Buccal Nerve Trunk Block Anesthetizes the Buccal Mucosa Beyond the Papilla of the Parotid Duct.

PURPOSE: The limited area of anesthesia of the buccal mucosa with concomitant conventional buccal nerve block (conventional BNB) may be involved in failed inferior alveolar nerve block (IANB). The aims of this study were to examine the extent of anesthesia by buccal nerve trunk block (BNTB) and compare the success rates of IANB with BNB. METHODS: This prospective parallel-group randomized single-blinded clinical trial included patients scheduled for removal of a mandibular third molar at the Nippon Dental University Hospital between September 2021 and March 2022. The primary predictor variable was the approach for BNB (BNTB vs conventional BNB). The primary outcome was the extent of tactile sensory loss and anesthesia of the buccal mucosa. The secondary outcomes included onset time and duration of BNBs and the success rate of the IANB with concomitant BNB for third molar extraction, assessed by the proportions of intraoperative pain perception and supplemental infiltration anesthesia. The other study variables were sex, age, and injection side. Comparisons were analyzed by Fisher's exact test or the Mann-Whitney U test. The P value was set to .05. RESULTS: A total of 38 patients (14 male, 24 female) with a mean age of 28.9 years (range, 18 to 67 years) were enrolled, with 19 patients each in the BNTB group and conventional BNB group. The effective tactile sensory loss rates at ∼5 mm above the height of the papilla of the parotid duct of the premolar and molar regions were greater following BNTB (71 and 95%, respectively) than following conventional BNB (37%; P < .01 and 58%; P < .01, respectively). The proportions of intraoperative pain perception of the BNTB group and the conventional BNB group were 10 and 42% (P = .06), respectively, and those of supplemental infiltration anesthesia were 5 and 26% (P = .18), respectively. CONCLUSIONS: BNTB provided a wider extent of anesthesia of the buccal mucosa than conventional BNB and may improve the anesthesia success of IANB for removal of mandibular third molars.

Usefulness of preoperative computed tomography findings for airway management in patients with acute odontogenic infection: a retrospective study.

Odontogenic infection is more likely to affect the airway and interfere with intubation than non-odontogenic causes. Although anesthesiologists predict the difficulty of intubation and determine the method, they may encounter unexpected cases of difficult intubation. An inappropriate intubation can cause airway obstruction due to bleeding and edema by damaging the pharynx and larynx. This study was performed to determine the most important imaging findings indicating preoperative selection of an appropriate intubation method. This retrospective study included 113 patients who underwent anti-inflammatory treatment for odontogenic infection. The patients were divided into two groups according to the intubation method: a Macintosh laryngoscope (45 patients) and others (video laryngoscope and fiberscope) (68 patients). The extent of inflammation in each causative tooth, the severity of inflammation (S1-4), and their influence on the airway were evaluated by computed tomography. The causative teeth were mandibular molars in more than 90%. As the severity of inflammation increased, anesthesiologists tended to choose intubation methods other than Macintosh laryngoscopy. In the most severe cases (S4), anesthesiologists significantly preferred other intubation methods (33 cases) over Macintosh laryngoscopy (9 cases). All patients with S4 showed inflammation in the parapharyngeal space, and the airway was affected in 41 patients. The mandibular molars were the causative teeth most likely to affect the airway and surrounding region. In addition to clinical findings, the presence or absence of inflammation that has spread to the parapharyngeal space on preoperative computed tomography was considered an important indicator of the difficulty of intubation.

Anesthetic Management of a Patient With Catecholaminergic Polymorphic Ventricular Tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited arrhythmogenic disorder induced by adrenergic stress. Electrophysiologically, it is characterized by emotional stress- or exercise-induced bidirectional ventricular tachycardia that may result in cardiac arrest. Minimizing perioperative stress is critical as it can reduce fatal arrhythmias in patients with CPVT. Dexmedetomidine (DEX), a centrally acting sympatholytic anesthetic agent, was used in the successful intravenous (IV) moderate sedation of a 27-year-old female patient with CPVT, a history of cardiac events, and significant dental fear and anxiety scheduled to undergo mandibular left third molar extraction. Oral surgery was successfully performed under DEX-based IV sedation to reduce stress, and no arrhythmias were observed. IV sedation with DEX provided a sympatholytic effect with respiratory and cardiovascular stability in this patient with CPVT who underwent oral surgery.

