Gag Reflex Research Articles

Application of panoramic radiography with a multilayer imaging program for detecting proximal caries: a preliminary clinical study.

The aim of this study is to introduce a novel program of panoramic radiography that shows 41 multilayer images from the buccal to lingual aspects in a region of interest, and to evaluate the effectiveness of this program for detecting proximal caries. In total, 480 premolars and molars on 30 panoramic radiographs taken with the multilayer imaging program were included in this study. The presence or absence of caries in 960 proximal surfaces was assessed by three experienced oral and maxillofacial radiologists as a consensus-based gold-standard. Two general dentists evaluated and scored proximal caries on 980 surfaces on panoramic radiographs with and without the multilayer imaging program. The two general dentists' scores were compared with the gold-standard, and were analyzed for sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic (ROC) curve with and without using the program. The area under the ROC curve was analyzed using STATA/SE 13.1. When the multilayer imaging program was used for panoramic radiography, the inter- and intraobserver agreement of the two general dentists improved. All values, including the area under the ROC curve, were higher when the multilayer imaging program was used than when it was not used. The area under the ROC curve showed a statistically significant improvement only in Observer 1, whose diagnostic ability was poorer than that of Observer 2. This multilayer imaging program might help the inexperienced dentist to improve the diagnostic accuracy of proximal caries. If further studies would be performed in various clinical application, it could be useful when intraoral radiography taking is difficult for reasons such as mouth-opening limitations and the gag reflex of the patients.

A role for neurokinin 1 receptor expressing neurons in the paratrigeminal nucleus in bradykinin-evoked cough in guinea-pigs.

Airway projecting sensory neurons arising from the jugular vagal ganglia terminate centrally in the brainstem paratrigeminal nucleus, synapsing upon neurons expressing the neurokinin 1 receptor. This study aimed to assess the involvement of paratrigeminal neurokinin 1 receptor neurons in the regulation of cough, breathing and airway defensive responses. Lesioning neurokinin 1 receptor expressing paratrigeminal neurons significantly reduced cough evoked by inhaled bradykinin but not inhaled ATP or tracheal mechanical stimulation. The reduction in bradykinin-evoked cough was not accompanied by changes in baseline or evoked respiratory variables (e.g. frequency, volume or timing), animal avoidance behaviours or the laryngeal apnoea reflex. These findings warrant further investigations into targeting the jugular ganglia and paratrigeminal nucleus as a therapy for treating cough in disease. Jugular vagal ganglia sensory neurons innervate the large airways and are thought to mediate cough and associated perceptions of airway irritations to a range of chemical irritants. The central terminals of jugular sensory neurons lie within the brainstem paratrigeminal nucleus, where postsynaptic neurons can be differentiated based on the absence or presence of the neurokinin 1 (NK1) receptor. Therefore, in the present study, we set out to test the hypothesis that NK1 receptor expressing paratrigeminal neurons play a role in cough evoked by inhaled chemical irritants. To test this, we performed selective neurotoxin lesions of NK1 receptor expressing neurons in the paratrigeminal nucleus in guinea-pigs using substance P conjugated to saporin (SSP-SAP). Sham lesion control or SSP-SAP lesion guinea-pigs received nebulised challenges, with the pan-nociceptor stimulant bradykinin or the nodose ganglia specific stimulant adenosine 5'-triphosphate (ATP), in conscious whole-body plethysmography to study cough and associated behaviours. Laryngeal apnoea reflexes and cough evoked by mechanical stimulation of the trachea were additionally investigated in anaesthetised guinea-pigs. SSP-SAP significantly and selectively reduced the number of NK1 receptor expressing neurons in the paratrigeminal nucleus. This was associated with a significant reduction in bradykinin-evoked cough, but not ATP-evoked cough, mechanical cough or laryngeal apnoeic responses. These data provide further evidence for a role of jugular vagal pathways in cough, and additionally suggest an involvement of NK1 receptor expressing neurons in the paratrigeminal nucleus. Therefore, this neural pathway may provide novel therapeutic opportunities to treat conditions of chronic cough.

