Mechanical contraction properties and roles in velar movements of tensor veli palatini muscle

The present study was intended to clarify the mechanical contraction properties and to investigate roles in velar movements of the tensor veli palatini (TVP) muscle in dogs. The dogs used in the experiments were anesthetized intra-peritoneally with sodium pentobarbital. Experiment I: Tension of the TVP muscle was induced by stimulation to the motor nerve and was recorded: 1. The contraction time and half relaxation time of maximal isometric twitch of the muscle were 13.7 +/- 0.7 msec and 10.4 +/- 1.2 msec, respectively. 2. A clear summation of muscle contractions was obtained with stimulation at 20 Hz with maximal tetanic tension at 90 Hz. The tetanus twitch tension ratio was found to be 10.7 +/- 1.1. Experiment II: The role of the TVP muscle in velar movements was investigated from the standpoint of upper airway patency. In addition, the effect of fracture of the pterygoid hamulus and transection of the TVP muscle at the pterygoid hamulus on velar movements were also investigated. The results indicated the following: 1. Upon electrical stimulation of the motor nerve of the TVP muscle, the anterior part of the soft palate was displaced laterally with the subsequent expansion of the epipharynx. 2. Negative pressure in the nasal cavity was observed with the respiratory activity of the TVP muscle after tracheostomy, but not in the oral cavity. 3. Contraction of the TVP muscle decreased nasal airway resistance when intranasal airflow was confirmed at levels higher than 120 ml/sec. 4. After fracture of the pterygoid hamulus, contraction of the TVP muscle produced expansion of the epipharynx but less than that prior to the treatment. The fracture did not change nasal airway resistance. 5. After transection of the TVP muscle at the pterygoid hamulus, the contraction of the TVP muscle did not produce any velar movements. Neither expansion of the epipharynx nor changes in nasal airway resistance were observed.     

Bursitis of the tensor veli palatini muscle with an osteophyte on the pterygoid hamulus

Many patients with temporomandibular joint dysfunction and/or myofascial pain syndrome have numerous symptoms. In cases of multiple complaints, an attempt should be made to resolve symptoms on a step-by-step basis. In this case report, a patient was treated for only one of her numerous complaints, that is, a burning sensation on her palate when she touched the right tuberosity area with her tongue or finger.     

Morphological characterization of the levator veli palatini muscle in children born with cleft palates.

OBJECTIVE: The aim of this study was to analyze, morphologically and biochemically, one of the soft palate muscles, the levator veli palatini (LVP), in children born with cleft palate. SUBJECTS AND METHODS: Biopsies were obtained from nine male and three female infants in connection with the early surgical repair of the hard and soft palate. Samples from five adult normal LVP muscles were used for comparison. The muscle morphology, fiber type and myosin heavy chain (MyHC) compositions, capillary supply, and content of muscle spindles were analyzed with different enzyme-histochemical, immunohistochemical, and biochemical techniques. RESULTS: Compared with the normal adult subjects, the LVP muscle from the infantile subjects with cleft had a smaller mean fiber diameter, a larger variability in fiber size and form, a higher proportion of type II fibers, a higher amount of fast MyHCs, and a lower density of capillaries. No muscle spindles were observed. Moreover, one-third of the biopsies from the infantile subjects with cleft LVP either lacked muscle tissue or contained only a small amount. CONCLUSIONS: The LVP muscle from children with cleft palate has a different morphology, compared with the normal adult muscle. The differences might be related to different stages in maturation of the muscles, changes in functional demands with growth and age, or a consequence of the cleft. The lack of contractile tissue in some of the cleft biopsies offers one possible explanation to a persistent postsurgical velopharyngeal insufficiency in some patients, despite a successful surgical repair.     

Magnetic resonance imaging of the levator veli palatini muscle in speakers with repaired cleft palate.

OBJECTIVE: To obtain detailed anatomic and physiologic information on the levator veli palatini muscle from MRI in individuals with repaired cleft palate and to compare the results with those from normal subjects reported by Ettema et al. (2002). DESIGN: Prospective study. SETTING: University-based hospital. PARTICIPANTS: Four men (ages 22 to 43 years) with repaired cleft lip and palate. MAIN OUTCOME MEASURES: Four quantitative measurements of the levator veli palatini muscle from rest position and dynamic speech magnetic resonance images were obtained: the distance between the origins of the muscle, angle of origin of the muscle, muscle length, and muscle thickness. RESULTS: The length and thickness of the levator veli palatini muscle varied among the subjects and were different from measurements obtained from normal subjects in a previous study. The distance between origin points, length, and thickness of the levator veli palatini muscle were smaller than those of the normal subjects. There were systematic changes of the levator veli palatini muscle, depending upon vowel and consonant types. Levator veli palatini muscle angle of origin and length became progressively smaller from rest, nasal consonants, low vowels, high vowels, and fricative consonants. These changes are consistent with those of the normal subjects. CONCLUSIONS: This study contributes to a better understanding of cleft palate anatomy in comparison with normal anatomy of the levator veli palatini muscle. The use of MRI shows promise as an important tool in the diagnosis and eventual aid to treatment decisions for individuals born with cleft palate.     

