Levator Veli Research Articles

口蓋裂患者の口蓋帆挙筋の組織像と筋電図

In some patients with cleft palate (CP), velopharyngeal insufficiency persists after palatoplasty. In order to determine whether such insufficiency is due to the pathological changes of the levator veli palatini (LVP) muscle, we examined histologically the LVP muscles of 35 patients with CP and of six control patients with congenital microtia. Electromyographic records were obtained of the LVP muscles of 12 patients with CP after palatoplasty.The muscle structures were well preserved in seven of 35 patients with CP. Among the other 28 patients, perimysial fibrosis was observed in 13, variations in fiber caliber in seven and internal nuclei in one, but these findings were also observed in the control group. The incidence of each finding was not significantly different between the two groups. Electromyography revealed the mean action potential during phonation of the sound “ah” to be 825 μV. Effective elevation of the soft palate was correlated with neither the histology nor the action potential of the LVP muscle.Therefore velopharyngeal insufficiency persisting after palatoplasty is considered not to be due to pathological changes in the LVP muscle.

粘膜下口蓋裂例の中耳疾患

The association between middle ear disease and abnormal pathway of the levator veli palatini muscle was investigated by otological and endoscopic examination in patients with submucous clef palate (SMCP).The characteristics of middle ear diseases of SMCP patients were similar to those of cleft palate patients, suggesting that the morphology and function of the eustachian tube system are similar in those two types of cleft palate.In SMCP patients after palatoplasty, middle ear disease was less common in patients with levator muscle sling formation than in those without muscle sling formation. The abnormal pathway of the levator muscle was thought to have some effect on the middle ear. Some patients without muscle sling formation, however, had no middle ear disease, suggesting that other anatomical anomalies of the eustachian tube system also play an important role in the high incidence of middle ear disease in cleft palate patients.

Effects of Oral Air Pressure and Nasal Air Flow Rate on Levator Veli Palatini Muscle Activity in Patients with Speech Appliance

Effects of Oral Air Pressure and Nasal Air Flow Rate on Levator Veli Palatini Muscle Activity in Patients with Speech Appliance

Muscle Spindles in the Human Levator Veli Palatini and Palatoglossus Muscles

Muscle spindles are present in many muscles of the speech mechanism including those of the jaw, tongue, larynx, and respiratory system. Past investigations that have examined muscles of the velopharynx for the presence of muscle spindles have reported their existence only in the tensor veli palatini and palatoglossus muscles. The present investigation has demonstrated the existence of muscle spindles in two muscles of the human velopharynx--the levator veli palatini (LVP) and palatoglossus muscles. Seven LVP and two palatoglossus muscles were embedded in paraffin blocks, serially sectioned at 8 microns, and selected slides were stained by a modified Gomori trichrome technique. Scanning by light microscopy at 40x revealed spindles in all of the muscles examined. This positive finding likely reflects the use of a more chromatically distinctive staining procedure and a higher scanning magnification than were used in prior investigations. The potential roles of muscle spindles in velopharyngeal function are addressed.

The levator veli palatini muscle of children. (Portuguese) Rev

The levator veli palatini muscle of children. (Portuguese) Rev

The Morphometry and Three-Dimensional Structure of the Adult Eustachian Tube: Implications for Function

An accurate description of the functioning Eustachian tube (ET) requires a thorough knowledge of the anatomic relationships of its components. To this end, 15 "normal" adult ETs were obtained, sectioned, and stained with hemotoxylin-eosin. Descriptive and quantitative data of ET structures and their relationships were obtained. Eustachian tube length was normalized and comparisons between specimens made. This analysis suggests (1) in its midsection the cartilage is loosely attached to the cranial base; (2) the deep portion of the tensor veli palatini (TVP) originates from the lateral lamina and the fibrous portion of the lateral membraneous wall; and (3) the levator veli palatini (LVP) can interact with the ET primarily via the elongated medial lamina in the anterior portion of the ET. These observations suggest the ET is opened by a medial rotation of cartilage effected primarily by the TVP, but aided anteriorly by the LVP.

Muscle Spindles in the Velopharyngeal Musculature of Humans

Seven muscles in the velopharyngeal region of humans were studied histologically to determine the presence of muscle spindles. Typical spindles were found in palatoglossus and tensor veli palatini with a greater number in the latter. Spindles were not found in levator veli palatini, palatopharyngeus, musculus uvulae, salpingopharyngeus, or the superior pharyngeal constrictor.

