Inferior alveolar nerve block obtained maximum anesthetic effect using a small dose of local anesthetic agent, which also has low a complication incidence. Complications of an inferior alveolar nerve block include direct nerve damage, bleeding, trismus, temporary facial nerve palsy, and etc. Among them, the major iatrogenic complication is dental needle fracture. A fragment that disappears into the soft tissue would be hard to remove, giving rise to a legal problem. A 31-year-old woman was referred for the removal of a broken needle, following an inferior alveolar nerve block. Management involved the removal of the needle under local anesthesia with pre- and peri-operative computed tomography scans.
Broken dental needle; Inferior alveolar nerve block; Cone-beam computed tomography; Foreign body migration
Hypoesthesia after an inferior alveolar nerve (IAN) block does not commonly occur, but some cases are reported. The causes of hypoesthesia include a needle injury or toxicity of local anesthetic agents, and the incidence itself can cause stress to both dentists and patients. This case presents a hypoesthesia on mental nerve area followed by IAN block anesthesia with 2% lidocaine. Prescription of steroids for a week was performed and periodic follow up was done. After 1 wk, the symptoms got much better and after 4 mon, hypoesthesia completely disappeared. During this healing period, only early steroid medication was prescribed. In most cases, hypoesthesia is resolved within 6 mon, but being aware of etiology and the treatment options of hypoesthesia is important. Because the hypoesthesia caused by IAN block anesthesia is a mild to moderate nerve injury, early detection of symptom and prescription of steroids could be helpful for improvement of the hypoesthesia.
Hypoesthesia; Inferior alveolar nerve block; Lidocaine; Local anesthetics; Medication
We report a patient with a posterior inferior cerebellar artery (PICA) aneurysm and an incidental facial nerve schwannoma at the cerebellopontine angle (CPA). A 46-year-old woman presented with the sudden onset of a severe headache, nausea, and vomiting. She had no other abnormal neurological symptoms and signs. Computed tomography (CT) showed hemorrhage in the fourth ventricle. Cerebral angiography demonstrated an aneurysm arising from the tonsillomedullary segment of the left PICA. A facial nerve schwannoma was incidentally found as the aneurysm was being clipped. The aneurysm was clipped via a left transcondylar approach. Subsequently, the schwannoma (2 × 3 × 2 mm) was resected from the facial nerve fascicles, and the facial nerve was preserved. Postoperatively, the patient developed mild to moderate dysfunction of the facial nerve (House-Brackmann grade III [H-B III]) but her hearing was intact. Both a facial nerve schwannoma involving the CPA and an aneurysm involving the PICA can be managed through the transcondylar approach. An asymptomatic facial nerve schwannoma can be resected safely with minimal facial nerve dysfunction.
Facial nerve schwannoma; PICA; aneurysm; transcondylar approach
Background and aims
Dentists administer thousands of local anesthetic injections every day. Injection to a highly vascular area such as pterygomandibular space during an inferior alveolar nerve block has a high risk of intravascular needle entrance. Accidental intravascular injection of local anesthetic agent with vasoconstrictor may result in cardiovascular and central nervous system toxicity, as well as tachycardia and hypertension. There are reports that indicate aspiration is not performed in every injection. The aim of the present study was to assess the incidence of intravascular needle entrance in inferior alveolar nerve block injections.
Materials and methods
Three experienced oral and maxillofacial surgeons performed 359 inferior alveolar nerve block injections using direct or indirect techniques, and reported the results of aspiration. Aspirable syringes and 27 gauge long needles were used, and the method of aspiration was similar in all cases. Data were analyzed using t-test.
15.3% of inferior alveolar nerve block injections were aspiration positive. Intravascular needle entrance was seen in 14.2% of cases using direct and 23.3% of cases using indirect block injection techniques. Of all injections, 15.8% were intravascular on the right side and 14.8% were intravascular on the left. There were no statistically significant differences between direct or indirect block injection techniques (P = 0.127) and between right and left injection sites (P = 0.778).
According to our findings, the incidence of intravascular needle entrance during inferior alveolar nerve block injection was relatively high. It seems that technique and maneuver of injection have no considerable effect in incidence of intravascular needle entrance.
Inferior alveolar nerve; injection; local anesthesia
Idiopathic facial nerve palsy (Bell's palsy) is a very common condition that affects active population. Despite its generally benign course, a minority of patients can remain with permanent and severe sequelae, including facial palsy or dyskinesia. Hypoglossal to facial nerve anastomosis is rarely used to reinnervate the mimic muscle in these patients. In this paper, we present a case where a direct partial hypoglossal to facial nerve transfer was used to reinnervate the upper and lower face. We also discuss the indications of this procedure.
