Timing of videofluoroscopic,manometric events,and bolus transit during the oral and pharyngeal phases of swallowing

The aims of this study were to evaluate and quantify the timing of events associated with the oral and pharyngeal phases of liquid swallows. For this purpose, we recorded 0–20 ml barium swallows in three groups of volunteers using videoradiographic, electromyographic, and manometric methods. The study findings indicated that a leading complex of tongue tip and tongue base movement as well as onset of superior hyoid movement and mylohyoid myoelectric activity occurred in a tight temporal relationship at the inception of swallowing. Two distinct general types of normal swallows were observed. The common “incisor-type” swallow began with the bolus positioned on the tongue with the tongue tip pressed against the upper incisors and maxillary alveolar ridge. At the onset of the “dipper-type” swallow the bolus was located beneath the anterior tongue and the tongue tip scooped the bolus to a supralingual location. Beginning with tongue-tip peristaltic movement at the upper incisors, the two swallow types were identical. Swallow events that occurred after lingual peristaltic movement at the maxillary incisors showed a volume-dependent forward migration in time that led to earlier movement of the hyoid and larynx as well as earlier opening of the upper esophageal sphincter in order to receive the large boluses that arrived sooner in the pharynx during the swallow sequence than did smaller boluses. The study findings indicated that timing of swallow events should be considered in reference to both swallow type and bolus volume. The findings also indicated an important distinction between peristaltic transit and bolus clearance.     

Gender Effects on Airway Closure in Normal Subjects

The present study was designed to examine age and gender differences with respect to the duration of laryngeal closure, the onset of laryngeal closure in relation to the first cricopharyngeal opening, and the duration of cricopharyngeal opening for six different groups: normal younger men and women (22–29 years), normal middle-aged men and women (45–53 years), and normal older men and women (81–94 years) (10 subjects in each group for a total of 60 subjects). Data were collected by means of videofluoroscopic studies. During swallows of liquid barium, results indicated that normal older subjects had longer cricopharyngeal opening than younger subjects (P = 0.044). Results also revealed that the mean duration of laryngeal closure was significantly longer in women than in men (P = 0.013). The onset of laryngeal closure was significantly earlier in women than in men (P = 0.006). Also, bolus volume effects were observed for both the duration of laryngeal closure (P < 0.0001) and cricopharyngeal opening (P < 0.0001). During liquid barium swallows there was a linear increase in both the duration of laryngeal closure and cricopharyngeal opening.     

Effects of Age, Gender, Bolus Volume, and Trial on Swallowing Apnea Duration and Swallow/Respiratory Phase Relationships of Normal Adults

The effects of age, gender, bolus volume, and trial on swallowing apnea duration (SAD) and swallow/respiratory phase relationships were examined. Sixty adults, composed of ten males and ten females in each of three age groups (i.e., 20–39, 40–59, and 60–83 years), participated. SAD was assessed via nasal airflow during saliva swallows and 10-, 15-, 20-, 25-mL bolus volumes across three trials. Results revealed SAD is consistent across trial (p>0.05). Significant main effects of age, gender, and bolus volume were found (p<0.05), i.e., elderly adults had longer SAD than young and middle-aged adults; women had longer SAD than men; and SAD increased as bolus volume increased. With respect to saliva swallows, a significant interaction of age by gender was found (p<0.05), i.e., males exhibited a decrease in SAD with increasing age while females exhibited an increase in SAD with increasing age. Concerning swallow/respiratory phase relationships, the pattern of exhale–swallow–exhale was evident during 62% of participants' swallows. Furthermore, age, gender, or bolus volume did not predict the pattern of exhale–swallow–exhale (p>0.05). Submitted February 23, 2000; accepted October 2, 2000     

