[Study on pharyngeal wall floppiness of patients with obstructive sleep apnea-hypopnea syndrome attributable to non-structural factors]

Objective: Acoustic pharyngealmetry technology is utilized to evaluate the change and clinical significance of obstructive sleep apnea-hypopnea syndrome (OSAHS) patients caused by non-upper airway structural factor and normal individuals' PWF(pharyngeal wall floppiness). Methods: Acoustic pharyngealmetry instrument of Ecconvision was utilized to examine 102 OSAHS patients and 50 normal individuals, separately recorded their volume of pharyngeal cavity in sit or supine position, calculated PWF in sit or supine position, and SPSS 12.0 of tware was used to analyze data. Results: PWF was 0.14±0.09 in sit position and PWF was 0.21±0.10, (t=5.96, t=9.63, P<0.001)in supine position of OSAHS group, which were all significantly higher than those of control group. PWFs in supine position of OSAHS group and control group were evidently higher than PWF(t=-11.91, P<0.001; t=-2.32, P=0.025) in sit position. ΔPWF(PWF_supine-PWF_sit)was 0.063±0.054 in OSAHS group which was significantly greater than in control(F=41.173, P<0.01). PWF in sit position and supine position were all positively related with age(r=0.714, r=0.735, P<0.001)while irrelevant with BMI(P>0.05). Conclusions: PWF can be utilized to be an index to reflect the physiological feature of upper airway. PWF can more precisely reflect upper airway collapsibility of OSAHS patients on the condition of PWF in supine position. Pharyngeal wall floppiness quantified as a high PWF index is a non-structure vital factor of OSAHS patients and plays a role of guiding us to make personal treatment plans for OSAHS patients.

Differential Response Pattern of Oropharyngeal Pressure by Bolus and Dry Swallows

The aim of this study was to determine if bolus and dry swallow showed similar pressure changes in the oropharynx using our newly developed device. A unique character of it includes that baropressure can be measured with the sensor being placed in the balloon and can assess the swallowing mechanics in terms of pressure changes in the oropharynx with less influences of direct contacts of boluses and oropharyngeal structures during swallow indirectly. Fifteen healthy subjects swallowed saliva (dry), 15 ml of water, 45 ml of water, and 15 ml of two different types of food in terms of viscosity (potage soup-type and mayonnaise-type foods). Suprahyoid muscle activity was recorded simultaneously. Three parameters, area under the curve (AUC), peak amplitude, and duration of pressure, were analyzed from each swallow. Almost all of the bolus swallowing events had biphasic baropressure responses consisting of an early phase and late phase (99%), whereas 90% of the saliva swallowing events had a single phase. AUC, peak, and duration displayed greater effects during the late phase than during the early phase. Baropressure of the early phase, but not of the late phase, significantly increased with increasing volume; however, small but significant viscosity effects on pressure were seen during both phases. Peak pressure of the late phase was preceded by maximum muscle activity, whereas that of the early phase was seen when muscle activity displayed a peak response. These findings indicated that our device with the ability to measure baropressure has the potential to provide additional parameter to assess the swallow physiology, and biphasic baropressure responses in the early and late phases could reflect functional aspects of the swallowing reflexes.

Clinically significant anatomical variation of the retropharyngeal internal carotid arteries

Although interpatient variations in the course and anatomy of extracranial internal carotid arteries (EICAs) have been described previously, intrapatient variability is rarely cited in the literature. Distance between EICAs and the pharyngeal wall is an important determinant of vascular injury risk. A retropharyngeal EICA has crucial implications in patients undergoing pharyngeal procedures, and important in otorhinolaryngology and emergency medicine. Surgical exploration without identification of anatomical landmarks, or emergent intubation in the emergency room poses high risk for EICA injury. Other critical clinical considerations include intra-arterial involvement of tonsillitis, peritonsillar abscesses, or parapharyngeal neoplasms due to close proximity to the EICA. We present 2 cases with short-term change in retropharyngeal course of EICA to highlight this further. Although no clear etiology for these changes has been identified, we hypothesize that embryology, weight alterations, atherosclerotic disease, and postradiation changes are contributory. Thus, one radiologic study does not exclude variation in vascular anatomy.

