Mandibular Subluxation Research Articles

Mandibular Subluxation for Distal Cervical Exposure of the Internal Carotid Artery

Surgical access to the distal segment of the cervical internal carotid artery (ICA) is a challenge because of the limited exposure imposed by bony structures and concern regarding cranial nerve and major vasculature injury. Our objective is to quantify the additional exposure of the distal cervical ICA obtained with mandibular subluxation (MS) compared with maneuvers that do not mobilize the mandible. Thirty dissections of the cervical ICA and common carotid artery bifurcation were performed on fresh cadavers. The length of the ICA exposure was measured from the carotid bifurcation to the most distally exposed ICA after sectioning the posterior belly of the digastric and stylohyoid muscles, removal of the styloid process, and MS. After MS, a 5.52 +/- 1.00 cm mean exposure of the cervical ICA was obtained. Comparison between the second and third measures revealed an average additional exposure of the ICA of 0.77 cm, corresponding to an additional 16.2% (P < .001). Neck length, sex, and age showed no correlation with the ICA exposure. MS provided an additional exposure of the distal segment of the cervical ICA and may be useful in selected cases to improve access. However, staged maneuvers should be used, and the need for MS depends on the level and extension of the lesion.

Large Symptomatic Carotid Body Tumor Resection Aided by Preoperative Embolization and Mandibular Subluxation

Carotid body tumors (CBT) are rare and usually benign neoplasms (60%-90%), originating from the mesoderm and neural ectoderm. In view of the extensive and unrelenting growth of unresected CBT, encasing vital neurovascular structures, and the significant incidence of malignancy (> or = 10%), surgical excision is the standard treatment of choice. Despite progress in CBT imaging and surgical technique, cranial nerve deficit, stroke, and death continue to affect 10% to 40% of patients undergoing curative surgical resection, particularly in large tumors proximal to the skull base. In such cases, CBT shrinkage by preoperative embolization, improved surgical access utilizing mandibular subluxation, and electroencephalographic monitoring combined with meticulous surgical technique may enable curative tumor resection, without prohibitive morbidity. In light of associated disability, preoperative acknowledgment of the ever-present substantial risk of cranial nerve injury cannot be overemphasized. We report on a patient with a large symptomatic CBT treated surgically with the aid of mandibular subluxation and preoperative embolization.

Mandibular subluxation and stabilization for access in distal carotid endarterectomy

J Oral Maxillofac Surg 61:406-408, 2003

The unexpected difficult airway and lingual tonsil hyperplasia: a case series and a review of the literature.

An unexpected difficult intubation occurs because physical examination of the airway is imperfect in predicting it. Lingual tonsil hyperplasia (LTH) is one risk factor for an unanticipated failed intubation that is not detectable during a routine oropharyngeal examination. The authors attempted to determine the incidence of LTH in unanticipated failed intubation in patients subjected to general anesthesia. Thirty-three patients with unanticipated failed intubation via direct laryngoscopy were subjected to airway examinations and fiberoptic pharyngoscopy to determine the cause(s) of failure. Mouth opening, mandibular subluxation, head extension, thyromental distance, and Mallampati airway class were recorded. Fiberoptic pharyngoscopy was then performed to evaluate the base of the tongue and valleculae. Of these 33 patients, none had an airway examination that suggested a difficult intubation. The lungs of 12 patients were difficult to ventilate by mask. In 15 patients, airway measurements were within normal limits with Mallampati class of I or II. Ten patients had a Mallampati class III airway, 6 associated with obesity and 5 with mildly limited head extension. Among the 5 morbidly obese patients, most of the weight was distributed on the lower trunk and body. The 3 remaining patients had a thyromental distance of 6 cm or less but otherwise had a normal airway examination. The only finding common to all 33 patients was LTH observed on fiberoptic pharyngoscopy. Lingual tonsil hyperplasia can interfere with rigid laryngoscopic intubation and face mask ventilation. Routine physical examination of the airway will not identify its presence. The prevalence of LTH in adults and the extent of its contribution to failed intubation is unknown.

