Functional anatomy of levator veli palatini muscle and tensor veli palatini muscle in association with eustachian tube cartilage

The anatomic relationships among the levator veli palatini muscle (LVPM), the tensor veli palatini muscle (TVPM), and the eustachian tube (ET) cartilage were investigated by computer-aided 3-dimensional reconstruction and measurement methods. The study used 13 normal temporal bone-ET specimens obtained from 13 individuals (range of age at death, 3 months to 88 years). This study revealed several anatomic features of the anterior cartilaginous portion of the ET. First, the LVPM is always located inferolateral to the inferior margin of the medial lamina (ML) of the ET cartilage. Second, the LVPM has a large cross-sectional area throughout the extent of the anterior cartilaginous portion of the ET. Third, although the LVPM lies close to the ML of the ET cartilage (0.44+/-0.16 mm in children and 1.02+/-0.58 mm in adults), there is no region of attachment. Finally, the TVPM is not attached to the lateral lamina (LL) of the ET cartilage of the anterior quarter of the cartilaginous portion. Accordingly, it could be assumed that the most anterior cartilaginous portion of the ET is opened primarily by the contraction of the LVPM, which causes a superior-medial rotation of the ML. Furthermore, since the contraction time of the LVPM is reported to be longer than that of the TVPM, the anterior cartilaginous portions of the ET may remain open, even after the middle to posterior cartilaginous portions are closed after relaxation of the TVPM. This process would produce a pumping action of the ET in the direction from the middle ear to the pharyngeal side. The pumping function may be beneficial to clearance of the middle ear.     

Postnatal changes in the connective tissue in the region lateral to the eustachian tube: possible relationship to tube function

In order to delineate the possible role of connective tissue (CT) in the region lateral to the eustachian tube (ET) between the ET lumen and the tensor veli palatini muscle (TVPM), we studied the postnatal changes in the CT in histologic sections of human ET. In fetuses and neonates, the lateral region was filled with mesenchyme. Loose collagenous CT appeared first at 2 weeks of age, and in subjects older than 4 years of age, the collagen formed dense, meshlike structures attaching to both the subepithelial CT layer of the ET and the tendonlike membrane of the TVPM. Along the long axis of the ET, those attachments were distributed mainly in the region at the posterior part of the cartilaginous portion of the ET. Attachments to the subepithelial CT layer of the ET were distributed mainly in the upper half of the region. The dense, meshlike collagenous CT might help the ET to be opened by drawing the lateral wall of the ET lumen through inferolateral movement of the tendonlike membrane of the TVPM when the TVPM contracts. It may work to open mainly the parts that include the narrowest portion of the ET, and also the upper aspect of the ET lumen. Incomplete development of this structure in infants may be one of the factors associated with dysfunction in ET opening.     

Rat eustachian tube and its musculature

The objective of this study was to evaluate the anatomy of the eustachian tube (ET) of the rat and the paratubal musculature. Microdissection and serial sections were used. The ET consists of collapsible membranous and membranocartilaginous segments and a noncollapsible bony segment. Tubal muscles are attached to the collapsible part; the salpingopharyngeus muscle (SPM) is well developed and consists of 3 distinct groups of muscle fibers; the tensor veli palatini muscle (TVPM) consists of 2 functionally different groups of fibers, but only 1 group assists in opening the ET. Attachment of the fibers of the SPM and TVPM that are involved in tubal opening is confined to the dorsal portion of the ET. This finding, together with the earlier observation that this part is mainly lined by squamous epithelium, strongly suggests that the dorsal part has a ventilatory function. The ventral portion of the ET, which is lined by ciliated-secretory epithelium and lacks the attachment of muscle fibers that can dilate the lumen, is assumed to serve clearance. The anatomic position of the levator veli palatini muscle suggests that this muscle contributes to the protective function of the ET. These findings are discussed with regard to the ET in humans.     