Hemodynamic Impact of Drug Interactions With Epinephrine and Antipsychotics Under General Anesthesia With Propofol.

OBJECTIVE: Antipsychotic drugs exhibit α-1 adrenergic receptor-blocking activity. When epinephrine and antipsychotic drugs are administered in combination, ß-2 adrenergic effects are thought to predominate and induce hypotension. This study aimed to assess hemodynamic parameters in patients regularly taking antipsychotics who were administered epinephrine-containing lidocaine under general anesthesia in a dental setting. METHODS: Thirty patients taking typical and/or atypical antipsychotics and scheduled for dental procedures under general anesthesia were enrolled. Five minutes after tracheal intubation, baseline systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and percutaneous oxygen saturation (SpO2) measurements were taken. The SBP, DBP, HR, and SpO2 measurements were repeated 2, 4, 6, 8, and 10 minutes after the injection of 1.8 mL of 2% lidocaine (36 mg) with 1:80,000 epinephrine (22.5 mcg) via buccal infiltration. RESULTS: Differences between the baseline measurements and those of each time point were analyzed using Dunnett test, and no statistically significant changes were observed. CONCLUSIONS: Our findings demonstrate that the use of epinephrine at a clinically relevant dose of 22.5 mcg for dental treatment under general anesthesia is unlikely to affect the hemodynamic parameters of patients taking antipsychotic medications.

Anesthetic Management of a Juvenile Hyaline Fibromatosis Patient With Trismus and Cervical Movement Limitation.

Juvenile hyaline fibromatosis (JHF) is a rare autosomal recessive disease characterized by the presence of tissue nodules, joint contractures, and gingival hyperplasia. With a 1-year-9-month-old female patient scheduled for a gingivectomy and excision of a lower lip mass under general anesthesia, it was anticipated that airway management would be difficult because of trismus and limited cervical movement. Intubation with video-laryngoscopic assistance could not be achieved because gingival hyperplasia and trismus prevented blade insertion and manipulation. Therefore, 2 endotracheal tubes were used: 1 used as a nasopharyngeal airway for assisted ventilation, and 1 used for intubation along with a flexible fiberoptic scope. This case demonstrated a useful method for managing ventilation and intubation in patients with JHF, particularly when the use of oral airway devices is difficult.

Anesthetic Management of a Patient With Systemic Sclerosis and Microstomia.

Systemic sclerosis (SSc) is an autoimmune disease that can cause fibrosis in vital organs, often resulting in damage to the skin, blood vessels, gastrointestinal system, lungs, heart, and/or kidneys. Patients with SSc are also likely to develop microstomia, which can render dental treatment difficult and painful, thereby necessitating advanced anesthetic management. This is a case report of a 61-year-old woman with a history of SSc with microstomia, interstitial pneumonia, and gastroesophageal reflux disease in whom intravenous moderate sedation was performed using a combination of dexmedetomidine and ketamine for dental extractions. Both anesthetic agents are known to have analgesic effects while minimizing respiratory depression. Consequently, the increased discomfort caused by opening the patient's mouth and stretching the buccal mucosa was sufficiently managed, permitting an increase in maximum interincisal opening and completion of treatment without complications. Patients with SSc present with serious comorbidities that can negatively impact anesthetic management, so the implementation of an anesthetic plan that takes such risks into account is required. Furthermore, emergency airway management is likely to be difficult in patients with microstomia. For intravenous moderate sedation, combined use of dexmedetomidine and ketamine, which have analgesic effects while minimizing respiratory depression, may be particularly effective in patients with SSc and microstomia.

Anesthetic Management of a Pediatric Patient With Cardiofaciocutaneous Syndrome.

Cardiofaciocutaneous (CFC) syndrome is a rare condition characterized by congenital heart disease, craniofacial dysmorphology, and dermatological abnormalities. CFC syndrome is one of the RASopathies, a family of syndromes that also includes Noonan and Costello syndromes, all with underlying gene mutations involving the Ras/mitogen-activated protein kinase pathways. Important considerations for anesthesiologists caring for these patients include the need to evaluate for possible cardiac defects, anticipating and planning for potentially difficult airway management, and the consideration of potential weakness of the respiratory muscles. Musculoskeletal abnormalities, such as muscle weakness and decreased muscle mass, are observed in all RASopathies, but are particularly prominent in CFC syndrome. In patients with CFC syndrome who experience respiratory muscle weakness, the use of desflurane and remifentanil may aid in a faster recovery and effectively help reduce the risk of respiratory complications, such as respiratory depression, following general anesthesia because of their rapid metabolism or elimination.