Vertical Ramus Osteotomy Allows Exposure of the Distal Internal Carotid Artery to the Base of the Skull

Exposure of the distal internal carotid artery (ICA) above the level of the second cervical vertebra can be difficult and often require maneuvers such as division of the digastric muscle or mandibular subluxation. These techniques increase exposure but may not provide adequate access. We report a series of eight cases in which vertical division of the mandibular ramus provided access of the ICA up to the base of the skull. Over the last 10 years, eight patients underwent vertical ramus osteotomy (VRO) to aid in distal ICA exposure. Preoperative arteriography revealed ICA lesions within 1.5 cm of the skull base. Indications for surgery were compelling and included gunshot wounds to zone III of the neck (n = 2), transient ischemic attack (n = 2), and preocclusive stenosis (n = 4). VRO was performed through a standard vertical neck incision and was created from the depth of the sigmoid notch to the angle of the mandible after elevating the masseter muscle from the bone. Miniature titanium plates were used to reapproximate the mandible after endarterectomy (n = 5), bypass (n = 2), or arterial repair (n = 1). We found that VRO provides reliable exposure of the distal ICA up to the base of the skull. Unlike mandibular subluxation, it requires no pre-incision preparation, thus mandibulotomy can be performed after carotid artery dissection has begun, and may even be avoided. VRO is especially useful when carotid artery pathology unexpectedly extends beyond the usual field of exposure. Work on the carotid artery at the skull base is associated with significant complications and should be reserved for compelling indications.

Mandibular subluxation for distal internal carotid exposure: Technical considerations

Purpose: Carotid endarterectomy (CEA) has become one of the most commonly performed vascular procedures, because of the beneficial outcome it has when compared with medical therapy alone and because of the anatomic accessibility of the artery. In cases of distal carotid occlusive disease, high cervical carotid bifurcation, and some reoperative cases, access to the distal internal carotid artery may limit surgical exposure and increase the incidence of cranial nerve palsies. Mandibular subluxation (MS) is recommended to provide additional space in a critically small operative field. We report our experience to determine and illustrate a preferred method of MS. Methods: Techniques for MS were selected based on the presence or absence of adequate dental stability and periodontal disease. All patients received general anesthesia with nasotracheal intubation before subluxation. Illustrations are provided to emphasize technical considerations in performing MS in 10 patients (nine men and one woman) who required MS as an adjunct to CEA (less than 1% of primary CEAs). Patients were symptomatic (n = 7) or asymptomatic (n = 3) and had high-grade stenoses demonstrated by means of preoperative arteriography. Results: Subluxation was performed and stabilization was maintained by means of: Ivy loop/circumdental wiring of mandibular and maxillary bicuspids/cuspids (n = 7); Steinmann pins with wiring (n = 1); mandibular/maxillary arch bar wiring (n = 1); and superior circumdental to circummandibular wires (n = 1). MS was not associated with mandibular dislocation in any patient. No postoperative cranial nerve palsies were observed. Three patients experienced transient temporomandibular joint discomfort, which improved spontaneously within 2 weeks. Conclusion: Surgical exposure of the distal internal carotid artery is enhanced with MS and nasotracheal intubation. We recommend Ivy loop/circumdental wiring as the preferred method for MS. Alternative methods are used when poor dental health is observed. (J Vasc Surg 1999;30:1116-20.)

Response to Electroconvulsive Therapy in a Quadriplegic Patient

Response to Electroconvulsive Therapy in a Quadriplegic Patient

Management of Carotid Artery Stenosis: A Review

Carotid endarterectomy clearly benefits high stroke-risk patients, but its value for asymptomatic patients is still being debated. If a high exposure is necessary for redo procedures or distal aneurysms, mandibular subluxation and styloidectomy may be required. Perioperative mortality and morbidity are acceptably low. Restenosis occurs in few patients.