Temporal bone morphometric study on the eustachian tube and its associated structures in patients with chromosomal aberrations

This study characterized phenotypic anomalies of the eustachian tube (ET) and its associated structures in individuals with various chromosomal aberrations (trisomies 13, 18, 21, and 22 and inversion of chromosome 1). The morphological characteristics of the ET and its accessory structures from 10 temporal bone-ET specimens, obtained from 10 individuals with chromosomal aberrations who ranged from the 26th gestational week to 1 year in age, were compared with the same structures from 21 age-matched control subjects without anomalies. The subjects with chromosomal aberrations had a significantly smaller volume of the lateral lamina (LL) of the ET cartilage, a reduced attachment of the tensor veli palatini muscle (TVPM), and, in some cases, a reduced volume of the lumen of the cartilaginous ET. The volume of the medial lamina (ML) of the ET cartilage was normal at birth, but smaller in specimens more than 2 months of age; this finding suggests that the prenatal development was normal, but that the postnatal growth was retarded. The subjects with chromosomal aberrations also displayed a smaller ratio of the volume of the LL to that of the ML (LL/ML ratio). Our results suggest that individuals with various chromosomal aberrations have rather similar anomalies of the ET and its associated structures. We speculate that these anomalies might be closely related to ET dysfunction in these patients.     

Anomaly of the eustachian tube and its associated structures in patients with multiple congenital malformation: a histopathological and morphometric study

Two temporal bone-eustachian tube (ET) specimens; one from a 1-day-old female newborn with Townes Syndrome (Case 1) and the other from a 15-year-old female with oral-facial-digital syndrome (Case 2) were studied histopathologically and morphometrically. Both specimens had anomalies of the ET and its associated structures as compared with eight age-matched control cases without anomaly (six cases for Case 1 and two cases for Case 2, respectively). Case 1 had a weak attachment of the tensor veli palatini muscle (TVPM) to a poorly developed lateral lamina (LL) of the ET cartilage, a large voluminous medial lamina (ML) of the ET cartilage, a small voluminous ET lumen with a few ridges of mucosal folds, poorly developed ET glands and a poorly developed levator veli palatini muscle (LVPM). Case 2 had a short and longitudinally elongated ET lumen that was insufficiently covered with a poorly developed ML and LL and an aberrant course of the LVPM. Both cases were accompanied by a mild inner ear anomaly (slightly shortened cochlea). We discuss the implications of the observed anomalies with regard to functional and clinical issues. In particular, we speculate that these ET anomalies may closely be related to potential ET dysfunction with high susceptibility to otitis media.     

Histopathological changes of the eustachian tube cartilage and the tensor veli palatini muscle with aging.

OBJECTIVES: The eustachian tube (ET) and the tensor veli palatini muscle (TVPM) are thought to play an important role in ventilatory function. Calcification of the ET cartilage and the replacement of TVPM by fat tissue are often observed histologically in elderly patients. To our knowledge, however, there are no quantitative studies of these pathological findings in relation to age. STUDY DESIGN: The calcification of the ET cartilage and the atrophy of the TVPM in 36 normal human temporal bones obtained from 36 individuals with ages ranging from 2 days to 88 years were investigated. METHODS: The number of calcified chondrocytes in the midportion of the ET cartilage was quantified as the average number of cells per square millimeter. Atrophy of the TVPM was evaluated at the midportion of the site where the TVPM is attached to the tip of lateral lamina of ET cartilage. A grade of 0, 1, 2, 3, or 4 was assessed for each section, which indicated approximately 0% to 5%, 5% to 30%, 30% to 70%, 70% to 95%, or 95% to 100% of the TVPM replacement by fat tissue, respectively. RESULTS: A statistically significant correlation was found between the number of the calcified cells and aging (P < .001). A statistically significant correlation was also found between the degree of the atrophy of TVPM and aging (P < .001). CONCLUSIONS: The calcification of the ET cartilage and the atrophy of the TVPM are closely associated with aging. Therefore, it is suggested that these two findings may be a predisposing factor for ET dysfunction in elderly adults.     

