial vascular cells at different times.

[The risk factors and analysis of complications after regenerative interventions in surgery of oral cavity]

Most spreaded risk factors in reconstructive and plastic surgery of oral cavity were analyzed. Trustworthy monitoring of rate of the complications occurrence in augmentation of the jaws bones was conducted, depending on the risk factor.

Vascular analysis as a proxy for mechanostransduction response in an isogenic, irradiated murine model of mandibular distraction osteogenesis

INTRODUCTION

Head and neck cancer is a debilitating and disfiguring disease. Although numerous treatment options exist, an array of debilitating side effects accompany them, causing physiological and social problems. Distraction osteogenesis (DO) can avoid many of the pathologies of current reconstructive strategies; however, due to the deleterious effects of radiation on bone vascularity, DO is generally ineffective. This makes investigating the effects of radiation on neovasculature during DO and creating quantifiable metrics to gauge the success of future therapies vital. The purpose of this study was to develop a novel isogenic rat model of impaired vasculogenesis of the regenerate mandible in order to determine quantifiable metrics of vascular injury and associated damage.

METHODS

Male Lewis rats were divided into two groups: DO only (n=5) AND Radiation Therapy (XRT)+DO (n=7). Afterwards, a distraction device was surgically implanted into the mandible. Finally, they were distracted a total of 5.1mm. Animals were perfused with a radiopaque casting agent concomitant with euthanasia, and subsequently demineralization, microcomputed tomography, and vascular analysis were performed.

RESULTS

Vessel volume fraction, vessel thickness, vessel number, and degree of anisotropy were diminished by radiation. Vessel separation was increased by radiation.

CONCLUSION

The DO group experienced vigorous vessel formation during distraction and neovascularization with a clear, directional progression, while the XRT/DO group saw weak vessel formation during distraction and neovascularization. Further studies are warranted to more deeply examine the impairments in osteogenic mechanotransductive pathways following radiation in the murine mandible. This isogenic model provides quantifiable metrics for future studies requiring a controlled approach to immunogenicity.

Facial swelling in a sickle cell patient

Sickle cell disease (SCD) is characterized as a chronic hemolytic anemia with vaso-occlusive crises that result in multisystem organ damage. Bone marrow is one of the more common sites of these crises, presumably due to marrow hypercellularity that impairs blood flow- leading to regional hypoxia and subsequent infarction. Infarcts of facial bones are considered an uncommon complication of SCD. When infarcts occur in facial bones, the mandible and orbital bones are the most commonly affected. Overall, the clinical presentation of facial bone infarctions may mimic an infectious process, such as cellulitis, an abscess, or, more commonly, osteomyelitis. The purpose of this paper was to present the case of a patient with a confluence of symptoms in the face as a result of her sickle cell disease.

Mineralised Collagen Scaffolds Loaded with Stromal Cell-derived Factor-1 Improve Mandibular Bone Regeneration

OBJECTIVE

To create an in situ matrix environment conducive to stem cells from host bone marrow to promote bone regeneration.

METHODS

Three-dimensional porous, mineralised collagen (MC) scaffolds were prepared using a freeze-drying process. The microstructure of scaffolds was observed by field emission scanning electron microscopy. The Bose BioDynamic test system was applied to examine their mechanical properties in wet conditions. The effect of scaffolds loaded with stromal cellderived factor-1α (SDF-1α) on migration of stem cells was assessed using a 24-well transwell system. SDF-1α-loaded scaffolds were implanted in the critical size defect in rats and histological staining was used to evaluate the new bone formation.

RESULTS

Mechanical testing showed that the MC scaffold featured an increased Young's modulus compared with the pure collagen (Col) scaffold in wet conditions. In addition, the MC scaffold loaded with SDF-1α chemokine improved bone marrow stromal cells' migration. When implanted in mandibular bone defects with 5 mm diameter, the MC scaffolds containing SDF-1α significantly improved the formation of new bone and blood capillaries within the scaffolds, compared with the SDF-1α-loaded Col scaffolds and the control group.

CONCLUSION

The mineralised collagen scaffolds loaded with SDF-1α, which creates a matrix environment conducive to stem cell migration, can be exploited to improve bone self-repair as an alternative to contemporary cell seeding approaches.

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.