Potential mechanisms of opioid depression of the laryngeal adductor reflex: insights from a neuromechanical model of the respiratory control system

Opioid use increases the risk of aspiration and pneumonia, presumably through depression of protective reflexes that prevent intrusion of foreign material into the airways. The laryngeal adductor reflex (LAR) is an airway protective behavior that utilizes bilateral thyroarytenoid (TA) muscles and prevents material entering the trachea and lungs. The operational features and specific neural mechanisms which regulate and coordinate the occurrence of the LAR to prevent aspiration during opioid use are not fully understood. In vivo experiments were conducted using unilateral electrical stimulation of the superior laryngeal nerve (SLN) to induce the LAR. Systemic opioid administration preferentially attenuated the contralateral LAR, which is consistent with dysregulation of airway protection. We speculated that computational modeling of a specific LAR circuit would provide testable hypotheses that could account for this effect of opioids on the LAR. We have developed a predictive computational model which incorporates a distributed neural network that excites expiratory laryngeal motoneurons (ELM). The stochastic neural network simulator consists of discrete “integrate and fire” populations. The model circuit was informed by response patterns during the LAR of neurons in the regions of the nucleus tractus solitarius (NTS), the reticular formation (RF), and the ventrolateral respiratory column (VRC). With our network scale model, we simulated modulation of the LAR during administration of opioids by decreasing input currents to neurons in the RF that provide presynaptic input to ELMs of the VRC and then we activated laryngeal receptors. Simulator outputs were compared to collected in vivo data. Computer simulations reproduced the temporal features of the LAR, and the unilateral effects of opioids on the LAR by increasing potassium conductance of presynaptic neurons, depressing presynaptic terminal excitability, and hyperpolarizing ELM populations. Simulations of the LAR and phasic breathing suggest that an important area of focus for modeling efforts will be (i) refining the spatiotemporal characteristics of the behavior, (ii) the potential role of NTS laryngeal interneuronal networks in the effects of opioids, and (iii) synaptic regulation of oscillatory behavior of the LAR.Support or Funding InformationSupported by NIH HL131716, 3OT2OD023854, and NS 110169.

Laryngeal Adductor Reflex Motor Bursts Rapidly Oscillate in the Cat

The laryngeal adductor reflex (LAR) is a protective behavior induced by stimulation of upper airway afferents. Laryngeal afferent information reaches interneurons in the medulla via the superior laryngeal nerve (SLN). Expiratory laryngeal motoneurons (ELMs) are subsequently excited causing contraction of the thyroarytenoid (TA) and posterior cricoarytenoid (PCA) muscles. The LAR consists of a short latency (~10 ms), short duration (~10 ms) burst (R1) and a longer latency (~40ms) burst (R2) in laryngeal electromyogram (EMG) activity. We have shown that R1 LAR magnitude undergoes frequency‐dependent depression in response to electrical stimulation (eStim) of the SLN. Based on preliminary observations, we hypothesized that the R1 component of the LAR induced by SLN eStim oscillates. In anesthetized, spontaneously breathing cats (n=12: 7 males, 5 females), we recorded EMG activity from the TA bilaterally and the PCA unilaterally. The SLN was electrically stimulated at 2 or 20 Hz to evoke TA LAR ipsilateral to stimulation (iTA). No sex differences in TA or PCA LAR EMG magnitude were observed. Consistent with previous findings, TA LAR magnitude differed with breathing phase; normalized iTA LAR magnitude was 10% larger during expiration compared to inspiration. TA LAR contralateral to stimulation (cTA) and ipsilateral PCA LAR magnitudes were not breathing phase dependent. TA and PCA LAR EMG oscillations were highly variable across animals (range: 244 to 1140 Hz). Mean iTA EMG frequency was decreased at 20 Hz (2 to 20 Hz: 616 to 518 Hz, p=0.05). Mean cTA periodicity trended down at 20 Hz (2 to 20 Hz cTA: 647 to 531 Hz, p=0.07). In separate decerebrate, paralyzed cats (n=13), extracellular recordings of neurons in the ventral respiratory column (VRC) with multiple electrode arrays were conducted. Peristimulus time histograms provided evidence that ELMs oscillated at frequencies following SLN eStim similar to the lower range of periodicities in TA EMGs in unparalyzed animals. A subset of neurons recorded in the VRC were excited or inhibited by SLN eStim at short latencies. Spike train analysis suggested that ELM oscillations could be accounted for by synaptic inhibition and excitation from laryngeal‐responsive VRC inspiratory, expiratory, and non‐breathing modulated neurons. We conclude that the LAR is temporally regulated by a complex, anatomically distributed brainstem network that is capable of strong synchrony in response to stimulation of laryngeal afferents. We speculate that the function of this laryngeal‐responsive network is to exert tight regulatory control over LAR patterning.Support or Funding InformationSupported by NIH HL131716 and 3OT2OD023854