Computer-aided 3-D temporal bone anatomy for cochlear implant surgery

To define anatomical relationships important in cochlear implantation, computer-aided three-dimensional reconstruction and measurement of middle and inner ear structures in six normal temporal bones were performed. Our findings were as follows: 1. When viewed from the posterior hypotympanotomy (facial recess) approach, the inferior 10% to 30% of the round window (RW) membrane was visible in only half the cases. 2. The most inferior portion of the basal turn of the scala tympani was not only inferior but also slightly anteriorly behind the RW membrane in more than half the cases. 3. The shortest distances from the aperture of the RW niche and from the margin of the RW to the stapes head were 2.38 +/- 0.33 and 2.15 +/- 0.22 mm, respectively. 4. The distance between the RW and the most inferior portion of the basal turn scala tympani was 5.15 +/- 0.34 mm. 5. The direction of the electrode advancement lay at a sharp angle to the inferior part of the RW (mean 31.9 +/- 3.6 degrees). 6. The direction from the RW to the most inferior portion of the basal turn scala tympani lay 16.0 +/- 5.3 degrees anteroinferior to the direction of the advancement of the electrode to the RW. 7. The distance between the margin of the RW and the basilar membrane of the cochlea was 0.58 +/- 0.10 mm at the superior aspect of the RW, and was 1.23 +/- 0.12 mm at the lateral aspect of the RW. 8. Dissecting away less than 1 mm (mean 0.7 +/- 0.27 mm) of the RW margin inferiorly or inferolaterally was enough to permit straight insertion of the electrode in most cases.     

Insertion of the tensor veli palatini muscle into the eustachian tube cartilage in cleft palate cases

Differences in insertion of the tensor veli palatini muscle (TVPM) into the lateral lamina of the eustachian tube (ET) cartilage between cleft palate (CP) cases and controls were investigated histologically. Thirty temporal bones with entire ETs were studied: 10 from individuals with CP and 20 controls. The ratio of the length of the ET cartilage with insertion of the TVPM to its total length from the nasopharyngeal end to near the tubal isthmus was calculated in all 30 cases. In all 20 controls, but in only 6 of 10 CP cases, the TVPM inserted into the lateral lamina of the ET cartilage at its tip portion (chi 2 test, p less than .025). The ratio was significantly smaller in CP cases (0.178 +/- 0.172) than in controls (0.419 +/- 0.120) (t = 4.305, p less than .001). We believe that abnormal insertion of the TVPM into the ET cartilage is one of the causes of the functional obstruction of the ET that contributes to the frequent bouts of otitis media experienced by those with cleft palate.     

Difference in attachment of the tensor veli palatini muscle to the eustachian tube cartilage with age

To test a hypothesis that ventilation of the eustachian tube (ET) varies with age, we investigated the relationship between age and the attachment of the tensor veli palatini muscle (TVPM) to the lateral lamina of the ET cartilage in 12 normal human temporal bones obtained from individuals 3 months to 81 years old. We used computer-aided 3-dimensional reconstruction and measurement methods. We found that the length of the TVPM attachment and its ratio to the length of the ET, especially that of the cartilaginous portion of the ET, increases with age from infancy to adulthood, and decreases with age from young adulthood to later life. These findings are thought to be related to postnatal development and aging. The possibility of differences in ventilation function with age is discussed.     

Postnatal change on the location of Ostmann's fatty tissue in the region lateral to Eustachian tube