Mechanical contraction property of the levator veli palatini muscle

Twenty adult dogs anesthetized with sodium pentobarbital were used as experimental animals in an analysis of the mechanical contraction properties of the levator veli palatini muscle. The following results were obtained: the contraction time and half relaxation time of maximal isometric twitch of the muscle were revealed to be 43 msec and 33 msec, respectively; a summation curve was obtained with stimulation at 15 Hz and maximal tetanic tension was at 70 Hz. The average of the tetanic tension ratio was found to be 5.7. The maximum rate of tension rise was observed at 150 Hz, and the value was twice the rate of the twitch contraction. The duration time of the active state plateau showed values of 3.9 to 4.5 msec. The contraction time of the levator veli palatini muscle closely resembles that of the intrinsic laryngeal and the orbicularis oris muscle.     

Neuroanatomical considerations of palatal muscles: tensor and levator veli palatini

The tensor veli palatini (TVP) and levator veli palatini (LVP) muscles are intimately associated with the soft palate and knowledge of their anatomy and physiology is essential for palatoplasty. Controversy regarding the function and innervation of these muscles still exists. The purpose of this study was to identify the location of motoneurons within the brainstem which innervate the TVP and LVP using the current neuroanatomical tracing technique of retrograde axonal transport of horseradish peroxidase (HRP). HRP was injected into each of these muscles in adult cats. Following a twenty-four hour survival the animals were sacrificed, the brain removed and processed using tetramethyl benzidene . TVP motoneurons were located in the rostral two-thirds of the ventromedial division of the trigeminal motor nucleus. LVP motoneurons were located in the rostral 2 mm of the nucleus ambiguus ipsilaterally and to a lesser extent contralaterally as well as in the retrofacial nucleus ipsilaterally. Our study has addressed neuroanatomical aspects essential to an understanding of the structure and function of the palatal muscles. Unraveling the central connections of the TVP, LVP motoneurons may clarify understanding of such complex functions as swallowing, sucking, blowing and speech.     

Muscle spindle distribution in the levator veli palatini muscle in the rat.

We previously reported that the levator veli palatini muscle (LVP) in the rat is innervated by the glossopharyngeal nerve. The LVP positioned between the mouth and nasopharynx, has important roles in respiration, swallowing, and speech. Muscle spindles, structures scattered through skeletal muscles, appear to function like miniature strain gauges, sensing the degree of tension in the muscle. Muscle spindles were demonstrated in the rat's LVP in our neurophysiologic and histologic studies. We think the stretch of LVP modulates the rapid movements of the LVP by the proprioceptive component of the muscle spindle. Our results infer it is important to protect the innervation and the muscle spindles of the LVP from damage during any surgical dissection of the soft palate musculature.     

Levator veli palatini muscle fatigue during phonation in speakers with cleft palate with borderline velopharyngeal incompetence.

OBJECTIVE: This study examined whether the levator veli palatini muscle in speakers with borderline velopharyngeal incompetence (BVP) with surgically treated cleft palate might be more fatigable during speech than that in speakers without clefts. DESIGN: Each subject was asked to pronounce the syllable /pu/ more than 50 times at a rate of one time per second. Mean power frequency (MPF) of one syllable was obtained from electromyogram data of the levator muscle by power spectral analysis. PARTICIPANTS: Five patients with postsurgical cleft palates, who were identified as having BVP by nasopharyngeal fiberscopy, served as subjects, and five participants without clefts served as the control group. RESULTS: In all participants without clefts, the slopes of the regression line relating MPF to the course of syllable repetition were negative but not significant. However, in all participants with BVP, the slopes of the regression line were significantly negative. CONCLUSIONS: These findings demonstrated that the levator muscle of speakers with BVP was more fatigable than that of speakers without clefts during repetition of syllables. This study suggests that the fatigability of levator muscle contributed to mild hypernasality in patients with BVP.     