Levator Veli Palatini Muscle and Eustachian Tube Function

Thirty previously unoperated patients with submucous cleft palate, occult submucous cleft palate, and unilateral congenital paralysis of the levator veli palatini muscle were examined. All patients were subjected to a comprehensive otoscopic, endoscopic, audiologic, and tympanometric evaluation. A correlation was made between levator veli palatini muscle anomalies, eustachian tube orifice anomalies, and middle ear ventilation and disorders. Normal middle ear ventilation was found in 23 patients. Negative middle ear pressure that consequently normalized following treatment of coexisting sinusitis was found in 3 patients. Only in 4 patients was chronic middle ear disease found. In one of them, middle ear effusion disappeared following successful treatment of sinusitis. Our conclusion is that the levator veli palatini muscle has no significant function in the opening mechanism of the eustachian tube and must be considered as a velopharyngeal valve muscle only.

Levator Veli Palatini Muscle and Eustachian Tube Function

Thirty previously unoperated patients with submucous cleft palate, occult submucous cleft palate, and unilateral congenital paralysis of the levator veli palatini muscle were examined. All patients were subjected to a comprehensive otoscopic, endoscopic, audiologic, and tympanometric evaluation. A correlation was made between levator veli palatini muscle anomalies, eustachian tube orifice anomalies, and middle ear ventilation and disorders. Normal middle ear ventilation was found in 23 patients. Negative middle ear pressure that consequently normalized following treatment of coexisting sinusitis was found in 3 patients. Only in 4 patients was chronic middle ear disease found. In one of them, middle ear effusion disappeared following successful treatment of sinusitis. Our conclusion is that the levator veli palatini muscle has no significant function in the opening mechanism of the eustachian tube and must be considered as a velopharyngeal valve muscle only.

Levator Veli Palatini Muscle and Eustachian Tube Function

Levator Veli Palatini Muscle and Eustachian Tube Function

先天性鼻咽腔閉鎖不全症の中耳疾患

To clarify the incidence of middle ear disease in patients with congenital velopharyngeal insufficiency (CVPI), we observed the shape of the velopharynx by a videofluorography and the movement of the lateral pharyngeal wall and soft palate with a flexible fxberscope. The findings of otoscopy, audiometry, and tympanometry were also recorded.Otitis media with effusion was the most common findings. The shape of the velopharynx had no relation to the incidence of middle ear disease. On the other hand, middle ear diseases were uncommon in CVPI patients with a good mobility of the lateral pharyngeal wall and soft palate. It was thought that the mobility of the velopharyngeal muscles, such as a levator veli palatini, might have some effect on conditions in the middle ear.

Age-related morphologic differences in the components of the eustachian tube/middle ear system.

The current study utilized a three-dimensional computer graphics technique to analyze the size, shape, and positional associations of the eustachian tube (ET) cartilage and lumen, the levator veli palatini (LVP) muscle, and the tensor veli palatini (TVP) muscle. Older specimens 7 years and above (n = 13) were compared to young specimens less than 7 years (n = 4). Our results suggest that changes in ET function associated with age could result from size and shape differences in the ET cartilage and changes in the position of the LVP and TVP muscles.

The levator veli palatini muscle arises from the second branchial arch: a hypothesis.

The levator veli palatini muscle arises from the second branchial arch: a hypothesis.

The blood supply of the levator and tensor veli palatini muscles

The blood supply of the levator and tensor veli palatini muscles

くしゃみ発作時における喉頭の関与

This paper describes an aerodynamic and electromyographic study of the sneeze. A sneeze is characterized by a deep inspiration followed by an abrupt expulsive expiration. The sneeze consists of three phases; inspiratory (preparatory), compressive (minimum flow) and expiratory. In the compressive phase the airway is temporarily obstructed while the intrathoracic pressure is elevated by contractions of the expiratory muscles. The study attempted to determine if the point of obstruction was at the level of the glottis similar to that observed in the cough. Aerodynamic studies using the body plethysmograph show that intrathoracic compression is greatest during the compressive phase, and that expiratory air, when present, is expelled only through the mouth. Electromyographic data show that the diaphragm (DIA) and posterior circoarytenoid (PCA) muscles are activated during the inspiratory phase and then the rectus abdominis (RA), thyroarytenoid (TA) and levator veli palatini (LP) muscles are activated during the compressive and expiratory phases. The interrelationship among these muscle groups appears to be extremely delicate as seen in the transition between the compressive and expiratory phase where an abrupt change in TA and PCA activity is observed while the RA and LP continue to be active. In cases where delayed activation of the PCA is observed the subglottic pressure created was not sufficiently high to perform an effective sneeze. From these aerodynamic and electromyographic data the authors conclude that in the sneeze the glottis is the occlusive point necessary for the elevation of the intrathoracic pressure.