Codeine Asymmetrically Inhibits The Laryngeal Adductor Reflex

The laryngeal adductor reflex (LAR) is a fundamental airway protective behavior that prevents penetration of material from the upper airway into the trachea. Aspiration risk increases in humans after a single dose of an opioid and pneumonia is a common occurrence in opioid users. The LAR consists of a short latency (~10 ms), short duration (~10 ms) burst (R1) and a longer latency (~40ms) burst (R2) in laryngeal electromyogram (EMG) activity. The R1 LAR is thought to be primarily a brainstem reflex. We hypothesized that systemic administration of codeine, one of the most commonly prescribed opioids, would suppress the R1 LAR in an animal model that robustly expresses airway protective behaviors. The LAR was elicited in anesthetized, spontaneously breathing cats (n=13) by electrical stimulation (2 Hz, 0.1 ms pulse duration) of the superior laryngeal nerve (SLN) or mechanical stimulation of the vocal folds with a von Frey filament. Bilateral thyroarytenoid (TA) and midline posterior cricoarytenoid (PCA) muscle electromyograms (EMGs) were recorded. The R1 LAR manifested as a short latency (approx. 10 ms) evoked response consisting of peaks and troughs in both the TA and the PCA EMGs. Codeine (0.1–10 mg/kg, iv) dose dependently inhibited the magnitude of the contralateral TA and PCA LAR by approximately 60% but had no significant effect on the LAR in the ispilateral TA EMG. Similar lateralization of the effect of codeine was observed in animals in which the LAR was elicited by mechanical stimulation of the vocal folds. These effects were similar in animals whether only one or both SLNs were sectioned. In separate animals, the codeine dose response was conducted after pretreatment with the NMDA antagonist, MK‐801 (10 μg/kg) via the vertebral artery. MK‐801 enabled depression of the TA LAR on the ipsilateral side by iv codeine, but did not enhance the reduction in the contralateral TA or PCA LAR relative to animals that only received this opioid. These findings support lateralized suppression of the LAR by opioids that is mediated by central NMDA receptors. The differing effects of codeine on the LAR in the PCA and ipsilateral TA EMGs suggest that opioids may disrupt laryngeal protective actions through asymmetric positioning of the vocal folds.Support or Funding InformationSupported by NIH HL131716 and 3OT2OD023854

Airway Protection—A Role for Vagal P2RY1 Receptors

Recent events bring the importance of respiratory health to the forefront of our collective attention. In this issue of Cell, a new study by Prescott and Umans etal. reveals how a dedicated laryngeal sensory motor reflex circuit protects our airways from aspirated foods or liquids.