OBJECTIVE: To delineate a possible role of protective function by Ostmann's fatty tissue (OF) in the lateral region to Eustachian tube (ET). STUDY DESIGN: Morphometric and histopathological examination on human temporal bones. METHODS: OF in the region lateral to the cartilaginous portion of the ET between the ET lumen and the tensor veli palatini muscle (TVP) was studied histopathologically and morphometrically by analyzing a series of vertically cut histologic sections for the ET structures. Sections were obtained from 25 individuals with age ranging from 33 gestational weeks to 38 years at the time of their death. RESULTS: In fetus and neonates, the region lateral to ET was filled with mesenchyme. OF appeared first in this region at 2-3 weeks postnatally, and increased in volume with development of the ET. In the cases of older children and adults (Group-B), the ratio of the volume of OF in the region to that of ET lumen (OF/L) was significantly higher in the posterior half than in the anterior half of the cartilaginous portion of ET. However, in the cases of infants and younger children (Group-A), there was no significant difference in the ratio between the two regions. In the posterior half of the cartilaginous portion of ET, OF/L was significantly higher in Group-B than in Group-A, while in the anterior half, there was no significant difference in the ratio between two age groups (Group-A and B). CONCLUSIONS: In Group-B, the dominant OF in the area of the posterior half of the cartilaginous region, which includes the narrowest portion of ET, may be responsible for restoring the ET lumen back to its closed static condition after active tubal opening by contraction of TVP. This is thought to be important for protection of the middle ear. On the other hand, in Group-A, poor OF near the narrowest portion of ET may cause insufficient restoration of the ET lumen and increased risk of developing otitis media (OM).     

Analysis of eustachian tube function by video endoscopy

OBJECTIVE: Human eustachian tubes (ET) were inspected in vivo endoscopically, and video recordings were made for careful slow-motion analysis of normal physiologic function. SETTING: Ambulatory office in a tertiary referral center. SUBJECTS: Thirty-four adults, 17 with no history of ET dysfunction (2 of whom had tympanic membrane perforations), 17 with known ET dysfunction. INTERVENTIONS: Transnasal endoscopic examination of the nasopharyngeal opening of the eustachian tube during rest, swallowing, and yawning. MAIN OUTCOME MEASURES: Video analysis of ET opening movements. RESULTS: Normal ETs had four consistent sequential movements: (1) palatal elevation causing passive, then active, rotation of the medial cartilaginous lamina; (2) lateral excursion of the lateral pharyngeal wall; (3) dilation of the lumen, caused primarily by tensor veli palatini muscle movement beginning distally and inferiorly, then opening proximally and superiorly; and (4) opening of the tubal valve at the isthmus caused by dilator tubae muscle contraction. Dysfunctional ETs had intraluminal edema, polyps, or minimal muscle movement. CONCLUSIONS: Slow-motion endoscopic video analysis may be a useful new technique for the study of eustachian tube physiology. Consistent muscle movement patterns were demonstrated in normal subjects but were absent in abnormal subjects. More studies of normal and abnormal patterns are needed to establish useful clinical correlates.     

Postnatal development of eustachian tube cartilage. A study of normal and cleft palate cases

Infants with cleft palate (CP) display eustachian tube (ET) dysfunction. This study compared the postnatal development of the volume of ET cartilage in 34 normal cases and 10 CP cases using a personal computer. In cases with age under 1 month old, the total volume of ET cartilage was 61.94+/-20.89 mm(3) (mean+/-S.D.) in 16 normal control cases and 50.07+/-24.69 mm(3) in nine CP cases (t-test, not significantly different from normal). The ratio of lateral lamina (LL) to medial lamina (ML) volume (LL/ML) was reduced significantly (t-test, P<0.001) from 0.23+/-0.07 in 16 normal control cases to 0.09+/-0.05 in nine CP cases under 1 month old. In 34 normal ET cases whose ages were under 20 years, statistically significant positive correlations were found between the total volume of ET cartilage (y1) and age (x), volume of LL (y2) and age, and volume of ML (y3) and age (P<0.01, r=0.731, 0.614, 0.719). The regression lines were y1=20.37x+95.57, y2=2.02x+15.60, and y3=18. 35x+79.97. With the result obtained from this study, it is assumed that immaturity of the ET cartilage in infants, especially that of LL of the ET cartilage in CP infants, may be a significant risk factor for developing otitis media with effusion.     