Cas9-mediated excision of Nematostella brachyury disrupts endoderm development, pharynx formation and oral-aboral patterning

The mesoderm is a key novelty in animal evolution, although we understand little of how the mesoderm arose. brachyury, the founding member of the T-box gene family, is a key gene in chordate mesoderm development. However, the brachyury gene was present in the common ancestor of fungi and animals long before mesoderm appeared. To explore ancestral roles of brachyury prior to the evolution of definitive mesoderm, we excised the gene using CRISPR/Cas9 in the diploblastic cnidarian Nematostella vectensis Nvbrachyury is normally expressed in precursors of the pharynx, which separates endoderm from ectoderm. In knockout embryos, the pharynx does not form, embryos fail to elongate, and endoderm organization, ectodermal cell polarity and patterning along the oral-aboral axis are disrupted. Expression of many genes both inside and outside the Nvbrachyury expression domain is affected, including downregulation of Wnt genes at the oral pole. Our results point to an ancient role for brachyury in morphogenesis, cell polarity and the patterning of both ectodermal and endodermal derivatives along the primary body axis.

Barbed snore surgery for concentric collapse at the velum: The Alianza technique

Recently, new conservative and non-resective surgical techniques, including palatopharyngeal surgical lifting and suspension (the 'Roman blinds technique') and modular barbed snore surgery (MBSS), have been successfully introduced for the treatment of obstructive sleep apnea syndrome (OSAS). This pilot longitudinal study describes our preliminary experience with the 'Alianza technique' (the simultaneous use of Roman blinds and MBSS) in mild to moderate OSAS patients with concentric pharyngeal collapse at the velum, previously documented by means of drug-induced sleep endoscopy. Effectiveness of the surgical procedure was assessed by means of the Epworth sleepiness scale (ESS), overnight polysomnography, and a 0-10 snoring visual analogue scale (VAS); tolerability was assessed by means of a 0-10 pain VAS. The final analysis relating to 19 patients (18 males; 94.8%), with a mean age of 43.8 ± 8.8 years, showed a statistically significant reduction in mean post-operative apnea-hypopnea indexes (22.3 ± 5.1 vs 7.0 ± 9.4 events/hour; p-value = 0.002) and mean ESS scores (11.3 ± 5.4 vs 3.9 ± 4.0; p-value < 0.001). There was also a significant decrease in mean post-operative snoring VAS scores (9.5 ± 0.7 vs 2.1 ± 1.7; p-value < 0.001). Surgery was well tolerated in most patients (mean pain VAS scores on day seven: 2.4 ± 1.4), and there were no major complications. In experienced hands, the Alianza can be considered an effective and safe technique for the treatment of mild to moderate OSAS.

Correlation between the position of hyoid bone and subregions of the pharyngeal airway space in lateral cephalometry and cone beam computed tomography

OBJECTIVE

To correlate the pharyngeal airway subregions with the positioning of the hyoid bone.

MATERIAL AND METHODS

The study examined 107 lateral cephalometric (LC) and cone beam computed tomography (CBCT) images. Linear and volumetric measurements of the pharyngeal subregions were made and correlated to linear measurements using hyoid triangle analysis on images of LC and multiplanar (MPR) and three-dimensional (3D) reconstructions of CBCT.

RESULTS

There was significant correlation between linear measurements of the pharyngeal subregions and hyoid bone position in LC images and in MPR and 3D reconstructions of the CBCT. Correlations were more frequent in the oropharynx and hypopharynx, especially for LC images. No correlations were observed between LC images or CBCT reconstructions and the volumetric measurements of the pharyngeal subregions and the position of the hyoid bone.

CONCLUSION

The hyoid bone position showed more correlations with oropharynx and hypopharynx airway measurements. The hyoid triangle method was not applicable to 3D images, since it showed a smaller number of measures correlated to the hyoid bone position.

PHRED-1 is a divergent neurexin-1 homolog that organizes muscle fibers and patterns organs during regeneration

Regeneration of body parts requires the replacement of multiple cell types. To dissect this complex process, we utilized planarian flatworms that are capable of regenerating any tissue after amputation. An RNAi screen for genes involved in regeneration of the pharynx identified a novel gene, Pharynx regeneration defective-1 (PHRED-1) as essential for normal pharynx regeneration. PHRED-1 is a predicted transmembrane protein containing EGF, Laminin G, and WD40 domains, is expressed in muscle, and has predicted homologs restricted to other lophotrochozoan species. Knockdown of PHRED-1 causes abnormal regeneration of muscle fibers in both the pharynx and body wall muscle. In addition to defects in muscle regeneration, knockdown of PHRED-1 or the bHLH transcription factor MyoD also causes defects in muscle and intestinal regeneration. Together, our data demonstrate that muscle plays a key role in restoring the structural integrity of closely associated organs, and in planarians it may form a scaffold that facilitates normal intestinal branching.