P48 A case of myasthenia gravis presenting to the rheumatology clinic

Abstract Background A 32-year-old Lithuanian lady, with a 6-year history of undifferentiated inflammatory arthritis and autoimmune neutropenia, contacted her rheumatologist reporting a constellation of new symptoms. This began with a month’s history of facial weakness and slurred speech. She progressively experienced nasal regurgitation on drinking fluids, reduced exercise tolerance, as well as difficulty chewing, swallowing, and coughing. Her symptoms initially came on in the evening but subsequently appeared earlier in the day. There were no symptoms suggestive of infection. Her arthritis had been well-controlled on hydroxychloroquine and sulfasalazine. She was previously on methotrexate, but this was discontinued due to plans to conceive. Methods Clinical examination during an urgent outpatient review yielded dysphonic, mildly dysarthric speech. Extraocular movements were normal with no ophthalmoplegia. There was mild lower motor neurone facial weakness and an absent gag reflex. She demonstrated fatiguability on repetitive tongue movements and arm abduction. There were no upper motor neurone or cerebellar signs. Blood tests showed normal inflammatory markers, full blood count, creatine kinase, immunoglobulins, liver, and renal profile. Her anti-nuclear antibody titre, previously weakly positive at time of diagnosis of inflammatory arthritis, was 1:1280 (homogenous). Anti-cyclic citrullinated peptide, rheumatoid factor, and extractable nuclear antigens were negative. Virology screen was unremarkable. Neurology input was sought. Anti-acetylcholine receptor antibody was positive at 5.2nmol/L (normal range 0-0.45nmol/L), anti-muscle specific receptor tyrosine kinase antibody was negative. Nerve conduction studies showed decremental response on repetitive stimulation of her left nasalis, consistent with a post-synaptic neuromuscular junction transmission disorder. There was no evidence of myopathy. Results The clinical symptoms and the investigations led to the diagnosis of myasthenia gravis with predominant bulbar features. Computed tomography showed no evidence of thymoma or thymic hyperplasia. Magnetic resonance imaging of the brain showed no evidence of space-occupying lesion or brainstem abnormality. She initially received pyridostigmine 30mg three times daily with propantheline cover to which she reported a good response. A viral illness led to deterioration of her symptoms of breathlessness and worsening dysphagia resulting in a hospital admission. She received intravenous immunoglobulins 20g daily for three days. Hydroxychloroquine and sulfasalazine were replaced with methotrexate 15mg weekly. She now remains on pyridostigmine 90mg five times daily and 10mg prednisolone daily with good effect. Conclusion Myasthenia gravis is a rare condition (prevalence of 10-20 per 100,000 in the United Kingdom). However, this occurs at a higher prevalence in autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. This case illustrates the importance of remaining vigilant about symptoms which patients may disclose in the rheumatology clinic which may not fit with their known diagnosis. Her previous use of methotrexate for her arthritis could have masked her myasthenic symptoms which became apparent after the drug was stopped for a prolonged period. Disclosures S. Yeoh None. S. Salam None. G. Christofi None. V. Morris None.

Acupuncture for Relief of Gag Reflex in Patients Undergoing Transoesophageal Echocardiography-A Protocol for a Randomized Placebo-Controlled Trial.

Background: Gagging during transesophageal echocardiography examination (TEE) can be distressing and even dangerous for patients. The needling of acupuncture point CV24 was described to be effective in reducing the gag reflex during TEE in patients with ischemic stroke or transient ischemic attack. Methods: We describe a proposal for a prospective, randomized, patient, practitioner and assessor-blinded, single-center trial with two arms/groups; real acupuncture will be compared to placebo acupuncture. A total of 60 (30 per group) patients scheduled for elective TEE in order to exclude a cardiac embolic source, endocarditis or for valve failure evaluation will be recruited according to patients’ selection criteria and receive either indwelling fixed intradermal needles at acupoints CV24 and bilateral PC6 or placebo needles at the same areas. Patients, the practitioners who will perform the TEE procedure, and the assessor of the outcome measures will be unaware of the group’s (real or placebo) allocation. Results: The primary outcome is the intensity of gagging, measured using verbal rating scale (VRS-11) from 0 = no gagging to 10 = intolerable gagging. Secondary outcomes include the incidence of gagging, the use of rescue medication, patients’ satisfaction with relief of unwanted side effects during TEE procedure, success of patients’ blinding (patients’ opinion to group allocation), heart rate and oxygen saturation measured by pulse oxymetry. Conclusions: To study the effects of acupuncture against gagging during TEE, we test the needling of acupoints CV24 and PC6 bilaterally. A placebo acupuncture is used for the control group. Trial registration number: NCT NCT0382142.