Length of the eustachian tube and its postnatal development: computer-aided three-dimensional reconstruction and measurement study

Eleven normal human temporal bone-eustachian tube (ET) specimens obtained from 11 individuals whose ages were 3 months to 88 years were studied to investigate the path length along the ET lumen and its postnatal development by means of a computer-aided 3-dimensional reconstruction and measurement method. The path length of the ET lumen of the 3-month-old infant was 21.2 mm, and its growth was in correlation with age to attain its adult length (average, 37.00 +/- 4.16 mm). The ratio of the length of the cartilaginous portion together with the junctional portion to the length of the bony portion was 8:1 in an infant at the age of 3 months and 4:1 in adults. That the bony portion of the ET develops relatively more than the cartilaginous and junctional portions may cause this finding. In addition, there is a developmental shift in the orientation of the cartilaginous portion with respect to the bony portion of the ET. In children, the cartilaginous and bony portions are both aligned with the line that connects the pharyngeal orifice and the tympanic orifice. In adults, however, the cartilaginous portion is angled inferiorly and laterally from the bony portion. This change may reflect the relative growth of the face.     

The evaluation of eustachian tube paratubal structures using magnetic resonance imaging in patients with chronic suppurative otitis media

Conclusion Eustachian tube (ET) dysfunction, which plays a role in the pathogenesis chronic suppurative otitis media (CSOM), does not seem to be due to differences in paratubal structures. Objective The aim of this study was to compare the magnetic resonance imaging (MRI) findings of the paratubal structures of the ET between normal ears and ears in patients with CSOM. Methods The MRI records of 40 patients who underwent tympanomastoidectomy for a diagnosis of CSOM were reviewed retrospectively. The healthy ears served as the control group. The length, diameter, surface area and volume of the tensor veli palatini muscle (TVPM) and levator veli palatini muscle (LVPM) were measured, in addition to the diameter of the pharyngeal orifice of the ET, volume of the Ostmann fat pad, bimucosal thickness of the lumen of the ET, and mucosal thickness. Results In the pathological ears, the mean length of the TVPM and LVPM was 22.6?mm and 19.3?mm, the mean diameter was 3.2 and 5.3?mm, and the mean volume was 1.75 and 3.2?cm³, respectively. In addition, the mean diameter of the pharyngeal orifice of the ET was 1.9?mm. There were no significant between-group differences in the paratubal structures (p?>?0.05).     

The superiorly based auricular flap

A regional random pattern flap is described which may be used to cover the mastoid area in cases in which the inferior auricle and adjacent tissue have been removed by trauma or surgery. The viability of this vascularized tissue offers a distinct advantage over skin grafting when protection of exposed facial nerve and mastoid contents is required, especially when compromised by irradiation or infection. The superiorly based auricular flap is created by removing all cartilage from the auricular remnant. The resulting skin-perichondrial flap, covering the medial and lateral surfaces of the upper ear, is unfolded to cover the inferiorly located defect. The resulting cosmetic deformity, with loss of upper auricle contour, is a disadvantage of this flap which may be mitigated by the use of a prosthesis. After the superiorly based auricular flap is described, a case is presented.     

Histopathologic study of the human eustachian tube and its surrounding structures following irradiation for carcinoma of the oropharynx

OBJECTIVE: To describe a histopathologic analysis of a human temporal bone demonstrating patulous changes of the eustachian tube (ET) and its surrounding structures following radiation therapy. DESIGN: Retrospective histopathologic case review and comparison with an age-matched control. SETTING: Elizabeth McCullough Knowles Otopathology Laboratory, University of Pittsburgh School of Medicine, Pittsburgh, Pa. RESULTS: A widened patulous ET was verified by demonstrating fibrous tissue replacement of the surrounding supporting structures related to the ET. The ET lumen was patulous and wider than the control case. Ostmann fatty tissue, the levator veli palatini muscle, and submucosal glands around the ET cartilage were replaced by dense connective tissue. CONCLUSION: This is the first histopathologic report, to our knowledge, demonstrating the effects on the ET lumen and supporting structures following acute weight loss, possible tumor infiltration, and radiation changes for carcinoma of the oropharynx.     