Upper esophageal sphincter opening and modulation during swallowing

Studies were done on 8 normal subjects with synchronized videofluoroscopy and manometry to facilitate a biomechanical analysis of upper esophageal sphincter opening and volume-dependent modulation during swallowing. Movements of the hyoid and larynx, dimensions of sphincter opening, and intraluminal sphincter pressure were determined at 1/30th-s intervals during swallows of 1, 5, 10, and 20 ml of liquid barium. Our analysis subdivided upper esophageal sphincter activity during swallowing into five phases: (a) relaxation, (b) opening, (c) distention, (d) collapse, and (e) closure. Sphincter relaxation occurred during laryngeal elevation and preceded opening by a mean period of 0.1 s. Opening occurred as the sphincter was pulled apart via muscular attachments to the hyoid such that the hyoid coordinates at which sphincter opening and closing occurred were constant among bolus volumes. Sphincter distention after opening was modulated by intrabolus pressures rather than graded hyoid movement. The generation of intrabolus pressure coincided with the posterior thrust of the tongue that culminated in pharyngeal wall contact and the initiation of pharyngeal peristalsis. Larger volume swallows were associated with greater intrabolus pressure and increased bolus head velocity. The duration of sphincter opening increased in conjunction with a prolongation of the anterior-superior excursion of the hyoid and a delay in the onset of pharyngeal peristalsis (the event that determined the timing of sphincter closure). We conclude that transsphincteric transport of increasing swallow bolus volumes is accomplished by modulating sphincter diameter, opening interval, and flow rate (reflected by bolus head velocity). Furthermore, upper esophageal sphincter opening is an active mechanical event rather than simply a consequence of cricopharyngeal relaxation.     

健康老年妇女吞咽功能的研究

目的　通过电视X线透视吞咽功能的研究 ,评价健康老年妇女液体吞咽运动 ,并对液体吞咽运动的影响因素进行分析。　方法　 4 0例健康老年妇女 ,老年前期组 (5 0～ 5 9岁 ) 2 0例 ;老年组 2 0例 ,年龄 6 0～ 79岁。进行电视X线透视液体吞咽功能检查 ,分别对口咽部相关结构进行运动学分析 ,比较不同液体食团体及年龄对健康老年妇女吞咽的影响。　结果　 (1 )老年组较老年前期组渗透、口咽部滞留发生率增高 ,两组渗透发生率分别为 :7 5 %、3 8% ;口腔滞留发生率分别为 :1 2 5 %、6 3% ;咽腔滞留发生率分别为 :2 6 5 %、1 7 5 % ;口咽传递时间、腭咽部关闭时间及环咽部开放时间延长 (均为P <0 0 5 ) ;喉、舌骨向上运动距离增大 (P <0 0 5 )。 (2 ) 1 0ml食团较 1ml渗透、口咽部滞留发生率增高 ,两组渗透发生率分别为 :8 8%、2 5 % ;口腔滞留发生率分别为 :1 3 8%、5 0 % ;咽腔滞留发生率分别为 :31 3%、1 3 8% ;口传递时间缩短而环咽部开放时间延长 (均为P <0 0 5 ) ;喉向上、前运动 ,舌骨向前、向上运动的距离增大 (P <0 0 5 )。　结论　临床应用电视X线透视吞咽功能检查并对口咽期吞咽功能进行运动学分析是可行的 ;年龄及食团体积均影响健康老年妇女的液体吞咽功能     

Gender Effects on Airway Closure in Head and Neck Cancer Patients

Age, gender, and bolus effects on the duration of laryngeal closure, the onset of laryngeal closure in relation to the first cricopharyngeal opening, and the duration of cricopharyngeal opening in head and neck cancer patients have not been well documented. Thirty-three head and neck cancer patients (middle-aged women and men, and older women and men) were evaluated with videofluoroscopy before and 3?months after their cancer treatment. At 3?months post-treatment, the mean duration of laryngeal closure was longer for women than for men at 1-, 5-, and 10-ml bolus volumes. The duration of laryngeal closure at 3?months post-treatment and the duration of cricopharyngeal opening at both pretreatment and 3?months post-treatment increased as liquid bolus volume increased. Gender effects were observed in the duration of laryngeal closure during swallow. Bolus effects were observed in the duration of laryngeal closure and cricopharyngeal opening.     

Effects of stroke‐induced damage to swallow‐related areas in the brain on swallowing mechanics of elderly patients

Aim: Our objective was to determine the relationship between defective swallowing mechanics and the location of brain lesions in stroke patients. Methods: We evaluated swallowing mechanics in 37 stroke patients and 10 age‐matched control subjects by videofluoroscopy. Subjects were asked to swallow 10 successive 1.0‐mL and three successive 2.5‐mL boluses of barium suspension at intervals of approximately 15–30 s. We measured oral transit time, pharyngeal delay time and pharyngeal transit time. Results: Patients could be divided into two groups based on the pharyngeal delay time for a 1.0‐mL bolus swallow. One group showed little variation during successive swallowing tests, similar to the control group. In the other group pharyngeal delay times varied during successive trials often tending to increase with successive swallows. Magnetic resonance imaging studies of the brain revealed infarcts or hemorrhages in swallow‐related areas in the latter group, while in the former group lesions were localized to areas unrelated to swallowing. Conclusion: Damage to swallow‐related areas may reduce their sensitivity to incoming signals from the oral cavity thereby impairing preparations to generate motor command signals and compromising their ability to send sufficient voluntary descending command signals to activate the swallowing central pattern generator located in the medulla. This deficiency becomes more evident with successive swallows and manifests as impaired swallowing mechanics.     