Technical Adjuncts in the Treatment of Large Internal Carotid Artery Aneurysms

Aneurysms of the internal carotid artery are dangerous lesions because of thromboembolism and, occasionally, rupture. The aneurysms enlarge slowly but relentlessly, and can also cause permanent pressure damage to nearby cranial nerves. Spontaneous cure by thrombosis is rare, and often is associated with stroke. Repair of the internal carotid artery with an interposition saphenous vein graft is the preferred treatment. Temporary inlying shunts and mandibular subluxation may be required in lesions that are near the base of the skull.

Mandibular subluxation as an adjunct to exposure of the distal internal carotid artery in endarterectomy surgery: Frim DM, Padwa B, Buckley D, et al. J Neurosurg 83:926, 1995

Mandibular subluxation as an adjunct to exposure of the distal internal carotid artery in endarterectomy surgery: Frim DM, Padwa B, Buckley D, et al. J Neurosurg 83:926, 1995

Mandibular subluxation as an adjunct to exposure of the distal internal carotid artery in endarterectomy surgery

The location of the carotid artery bifurcation and the distance atherosclerotic disease extends distally in the internal carotid artery (ICA) are two factors that contribute to the technical difficulty of carotid endarterectomy. When the bifurcation is high (above C-3) or the disease extends distally, standard approaches may not provide adequate exposure for dissection of plaque or for arteriotomy repair. A simple method of mandibular subluxation is described for added exposure of the distal carotid artery. The criteria for use of this method include: a carotid bifurcation at or above C-2; disease extending to within 2 cm of the skull base; and a small-caliber distal ICA lumen with the expectation of a patch graft extending close to the skull base. In dentulous patients, the mandible is subluxed by attaching an intradental wire from the ipsilateral mandibular bicuspid to an intradental wire around the contralateral maxillary bicuspid. In edentulous patients, a wire is placed around the ipsilateral mandible and secured to a wire placed through the anterior nasal spine. The entire preoperative subluxation requires 10 to 15 minutes under anesthesia and an additional 1 to 2 minutes postoperatively to remove the wires. A single skin suture and an absorbable intraoral suture were placed in some edentulous patients. This technique has been evaluated over a 15-month reference period during which 115 carotid endarterectomies were performed. The criteria stated above were met in seven cases (six patients, 6%) and jaw subluxation was performed preoperatively. An additional 1 to 2 cm of distal exposure was obtained by using this technique and endarterectomy proceeded without complication. A slight "shift" of the standard anatomical landmarks occurred due to the movement of the mandible, which was easily recognized. There were no significant postoperative complaints related to the subluxation; specifically, no temporomandibular joint pain, no other postoperative pain, and no tooth damage were encountered. It is concluded that this relatively simple approach to mandibular subluxation provided significant added exposure to the distal ICA without notably increasing operative time. In addition, there was no morbidity and little additional care was needed when compared with other more radical approaches to high carotid artery exposure.

Atypical migratory stomatitis and Munchausen syndrome presenting as periorbital ecchymosis and mandibular subluxation

Stomatitis areata migrans, unlike its analogue on the tongue, migratory glossitis, is not easily recognized and is so uncommon and varied in appearance that it may escape definitive diagnosis. It may be so puzzling to the clinician that the patient's credibility may be questioned. A detailed report of a case is presented in which an atypical migratory stomatitis went undiagnosed. Bizarre patient behavior followed in the form of self-inflicted injury (Munchausen syndrome) as the patient attempted to convince the care providers of the true existence of lesions in order to maintain their interest and to obtain relief from discomfort.

Selection of the approach to the distal internal carotid artery from the second cervical vertebra to the base of the skull

Although several approaches for exposure of distal internal carotid artery lesions have been reported, the precise anatomic levels for which each of these maneuvers are most appropriate have not been well described. Since these techniques may require preoperative preparation, it is useful to determine in advance how much exposure will be needed and to select the most suitable and effective technique. We used anatomic dissection in 12 human cadaver specimens (24 carotid bifurcations) to define the limits of distal internal carotid artery exposure by several commonly advocated methods. The standard anterior approach along the sternocleidomastoid muscle allowed exposure of the internal carotid artery to the level of the upper one third of the second cervical vertebra. The upper limit of this exposure was extended to the middle of the first cervical vertebra by division of the posterior belly of the digastric muscle. Anterior subluxation of the mandible increased the distal exposure of the internal carotid artery to the superior border of the first cervical vertebra. Styloidectomy in combination with the preceding maneuvers extended the exposure an additional 0.5 cm cephalad. Lateral mandibulotomy did not significantly extend exposure beyond that obtained with mandibular subluxation and styloidectomy. Exposure of the internal carotid artery in the 1 cm immediately below the base of the skull required a posterior approach with mastoidectomy.