Parathyroid hormone reverses radiation induced hypovascularity in a murine model of distraction osteogenesis

BACKGROUND

Radiation treatment results in a severe diminution of osseous vascularity. Intermittent parathyroid hormone (PTH) has been shown to have an anabolic effect on osteogenesis, though its impact on angiogenesis remains unknown. In this murine model of distraction osteogenesis, we hypothesize that radiation treatment will result in a diminution of vascularity in the distracted regenerate and that delivery of intermittent systemic PTH will promote angiogenesis and reverse radiation induced hypovascularity.

MATERIALS AND METHODS

Nineteen Lewis rats were divided into three groups. All groups underwent distraction of the left mandible. Two groups received radiation treatment to the left mandible prior to distraction, and one of these groups was treated with intermittent subcutaneous PTH (60 μg/kg, once daily) beginning on the first day of distraction for a total duration of 21 days. One group underwent mandibular distraction alone, without radiation. After consolidation, the rats were perfused and imaged with micro-CT angiography and quantitative vascular analysis was performed.

RESULTS

Radiation treatment resulted in a severe diminution of osseous vascularity in the distracted regenerate. In irradiated mandibles undergoing distraction osteogenesis, treatment with intermittent PTH resulted in significant increases in vessel volume fraction, vessel thickness, vessel number, degree of anisotropy, and a significant decrease in vessel separation (p < 0.05). No significant difference in quantitative vascularity existed between the group that was irradiated, distracted and treated with PTH and the group that underwent distraction osteogenesis without radiation treatment.

CONCLUSIONS

We quantitatively demonstrate that radiation treatment results in a significant depletion of osseous vascularity, and that intermittent administration of PTH reverses radiation induced hypovascularity in the murine mandible undergoing distraction osteogenesis. While the precise mechanism of PTH-induced angiogenesis remains to be elucidated, this report adds a key component to the pleotropic effect of intermittent PTH on bone formation and further supports the potential use of PTH to enhance osseous regeneration in the irradiated mandible.

A model of mandibular irradiation in the rabbit: preliminary results

Radiotherapy is widely used in the treatment of head and neck cancers. Its major adverse effect is osteoradionecrosis, which can occur during the whole life of the patient, involving the vital prognosis. The aim of the study was to develop a model for irradiation of the rabbit mandible in order to have a better knowledge of radiotherapy-induced bone alterations and thus a better prevention and treatment of osteoradionecrosis. The control group consisted in 7 rabbits and was used to assess anatomical and histological parameters of the rabbit's mandible. A first group of 14 rabbits was weekly irradiated at doses of 5.5 Gy during 5 weeks, at a total dose of 46.8Gy. Sacrifices were done at 1 week, 4 weeks, 12 weeks and 24 weeks. As histological analysis did not reveal statistical differences with the control group, a second group (3 rabbits) was weekly irradiated at 8.0, 8.5 and 9 Gy during 5 weeks. The first histological results seem to show vascular alterations, bone cells decrease and alterations of bone architecture. The role of intra alveolar collagen sponges, PRF®, ultrasounds and stem cells in bone regeneration after radiotherapy will be further studied.

[Blood circulation features by treatment of multiply mandible fractures by means of transosseus osteosynthesis]

The multiple injury of the mandible was modeled experimentally in 27 adult mongrel dogs with subsequent fixation using a device for transosseous osteosynthesis. The special features of soft tissue hemodynamics in the injury zone and contralateral symmetrical part were studied. It has been determined that the unidirectional changes in functional properties of the arterial bed vessels occur under the conditions created, and these changes are more marked on the injury side and characterized by vasodilatation. Circulation in the injury zone doesn't recover by the end of fixation. Performing the measures directed for the improvement of vascular elastotonic properties during mandibular fracture treatment will allow to decrease the degree of hemodynamics disorders in paraosseous tissues, as well as will have a positive effect on a final clinical outcome.

[The mental foramen or "the crossroads of the mandible." An anatomic and clinical observation]

This paper presents a clinical and anatomical review of the mental foramen (MF) based on recent publications (since 1990). Usually, the MF is located below the 2nd premolar or between the two premolars, but it may also be positioned below the 1st premolar or below the mesial root of the 1st molar. At the level of the MF, lingual canals may join the mandibular canal (hence the term "crossroads"). Accessory MF are frequently described in the literature with large ethnic variations in incidence. The emergence pattern of the mental canal usually has an upward and posterior direction. The presence and extent of an "anterior loop" of the mental canal may be overestimated with panoramic radiography. Limited cone-beam computed tomography currently appears to be the most precise radiographic technique for assessment of the "anterior loop". The mental nerve exiting the MF usually has three to four branches for innervation of the soft tissues of the chin, lower lip, facial gingiva and mucosa in the anterior mandible. The clinician is advised to observe a safety distance when performing incisions and osteotomies in the vicinity of the MF.