Preliminary Temporal Measurement Analysis of Normal Oropharyngeal Swallowing in Infants and Young Children

Temporal measures of normal pediatric oropharyngeal deglutition have not been studied. Knowledge of range and variation of normative temporal measures could define abnormal deglutition and assist in design of appropriate compensatory and rehabilitative treatment techniques. The purpose of this retrospective study was to determine temporal measurements for oral filling, oral transit, onset of laryngeal closure, time of bolus arrival at the valleculae, pharyngeal delay, pharyngeal transit, and UES opening. Videofluoroscopic swallow studies of 15 normally swallowing pediatric subjects were divided into three age groups and method of liquid delivery. Mean, standard deviation, percentages, and extension of the median were utilized to determine relationships of temporal measures. Mean temporal duration increased with age for oral filling, oral transit time, time of laryngeal closure, UES opening, and pharyngeal delay time. However, no significant differences were found between age groups indicating a deglutitive biomechanical adaptation to growth of the oral and pharyngeal cavity. Feeding method for bottle versus cup mean duration increased for oral transit time, laryngeal closure time, UES opening, and pharyngeal delay time. Bolus head location relative to onset of laryngeal vestibule closure changed with increased age and method of feeding. Temporal measures were not significantly different for age groups or feeding methods. Bolus location was at or fully contained in the valleculae at the onset of laryngeal closure and appeared to be a normal finding in functional pediatric swallows and is not indicative of a delay or disorder.     

Videofluoroscopic Evaluation of Swallowing in Chagas�� Disease

Dysphagia is the most common digestive symptom reported by patients with Chagas’ disease. The condition results from abnormalities of esophageal motility. Our hypothesis is that there are also alterations of oral and pharyngeal transit during swallowing. We studied by videofluoroscopy the oral and pharyngeal transit during swallowing in 17 patients with dysphagia, a positive serologic test for Chagas’ disease, and radiologic demonstration of esophageal involvement. The study also included 15 asymptomatic healthy volunteers. Each subject swallowed in duplicate 5 and 10 ml of liquid and paste barium boluses. Chagas’ disease patients had a longer oropharyngeal transit with the 5-ml liquid bolus (p = 0.03), and a longer oral transit (p = 0.01) and pharyngeal transit (p = 0.04) with the 10-ml liquid bolus than controls. There was no difference between patients and controls with swallows of the 5-ml paste bolus. With swallows of the 10-ml paste bolus, the oropharyngeal transit (p = 0.05), pharyngeal transit (p = 0.04), pharyngeal clearance (p = 0.02), and UES opening (p = 0.01) took a longer amount of time in Chagas’ disease patients than in controls. We conclude that the duration of pharyngeal transit is longer in patients with Chagas’ disease than in normal subjects, especially with a bolus of pasty consistency and a volume of 10 ml.     

Videomanometric Analysis of Supraglottic Swallow, Effortful Swallow, and Chin Tuck in Healthy Volunteers

Simultaneous videoradiography and solid-state manometry (videomanometry) was applied in eight healthy volunteers (four women, four men; age range 25–64 years, mean age 41 years) without swallowing problems. Three different swallowing techniques were tested; supraglottic swallow, effortful swallow, and chin tuck. Seven videoradiographic variables and six manometric variables were analyzed. The supraglottic swallowing technique did not differ significantly from that of the control swallows. The effortful swallow had a significantly (p= 0.0001) reduced hyoid–mandibular distance preswallow due to an elevation of the hyoid and the larynx, which caused a significantly (p= 0.007) reduced maximal hyoid movement and a significantly (p= 0.009) reduced laryngeal elevation during swallow. The chin tuck swallow had a significantly (p= 0.001) reduced laryngohyoid distance and also a significantly (p= 0.004) reduced hyoid–mandibular distance. The chin tuck swallow also displayed significantly (p= 0.003) weaker pharyngeal contractions. Videomanometry allows for analysis of bolus transport, movement of anatomical structures, and measurement of intraluminal pressures. These variables are important when evaluating swallowing techniques. In the present study, we made a few observations that never have been reported before. When healthy volunteers performed supraglottic swallow, they performed the technique somewhat differently. Therefore, we assume dysphagic patients would need a substantial period of training to perform a technique efficiently. Chin tuck could impair protection of the airways in dysphagic patients with weak pharyngeal constrictor muscles.     