A 53-year-old woman presenting a spontaneous complete (House and Brackmann grade 6) facial palsy on her left side showed no improvement after 13 months of conservative treatment. Electromyography (EMG) showed complete denervation of the mimic muscles. A direct partial hypoglossal to facial nerve anastomosis was performed, including dissection of the facial nerve at the fallopian canal. One year after the procedure, the patient showed House and Brackmann grade 3 function in her affected face.
Partial hypoglossal–facial anastomosis with intratemporal drilling of the facial nerve is a viable technique in the rare cases in which severe Bell's palsy does not recover spontaneously. Only carefully selected patients can really benefit from this technique.
Bell's palsy; facial palsy; hypoglossal–facial anastomosis; nerve transfer
The conventional inferior alveolar nerve block (conventional technique) has potential risks of neural and vascular injuries. We studied a method of inferior alveolar nerve block by injecting a local anesthetic solution into the pterygomandibular space anterior to the mandibular foramen (anterior technique) with the purpose of avoiding such complications. The insertion angle of the anterior technique and the estimation of anesthesia in the anterior technique were examined. The predicted insertion angle measured on computed tomographic images was 60.1 +/- 7.1 degrees from the median, with the syringe end lying on the contralateral mandibular first molar, and the insertion depth was approximately 10 mm. We applied the anterior technique to 100 patients for mandibular molar extraction and assessed the anesthetic effects. A success rate of 74% was obtained. This is similar to that reported for the conventional technique but without the accompanying risks for inferior alveolar neural and vascular complications.
Despite of various neurophysiologic monitoring methods under general anesthesia, functional mapping at awake state during brain surgery is helpful for conservation of speech and motor function. But, awake craniotomy in children or adolescents is worrisome considering their emotional friabilities. We present our experience on anesthetic management for awake craniotomy in an adolescent patient. The patient was 16 years old male who would undergo awake craniotomy for removal of brain tumor. Scalp nerve block was done with local anesthetics and we infused propofol and remifentanil with target controlled infusion. The patient endured well and was cooperative before scalp suture, but when surgeon sutured scalp, he complained of pain and was suddenly agitated. We decided change to general anesthesia. Neurosurgeon did full neurologic examinations and there was no neurologic deficit except facial palsy of right side. Facial palsy had improved with time.
Adolescent; Awake craniotomy; Nerve block
In a double-blind study conducted in 112 patients undergoing removal of four impacted third molar teeth, etidocaine hydrochloride 1.5% solution with epinephrine 1:200,000 and lidocaine hydrochloride 2.0% solution with epinephrine 1:100,000 were used, one on each side of the face, to produce inferior alveolar nerve block, infiltration anesthesia of the maxillary tooth and hemostasis of the mucoperiosteum around each tooth.
Surgically adequate anesthesia was rapidly produced by both agents but the duration of action of etidocaine was longer than that of lidocaine as reflected in more prolonged numbness of the lip and delayed onset of pain. Moreover, after etidocaine treatment fewer patients reported severe pain as the local anesthesia receded. No adverse local or systemic effects were observed in, or reported by, any of the patients.
Cephalic tetanus is defined as a combination of trismus and paralysis of one or more cranial nerves. Cranial nerves III, IV, VI, VII, and XII may be affected, but the facial nerve is most frequently implicated. A 64-year-old female visited hospital for left ptosis followed by facial palsy after a left forehead abrasion in a car accident. At nine days post injury, left ptosis developed, left facial palsy developed twelve days post injury, and at fifteen days post injury, trismus and dysphagia developed. The following day, there was progression of symptoms to generalized tetanus, such as dyspnea and generalized rigidity. Videofluoroscopic swallow study showed penetration and aspiration. We report a case of cephalic tetanus with ptosis, facial palsy, and dysphagia, which progressed to generalized tetanus.
Cephalic tetanus; Ptosis; Facial palsy
Dental procedures in the maxilla typically require multiple injections and may inadvertently anesthetize facial structures and affect the smile line. To minimize these inconveniences and reduce the number of total injections, a relatively new injection technique has been proposed for maxillary procedures, the anterior and middle superior alveolar (AMSA) nerve block, which achieves pulpal anesthesia from the central incisor to second premolar through palatal approach with a single injection. The purpose of this article is to provide background information on the anterior and middle superior alveolar nerve block and demonstrate its success rates of pulpal anesthesia using the conventional syringe.