Iliac crest fresh-frozen allografts and autografts in maxillary and mandibular reconstruction: a histologic and histomorphometric evaluation

AIM

The aim of this paper was to compare histologically and histomorphometrically the osseointegration of iliac crest fresh-frozen allografts and autografts in human pre-prosthetic maxillary and mandibular onlay bone blocks reconstruction.

METHODS

Twelve patients with edentulous atrophic ridges, scheduled for implant-supported prosthetic restorations, underwent reconstruction using iliac crest fresh-frozen allografts (group A, six patients) or autografts (group B, six patients). Four-to-nine months later implants were placed in the augmented areas and bone specimens were simultaneously obtained using trephine burs. The specimens were processed for ground sections and evaluated histologically and histomorphometrically.

RESULTS

The postoperative course was uneventful in all patients in group B and in all except one in group A. Late complications occurred in 5 patients of group A. Dental implants could be inserted in all cases. Specimens from group A showed a vascularized bone with osteoprogenitor stem cells and medium-high grade of bone remodeling. Small areas of necrotic bone were observed sporadically. Sections obtained from group B revealed an advanced stage of bone remodeling. The histomorphometric analysis showed in group A a mean proportion of 24.7±14.7% for lamellar bone, 28.4±13.3% for newly formed bone and 46.9±16.9% for bone marrow; in group B the corresponding values were 25.3±15.3%, 22.9±11.0%, 51.7±15.7%. No statistically significant difference was found (Wilcoxon Test; P>0.05).

CONCLUSION

There were no significant histological differences between group A and B. Larger studies with long term follow-up are needed to confirm that fresh-frozen allografts are a reliable alternative to autografts.

[Mandible regional blood circulation peculiarities by dental implants placement]

The paper presents data on regional blood circulation in mandible implant placement sites. Rheographic assessment in 50 patients divided in two groups according to implant placement protocol revealed that circulation volume and peripheral vessels tonus restored on the 14th day after implant placement with wound draining while in conventional implant placement protocol these values remained disturbed even 21 days after surgical procedure.

Contralateral de novo intraosseous arteriovenous malformation in a child with arteriovenous malformation of mandible treated by endovascular embolotherapy. A case report

We describe our experience of the development of contralateral de novo intraosseous AVMs in a ten-year-old girl with AVMs of the mandible who underwent endovascular embolotherapy. She initially presented with intermittent oral bleeding. Computed tomography and digital subtraction angiography demonstrated intraosseous AVMs within the right mandible. The AVMs were treated by transosseous direct-puncture and transarterial embolization with Guglielmi detachable coils and n-butyl cyanoacrylate glue. However, de novo intraosseous AVMs developed within the previously healthy contralateral mandible and resulted in dangerous oral bleeding. Therefore, we suggest regular follow-up and prompt retreatment of any residual mandibular AVMs in patients undergoing endovascular or surgical treatment to prevent subsequent development of "secondary" AVMs and life-threatening oral bleeding.

Appearance of anatomical structures of mandible on panoramic radiographs in Iranian population

PURPOSE

Currently panoramic radiography is used for diagnosis of dental and bone lesions, but anatomical structures also can be seen and may be useful in dental managements. This study aimed to investigate the visibility of some important mandibular features relating to neurovascular structures in Iranian population.

MATERIALS AND METHODS

Panoramic radiographs were taken by Planmeca machine from 412 patients using standard exposure. The position of patient was in compliance with standard protocol. Then mandibular incisive canal was evaluated and data were analyzed statistically.

RESULTS

Mental foramen, anterior loop of mental nerve and incisive canal could be observed in 84.2, 66 and 51.7% of the cases. Respectively, lingual foramen was observed in only 6.1% of the radiographs. Gender doesn't affect on the visibility of these structures. There was a relationship between mandibular foramen and canal with age.

CONCLUSION

Mandibular incisive canal was considered in 51.7% of cases, it was observed that the result obtained was more than those of other researches.