Three-dimensional computer graphics of the eustachian tube

Images of the eustachian tube from various directions were obtained using computer graphics. Serial cross sections of a human temporal bone specimen including the eustachian tube were digitized for reconstruction. Wire-frame models of the structures such as the eustachian tube lumen, the tubal cartilage, the tensor veli palatini muscle, and the levator veli palatini muscle were drawn. Through observation of the eustachian tube from various directions with the tubal muscles attached or detached, the physiology of the eustachian tube system could be understood more clearly.

Neural control of middle ear aeration.

This study investigates the afferent and efferent pathways by which respiratory neurons in the brain can monitor and regulate middle ear aeration. Experiments were performed on 11 adult cynomolgus monkeys (Macaca fascicularis). The neural tracer, horseradish peroxidase, was placed on the transected nerves of the tympanic plexus in four animals. Horseradish peroxidase-labeled nerve terminal fields were observed in the ipsilateral respiratory subnuclei of the nucleus of the solitary tract. This may represent the sensory pathway by which the degree of middle ear aeration is monitored by the brain. Horseradish peroxidase was injected into the eustachian tube muscles in six of the monkeys, and horseradish peroxidase-labeled motoneurons were observed in the ipsilateral trigeminal motor nucleus (tensor palati muscle) and nucleus ambiguus (levator palati muscle). These brain-stem motor nuclei may represent the efferent pathways by which the degree of middle ear aeration is regulated. The results of these primate experiments confirm our earlier studies on rabbits and cats. A theory for the neural control of middle ear aeration is proposed.

Localization of motoneurons innervating the Eustachian tube muscles in cat.

The localizations of the motoneurons supplying the tensor tympani muscle (TTM), tensor veli palatini muscle (TVPM) and levator veli palatini muscle (LVPM) were determined by retrograde transport of horseradish peroxidase (HRP) in the cat. TTM motoneurons were found ipsilaterally outside the trigeminal motor nucleus in an area just ventral to it. TVPM motoneurons were distributed mainly in the ventral part of the ipsilateral trigeminal motor nucleus. They were more compactly distributed in the rostral part of the nucleus than in the caudal part. LVPM motoneurons were found in the ipsilateral nucleus ambiguus. There were no HRP-labelled cells in the contralateral nucleus ambiguus.

口蓋裂例の咽頭側壁，軟口蓋の運動と聴力，ティンパノグラムとの関係

We observed the movement of the lateral pharyngeal wall and soft palate by a flexible fiberscope in 80 cases of cleft palate. The findings of otoscopy, audiometry and tympanometry were recorded at the same time.The frequency of normal hearing was significantly high in the group with “good” movement of the lateral pharyngeal wall and soft palate. Also, the rate of type A pattern tympanogram was significantly high in the group with “good” movement of the lateral pharyngeal wall.The main muscle involved in the movement of the lateral pharyngeal wall and soft palate appears to the levator veli palatini muscle. Accordingly, “good” movement of the lateral pharyngeal wall and soft palate indicates that the function of the levator veli palatini muscle is good. Therefore, our results showed that good function of the levator veli palatini muscle had a desirable effect on the state of the middle ear.

鼓膜チューブ挿入児の音響耳管検査成績 チューブ抜去時期の検討

The present study investigated the eustachian tube function in children with otitis media with effusion (OME) and also evaluated the effectiveness of adenoidectomy in such patients. The subjects consisted of 32 children with OME, all of whom underwent tube insertion and adenoidectomy, resulting in an improved hearing level to a range of 0-10dB. Sonometric auditory function test was carried out on the patients whose tube was in place and the middle ear was well aerated. Normal transmission of sound was observed in 71.4% of these children. However, it was seen in only 2% of the children not surgically treated. Satisfactory tubal function was noted in patients whose ventilation tubes remained in place for a period of 250 days or longer. It is, therefor, suggested that the optimal timing of tube extraction should be approximately eight months post-operatively, at which time the eustachian tube appears to tart functioning well.Our second study measured intranasal pressure in children with OME when they performed Toynbee's manuever. Some children were treated with adenoidectomy with tube insertion and the others were not surgically treated, and the results were 5.66±2.92mm H2O and 3.93±1.79mm H2O, respectively. A significantly high intranasal pressure seen in patients with OME who had undergone adenoidectomy seems to account for the effective nasopharyngeal closure that had occurred as a result of improved movement of the soft palate including the levator veli palatine muscle. From these findings, it was concluded that adenoidectomy facilitates opening the tubal lumen by the tensor veli palatine muscle.