The Internal Superior Laryngeal Nerve in Humans: Evidence for Pure Sensory Function.

To determine if the internal branch of the superior laryngeal nerve (iSLN) provides direct motor innervation to the interarytenoid muscle, a laryngeal adductor critical for airway protection. We studied the iSLN-evoked motor response in the interarytenoid and other laryngeal muscles. If the iSLN is purely sensory, there will be no detectable short latency motor response upon supramaximal stimulation, indicating the absence of a direct efferent conduction path. Intraoperative case series. In seven anesthetized patients undergoing laryngectomy for unilateral laryngeal carcinoma, the iSLN of the unaffected side was electrically stimulated intraoperatively with 0.1-ms pulses of progressive intensities until supramaximal stimulation was reached. Electromyographic responses were measured in the ipsilateral interarytenoid, thyroarytenoid, and cricothyroid muscles. None of the subjects exhibited short-latency interarytenoid motor responses to iSLN stimulation. Supramaximal electrical stimulation of the intact iSLN evoked ipsilateral motor responses with long latencies: 18.7-38.5 ms in the interarytenoid (n = 6) and 17.8-24.9 ms in the thyroarytenoid (n = 5). Supramaximal stimulation of the recurrent laryngeal nerve evoked ipsilateral motor responses with short latencies: 1.6-3.9 ms in the interarytenoid (n = 6) and 1.6-2.7 ms in the thyroarytenoid (n = 6). The iSLN provides no functional efferent motor innervation to the interarytenoid muscles. The iSLN exclusively evokes an interarytenoid motor response via afferent activation of central neural circuits that mediate the laryngeal reflex arc. These findings suggest that the role of the iSLN in vital laryngopharyngeal functions, such as normal swallowing and protection of the airway from aspiration, is purely sensory. 4 Laryngoscope, 131:E207-E211, 2021.

Three-Dimensional Printed Silicone Bite Blocks for Radiotherapy of Head and Neck Cancer—A Preliminary Study

Conventional methods that have been developed to immobilize the mouth and tongue for radiotherapy (RT) in head and neck cancer (HNC) treatment have been unsatisfactory. We, therefore, developed three-dimensional (3D), customizable, silicone bite blocks and examined their clinical feasibility. For HNC patients, before RT, the 3D printed bite blocks were fabricated based on primary computed tomography (CT) simulation images. The placement of the 3D bite blocks was followed by a secondary CT simulation before RT planning was finalized. Dosimetric parameters and positioning verification achieved with the propose bite blocks were compared with conventional universal oral corks. The 3D printed bite blocks were conformal to the occlusal surface, ensuring immobilization of the tongue without eliciting a gag reflex, and an elastic and firm texture that supports opening of the mouth, with a smooth surface with tolerable intraoral tactility. The dosimetry of patients using the proposed bite blocks showed better coverage of the planning target volume and surface of a tumour bed along with reduction in normal tissue doses. Good concordance of positioning by 3D printed bite blocks during the RT course was verified. The 3D printed bite blocks with silicone might be a customizable, safe, and practical advanced technology in RT for HNC.

내전근 반사를 이용한 뇌간 종양 수술중 신경계 감시의 소아 증례

내전근 반사를 이용한 뇌간 종양 수술중 신경계 감시의 소아 증례

The correlation of gagging threshold with intra-oral tactile and psychometric profiles in healthy subjects: A pilot study.