Axially vascularized bone substitutes: a systematic review of literature and presentation of a novel model

INTRODUCTION

The creation of axially vascularized bone substitutes (AVBS) has been successfully demonstrated in several animal models. One prototypical indication is bone replacement in patients with previously irradiated defect sites, such as in the mandibular region. The downside of current clinical practice, when free fibular or scapular grafts are used, is the creation of significant donor site morbidity.

METHODS

Based on our previous experiments, we extended the creation of an arterio-venous loop to generate vascularized bone substitutes to a new defect model in the goat mandibula. In this report, we review the literature regarding different models for axially vascularized bone substitutes and present a novel model demonstrating the feasibility of combining this model with synthetic porous scaffold materials and biological tissue adhesives to grow cells and tissue.

RESULTS

We were able to show the principal possibility to generate axially vascularized bony substitutes in vivo in goat mandibular defects harnessing the regenerative capacity of the living organism and completely avoiding donor site morbidity.

CONCLUSION

From our findings, we conclude that this novel model may well offer new perspectives for orthopedic and traumatic bone defects that might benefit from the reduction of donor site morbidity.

Deferoxamine reverses radiation induced hypovascularity during bone regeneration and repair in the murine mandible

BACKGROUND

Deferoxamine (DFO) is an iron-chelating agent that has also been shown to increase angiogenesis. We hypothesize that the angiogenic properties of DFO will improve bone regeneration in distraction osteogenesis (DO) after x-ray radiation therapy (XRT) by restoring the vascularity around the distraction site.

MATERIAL AND METHODS

Three groups of Sprague-Dawley rats underwent distraction of the left mandible. Two groups received pre-operative fractionated XRT, and one of these groups was treated with DFO during distraction. After consolidation, the animals were perfused and imaged with micro-CT to calculate vascular radiomorphometrics.

RESULTS

Radiation inflicted a severe diminution in the vascular metrics of the distracted regenerate and consequently led to poor clinical outcome. The DFO treated group revealed improved DO bone regeneration with a substantial restoration and proliferation of vascularity.

CONCLUSIONS

This set of experiments quantitatively demonstrates the ability of DFO to temper the anti-angiogenic effect of XRT in mandibular DO. These exciting results suggest that DFO may be a viable treatment option aimed at mitigating the damaging effects of XRT on new bone formation.

Distribution of endosseous bony canals in the mandibular symphysis as detected with cone beam computed tomography

PURPOSE

The purpose of this article was to investigate the distribution of endosseous bony canals in the anterior mandible using cone beam computed tomography (CBCT) technology.

MATERIALS AND METHODS

Two hundred ninety-nine images based on CBCT of the anterior mandible were analyzed for the presence of endosseous canals. The bony canals were observed in relationship to the adjacent anatomical structures, and relationships between their topographic variability and patient age and gender were analyzed.

RESULTS

Bony canals were found in the anterior mandible in almost 86% of the examined patients, independent of age and gender. The highest regional frequency was seen in the midline area, followed by the lateral incisor and canine regions. The length of the canals ranged from 5 to 15 mm (mean, 10.55 mm). Multiple (two or three) canals were also observed in approximately 9% of the scans. Varying appearances of these bony canals in the symphysis region were also demonstrated.

CONCLUSIONS

Endosseous canals in the mandibular symphysis were found using CBCT scans. CBCT seems to be an important diagnostic technique for evaluation of the exact distribution of bony canals in the symphysis region that may help reduce the risk of surgical complications.

Angiogenesis in the reparatory mucosa of the mandibular edentulous ridge is driven by endothelial tip cells

Sprouting angiogenesis is led by specialized cell--the endothelial tip cells (ETCs) which can be targeted by pro- or anti-angiogenic therapies. We aimed to perform a qualitative study in order to assess the guidance by tip cells of the endothelial sprouts in the repairing mucosa of the edentulous mandibular crest. Mucosa of the mandibular edentulous ridge was collected from six adult patients, prior to healing abutment placement (second surgery). Slides were prepared and immunostained with antibodies for CD34 and Ki67. The abundant vasculature of the lamina propria was observed on slides and the CD34 antibodies labeled endothelial tip cells in various stages of the endothelial sprouts. Ki67 identified positive endothelial cells, confirming the proliferative status of the microvascular bed. According to the results, the in situ sprouting angiogenesis is driven by tip cells in the oral mucosa of the edentulous ridge and these cells can be targeted by various therapies, as required by the local pathologic or therapeutic conditions.