Materials and Methods:
Thirty Caucasian patients (16 men and 14 women) with an average age of 22 years-old, belonging to the School of Dentistry of Los Andes University, were selected. All the patients received an AMSA nerve block on one side of the maxilla using the conventional syringe, 1 ml of lidocaine 2% with epinephrine 1:100.000 was injected to all the patients.
The AMSA nerve block obtained a 66% anesthetic success in the second premolar, 40% in the first premolar, 60% in the canine, 23.3% in the lateral incisor, and 16.7% in the central incisor.
Because of the unpredictable anesthetic success of the experimental teeth and variable anesthesia duration, the technique is disadvantageous for clinical application as the first choice, counting with other techniques that have greater efficacy in the maxilla. Although, anesthetizing the teeth without numbing the facial muscles may be useful in restorative dentistry.
AMSA nerve block; dental anesthesia; local anesthesia; maxillary nerve
To examine the neurophysiologic status in patients with idiopathic facial nerve palsy (Bell's palsy) and Ramsay Hunt syndrome (herpes zoster oticus) within 7 days from onset of symptoms, by comparing the amplitude of compound muscle action potentials (CMAP) of facial muscles in electroneuronography (ENoG) and transcranial magnetic stimulation (TMS).
The facial nerve conduction study using ENoG and TMS was performed in 42 patients with Bell's palsy and 14 patients with Ramsay Hunt syndrome within 7 days from onset of symptoms. Denervation ratio was calculated as CMAP amplitude evoked by ENoG or TMS on the affected side as percentage of the amplitudes on the healthy side. The severity of the facial palsy was graded according to House-Brackmann facial grading scale (H-B FGS).
In all subjects, the denervation ratio in TMS (71.53±18.38%) was significantly greater than the denervation ratio in ENoG (41.95±21.59%). The difference of denervation ratio between ENoG and TMS was significantly smaller in patients with Ramsay Hunt syndrome than in patients with Bell's palsy. The denervation ratio of ENoG or TMS did not correlated significantly with the H-B FGS.
In the electrophysiologic study for evaluation in patients with facial palsy within 7 days from onset of symptoms, ENoG and TMS are useful in gaining additional information about the neurophysiologic status of the facial nerve and may help to evaluate prognosis and set management plan.
Bell palsy; Herpes zoster oticus; Transcranial magnetic stimulation; Prognosis
Periodontal procedures require injection of local anesthetic solution to avoid patient discomfort. Multiple injections are required to anesthetize the anterior maxilla in the region of the premolars to incisors. Anterior middle superior alveolar nerve block is a single palatal injection technique, which anesthetizes the facial and palatal gingiva as well as pulp in the region of the maxillary central incisors to the premolars without any collateral facial anesthesia. This case series presents the application of the anterior middle superior alveolar nerve block in periodontal therapy.
Anterior middle superior alveolar nerve block; local anesthesia; pain management; scaling and root planing; periodontal surgery
The strict definition of the Ramsay Hunt syndrome is peripheral
facial nerve palsy accompanied by an erythematous vesicular rash on the
ear (zoster oticus) or in the mouth. J Ramsay Hunt, who described
various clinical presentations of facial paralysis and rash, also
recognised other frequent symptoms and signs such as tinnitus, hearing
loss, nausea, vomiting, vertigo, and nystagmus. He explained these
eighth nerve features by the close proximity of the geniculate ganglion
to the vestibulocochlear nerve within the bony facial canal. Hunt's
analysis of clinical variations of the syndrome now bearing his name
led to his recognition of the general somatic sensory function of the
facial nerve and his defining of the geniculate zone of the ear. It is
now known that varicella zoster virus (VZV) causes Ramsay Hunt syndrome.
Compared with Bell's palsy (facial paralysis without rash),
patients with Ramsay Hunt syndrome often
have more severe paralysis at onset and are less likely to recover
completely. Studies suggest that treatment with prednisone and
acyclovir may improve outcome, although a prospective randomised
treatment trial remains to be undertaken. In the only prospective study
of patients with Ramsay Hunt syndrome, 14% developed vesicles after
the onset of facial weakness. Thus, Ramsay Hunt syndrome may initially
be indistinguishable from Bell's palsy. Further, Bell's palsy is
significantly associated with herpes simplex virus (HSV) infection. In
the light of the known safety and effectiveness of antiviral drugs
against VZV or HSV, consideration should be given to early treatment of
all patients with Ramsay Hunt syndrome or
Bell's palsy with a 7-10 day course of famciclovir (500 mg, three
times daily) or acyclovir (800 mg, five times daily), as well as oral
prednisone (60 mg daily for 3-5 days).