Excessive gag reflex could be problematic for adequate dental care. Although various factors may increase the susceptibility to gagging, its contributing factors have not been fully determined. This study aimed to determine whether gag reflex was associated with tactile sensitivity and psychological characteristics. Fifteen volunteers of healthy males and females each were recruited for this study. After completing a questionnaire describing the self-perceived gag reflex activity, a disposable saliva ejector was inserted along the palate into the mouth until gagging was evoked. The ratio of the insertion depth to the palatal length was used as an index for the gagging threshold. The two-point discrimination (TPD) and Semmes-Weinstein monofilament (SWM) tests were performed to assess the tactile sensitivity of the palatal regions (hard palate, anterior and posterior soft palate). The Symptom Checklist-90-Revised was used to investigate the relationship between the gagging threshold and the psychological status. Our findings showed that the gagging threshold had a significant positive correlation with the TPD and SWM thresholds on the hard palate. The psychological profiles of psychoticism and hostility score were also significantly correlated with the gagging threshold. However, there were no significant differences in the tactile and gagging thresholds, as well as the psychological profiles, between males and females. Our results suggested that the tactile sensitivity of the anterior palate is a determining factor for the gagging threshold and implied that the initial response of the oral entry site to stimulation may lead to the development of gag reflex.

Laryngeal reflex responses in pediatric anesthesia.

Laryngeal and respiratory reflexes are vitally important defense mechanisms against foreign body aspiration, safeguarding airway patency, and ventilation. These highly preserved automatisms easily overrule external influences like willpower or (anesthetic) medication. Prevention and anticipation are, therefore, the essential strategies to avoid adverse events and damage, and treatment is most effective in the early stage of the reflex response. The physiology and pathophysiology of the various defensive reflexes as well as a comprehensive anesthetic approach to prevention and treatment are outlined in this review.

Inter- and Intra-Rater Reliability of Laryngeal Sensation Testing with the Touch Method During Flexible Endoscopic Evaluations of Swallowing.

Sensation is an integral component of laryngeal control for breathing, swallowing, and vocalization. Laryngeal sensation is assessed by elicitation of the laryngeal adductor reflex (LAR), a brainstem-mediated adduction of the true vocal folds. During Flexible Endoscopic Evaluations of Swallowing (FEES), the touch method can be used to elicit the LAR to judge laryngeal sensation. Despite the prevalence of this method in clinical practice and research, prior studies have yet to examine inter- and intra-rater reliability. Four speech-language pathologists rated 125 randomized video clips for the presence, absence, or inability to rate the LAR. Fifty percent of video clips were re-randomized and re-rated 1 week later. Raters then created guidelines and participated in formal consensus training sessions on a separate set of videos. Ratings were repeated post-training. Overall inter-rater reliability was fair (κ = 0.22) prior to training. Pre-training intra-rater reliability ranged from fair (κ = 0.35) to almost perfect (κ = 0.89). Inter-rater reliability significantly improved after training (κ = 0.42, P < .001), though agreement did not reach prespecified acceptable levels (κ ≥ 0.80). Post-training intra-rater reliability ranged from moderate (κ = 0.49) to almost perfect (κ = 0.85). Adequate inter-rater reliability was not achieved when rating isolated attempts to elicit the LAR. Acceptable within-rater reliability was observed in some raters 1 week after initial ratings, suggesting that ratings may remain consistent within raters over a short period of time. Limitations and considerations for future research using the touch method are discussed.