Bone regeneration in distraction osteogenesis demonstrates significantly increased vascularity in comparison to fracture repair in the mandible

BACKGROUND

Tissue analysis of bone regenerate has suggested an intense vascular response after mandibular distraction osteogenesis (DO). Quantifying and three-dimensionally imaging this vascular response could be of immense clinical import in efforts to advance the utility of bone regeneration and repair. Conventional quantification of vascular responses has heretofore focused on inexact, cumbersome measurements of blood flow and histologic vessel counting. Using micro-computed tomography after vessel perfusion, we posit that quantitative vascular metrics will be significantly higher in mandibular DO compared with those observed in fracture repair (FxR) after bony union.

METHODS

Sprague-Dawley rats underwent mandibular osteotomy and external fixator placement. A DO group (n=9) underwent a 5.1-mm distraction, whereas a FxR group (n=12) had a 2.1-mm fixed gap set. Forty days after surgery, Microfil was perfused into the vasculature, and imaging ensued. Vascular radiomorphometrics were calculated for the regions of interest. Independent-samples t-test was performed for comparison, with statistical significance set at P≤0.05.

RESULTS

Stereological analysis demonstrated statistically significant increases in the distracted vasculature compared with fracture repair: vessel volume fraction (5.4% versus 2.8%, P=0.030) and vessel number (0.86 versus 0.50 mm, P=0.014).

CONCLUSIONS

We report robust and quantifiable increases in vascular density in DO compared with FxR. Our findings support a significant distinction between the regenerative processes of mandibular DO from the reparative mechanisms controlling fracture healing. A better understanding of the differences between the 2 types of bone formation may enable clinicians to selectively optimize therapeutic outcomes in the future.

Endosseous arteries in the anterior mandible: literature review

PURPOSE

The purpose of this literature review was to investigate the topography of endosseous blood vessels supplying the anterior mandible to prevent complications both during and after oral surgical procedures.

MATERIAL AND METHODS

A comprehensive literature search of MEDLINE-PubMed was performed independently for articles describing the anatomical findings of endosseous blood vessels in the anterior part of the mandible. From about 31 related studies, 14 papers were selected based on specific selection criteria. These studies were related to radiologic findings and cadaver studies.

RESULTS

There is significant debate concerning the blood vessels supplying the anterior part of the mandible. Hence, in the literature reviewed, no clear consensus was established. There are no reports of severe endosseous bleeding from the mandible during surgical procedures in the symphysis. Based on computed tomographic images, some papers presented an exact intraosseous path of the canals, as well as frequent blood vessel anastomosis in this region. Dissection studies confirmed the presence of sublingual blood vessels penetrating into the bone.

CONCLUSIONS

The potential risk of bleeding upon perforation of vessels within the bone needs to be evaluated to avoid such complications. The management of intraoperative surgical problems is of significance.

Marginal mandibular branch of the facial nerve in human fetuses

OBJECTIVE

To observe the course of the marginal mandibular branch (MMB) and its relation to the inferior border of the mandible and facial vessels.

METHODS

This study was conducted in the Department of Anatomy, Gulhane Military Medical Academy, Etlik, Ankara, Turkey from February 2009 to April 2010. The 44 hemi-face specimens of 22 fetuses were selected for this study, and dissected under a stereomicroscope. The MMB relationship was evaluated between adjacent structures (like vessels and muscles) and the lower border of the mandible.

RESULTS

We found a number of one to 4 branches of the MMB. The MMB ran laterally to the facial vein in 42 (95.5%) of the 44 specimens. All the branches of the MMB ran laterally to the facial artery in 30 (68.2%) of the 44 specimens. In 2 specimens, it ran medially to the facial artery. In 10 specimens, the facial artery ran between 2 branches of the MMB. In 2 specimens, the 2 branches of the MMB ran between facial artery and vein. There were no statistical differences between the left and right sides, and in both genders.

CONCLUSION

The inferior border of the mandible may be an important landmark to avoid injury to the MMB of the facial nerve. It is for this reason, that surgeons who are willing to operate on this area should have a true knowledge and accurate judgement regarding the anatomy of this branch.