High-Resolution Manometry Evaluation of Pressures at the Pharyngo-upper Esophageal Area in Patients with Oropharyngeal Dysphagia Due to Vagal Paralysis

The motility of the pharynx, upper esophageal sphincter (UES), and proximal esophagus in patients with oropharyngeal dysphagia is still not entirely understood. High-resolution manometry (HRM) was recently added to the armamentarium for the study of this area. This study aims to describe HRM findings in patients with vagal paralysis. Sixteen patients (mean age 54 years, 69% females) with oropharyngeal dysphagia due to unilateral vagal paralysis were prospectively studied. All patients underwent HRM. Motility of the UES and at the topography of the velopharynx and epiglottis were recorded. (1) UES relaxation is compromised in a minority of patients, (2) epiglottis pressure does not follow a specific pattern, (3) vellum is hypotonic in half of the patients, (4) dysphagia is related to a low pharyngeal pressure, not to a flow obstruction at the level of the UES, and (5) aspiration is related to low pressures at the level of the UES and epiglottis and higher pressures at the level of the vellum. Pharyngeal motility is significantly impaired in patients with oropharyngeal dysphagia and unilateral vagal paralysis. In half of the cases, UES resting pressure is preserved due to unilateral innervation and relaxation is normal in most patients. Dysphagia therapy in these patients must be directed toward improvement in the oropharyngeal motility not at the UES.

How we do it: the intra-operative identification of a pharyngocele

A pharyngocele is an uncommon condition, where pharyngeal mucosa herniates through the thyrohyoid membrane. It can be difficult to locate when the patient is at rest. To locate the pharyngocele intra-operatively, a bag valve mask was used to inflate the herniated mucosa. We describe a cost-effective and simple way to locate the pharyngocele intra-operatively.

Diagnosis of Swallowing Disorders: How We Interpret Pharyngeal Manometry

PURPOSE OF REVIEW

We provide an overview of the clinical application of novel pharyngeal high-resolution impedance manometry (HRIM) with pressure flow analysis (PFA) in our hands with example cases.

RECENT FINDINGS

In our Centre, we base our interpretation of HRIM recordings upon a qualitative assessment of pressure-impedance waveforms during individual swallows, as well as a quantitative assessment of averaged PFA swallow function variables. We provide a description of two global swallowing efficacy measures, the swallow risk index (SRI), reflecting global swallowing dysfunction (higher SRI = greater aspiration risk) and the post-swallow impedance ratio (PSIR) detecting significant post-swallow bolus residue. We describe a further eight swallow function variables specific to the hypopharynx and upper esophageal sphincter (UES), assessing hypo-pharyngeal distension pressure, contractility, bolus presence and flow timing, and UES basal tone, relaxation, opening and contractility. Pharyngeal HRIM has now come of age, being applicable for routine clinical practice to assess the biomechanics of oropharyngeal swallowing dysfunction. In the future, it may guide treatment strategies and allow more objective longitudinal follow-up on clinical outcomes.

Influence of interface and position on upper airway collapsibility assessed by negative expiratory pressure

PURPOSE

Negative expiratory pressure (NEP) is a simple technique for the evaluation of upper airway collapsibility in patients with obstructive sleep apnea (OSA). Most studies evaluated NEP using a mouthpiece that may exclude the cephalic portion of the upper airway. We hypothesize that NEP determination is influenced by interface and position.

METHODS

We evaluated patients with suspected OSA using polysomnography, NEP (-5 cmH₂O in sitting and supine position with mouthpiece and nasal mask). A subgroup also underwent computed tomography (CT) of the upper airway.