Finally, some patients develop peripheral facial paralysis
without ear or mouth rash, associated with either a fourfold rise in
antibody to VZV or the presence of VZV DNA in auricular skin, blood
mononuclear cells, middle ear fluid, or saliva. This indicates that a
proportion of patients with "Bell's palsy" have
Ramsay Hunt syndrome zoster sine herpete. Treatment
of these patients with acyclovir and prednisone within 7 days of onset
has been shown to improve the outcome of recovery from facial palsy.
Introduction. Wegener's granulomatosis belongs to a group of systemic vasculitis diseases, which is characterized by necrotizing vasculitis and presence of granulomas. In a lot of cases, the first symptoms of the disease are observed in the head and neck region, but the bilateral facial nerve palsy occurs very rarely. Objective. The objective of our report was to describe the unusual course of Wegener's granulomatosis with the bilateral facial nerve paralysis, which subsided after application of steroids and immunosuppressive therapy in combination with surgical treatment. Results and Conclusions. Hearing loss may precede other symptoms in Wegener's granulomatosis. Ear pain and otorrhea may suggest the diagnosis of bacterial purulent otitis media and delay the proper diagnosis. In the presented case, considering the clinical course, it was necessary to apply both pharmacological and surgical treatments.
Intraoral local anesthesia is essential for delivering dental care. However, it is often perceived by some patients as the most painful and in some instances as the only painful part of the treatment, leading in extreme cases to avoidance of dental care. The present study measured the variables of pain, pressure, and discomfort caused by 4 commonly used local anesthesia injections: local infiltration, mental nerve block, inferior alveolar nerve block, and periodontal ligament injections. Patients were asked to grade pain, discomfort, and pressure on a visual analog scale as associated with needle insertion, operator finger position in the mouth, and pressure at injection. The inferior alveolar injection was graded to be the most painful followed by periodontal ligament and then mental nerve block injections. The periodontal ligament injections yielded the highest pressure scores. The inferior alveolar block injection yielded significantly more discomfort than local infiltration and mental nerve block injections when comparing finger and needle position. Local infiltration in the anterior maxillary region yielded the highest needle insertion and finger position discomfort scores. The present study suggests that the dental operator should be aware of local anesthesia injection pain, pressure, and discomfort together with efficacy of technique.
Local anesthesia; Oral anesthesia; Injection pain
The purpose of this prospective, randomized, double-blind study was to determine the anesthetic efficacy of a buffered lidocaine with epinephrine solution compared to a combination buffered lidocaine with epinephrine plus hyaluronidase solution in inferior alveolar nerve blocks. Thirty subjects randomly received an inferior alveolar nerve block using 1 of the 2 solutions at 2 separate appointments using a repeated-measures design. Mandibular anterior and posterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive readings of 80 were obtained. A postoperative survey was used to measure pain and trismus. The results demonstrated 100% of the subjects had profound lip numbness with both solutions for inferior alveolar nerve blocks. The anesthetic success rates for individual teeth ranged from 20 to 80%. There were no significant differences (P > .05) between the 2 solutions. However, the combination lidocaine/hyaluronidase solution resulted in a significant increase in postoperative pain and trismus. It was concluded that adding hyaluronidase to a buffered lidocaine solution with epinephrine did not statistically increase the incidence of pulpal anesthesia in inferior alveolar nerve blocks and, because of its potential tissue damaging effect, it should not be added to local anesthetic solutions for inferior alveolar nerve blocks.
We report a case of an 18-year-old male who presented with watering and inability to close the left eye completely since 6 months and inability to move both eyes outward and to close the mouth since childhood. Ocular, facial, and systemic examination revealed that the patient had bilateral complete lateral rectus and bilateral incomplete medial rectus palsy, left-sided facial nerve paralysis, thickening of lower lip and inability to close the mouth, along with other common musculoskeletal abnormalities. This is a typical presentation of Moebius syndrome which is a very rare congenital neurological disorder characterized by bilateral facial and abducens nerve paralysis. This patient had bilateral incomplete medial rectus palsy which is suggestive of the presence of horizontal gaze palsy or occulomotor nerve involvement as a component of Moebius sequence.