应用高分辨率测压研究不同食团对我国健康人食管动力的影响

目的 了解健康中国人食管动力对不同食团的反应.方法 对经过严格入选排除标准入选的18名受试者行高分辨率测压（HRM）,分析静息及不同食团（5 ml、10 ml、15 ml、20 ml水、黏胶及固体食团）吞咽时的食管动力特点.结果 固体吞咽时,蠕动起始速度（2.5±0.4）cm/s均低于其他各种类型食团（水及黏胶）,近段压力（74.6±7.2）mmHg均高于其他各种类型食团;固体吞咽时食管体部蠕动速度和食管各段收缩幅度与黏胶吞咽时比较均有差异.在各种形态食团的吞咽中,食管远段的压力总是高于近段,在5 ml、10 ml湿咽、黏胶吞咽和固体吞咽时,食管远段压力高于中段.5 ml液体吞咽及黏胶吞咽时,近段压力女性低于男性;10ml与20ml湿咽时,女性食管蠕动速度均低于男性.结论 不同食团诱发的食管蠕动速度和幅度是不同的,性别差异在食管蠕动速度及不同节段收缩幅度上无一致性结果.     

Hyoid-Bolus Transit Latencies in Normal Swallow

Pharyngeal swallow delay is frequently found in dysphagic patients and is thought to be a factor in a range of swallowing problems, including aspiration. Implicit in notions of swallow “delay” is a temporal interval between two events that is longer than normal. However, there appears to be little agreement about which referent events should be considered in determining delay. A number of pharyngeal bolus transit points and various pharyngeal gestures have been used in delays determined from fluoroscopic evidence, and other referents have been used in electromyographic and manometric studies of swallow. In this study latencies between the first movement of the hyoid and several pharyngeal bolus transit points were calculated from fluoroscopic swallow studies in normal nondysphagic adults. Means and standard deviations of these latencies are provided for a 3-cc and a 20-cc bolus and for both nonelderly and elderly adults. The data may be a useful resource for relating the specific latencies investigated to concepts of pharyngeal swallow delay, in particular, when assessing videofluoroscopic studies using a similar protocol.     

A Scintigraphic Study of Oral, Pharyngeal, and Esophageal Transit in Patients with Stroke

Although stroke affects mainly the oral and pharyngeal phases of swallowing, it may also impair esophageal contractions. Our hypothesis is that stroke may affect esophageal transit. The oral, pharyngeal, and esophageal transit was studied by the scintigraphic method in 26 patients (age range=26-83 years), eight of whom had mild dysphagia but all were able to feed orally and who had suffered an acute first-ever ischemic stroke 10-56 days (median = 43 days) before transit evaluation. The control group included 15 healthy volunteers (age range=27-86 years). All subjects swallowed a 5-ml liquid bolus and a 5-ml paste bolus labeled with technetium-99m phytate while sitting in front of the collimator of a gamma camara. The oral, pharyngeal, and proximal, middle, and distal esophageal transit was measured for 20 s. Three patients did not swallow the bolus during the scintigraphic evaluation. There was no difference between patients and controls with respect to oral and pharyngeal transit or clearance of liquid. For paste, the pharyngeal transit time was shorter for patients (0.48+/-0.17 s) than for controls (0.61+/-0.18 s, p=0.027). Also for the paste bolus, the residue in the mouth was greater in patients (18.4+/-13.6%) than in controls (10.2+/-4.9%, p=0.031). The liquid transit duration in the distal esophagus was shorter in patients with stroke (1.74+/-0.84 s) than in controls (2.68+/-1.65 s, p=0.028). There was no difference between patients and controls in esophageal residue. In conclusion, patients with stroke and able to feed orally may have alterations in the esophageal transit of a liquid bolus.     