Using cone beam computed tomography to determine safe regions for implant placement

This study sought to identify and follow the course of the incisive canal in the mental interforaminal region of the human mandible and to describe other anatomical landmarks present in this region. Cone beam computerized tomography (CBCT) studies for 40 patients were collected from the database at the Department of Oral & Maxillofacial Radiology, School of Dentistry, Lebanese University. Ten patients had edentulous mandibles; the other 30 had partially or completely dentate mandibles. Axial native images and panoramic and cross-sectional reconstructions were examined to assess the anatomical landmarks in the anterior mandible. Multiple neurovascular canals and foramina were clearly detected on CBCT studies of the mandible. Numerous foramina were seen on the internal surface of the mandible, even distant from the midline. The incisive canal was identified in 97.5% of the images. These anatomical landmarks should be evaluated carefully during preoperative planning.

[The retromolar canal (foramen retromolare). Overview and case report]

A 19-year old female patient was referred for removal of her wisdom teeth. The panoramic radiograph showed bilateral retromolar canals in the mandible. Since the retromolar canal is neglected in anatomical textbooks and is rarely documented in scientific publications, the case prompted us to perform further diagnostic examinations with informed consent by the patient. A limited cone beam computed tomography was made and, during the surgical removal of the patient's lower right wisdom tooth, a biopsy of the soft tissue bundle emerging from the retromolar foramen was taken. In accordance with the literature, the histology revealed myelinated nerve fibers, small arteries and venules. The limited data available in the literature about the retromolar canal report that this bony canal may convey an aberrant buccal nerve. In addition, sensory nerve fibers entering the retromolar canal from above and branching to the mandibular molars may evade a block anesthesia at the mandibular foramen. These rare anatomic features may explain why the elements of the retromolar canal account for failures of mandibular block anesthesia or postsurgical sensitivity changes in the supply area of the buccal nerve.

Vascular lesions of the maxillofacial region: a case report and review of the literature

There is frequently lack of understanding and apprehension among dental practitioners treating patients with vascular lesions of the oral and maxillofacial region. Arteriovenous malformations are rare lesions which can easily be misdiagnosed yet produce the very dramatic clinical presentation of severe life threatening oral bleeding. Much of this apprehension likely stems from a lack of understanding of these anomalies, including lesion behavior/ characteristics, clinical work-up, and treatment paradigms. A comprehensive, in depth review of the full spectrum of vascular lesions of the maxillofacial complex is beyond the scope of this review. The purpose of this article is to provide a comprehensive review of the diagnosis, treatment, and risks associated with these complex vascular anomalies and provide a case report. In 1982, Mulliken and Glowacki published a landmark article proposing characterization of vascular defects based on biologic and pathologic differences. Their work differentiated between two major categories of vascular lesions: hemangiomas and vascular malformations. Different categories, names, and treatment options have been advocated over the years with multiple outcomes. They can occur in various areas throughout the body, with 60 percent being located in the head and neck. The true mechanism of pathogenesis of vascular anomalies is still unclear. Embolization and surgery is often combined for extended cases to improve their facial contour and oral function. We present the case of a 29-year-old female that is 36 weeks pregnant and presented to University Hospital after having significant bleeding from her oral cavity. She was found to have a gingival lesion associated with a radiolucency in the right posterior mandible. During her stay she had an episode of acute bleeding that required an emergent exploration, embolization, and resection secondary to an Arteriovenous Malformation associated with the Inferior Alveolar Artery. We will discuss the presentation, treatment provided, and outcome of this patient. We will also cover the diverse group of congenital vascular malformations, and their pathologic, clinical, and radiologic diagnosis and management.

Management of vascular malformations of the mandible and maxilla

OBJECTIVES/HYPOTHESIS

Vascular malformations involving the mandible and maxilla are uncommon, and no uniform treatment of these lesions has been defined. The purpose of the study was to evaluate the effectiveness of treating vascular malformations with a multidisciplinary approach and emphasis on endovascular therapy.

STUDY DESIGN

Retrospective chart review of patients.

METHODS

The treatment of 31 patients (13 male and 18 female patients) with mandibular and/or maxillary vascular malformations presenting between 1979 to 2001 was reviewed.

RESULTS

Thirteen patients (42%) presented with mandibular vascular malformations, and an equal number of patients had maxillary vascular malformations. Five patients had involvement of both the mandible and maxilla. Twenty-six patients (84%) had adjacent soft tissue extension, whereas five patients had a vascular malformation isolated either to the mandible (four cases) or maxilla (one case). Twenty-six cases consisted of arterial vascular malformations, and five patients had venous and capillary types. Twenty-five patients (81%) were treated with embolization only, whereas six patients (19%) underwent combined embolization and surgical resection. "Cure" was defined as the complete eradication of disease or permanent resolution of symptoms with complete devascularization by embolization. The cure rates were 70% for mandibular malformations and 46% for maxillary lesions. None of the combined maxillary/mandibular lesions were cured, but all achieved improvement or stabilization of symptoms. The follow-up range was 1 to 22 years with an average follow-up of 6.7 years.