RESULTS

We studied a total of 86 subjects (72 male, age 46 ± 12 yrs, body mass index 30.0 ± 4.4 kg/m², neck circumference 40.0 ± 3.5 cm, AHI 32.9 ± 26.4, range 0.5 to 122.5 events/hour). NEP was influenced by interface and position (p = 0.007), and upper airway was more collapsible with mouthpiece than with nasal mask in sitting position (p = 0.001). Position influenced NEP and was worse in supine only when evaluated by nasal mask. Expiratory resistance (R _0.2) at 0.2 s during NEP was significantly higher and independent of position with mouthpiece than with nasal mask (20.7 versus 8.6 cmH₂O/L s^-1, respectively, p = 0.018). NEP evaluated with nasal mask in supine position and with mouthpiece in sitting position, but not when evaluated with mouthpiece in supine position, were correlated with upper airway anatomical measurements including tongue dimensions and pharyngeal length.

CONCLUSIONS

Interface and position influence NEP. NEP evaluated with nasal mask in supine position may convey more relevant information for patients under investigation for OSA than when evaluated with mouthpiece.

Clinicals And Upper Airway Characteristics in Obese Children with Obstructive Sleep Apnea

Introduction

Obesity is a factor that is strongly related to the occurrence of obstructive sleep apnea (OSA) in adults, although this association remains controversial for children.

Objective

The aim of this study was to compare the clinical and upper airway charactheristics, obtained by questionnaires, physical examination and laboratory tests, among obese children with and without OSA.

Method

This was aprospective cohort study. 44 obese children (body mass index above the 95th percentile) were included in the study. Questionnaires, physical examination of the upper airway, nasofibrolaryngoscopy, polysomnography, and laboratory allergic tests were performed.

Results

There were 22 male patients (50%), and the mean age was 7.6±2.5 years. OSA was present in 19 (43%) patients. There were no statistically significant differences between the groups with and without OSA, in relation to clinical or laboratory allergic parameters. For the upper airway assessments, hypertrophy of the pharyngeal (p=0.001) and palatine (p=0.049) tonsils were the only parameters associated with OSA, and a modified Mallampati index of class III/IV also demonstrated a tendency towards being statistically associated with OSA (p=0.081). Moreover, these findings were confirmed to be factors associated with OSA in this group of children according to a logistic regression analysis.

Conclusions

The occurrence rate of OSA in this obese pediatric population was high. Adenotonsillar hypertrophy and a modified Mallampati index of class III/IV were the factors associated with OSA.

Influence of mouth opening on oropharyngeal humidification and temperature in a bench model of neonatal continuous positive airway pressure

Clinical studies show that non-invasive respiratory support by continuous positive airway pressure (CPAP) affects gas conditioning in the upper airways, especially in the presence of mouth leaks. Using a new bench model of neonatal CPAP, we investigated the influence of mouth opening on oropharyngeal temperature and humidity. The model features the insertion of a heated humidifier between an active model lung and an oropharyngeal head model to simulate the recurrent expiration of heated, humidified air. During unsupported breathing, physiological temperature and humidity were attained inside the model oropharynx, and mouth opening had no significant effect on oropharyngeal temperature and humidity. During binasal CPAP, the impact of mouth opening was investigated using three different scenarios: no conditioning in the CPAP circuit, heating only, and heated humidification. Mouth opening had a strong negative impact on oropharyngeal humidification in all tested scenarios, but heated humidification in the CPAP circuit maintained clinically acceptable humidity levels regardless of closed or open mouths. The model can be used to test new equipment for use with CPAP, and to investigate the effects of other methods of non-invasive respiratory support on gas conditioning in the presence of leaks.

Dynamic swallowing study for globus patients

Objective

To examine whether pharyngeal swallowing function is impaired in globus patients with swallowing difficulty by dynamic swallowing study.

Methods

Dynamic swallowing studies were performed on 80 normal adult volunteers and 33 globus patients with swallowing difficulty. Objective parameters such as maximum displacement of the hyoid bone, pharyngeal transit time, pharyngeal constriction ratio, and maximum opening of the esophageal entrance were measured, which were closely associated with the pharyngeal swallowing function in the swallowing process.

Results

There were no significant differences between globus patients and normal adults in hyoid bone displacement, pharyngeal transit time, pharyngeal constriction ratio, or maximum opening of the esophageal entrance (p > 0.05).

Conclusion

The results of the dynamic swallowing study indicated that the pharyngeal swallowing function of globus patients was not impaired.