UES Opening and Cricopharyngeal Bar in Nondysphagic Elderly and Nonelderly Adults

The intent of the study was to investigate upper esophageal sphincter (UES) opening and cricopharyngeal bar, and their relationship to other swallowing variables, in elderly, nondysphagic subjects. Extent and duration of UES opening, hypopharyngeal transit time, hyoid displacement, hyoid-to-larynx approximation, and incomplete pharyngeal clearing were determined from fluoroscopic swallow studies in 84 nonelderly control subjects and 88 elderly subjects. No differences in these measures were found between elderly subjects with and without medical conditions, and data were subsequently pooled. Mild, moderate, or marked cricopharyngeal bars were identified in more than 30% of elderly subjects, and subsequent analyses were performed on the control group, the elderly group without bars, and the elderly group with bars. Maximum opening of the UES in the elderly bar group was significantly reduced compared with that of the elderly group without bars and the nonelderly control group. However, timing measures did not differentiate elderly subjects with bars from other elderly subjects and they suggest that prolonged transit times in the elderly cannot be explained by the presence of a cricopharyngeal bar. With the exception of hyoid displacement, all variables investigated differed significantly between the nonelderly and one or both of the elderly groups. With the exception of UES opening, variables examined generally did not differentiate the two elderly groups.     

Normal adult swallowing of liquid and viscous material: Scintigraphic data on bolus transit and oropharyngeal residues

Scintigraphic data are provided for 20 normal control subjects, 39–65 years of age. Each subject swallowed 10 cc of water and 10 cc of a more viscous material (1,100 centipoise) consisting of apple juice thickened with Thick-It, a commercial food thickener. The test substances were combined with 2.5 mCi Tc-99m sulfur colloid. Scintigraphic data were acquired in dynamic mode for 10 sec at 25 frames/sec as the subjects swallowed. Time-activity (TA) data were used to compute transit times, percentage residues in the mouth and pharynx, percent ingested, and a derived swallow efficiency score. The liquid was ingested in a single swallow by all subjects, and 9 cc was actually tranferred to the esophagus. In contrast, for the viscous material, 11/20 subjects performed a second clearing swallow within the 10-sec interval. On the first swallow with the viscous substance, an average of 7 cc was transferred to the esophagus. Scintigraphy offers an excellent technique for determining natural and preferred volumes for swallowing a variety of bolus consistencies, since it can quantify the volume of each swallow or partial swallow. In this group of subjects the oral discharge time was shorter with the viscous material than with the water, but the pharyngeal transit times were not significantly different for the two bolus consistencies. Numerical efficiency scores were lower for the viscous material, indicating that such a measure is bolus dependent.     

Predictors of Outcome following Cricopharyngeal Disruption for Pharyngeal Dysphagia

The indications for, and predictors of outcome following cricopharyngeal disruption in pharyngeal dysphagia are not clearly defined. Our purpose was to examine the symptomatic response to cricopharyngeal disruption, by either myotomy or dilatation, in patients with oral-pharyngeal dysphagia and to determine pretreatment manometric or radiographic predictors of outcome. Using simultaneous pharyngeal videoradiography and manometry, we studied 20 patients with pharyngeal dysphagia prior to cricopharyngeal diltation (n = 11) or myotomy (n = 8), and 23 healthy controls. We measured peak pharyngeal pressure, hypopharyngeal intrabolus pressure, upper esophageal sphincter diameter, and coordination. Response rate to sphincter disruption was 65%. The extent of sphincter opening was significantly reduced in patients compared with controls (p= 0.004), but impaired sphincter opening was not a predictor of outcome. Increased hypopharyngeal intrabolus pressures (>19 mmHg for 10 ml bolus; >31 mmHg for 20 ml bolus) was a significant predictor of outcome (p= 0.01). Neither peak pharyngeal pressure nor incoordination were predictors of outcome. In pharyngeal dysphagia, hypopharyngeal intrabolus pressure, and not peak pharyngeal pressure, is a predictor of response to cricopharyngeal disruption. The relationship between intrabolus pressure and impaired sphincter opening is an indirect measure of sphincter compliance which helps predict therapeutic response.     