CONCLUSION

The location and extent of vascular malformations dictate the treatment and resulting success. Endovascular therapy alone can effectively "cure" most mandibular and maxillary vascular malformations with limited soft tissue involvement. Extensive vascular malformations can be stabilized with control of symptoms, but eradication of the vascular malformation is unlikely even with combined surgery and embolization.

Face skin necrosis following embolization for arteriovenous malformations: a case report

INTRODUCTION

Arteriovenous malformations (AVMs) are rare in the oral and maxillofacial regions.

DISCUSSION

AVMs may induce severe complications such as uncontrollable bleeding. Superselective intra-arterial embolization is an effective method for this bleeding that is refractory to conservative treatment. Arterial embolization may cause ischemic complications. We report the case of a patient who developed face skin necrosis following bilateral facial artery embolization.

Anatomical variation of mental foramen. A case report

We have reported a case of triple mental foramina at the right side of the premolar region, which was discovered during reposition and ostheosynthesis of a mandible fracture. A review of the literature, was performed which disclosed no previous clinical cases reported but an incidence of 1.2% of triple foramina after investigating dry skulls or radiographics. The discussion stresses the importance of adequate preoperative radiological examination in the clinical situation especially when closed surgery is planned.

[Partial allotransplantation of the face including the mandible: a feasibility study]

OBJECTIVE

Facial grafts are useful in that they allow the repair of severe facial defects in one step in contrast to the actual available techniques which require staged procedures with limited cosmetic and functional results. The aim of our study was to determine whether it would be possible to include part of the mandible in a partial allotransplant of the face.

MATERIAL AND METHODS

An anatomical study on the arterial and venous vascularisation of the face and the mandible was performed on 7 heads. Then nine heads were used to describe an anatomical model of harvesting two-thirds of the lower face.

RESULTS

The study determined that a graft could be viable with a facial artery, inferior dental artery and two veins facial. Thus, a reliable method for harvesting hemi-mandible and total mandible is developed. The average sampling time was 4 hours and thirty minutes. Harvesting a total mandibular graft was more tedious because of the loss of joint laxity caused by the absence of mandibular osteotomy.

CONCLUSION

Partial allotransplant of the face including the mandible is feasible. In such transplantations, functional difficulties related to the temporo-mandibular joint and orthognathic problems need to be overcome.

Evaluation of vascular endothelial growth factor (VEGF) in interradicular bone marrow in olpadronate treated animals

Vascular endothelial growth factor (VEGF) is a protein that increases vascular permeability and induces the proliferation, migration and survival of endothelial cells. Bisphosphonates (BPs) are antiresorptive drugs that are widely used in the treatment of bone metabolism diseases and bone metastases. Since 2003, cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) have been reported. Few papers explain the mechanisms that induce BRONJ; some authors mention alterations in bone remodelling and a certain antiangiogenic effect of BPs. The aim of this study is to evaluate the expression of VEGF in bone marrow cells and the number of blood vessels and area occupied by them in animals treated with the BP sodium olpadronate (OPD). We used 16 Wistar rats, 60 days old, divided into two groups, experimental (OPD) and control. The OPD group received 0.3 mg/kg/week intraperitoneal OPD for 5 weeks. The control group received an equivalent intraperitoneal volume of physiological saline solution. After euthanasia, hemimandibles were processed and mesio-distal histological sections of the first molar were prepared. Sections were stained with hematoxylin-eosin (HE), immunohistochemical detection of VEGF was performed (sc-7269) and the following histomorphometric parameters were evaluated: In HE-stained sections--number of blood vessels per sq. mm. and percentage (%) of area occupied by blood vessels in relation to total area evaluated; in sections with immunohistochemical detection of VEGF--number of VEGF+ bone marrow cells per sq. mm. Data underwent statistical analysis. Number of blood vessels/mm2 was significantly lower in the OPD group (OPD: 92 +/- 16;

CONTROL

140 +/- 31; p < 0.05) and % vascular area/total area evaluated showed no significant difference (OPD: 15.6 +/- 6.1;

CONTROL

10.2 +/- 4.2). Number of VEGF+ cells/mm2 was lower in the OPD group than in the control group, with statistically significant differences (OPD: 7804.8 +/- 597;

CONTROL

13187.6 +/- 894; p < .001). The results of this study suggest that monosodium olpadronate has an antiangiogenic effect. Further studies are needed to reveal its potential as an antitumor agent and its connection with the onset of BRONJ.