The course of facial nerve innervation for the levator veli palatini muscle.

The present study was designed to determine the motor nerve pathway of the facial nerve to the levator veli palatini muscle. The experiments were carried out on 10 anesthetized rhesus monkeys. Recorded and analyzed were evoked EMG responses of the levator veli palatini and the orbicularis oris muscles by electrical stimulation to both the facial nerve and its branch within the cranium. Muscle action potentials (M-waves) from the two muscles could be recognized on stimulating the facial nerve at the petrosal area of the temporal bone. On stimulating the greater petrosal nerve, M-waves from the levator muscle could be elicited. By cutting off the greater petrosal nerve at the middle cranial fossa, M-waves from the levator muscle completely disappeared on stimulating the facial nerve at the petrosal area. Results indicated that the course of the facial nerve for the levator veli palatini muscle is through the greater petrosal nerve.     

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目的探讨先天性腭裂患者的腭帆提肌肌纤维型组成和分布,借以了解先天性腭裂患者肌纤维特点。方法对2008年1月至2008年7月于青岛大学医学院附属医院口腔颌面外科就诊的先天性腭裂患者20名,取其腭帆提肌组织进行冰冻切片,采用肌球蛋白ATP酶组织化学染色法,对其进行肌纤维分型研究。结果先天性腭裂患者腭帆提肌经肌球蛋白ATP酶组织化学染色后可分出两种肌纤维型,其中Ⅰ型纤维占(26.4±3.1)%,Ⅱ型纤维占(73.6±6.3)%,两者比较差异具有统计学意义。结论先天性腭裂患者的腭帆提肌肌纤维以Ⅱ型纤维为主。     

Tensor veli palatini muscle tension sling for eustachian tube function in cleft palate. Surgical technique and audiometric examination

The high incidence of middle ear effusion in cleft lip and/or palate infants and children led to the development of a tension sling for the tensor veli palatini muscle for better Eustachian tube function after intravelar veloplasty.--The surgical technique is outlined in this paper and an audiometric examination was conducted to determine the influence of this surgical modification, performed in the same procedure as the intravelar veloplasty, on the Eustachian tube function. The intra- and intergroup comparisons indicate that this surgical technique has a positive influence on the tube function.     

Magnetic resonance imaging of the levator veli palatini muscle during speech.

OBJECTIVE: To obtain detailed anatomic information on the levator veli palatini (LVP) muscle from magnetic resonance imaging (MRI). Quantitative measures of the configuration of the LVP muscle at rest and during speech activities were obtained. DESIGN: Prospective study using MRI of adult subjects with normal velopharyngeal mechanisms to determine anatomic and physiologic parameters of the levator muscle. The levator veli palatini muscle was imaged at rest and during speech activities consisting of nasal and non-nasal sounds mixed with vowels, consonants, or both (e.g., /ansa, asna, amfa, afma/). PARTICIPANTS: Ten normal healthy adults (five men, five women) between 21 and 53 years of age and free of oropharyngeal abnormalities. MAIN OUTCOME MEASURES: Two-dimensional spin echo static images and dynamic fast gradient echo images of the levator muscle in both the sagittal and oblique/coronal planes. RESULTS: On average across female (F) and male (M) subjects: distance between LVP muscle origin points, 52.6 mm (F), 54.6 mm (M); angle of levator muscle origin at rest, 64.5 degrees (F), 60.4 degrees (M); length of the levator muscle at rest, 44.1 mm (F), 46.4 mm (M); width of levator muscle at lateral margin of velum, 5.5 mm (F), 6.6 mm (M). Both the levator muscle angle of origin and length became progressively smaller from rest, nasal consonants, low vowels, high vowels, and fricatives for both female and male subjects. Across all subjects, there was a 19% reduction in length of the LVP muscle from rest position to fricative production. CONCLUSIONS: MRI is an effective method of imaging and measuring the LVP muscle and related structures in living subjects. Understanding the normal tissue distribution and quantification of the LVP muscle provides important information for development of a functional biomechanical model of the velopharynx and for improved surgical treatment.     