Supraglottic swallow,effortful swallow,and chin tuck did not alter hypopharyngeal intrabolus pressure in patients with pharyngeal dysfunction

Simultaneous videoradiography and solid-state manometry (videomanometry) were performed in 8 patients (4 women, 4 men; age range = 46–81 years, mean age = 70 years) with pharyngeal dysfunction in order to disclose any changes in intrabolus pressure during swallowing maneuvers. Five of the patients had severe pharyngeal dysfunction with frequent misdirected swallows. Three of the patients had moderate pharyngeal dysfunction with delayed initiation of pharyngeal swallow. Three different swallowing techniques were applied: supraglottic swallow, effortful swallow, and chin tuck. Pharyngeal intrabolus pressure was analyzed at the level of the inferior pharyngeal constrictor. Supraglottic swallow, effortful swallow, and chin tuck did not alter peak amplitude or duration of the intrabolus pressure.     

Speed of peristalsis in pharyngeal constrictor musculature: Correlation to age

In order to define the influence of age on pharyngeal constrictor peristalsis, four groups of individuals were examined with cineradiography (50 frames/s) during barium swallow. The speed varied between 6.3 and 21.3 cm/s (mean, 10.5). There was no significant difference between young nondysphagic volunteers and the three groups of dysphagic patients ages under 40, between 50 and 60, and over 75 years of age). However, the intrapersonal variation of peristaltic speed during three different swallows was small in young nondysphagic volunteers and large in dysphagic patients. The variation increased with age. Variation in speed is easy to register during cineradiography and should be considered as a criterion for definition of pharyngeal motor performance in dysphagic patients. Supported by grants from the “Gun and Bertil Stohnes Foundation”     

The Effect of an Effortful Swallow on the Normal Adult Esophagus

The effect of an effortful swallow on the healthy adult esophagus was investigated using concurrent oral and esophageal manometry (water perfusion system) on ten normal adults (5 males and 5 females, 20-35 years old) while swallowing 5-ml boluses of water. The effects of gender, swallow condition (effortful versus noneffortful swallows), and sensor site within the oral cavity, esophageal body, and lower esophageal sphincter (LES) were examined relative to amplitude, duration, and velocity of esophageal body contractions, LES residual pressure, and LES relaxation duration. The results of this study provide novel evidence that an effortful oropharyngeal swallow has an effect on the esophageal phase of swallowing. Specifically, effortful swallowing resulted in significantly increased peristaltic amplitudes within the distal smooth muscle region of the esophagus, without affecting the more proximal regions containing striated muscle fibers. The findings pertaining to the LES are inconclusive and require further exploration using methods that permit more reliable measurements of LES function. The results of this study hold tremendous clinical potential for esophageal disorders that result in abnormally low peristaltic pressures in the distal esophageal body, such as achalasia, scleroderma, and ineffective esophageal motility. However, additional studies are necessary to both replicate and extend the present findings, preferably using a solid-state manometric system in conjunction with bolus flow testing on both normal and disordered populations, to fully characterize the effects of an effortful swallow on the esophagus.     

Is the Anatomical Protrusion on the Posterior Hypopharyngeal Wall Associated with Cadavers of Only the Elderly?

Cricopharyngeal bars are commonly seen on a barium swallow radiologic examination and represent the failure of the cricopharyngeus to relax. Traditionally, the bars have been considered as functional or physiologic protrusions. Recently, anatomical cricopharyngeal protrusion has been found in about 30% of cadavers of the elderly, suggesting that such a structural change may become a physical barrier that affects the normal deglutition in a living person. This suggests that such a radiographic finding should be carefully considered when interpreting radiologic and manometrical examinations and managing dysphagia of the elderly. However, the finding of the anatomical cricopharyngeal protrusion was based on the observation of cadavers of the elderly (mean age = 77 years). The aim of this study was to further investigate whether such an anatomical cricopharyngeal protrusion exists in cadavers of other ages. Using the dissection method, we examined 63 human cadavers that were divided into three age groups: young adult (6 females and 10 males, age = 16–24 years old), adult (8 females and 23 males, age = 25–64 years old), and early elderly (5 females and 11 males, age = 65–69 years old). We found that 57 of the 63 cadavers had a smooth mucosal surface on the posterior hypopharyngeal and upper esophageal wall. A slightly thickened posterior muscular wall was observed at the cricoid level in six cadavers (five from the adult group and one from the early elderly group), but its boundary was not clearly identified. Taking the previous reports together, our results suggest that an anatomical cricopharyngeal protrusion is closely associated with the aging process.