Anesthetic management in corticobasal degeneration with central sleep apnea: A case report.

Corticobasal degeneration (CBD) is a rare neurodegenerative disease characterized by dystonia, cognitive deficits, and an asymmetric akinetic-rigid syndrome. Little information is available regarding anesthetic management for CBD patients. Our patient was a 55-year-old man with CBD complicated by central sleep apnea (CSA). Due to the risk of perioperative breathing instability associated with anesthetic use, a laryngeal mask airway was used during anesthesia with propofol. Spontaneous respiration was stable under general anesthesia. However, respiratory depression occurred following surgery, necessitating insertion of a nasopharyngeal airway. Since no respiratory depression had occurred during maintenance of the airway using the laryngeal mask, we suspected an upper airway obstruction caused by displacement of the tongue due to residual propofol. Residual anesthetics may cause postoperative respiratory depression in patients with CBD. Therefore, continuous postoperative monitoring of SpO2 and preparations to support postoperative ventilation are necessary.

General Anesthesia in a Glucose-6-Phosphate Dehydrogenase Deficiency Child: A Case Report.

We performed general anesthesia on a 3-year-old boy with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Patients with G6PD deficiency exhibit jaundice and anemia due to hemolysis caused by a lack of the G6PD enzyme. To maintain anesthesia, we used propofol and remifentanil, which may prevent hemolytic attacks by exerting an antioxidant effect. In addition, because the patient was in a high-risk group for the development of methemoglobinemia, we used mepivacaine as a local anesthetic. We liaised with the patient's attending physician to make sufficient arrangements, such as securing an emergency transfer on the day of anesthesia. The patient did not develop hemolytic attacks during or after the procedure, and he progressed well without problems.

Intravenous Sedation in Arnold-Chiari Malformation With Respiratory Failure.

Type II Arnold-Chiari malformation (ACM) is an abnormality in which the cerebellum, pons, and medulla oblongata are displaced downward into the spinal cord. Type II ACM is often complicated by respiratory depression, sleep-disordered breathing, and deglutition disorder as a result of medullary dysfunction and impairment of the lower cranial nerves. Bending and stretching of the neck is restricted, and anesthetic management is problematic in patients with the disorder. We performed dental treatment twice under intravenous sedation in a patient with intellectual disability with type II ACM complicated by hypercapnic respiratory failure. Propofol was used for the first sedation procedure. Repeated bouts of respiratory depression occurred on that occasion, so the airway was managed manually by lifting the jaw. However, aspiration pneumonitis occurred postoperatively. A combination of dexmedetomidine and midazolam was used for sedation on the second occasion, and the intervention was completed uneventfully without any respiratory depression. Our experience with this patient highlights the need for selection of an agent for intravenous sedation that does not require neck extension and has minimal effect on respiration in patients with type II ACM, who are at high risk of respiratory depression and pulmonary aspiration.

Ethanol-Induced Cervical Sympathetic Ganglion Block Applications for Promoting Canine Inferior Alveolar Nerve Regeneration Using an Artificial Nerve.

Polyglycolic acid collagen (PGA-C) tubes are bio-absorbable nerve tubes filled with collagen of multi-chamber structure, which consist of thin collagen films. Favorable clinical outcomes have been achieved when using these tubes for the treatment of damaged inferior alveolar nerve (IAN). A critical factor for the successful nerve regeneration using PGA-C tubes is blood supply to the surrounding tissue. Cervical sympathetic ganglion block (CSGB) creates a sympathetic blockade in the head and neck region thus increasing blood flow in the area. To ensure an adequate effect, the blockade must be administered with local anesthetics one to two times a day for several consecutive weeks; this poses a challenge when creating animal models for investigating this technique. To address this limitation, we developed an ethanol-induced CSGB in a canine model of long-term increase in blood flow in the orofacial region. We examined whether IAN regeneration via PGA-C tube implantation can be enhanced by this model. Fourteen Beagles were each implanted with a PGA-C tube across a 10-mm gap in the left IAN. The IAN is located within the mandibular canal surrounded by bone, therefore we chose piezoelectric surgery, consisting of ultrasonic waves, for bone processing, in order to minimize the risk of nerve and vessel injury. A good surgical outcome was obtained with this approach. A week after surgery, seven of these dogs were subjected to left CSGB by injection of ethanol. Ethanol-induced CSGB resulted in improved nerve regeneration, suggesting that the increased blood flow effectively promotes nerve regeneration in IAN defects. This canine model can contribute to further research on the long-term effects of CSGB.