Comparison of Spraying and Nebulized Lidocaine in Patients Undergoing Esophago-Gastro-Duodenoscopy: A Randomized Trial

Esophago-gastro-duodenoscopy (EGD) was performed under the topical anesthesia of the pharynx. However spraying lidocaine was found to be an annoying maneuver to patients, while nebulized lidocaine appeared to efficiently suppress gags and cough reflexes in airway anesthesia. This study aimed to compare the effectiveness of spraying and nebulized lidocaine for patients undergoing EGD.A total of 110 patients undergoing elective EGD, with a history of neither lidocaine intolerance nor irritable airways due to smoking, chronic obstructive pulmonary disease (COPD), upper respiratory infection, asthma, cardiac and pulmonary diseases and allergy to lidocaine were included. All patients were randomized into two groups: A- where 5 puffs (10 mg/puff) of spraying lidocaine were administered four times at 5-minute intervals, up to a total dose of 200 mg, and B-where 250 mg of nebulized lidocaine was administered via a nebulization kit with an oxygen face mask of 7 LPM for 15 minutes prior to the commencement of EGD. The procedure was performed by the same board-certified endoscopist The co-researcher who was blinded to the lidocaine administration technique assessed the ease of esophageal instrumentation as either difficult, poor; fair or excellent. Both the endoscopist and the patients expressed their satisfaction by using the numerical rating scale.The endoscopist expressed her satisfaction with instrumentation, which showed significant difference between group A and group B as 84.8 ± 8.3 and 79.2 ± 11.2, respectively. The co-researcher also found that group A patients responded to the ease of esophageal instrumentation better than those in group B. However nebulized lidocaine had significant advantages over spraying lidocaine, with better acceptance in patients undergoing EGD.The endoscopist expressed her approval of spraying lidocaine for taking less time to start the procedure, ease for instrumentation, less gag reflex during the procedure, less presence of hypersecretion, and smooth operation. However participants favored nebulized lidocaine administration.

The efficacy of dexmedetomidine and propofol for sedation in endoscopic ultrasonography: A comparative study

Background: Efficacy and safety of dexmedetomidine as a sedative agent has not been studied in a procedure such as endoscopic ultrasound (EUS) where propofol is being used extensively to provide a deep level of sedation. The present study was conducted to compare the efficacy of dexmedetomidine and propofol to achieve adequate sedation levels in patients undergoing EUS.Methods: Sixty patients scheduled for EUS under sedation for the diagnostic and therapeutic purpose were randomly divided into two groups. Thirty patients in Group D received dexmedetomidine while 30 Group P patients received propofol. The recovery from sedation was assessed using the modified Aldrete's score. Once the modified Aldrete's score of 10/10 was achieved, the patients' perception regarding the pain was assessed using the Visual Analog Scale (VAS) score. Primary outcome measures were VAS score and vital parameters, whereas secondary outcome measures were gag reflex and recovery from sedation using the modified Aldrete's score. Comparison of quantitative and qualitative variables between the groups was done using unpaired Student's t-test and Chi-square test or Fisher's exact test, respectively.Results: The absence of gag reflex was significantly higher in patients who received dexmedetomidine. Dexmedetomidine was found to have greater hemodynamic stability compared with propofol-treated patients. Dexmedetomidine achieved similar levels of sedation to propofol, although with a slower onset of sedation.Conclusions: The use of dexmedetomidine was associated with greater hemodynamic stability and absence of gag reflex.

Clinical orofacial and myofunctional manifestations in an adolescent with Noonan Syndrome: a case report

ABSTRACT Noonan syndrome is an autosomal dominant genetic disease with different manifestations, including Speech, Language and Hearing Sciences ones. The authors describe the orofacial and myofunctional manifestations of an adolescent diagnosed with Noonan syndrome, by consulting the Speech, Language and Hearing Sciences record of a 17-year-old male patient, who underwent screening and speech therapy evaluation with a confirmed genetic diagnosis of Noonan syndrome. The results were qualitatively analyzed. The patient had a long facial type, with a disproportion between the lower and middle thirds of the face, ogival palate, and Mallampati class IV. A deficit in mobility and sensitivity of phonoarticulatory organs was also identified, absence of pathological oral and gag reflexes, decreased lip tone and tongue tension, increased speed chewing and inefficient grinding, functional swallowing for assessed consistencies, mild verbal and nonverbal apraxia, and moderate dysarthria. The results confirmed the presence of alterations in the speech-language organs, proving the relevance of the Speech, Language and Hearing Sciences evaluation in Noonan Syndrome, to allow adequate follow-up and treatment.