Bilateral medial rectus palsy; facial diplegia; Moebius sequence
Background and aims
Current infiltration techniques for achieving anesthesia in dental procedures are not applicable in posterior mandibular region because of its dense cortical bone. The aim of this study was to evaluate the efficacy of a specific infiltration anesthesia in posterior mandibular teeth instead of inferior alveolar nerve block for restorative procedures.
Materials and methods
Crestal anesthesia (CA) was assessed both clinically and by computed tomography scan for its efficacy and side effects. A combination of an opaque material (Ultravist) and 2% lidocaine was used to trace the anesthetic solution. The combination was primarily injected in the gingival tissue of rabbit and was followed-up regularly for two weeks to assess any possible injury. After confirming its safety, a combination of these materials was injected to volunteers to assess efficacy and diffusion route. A total of 154 patients (77 female, 77 male) with matched bilateral posterior teeth in mandible were selected randomly and an IANB and CA were performed randomly and separately in different sessions for the contra lateral teeth. The onset of anesthesia, anesthesia duration, pain, blood pressure, pulse rate, and consumed volume of anesthetic solution was recorded for each technique. Data were analyzed using paired t-test.
There were no significant differences in clinical attachment loss, pocket depth, bone level, plaque index, and free gingival margin between the two flaps (p>0.05).
CA could be considered as a reliable and safe primary injection in posterior mandibular teeth for restorative treatments.
Crestal anesthesia; CT scan; inferior alveolar nerve block
Möbius syndrome is a heterogeneous congenital disorder that is linked to bilateral palsies of the cranial nerves VI and VII, resulting in congenital facial paralysis sometimes associated with impaired ocular abduction.
We present the case of a 44-year-old woman with Möbius syndrome and inferior recurrent keratitis secondary to scleral show in both eyes. We decided to use a cartilage graft from the ear in the inferior eyelid to avoid eyelid retraction and scleral show.
Patients with Möbius syndrome have a severe dysfunction of their facial mimic. Their treatment must be individualized, depending on their age, clinical examination and symptoms.
Möbius syndrome; Eyelid dysfunction; Inferior recurrent keratitis; Scleral show
A 34-year-old Chinese woman was admitted to the labour suite for induction of labour. She had no history of hypertension, vascular disease or coagulapathy. She was induced for less fetal movement at 38 weeks of gestation. Labour progressed smoothly, but immediately after delivery the patient had symptoms of facial neurological deficit, slurred speech and heaviness in the left side of the body. After completion of the third stage of labour, her condition soon deteriorated with left-sided facial palsy and left-sided dense hemiplegia. The patient was then transferred to the intensive care unit where an urgent CT scan was arranged for her. She was diagnosed as a case of right-sided stroke with dense left-sided hemiplegia and left facial palsy. She was placed under the care of the neurosurgical team for 2 weeks and was discharged on regular physiotherapy treatment. She had completely recovered 6 months later.
The most common technique to anesthetize mandibular primary teeth is inferior alveolar (I.A) nerve block injection which induces a relatively sustained anesthesia and in turn may potentially traumatize soft-tissues. Therefore, the need of having an alternative technique of anesthesia with a shorter term but the same efficacy is reasonable. The aim of this study was a comparison of the efficacy of two anesthetic techniques of mandibular primary first molar.
Materials and Methods:
In this randomized crossover clinical trial, 40 children with ages ranged from 5 years to 8 years whose mandibular primary first molars were eligible for pulpotomy, were selected and divided randomly into two groups. The right and left mandibular first molars of group A were anesthetized with infiltration and I. A nerve block techniques in the first and second sessions respectively. The left and right mandibular first molars of group B were anesthetized with I.A nerve block and infiltration techniques in the first and second sessions respectively. The severity of pain were measured and recorded according to sound-eye-motor scale by a certain person. Data was analyzed using Wilcoxon Signed Rank and Mann-Whitney U tests (P > 0.05).
The severity of pain was lower in infiltration technique versus I.A nerve block. There were no significant differences between the severities of pain on pulpal exposure of two techniques.
It seems that infiltration technique is more favorable to anesthetize the mandibular primary first molar compared to I.A nerve block.
Anesthetics; local/administration; nerve block/methods; pain measurement; pulpotomy/methods
To investigate the correlation between gadolinium enhanced magnetic resonance image (MRI) results and surgical findings of facial nerves in Bell's palsy and Ramsay Hunt syndrome.