Distal internal carotid exposure: A simplified technique for temporary mandibular subluxation

Distal internal carotid artery exposure can be technically demanding even for experienced vascular surgeons. Although a variety of techniques have been described to facilitate such exposure, temporary mandibular subluxation has emerged as the simplest and least debilitating approach. Current techniques for maintaining temporary mandibular subluxation during distal internal carotid artery procedures, including maxillomandibular arch bar fixation and circummandibular/transnasal wiring, have been time consuming and associated with complications. Over the last 4 years a new simplified technique of temporary mandibular subluxation fixation has been used in 14 patients requiring distal internal carotid exposure. Indications for operation included extended carotid endarterectomy (8), carotid body tumor excision (2), repair of distal internal carotid artery trauma (2), and repair of postendarterectomy pseudoaneurysm (2). Among patients with healthy teeth, unilateral temporary mandibular subluxation was maintained by interdental wiring from the ipsilateral mandibular bicuspids to the contralateral maxillary bicuspids. In edentulous patients or those with chronic periodontal disease, temporary mandibular subluxation was maintained with diagonal wiring between maxillary and mandibular Steinmann pins. No instances of malocclusion, dental injury, or local infection were observed. Transient postoperative cranial nerve dysfunction was observed in three patients. Transient ipsilateral temporomandibular joint pain occurred in three patients. Two patients developed permanent cranial nerve injuries unrelated to temporary mandibular subluxation. These data suggest that temporary mandibular subluxation by diagonal interdental/Steinmann pin wiring is safe, expeditious, and effective in facilitating exposure of the distal internal carotid artery.

Carotid Endarterectomy in a Patient With Ankylosing Spondylitis—A Case Report

Access to the cervical internal carotid artery may occasionally be limited by the mandible. Management of symptomatic carotid occlusive disease in a pa tient suffering from ankylosing spondylitis is described in which the carotid bifurcation is obscured by the vertical mandibular ramus. The application of technique usually reserved for high internal carotid artery lesions to this situa tion is discussed. In the case reported here, the preferred approach of mandibu lar subluxation allowed successful carotid endarterectomy.

Carotid endarterectomy for high plaques

Seventeen instances of high plaque (plaque extending up to the level of the second cervical vertebra) were encountered out of a total of 454 carotid endarterectomies (3.7 percent). With careful dissection and knowledge of anatomy superior to hypoglossal nerve, carotid endarterectomy was accomplished without resorting to mandibular subluxation or dislocation. There was no operative mortality or perioperative strokes. One patient had perioperative myocardial infarction and another sustained temporary glossopharyngeal nerve dysfunction. High carotid plaques were more common in male patients with bilateral stenoses or contralateral internal carotid occlusion and could be suspected by findings of preoperative carotid arteriography in some instances. In the majority of cases, extension of high plaque in a tongue-shaped manner on the posterior wall of the internal carotid artery was an unexpected finding at the time of carotid endarterectomy.

Mandibular subluxation for high carotid exposure

Twenty-four patients with internal carotid artery lesions extending above the second cervical vertebra underwent mandibular subluxation for additional exposure. The original technique of bilateral arch bar wiring requiring 90 minutes for application has evolved into a circummandibular/transnasal wiring technique requiring approximately 10 minutes. Subluxation of the mandibular condyle 10 to 15 mm anteriorly results in displacement of the mandibular ramus 20 to 30 mm anteriorly. This technique provides a marked increase in exposure of the internal carotid artery up to the base of the skull by transforming a triangular operating field into a rectangular field. The technique is quick, easy to perform, and not associated with objective or subjective temporomandibular joint dysfunction.