Prolonged neonatal intubation: Prosthodontics beyond dentistry

Neonates with respiratory distress, inadequate gag reflex, poor sucking, and swallowing commonly require intubation as a routine treatment modality in the neonatal intensive care unit. It can be done by the nasal or oral route. Although nasotracheal intubation reduces the movement of the tube, it has some serious repercussions such as airway obstruction and possible hypoxia, leading to labored breathing, occlusion of the nasal aperture during a crucial period of development, nasal infections, and hypertrophy of the nasal lining. Hence, oral route is preferred over the nasal route as the oral mucosa is less susceptible to infection. However, an infant with an orotracheal tube is at risk for complications such as accidental extubation, damage to the maxillary alveolar ridge, development of a cleft palate, defective dentition, tracheal mucosal damage, subglottic stenosis, and laryngeal damage. Therefore, in an effort to reduce these complications, an appropriate recognition and dental intervention is required by the prosthodontist who by conferring with the prescribing physician could device a customized intraoral appliance for the neonate on prolonged intubation. Various intraoral appliances are being used to stabilize the tubes for infants who require prolonged intubation. For the present review, the database from various digital platforms was searched for studies published on prolonged neonatal intubation. The palatal appliances effectively stabilize the orotracheal and orogastric intubation tubes and prevent the associated complications. Thus, this early prosthodontic treatment for neonates requiring prolonged intubation further expands the scope of prosthetic dentistry to newer horizons in patient care and management.

Assessment of the efficacy of nebulized local anesthesia using continuous positive airway pressure during fibroptic bronchoscopy

Background The administration of nebulized lidocaine before fiberoptic bronchoscopy (FOB) is preferred than conventional lidocaine spray methods in reducing complications, reducing the need for additional lidocaine doses, and decreasing the incidence of lidocaine adverse effects. The use of nebulized lidocaine through continuous positive airway pressure (CPAP) seems to be superior owing to rapid and deep deposition of the anesthetic agent. The aim of this research is to study if the use of nebulized lidocaine through CPAP is superior to the conventional methods of lidocaine spray before FOB. Patients and methods An observational prospective cohort study was performed in the Chest Department at Ain Shams University hospitals on 40 patients subjected to FOB. They were randomly divided into two groups: group A included 20 patients who underwent FOB using nebulized lidocaine through CPAP, and group B included 20 patients who underwent FOB using conventional lidocaine spray. After doing FOB, we noticed the need for additional doses of lidocaine to complete FOB, duration of FOB, easy entry of the FOB, and incidence of complications. Results Interestingly, patients in group A needed less additional doses of lidocaine spray to complete FOB. Moreover, they had less incidence of coughing and occurrence of gag reflex during FOB, and also less patients’ discomfort, but both duration of FOB and easy entry of the FOB are the same in both groups. Conclusion Administration of nebulized lidocaine through CPAP before FOB leads to decreased use of lidocaine with less incidence of its adverse effects when compared with conventional method of lidocaine spray, and also it has better patient acceptance than lidocaine spray owing to its unpleasant taste. So it should be recommended for use before FOB on a wider scale.

Use of training denture base and palateless dentures: Two different strategies in the management of severe gag reflex in edentulous patients

Gagging is a common problem encountered in clinical prosthodontic practice. In many cases gagging is of psychologic nature and should be treated before denture procedures are completed, so that the patient will be comfortable with well-constructed prostheses. Effective management of gag reflex includes a wide array of techniques ranging from use of common salt on the tip of tongue, acupressure, distraction, relaxation, pharmacotherapy and desensitization. This case report discusses how a holistic approach for gagging prevention and use of training denture base can facilitate denture wearing for a known potential gagger and also highlights how palateless denture helped overcome gagging in a patient with thick ropy saliva in another case.