[Haematoma of the floor of the mouth following implant surgery]

A patient experienced severe bleeding in the floor of the mouth as a consequence of the placement of 2 implants in the resorbed anterior segment of the mandible. The resulting swelling of the floor of the mouth caused a life-threatening obstruction of the trachea. The patient was urgently transferred to a hospital. Treatment there consisted of the administration of medication and intensive observation. In the literature an intubation or the carrying out of a tracheotomy with possible surgical interventions is also described. The cause lay in damage to the lingual cortical plate of the mandible and trauma of the underlying vascular structures. Especially the cuspid and bicuspid regions are vulnerable because of the often seen lingual concavity in the processus alveolaris. Serious atrophy of the processus alveolaris is also a predisposition. To reduce the probability of such complications knowledge of the local anatomy, good clinical inspection and various radiographic evaluations are important. In case of obstruction of the trachea it is of vital importance to immediately transport the patient to the nearest hospital for further treatment.

Vertical ridge augmentation using an equine block infused with recombinant human platelet-derived growth factor-BB: a histologic study in a canine model

This preclinical study evaluated the efficacy of purified recombinant human platelet-derived growth factor (rhPDGF-BB), combined with a novel equine hydroxyapatite and collagen (eHAC) bone block, in providing vertical bone regeneration in critical-size defects simulating localized mandibular alveolar bone atrophy. In addition, the impact of barrier membrane placement in growth factor-mediated bone regeneration was also studied. Bilateral posterior mandibular defects simulating severe localized bony atrophy were created in 12 adult foxhounds following removal of all four mandibular premolars. Three months later, the defects were grafted as follows: group A: eHAC block alone; group B: eHAC block + collagen membrane; group C: eHAC block + rhPDGF-BB; group D: eHAC block + rhPDGF-BB + membrane. The animals were sacrificed after 5 months and the grafted areas were examined histologically, radiographically, and clinically. Groups A and B (controls) exhibited little to no vertical bone regeneration. Group C demonstrated significant vertical bone regeneration, with dense, well-vascularized bone, high bone-to-implant contact, and accelerated replacement of graft particles with newly formed bone. In group D, with the imposition of a barrier membrane, robust bone regeneration was less evident when compared to group C. As in the first study in this series, the importance of the periosteum as a source of osteoprogenitor cells in growth factor-mediated regenerative procedures is examined.

Ethanol embolization of arteriovenous malformations of the mandible

BACKGROUND AND PURPOSE

Absolute ethanol was reported as an effective embolization of arteriovenous malformations (AVMs), but its use to treat AVMs in the mandible is not yet well established. Here, we present our clinical experience on treatment of mandibular AVMs with absolute ethanol.

MATERIALS AND METHODS

Eight consecutive patients with symptomatic AVMs of the mandible between August 2007 and September 2008 were enrolled in this study group. Among them, 6 patients underwent direct puncture embolization with absolute ethanol combined with coils, 1 patient underwent direct puncture embolization with absolute ethanol only, and the last patient had transarterial embolization with absolute ethanol alone. The use of coils decreased the flow and volume of the nidus, and then absolute ethanol embolization was directed against and obliterated the nidus completely. The procedure was performed with the patients under general anesthesia with nasal intubation, and the vital signs of the patients were constantly monitored during the injection of absolute ethanol. The total amount of absolute ethanol used per session was less than 1 mL/kg of body weight.

RESULTS

A total of 11 ethanol embolizations were performed on 8 patients, including 3 sessions with transarterial microcatheterization and 8 with direct puncture embolization. A venogram and control arteriogram performed immediately after the procedure were both obtained, which documented a significant thrombosis of the lesion in all patients. Follow-up examinations revealed that oral bleeding was controlled, the expansion of the external jugular vein in 5 cases was obliterated, and satisfactory shrinkage of the facial swelling was achieved. Follow-up angiography (mean, 4.2 months) was available in 4 patients, and there was no angiographic recurrence of the lesions. There were 3 cases with minor complications.

CONCLUSIONS

On the basis of our experience, treatment of AVMs in the mandible with absolute ethanol is a feasible, safe, and highly effective method.