腭裂整复术后腭帆提肌运动能力的观察

目的 观察腭裂及单纯唇裂患者在不同语音状态下腭帆提肌伸缩能力和倾斜角度的差异.方法 使用MRI拍摄3组研究对象:①单纯唇裂组(对照组)8例;②腭裂术后腭咽闭合功能不全组(velopharyngeal incompetence,VPI组)7例;③腭裂术后腭咽闭合功能完全组(velopharyngeal competence,VPC组)l0例,在静止位以及发"a"、"i"、"m"音时腭帆提肌的影像,并分析各图像中腭帆提肌垂直段的长度以及相对于面中份矢状面角度变化.结果 3组儿童随发"a"、"i"、"m"音,腭帆提肌垂直段的长度收缩率依次为[(13.5±11.7)%、(11.1±10.8)%、(8. 2±14.3)%];随发"a"、"i"、"m"音,相对于面中份矢状面角度依次变小[(43.18±4.984)°、(43.08±4.879)°、(39.48±5.046)°];3组研究对象发音时腭帆提肌长度和角度的变化差异无统计学意义(P＞0.05).结论 腭裂患者术后腭帆提肌的运动能力与单纯唇裂患者基本相同.     

Anatomic relationshiphs between the human levator and tensor veli palatini and the eustachian tube.

To define the interrelationships of the human levator and tensor veli palatini muscles and the Eustachian tube, fetal heads were serially sectioned and anatomic reconstruction done. Cephalometric points on fetal and adult skulls were compared to evaluate the effect of growth and development on these interrelationships. Based on the results of this study, we propose a mechanism for Eustachian tube function in the normal and in the cleft palate patient. This mechanism offers some explanations for many previously unexplained and paradoxical clinical observations.     

Change in levator veli palatini muscle activity for patients with cleft palate in association with placement of a speech-aid prosthesis.

OBJECTIVE: The purpose of this study was to examine whether a speech-aid prosthesis normalizes the activity of the levator veli palatini muscle for patients with cleft palate who exhibit velopharyngeal incompetence. DESIGN: Each subject was instructed to produce repetitions of /mu/, /u/, /pu/, /su/, and /tsu/ and to blow with maximum possible effort. Electromyographic (EMG) activity of the levator veli palatini muscle was recorded with and without a hybrid speech-aid prosthesis in place. PARTICIPANTS: The participants were five patients with repaired cleft palate who were routinely wearing a hybrid speech-aid prosthesis. RESULTS: With the prosthesis in place, the mean value of levator activity changed positively in relation to oral air-pressure change during blowing. Differences in levator activity in relation to speech samples were similar to those in normal speakers. With the prosthesis in place, levator activity for speech tasks was less than 50% of the maximum levator activity for all subjects. The findings were similar to those reported previously for normal speakers. CONCLUSION: Placement of the prosthesis changed EMG activity levels of the levator veli palatini muscle to levels that are similar to normal speakers. It is possible that, with the increase in the differential levator activity between speech and a maximum force task, the velopharyngeal mechanism has a greater reserve capacity to maintain velopharyngeal closure compared with the no-prosthesis condition.     

Sommerlad腭帆提肌重建术在不完全腭裂修复中的应用

目的：探讨一种具有良好腭咽功能、对上颌生长发育影响小的不完全性腭裂修复的新方法。方法：采用Sommerlad腭帆提肌重建术,对38例不完全性腭裂进行手术修复,术后应用语音分析、头颅侧位X线咽腔造影检查。结果：所有患者术后均一期愈合。28例（73．7％）没有做松弛切口,10例（26．3％）行两侧约5～10mm松弛切口。20例术后6个月复诊,其语音清晰度、高鼻音以及鼻漏气都得到明显改善。咽腔造影结果显示：17例达到完全腭咽闭合,3名软腭动度良好,发“i”时腭咽间隙在3mm以内。结论：Sommerlad腭帆提肌重建术可有效恢复腭帆提肌正常的解剖结构和位置,重建提腭吊带,获得良好的腭咽闭合;并可尽量不做松弛切口,避免了硬腭裸露骨面造成对上颁生长发育的影响,较好地解决了传统术式所遗留的问题,是一种值得推荐应用的功能性腭裂修复方法。     

腭帆提肌重建联合咽后壁瓣术在先天性腭裂中的临床应用

目的　探讨腭帆提肌重建联合咽后壁瓣术在先天性腭裂中的临床应用。方法　采用腭帆提肌重建联合咽后壁瓣术,共修补47例先天性腭裂患者,其中单侧完全性腭裂21例,不完全性腭裂26例。结果　所有患者均一期愈合,未出现腭瘘,随诊1~3年,语音清晰度满意。结论　腭帆提肌重建联合咽后壁瓣术较好地恢复了腭帆提肌正常的解剖结构和位置,获得了良好的腭咽闭合,并有效地降低了术后腭瘘的发生率,是一种值得推荐的功能性腭裂修复方法。