Blood circulation in the ascidian tunicate Corella inflata (Corellidae)

The body of the ascidian tunicate Corella inflata is relatively transparent. Thus, the circulatory system can be visualized by injecting high molecular weight fluorescein labeled dextran into the heart or the large vessels at the ends of the heart without surgery to remove the body wall. In addition, after staining with neutral red, the movement of blood cells can be easily followed to further characterize the circulatory system. The heart is two gently curved concentric tubes extending across the width of the animal. The inner myocardial tube has a partial constriction approximately in the middle. As in other tunicates, the heart is peristaltic and periodically reverses direction. During the branchial phase blood leaves the anterior end of the heart by two asymmetric vessels that connect to the two sides of the branchial basket. Blood then flows in both transverse directions through a complex system of ducts in the basket into large ventral and dorsal vessels which carry blood back to the visceral organs in the posterior of the animal. During the visceral phase blood leaves the posterior end of the heart in two vessels that repeatedly bifurcate and fan into the stomach and gonads. Blood velocity, determined by following individual cells in video frames, is high and pulsatory near the heart. A double peak in velocity at the maximum may be due to the constriction in the middle of the heart tube. Blood velocity progressively decreases with distance from the heart. In peripheral regions with vessels of small diameter blood cells frequently collide with vessel walls and cell motion is erratic. The estimated volume of blood flow during each directional phase is greater than the total volume of the animal. Circulating blood cells are confined to vessels or ducts in the visible parts of the animal and retention of high molecular weight dextran in the vessels is comparable to that seen in vertebrates. These are characteristics of a closed circulatory system.

[Imaging of the head and neck region]

Tumors of the head and neck are predominantly squamous cell carcinomas and those of the salivary glands are predominantly adenocarcinomas, adenoid cystic carcinomas and mucoepidermoid carcinomas. In 2011 the incidence of tumors of the oral cavity and pharynx in Germany was 6839 (5026 male and 1813 female) and of the larynx 1878 (1642 male and 236 female). The incidence of tumors of the nose and paranasal sinuses (467) and salivary glands (470) were much lower (www.krebsdaten.de/abfrage). The primary aim of imaging in head and neck cancer is staging of the disease and a precise assessment of tumor invasion. This information is essential for therapy decision-making (i. e. surgery or radiochemotherapy), planning of the extent of resection and subsequent reconstructive measures and also estimation of functional deficits after therapy. Computed tomography (CT) and magnetic resonance imaging (MRI) are the imaging modalities of choice but both have specific advantages and disadvantages. In certain cases both CT and MRI need to be performed for accurate treatment planning.

[Imaging of the head and neck region]

Tumors of the head and neck are predominantly squamous cell carcinomas and those of the salivary glands are predominantly adenocarcinomas, adenoid cystic carcinomas and mucoepidermoid carcinomas. In 2011 the incidence of tumors of the oral cavity and pharynx in Germany was 6839 (5026 male and 1813 female) and of the larynx 1878 (1642 male and 236 female). The incidence of tumors of the nose and paranasal sinuses (467) and salivary glands (470) were much lower ( www.krebsdaten.de/abfrage ). The primary aim of imaging in head and neck cancer is staging of the disease and a precise assessment of tumor invasion. This information is essential for therapy decision-making (i. e. surgery or radiochemotherapy), planning of the extent of resection and subsequent reconstructive measures and also estimation of functional deficits after therapy. Computed tomography (CT) and magnetic resonance imaging (MRI) are the imaging modalities of choice but both have specific advantages and disadvantages. In certain cases both CT and MRI need to be performed for accurate treatment planning.

Fiberoptic Guided Retrograde Intubation in an Anticipated Difficult Airway: Revival of an Antiquated Technique

Retrograde intubation is an invaluable technique which can be helpful in anticipated difficult airway situation. In this advanced era where fiberoptic intubation and video laryngoscopes are in abundant use, retrograde intubation is a forgotten technique. However, it may be useful in various difficult airway situations in this advanced era. In our case the patient had a bitter experience with previous fiberoptic intubation. Owing to that we had planned and performed a fiber optic guided retrograde intubation, where we had kept the fiberoptic bronchoscope in the pharynx keeping larynx and vocal cords in the focus to facilitate the emergence of guide wire through one of the nostrils as well as direct visual confirmation of intubation. This fiber optic guided retrograde intubation is a first reported case of its kind in a predicted difficult airway which can be beneficial in different difficult airway situations.