Can nerve regeneration on an artificial nerve conduit be enhanced by ethanol-induced cervical sympathetic ganglion block?

This study aimed to determine whether nerve regeneration by means of an artificial nerve conduit is promoted by ethanol-induced cervical sympathetic ganglion block (CSGB) in a canine model. This study involved two experiments-in part I, the authors examined the effect of CSGB by ethanol injection on long-term blood flow to the orofacial region; part II involved evaluation of the effect of CSGB by ethanol injection on inferior alveolar nerve (IAN) repair using polyglycolic acid-collagen tubes. In part I, seven Beagles were administered left CSGB by injection of 99.5% ethanol under direct visualization by means of thoracotomy, and changes in oral mucosal blood flow in the mental region and nasal skin temperature were evaluated. The increase in blood flow on the left side lasted for 7 weeks, while the increase in average skin temperature lasted 10 weeks on the left side and 3 weeks on the right. In part II, fourteen Beagles were each implanted with a polyglycolic acid-collagen tube across a 10-mm gap in the left IAN. A week after surgery, seven of these dogs were administered CSGB by injection of ethanol. Electrophysiological findings at 3 months after surgery revealed significantly higher sensory nerve conduction velocity and recovery index (ratio of left and right IAN peak amplitudes) after nerve regeneration in the reconstruction+CSGB group than in the reconstruction-only group. Myelinated axons in the reconstruction+CSGB group were greater in diameter than those in the reconstruction-only group. Administration of CSGB with ethanol resulted in improved nerve regeneration in some IAN defects. However, CSGB has several physiological effects, one of which could possibly be the long-term increase in adjacent blood flow.

Feasibility study of corticosteroid treatment for esophageal ulcer after EMR in a canine model.

BACKGROUND: Intralesional or systemic steroid administration is a promising strategy for the prevention of esophageal stricture after endoscopic therapy. The aim of this study was to evaluate the influence of steroid therapy on the process of healing of defects in the esophageal mucosa after endoscopic mucosal resection (EMR). METHODS: Nine beagle dogs were divided into three equal groups: group A, intralesional injection (n = 3), group B, peroral administration (n = 3), and group C, untreated control (n = 3). In group A, triamcinolone acetonide 1 ml (10 mg) was injected directly into the exposed submucosal layer immediately after EMR, and again on postoperative day (POD) 7. In group B, dogs were administered prednisolone 0.5 mg/kg/day orally for 14 days after EMR. In group C, 1 ml normal saline was injected by the same method as that used for group A. On POD 28, histological examination was performed to evaluate epithelialization, inflammation, angiogenesis, and atrophy of the muscularis propria. RESULTS: In groups A, B, and C, the mean ulcer area was 50.1, 22.7, and 7.4 mm(2), respectively. The difference between groups A and C was significant (p < 0.01). Inflammatory cells were significantly more evident in the lesions of group A than in those of group C (p < 0.05). In all groups, atrophy of the muscularis propria was evident. However, transmural destruction and fibrosis were observed only in group A. CONCLUSION: It was speculated that the esophageal ulcer causes the fibrosis of the submucosa and atrophy of the muscularis propria during process of healing. Intralesional steroid injection deepened the esophageal ulcers and delayed epithelialization, whereas systemic administration did not clearly improve the lesion healing process.

Observation of the esophagus, pharynx and lingual root by gastrointestinal endoscopy with a percutaneous retrograde approach.

AIM: To evaluate the efficacy of retrograde observation of the esophagus, pharynx, larynx and lingual root. METHODS: With the beagle dog under anesthesia, the anterior wall of the stomach was fixed on the abdominal wall in a similar way to percutaneous endoscopic gastrostomy. The gastrointestinal scope was inserted via a 12 mm laparoscopic port for subsequent retrograde observation from stomach to the oral cavity. RESULTS: With this technique, direct observation of gastric cardia was possible without restriction. The cervical esophagus was dilated well, also allowing clear observation of the hypopharyngo-esophageal junction. If the tongue was manually pulled out forward, observation of the lingual root was possible. CONCLUSION: This procedure is easy and effective for pre-treatment evaluation of the feasibility of endoscopic resection in cases of superficial carcinoma of head and neck.