Materials and Methods
From 1995 to 2004, MRI was performed on 13 patients with Bell's palsy or Ramsay Hunt syndrome, who were offered with surgical decompression of the facial nerve through the middle cranial fossa approach. Gadolinium enhanced MRI was performed on all patients and the enhancement of the facial nerve was evaluated by radiology specialists. Operative findings including the degree of the facial nerve segment swelling were examined. Furthermore, the time interval from the onset of palsy to surgery was evaluated.
Swelling of facial nerve segments was found in patients with enhanced facial nerves from MRI. The swelling of the facial nerve in the labyrinthine segment in particular was identified in all patients with enhanced labyrinthine segments in MRI. The intraoperative swelling of geniculate ganglion of facial nerve was found in 78% of patients with enhanced facial segment in MRI (p = 0.01). The intraoperative swelling of tympanic segment was observed from fourth to ninth weeks after the onset of palsy.
MRI enhancement of facial nerves in Bell's palsy and Ramsay Hunt syndrome is associated with the extent of intratemporal lesions of facial nerves, especially in the labyrinthine segment.
Bell's palsy; herpes zoster oticus; MRI; facial nerve
This comparative study using 20 healthy volunteers evaluated the anesthetic efficacy of 4% articaine in association with 2 different concentrations of epinephrine, 1:200,000 (G1) and 1:100,000 (G2). The first premolars were tested with a pulp tester to verify the anesthesia induced by the inferior alveolar nerve block. The following parameters were measured: period of latency (PL; interval between the end of anesthetic injection and absence of response to the maximum output--80 reading--of the pulp tester); complete pulpal anesthesia (CPA; period in which the subject had no response to maximal output of the pulp tester 80 reading); partial anesthesia (PA; interval between the first reading below 80 and the return to basal levels); and the anesthesia of the soft tissues (AST; period of time from onset of anesthesia until the return to normal sensation of the lip). The Wilcoxon test (alpha = 0.05) was used to analyze the data. No significant difference was found regarding PL (P = .47), CPA (P = .88), PA (P = .46), and AST (P = .85). The results indicated that both solutions presented the same clinical effectiveness in blocking the inferior alveolar nerve.
Isolated facial nerve palsy usually manifests as Bell's palsy. Lacunar infarct involving the lower pons is a rare cause of solitary infranuclear facial paralysis. The present unusual case is one in which the patient appeared to have Bell's palsy but turned out to have a pontine infarct.
A 47-year-old Asian Indian man with a medical history of hypertension presented to our institution with nausea, vomiting, generalized weakness, facial droop, and slurred speech of 14 hours' duration. His physical examination revealed that he was conscious, lethargic, and had mildly slurred speech. His blood pressure was 216/142 mmHg. His neurologic examination showed that he had loss of left-sided forehead creases, inability to close his left eye, left facial muscle weakness, rightward deviation of the angle of the mouth on smiling, and loss of the left nasolabial fold. Afferent corneal reflexes were present bilaterally. MRI of the head was initially read as negative for acute stroke. Bell's palsy appeared less likely because of the acuity of his presentation, encephalopathy-like imaging, and hypertension. The MRI was re-evaluated with a neurologist's assistance, which revealed a tiny 4 mm infarct involving the left dorsal aspect of the pons. The final diagnosis was isolated facial nerve palsy due to lacunar infarct of dorsal pons and hypertensive encephalopathy.
The facial nerve has a predominant motor component which supplies all muscles concerned with unilateral facial expression. Anatomic knowledge is crucial for clinical localization. Bell's palsy accounts for around 72% of facial palsies. Other causes such as tumors and pontine infarcts can also present as facial palsy. Isolated dorsal infarct presenting as isolated facial palsy is very rare. Our case emphasizes that isolated facial palsy should not always be attributed to Bell's palsy. It can be a presentation of a rare dorsal pontine infarct as observed in our patient.
We studied the spread of local anesthetic solution in the inferior alveolar nerve block by the injection of local anesthetic solution into the pterygomandibular space anterior to the mandibular foramen (anterior technique). Seventeen volunteers were injected with 1.8 mL of a mixture containing lidocaine and contrast medium utilizing the anterior technique. The course of spread was traced by fluoroscopy in the sagittal plane, and the distribution area was evaluated by lateral cephalograms and horizontal computed tomography. The results indicate that the contrast medium mixture spreads rapidly in the pterygomandibular space to the inferior alveolar nerve in the subjects who exhibited inferior alveolar nerve block effect. We concluded that the anesthetic effect due to the anterior technique was produced by the rapid distribution of anesthetic solution in the pterygomandibular space toward the mandibular foramen, and individual differences in the time of onset of analgesia may be due to differences in the histologic perineural tissues.