Squamous cell carcinoma in a wild European bullhead Cottus gobio

A pharyngeal tumor was found in a wild European bullhead. The tumor mass appeared underneath the operculum and was bilobed. The major neoplastic component showed diffuse epithelial squamous differentiation. Crossmonn's trichrome allowed identification of connective tissues whereas no neoplastic cells were stained. Periodic acid-Schiff was negative within the mass, and Giemsa did not show any further diagnostic significance. Immunohistochemistry showed diffuse positive cytoplasmic staining of the neoplastic population with an anti-human pancytokeratin antibody. Vimentin was negative and exclusively stained the stroma. On the basis of the morphological and immunohistochemical results, a squamous cell carcinoma was diagnosed.

Hamartoma of Palatine Tonsil: A Rare Case

Hamartomas are disorganized but benign masses composed of cells indigenous to the involved site. They have been reported in almost all organs but are rare in the head and neck region, especially the pharynx. We describe the case of a six-month-old male infant who presented with acute respiratory symptoms due to a pedunculated polypoid mass arising from his left palatine tonsil. He underwent a tonsillectomy and removal of the polyp after initial stabilization. Histopathological examination showed features consistent with hamartoma. The child had an uneventful recovery and follow-up after one year showed no evidence of recurrence. Our case highlights that rare benign lesions like hamartoma originating in the oral cavity, even in infants, can have such an acute presentation and should be considered in differential diagnosis.

Pharyngeal Satellite Cells Undergo Myogenesis Under Basal Conditions and Are Required for Pharyngeal Muscle Maintenance

The pharyngeal muscles of the nasal, oral, and laryngeal pharynxes are required for swallowing. Pharyngeal muscles are preferentially affected in some muscular dystrophies yet spared in others. Muscle stem cells, called satellite cells, may be critical factors in the development of pharyngeal muscle disorders; however, very little is known about pharyngeal satellite cells (PSC) and their role in pharyngeal muscles. We show that PSC are distinct from the commonly studied hindlimb satellite cells both transcriptionally and biologically. Under basal conditions PSC proliferate, progress through myogenesis, and fuse with pharyngeal myofibers. Furthermore, PSC exhibit biologic differences dependent on anatomic location in the pharynx. Importantly, PSC are required to maintain myofiber size and myonuclear number in pharyngeal myofibers. Together, these results demonstrate that PSC are critical for pharyngeal muscle maintenance and suggest that satellite cell impairment could contribute to pharyngeal muscle pathology associated with various muscular dystrophies and aging.

Otorhinolaryngology manifestations secondary to oral sex

INTRODUCTION

Over the last few years, oral and pharyngeal signs and symptoms due to oral sex have increased significantly. However, no review articles related to this subject have been found in the medical literature. The objective of our study was to identify otorhinolaryngological manifestations associated with orogenital/oroanal contact, both in adults and children, in the context of consensual sex or sexual abuse.

METHODS

We performed a review of the medical literature on otorhinolaryngological pathology associated with oral sex published in the last 20 years in the PubMed database.

RESULTS

Otorhinolaryngological manifestations secondary to oral sex practice in adults can be infectious, tumoral or secondary to trauma. The more common signs and symptoms found in the literature were human papillomavirus infection (above all, condyloma acuminata and papilloma/condyloma), oral or pharyngeal syphilis, gonococcal pharyngitis, herpes simplex virus infection and pharyngitis from Chlamydia trachomatis. The incidence of human papillomavirus -induced oropharyngeal carcinoma has dramatically increased. In children past the neonatal period, the presence of condyloma acuminatus, syphilis, gonorrhoea or palatal ecchymosis (the last one, unless justified by other causes) should make us suspect sexual abuse.

CONCLUSIONS

Sexual habits have changed in the last decades, resulting in the appearance of otorhinolaryngological pathology that was rarely seen previously. For this reason, it is important for primary care physicians to have knowledge about the subject to perform correct diagnosis and posterior treatment. Some sexual abuse cases in children may also be suspected based on the knowledge of the characteristic oropharyngeal manifestations secondary to them.

Upper airway changes following single-step or stepwise advancement using the Functional Mandibular Advancer

OBJECTIVES

Purpose of the present study was to determine and compare possible changes in the dimensions of the pharyngeal airway, morphology of the soft palate, and position of the tongue and hyoid bone after single-step or stepwise mandibular advancement using the Functional Mandibular Advancer (FMA).

PATIENTS AND METHODS

The sample included 51 peak-pubertal Class II subjects. In all, 34 patients were allocated to two groups using matched randomization: a single-step mandibular advancement group (SSG) and a stepwise mandibular advancement group (SWG). Both groups were treated with FMA followed by fixed appliance therapy; the remaining 17 subjects who underwent only fixed appliance therapy constituted the control group (CG). The study was conducted using pre- and posttreatment lateral cephalometric radiographs. Data were analyzed by paired t test, one-way analysis of variance, and Pearson's correlation coefficient.

RESULT

In the SWG and SSG, although increases in nasopharyngeal airway dimensions were not significant compared with those in the CG, enlargements in the oropharyngeal airway dimensions at the level of the soft palate tip and behind the tongue, and decreases in soft palate angulation, were significant. Tongue height increased significantly only in the SWG. Compared with the CG, while forward movement of the hyoid was more prominent in SSG and SWG, the change in the vertical movement of the hyoid was not significant. No significant difference between SWG and SSG was observed in pharyngeal airway, soft palate, tongue or hyoid measurements.

CONCLUSIONS

The mode of mandibular advancement in FMA treatment did not significantly affect changes in the pharyngeal airway, soft palate, tongue, and hyoid bone.

A local mechanism by which alcohol consumption causes cancer

Epidemiological data indicate that 5.8% of cancer deaths world-wide are attributable to alcohol consumption. The risk of cancer is higher in tissues in closest contact on ingestion of alcohol, such as the oral cavity, pharynx and esophagus. However, since ethanol is not mutagenic and the carcinogenic metabolite of ethanol (acetaldehyde) is mostly produced in the liver, it is not clear why alcohol use preferentially exerts a local carcinogenic effect. It is well known that ethanol causes cell death at the concentrations present in alcoholic beverages; however, this effect may have been overlooked because dead cells cannot give rise to cancer. Here I discuss that the cytotoxic effect of ethanol on the cells lining the oral cavity, pharynx and esophagus activates the division of the stem cells located in deeper layers of the mucosa to replace the dead cells. Every time stem cells divide, they become exposed to unavoidable errors associated with cell division (e.g., mutations arising during DNA replication and chromosomal alterations occurring during mitosis) and also become highly vulnerable to the genotoxic activity of DNA-damaging agents (e.g., acetaldehyde and tobacco carcinogens). Alcohol consumption may increase the risk of developing cancer of the oral cavity, pharynx and esophagus by promoting the accumulation of cell divisions in the stem cells that maintain these tissues in homeostasis. Understanding the mechanisms of carcinogenicity of alcohol is important to reinforce the epidemiological evidence and to raise public awareness of the strong link between alcohol consumption and cancer.

Macrophage density in pharyngeal and laryngeal muscles greatly exceeds that in other striated muscles: an immunohistochemical study using elderly human cadavers

Macrophages play an important role in aging-related muscle atrophy (i.e., sarcopenia). We examined macrophage density in six striated muscles (cricopharyngeus muscle, posterior cricoarytenoideus muscle, genioglossus muscle, masseter muscle, infraspinatus muscle, and external anal sphincter). We examined 14 donated male cadavers and utilized CD68 immunohistochemistry to clarify macrophage density in muscles. The numbers of macrophages per striated muscle fiber in the larynx and pharynx (0.34 and 0.31) were 5–6 times greater than those in the tongue, shoulder, and anus (0.05–0.07) with high statistical significance. Thick muscle fibers over 80 µm in diameter were seen in the pharynx, larynx, and anal sphincter of two limited specimens. Conversely, in the other sites or specimens, muscle fibers were thinner than 50 µm. We did not find any multinuclear muscle cells suggestive of regeneration. At the beginning of the study, we suspected that mucosal macrophages might have invaded into the muscle layer of the larynx and pharynx, but we found no evidence of inflammation in the mucosa. Likewise, the internal anal sphincter (a smooth muscle layer near the mucosa) usually contained fewer macrophages than the external sphincter. The present result suggest that, in elderly men, thinning and death of striated muscle fibers occur more frequently in the larynx and pharynx than in other parts of the body.