Strap muscle neurovascular supply

Objectives/Hypothesis: Knowledge and preservation of the neurovascular supply to strap muscles, such as the sternohyoid (SH) muscle, used in laryngotracheal reconstruction are important in preventing loss of tissue and bulk from ischemia and/or denervation. Study Design: Arteriovenous and neural supply variations to the strap muscles were examined in cadaver specimens. Methods: Strap muscle neurovascular supply was studied in 16 cadavers, including one transparent corrosion cast specimen with injected vessels. Results: For the upper SH and upper belly of the omohyoid (OMO), the arterial supply consistently arose from a branch of the superior thyroid artery (STA) most commonly terminating at the cricothyroid membrane. The inferior SH was supplied by the inferior thyroid artery. The ansa cervicalis innervated the SH inferiorly with a branch below the loop. Each arterial branch to the muscles had an accompanying venous tributary. The corrosion cast specimen demonstrated that the arterial lumen diameters were almost threefold larger in branches entering the upper SH, compared with the lower SH or OMO. Small intramuscular arteries without axial supply were found within the middle third of the upper SH, the lower SH, and the upper OMO. Conclusions: It is possible to preserve neurovascular integrity in an inferiorly based SH flap. The superior and medial borders are released, with dissection of vascular supply laterally and deep to the muscle, and preservation of the inferior terminal ansa branch.     

Distribution of substance P and the calcitonin gene-related peptide in the human tensor tympani muscle

Substance P-immunoreactive nerve fiber (SP-IR NF) and calcitonin gene-related peptide-immunoreactive nerve fiber (CGRP-IR NF) are important mediators of neurogenic inflammation and blood supply. SP-IR and CGRP-IR NFs in the tensor tympani muscle (TTM) of the human middle ear have yet to be described. In this study, the TTM, tympanic membrane, malleus in the middle ear and tensor veli palatini muscle (TVPM) were examined by whole-mount immunohistochemistry in tissue from Japanese subjects. Thirteen human cadavers (ranging in age from 46 to 90 years) were used in this study. SP-IR and CGRP-IR NFs were primarily found on vessels at the origin, insertion and belly of the surface of the TTM and on the internal surface of the tympanic membrane. These neural factors were also detected on the surface of the malleus and the insertion of the TVPM. Therefore, our results indicate that existence of the SP-IR and CGRP-IR NFs of the TTM and the TVPM may reflect muscle properties involved in pain or inflammation of the middle ear.     

会厌动脉的显微解剖研究及临床意义

目的通过对中国汉族成人尸体会厌滋养血管的显微解剖观察,为喉移植、修复、重建以及会厌相关疾病的研究提供相关的数据和形态学资料。方法采用10%甲醛常规防腐固定的头颈部正常、身体无明显畸形和外伤的成年尸体30具(男27具,女3具),常规颈部解剖下从舌骨至气管2~4环取下喉。在体式解剖显微镜下进行显微解剖,观察喉上动脉及其分支的分布、走行及形态,并将喉上动脉在甲状软骨上缘附近分出的一支分布、走行于会厌的动脉命名为“会厌动脉”。结果30具(60侧)尸体中会厌动脉均起源于喉上动脉。喉上动脉分支处外径平均(x-±s,以下同)为(1·06±0·16)mm,会厌动脉起始处外径平均为(0·79±0·13)mm。男性喉上动脉分支处外径平均为(1·09±0·12)mm,男性会厌动脉起始处外径平均为(0·81±0·11)mm。会厌动脉起始处到甲状软骨上角的垂直距离(27·16±3·85)mm。会厌动脉向上行于会厌前间隙的黏膜下疏松结缔组织和脂肪组织内,于会厌谷或杓会厌皱襞附近形成会厌动脉袢,再发出2~5个分支。动脉袢位于甲状舌骨膜处或会厌谷黏膜下疏松结缔组织和脂肪组织中,呈“M”、“N”、“Ω”“U”等形状。60侧中仅1侧在甲状舌骨膜外侧发出会厌动脉袢。结论会厌动脉袢是手术中会厌动脉最容易损伤的部位,在使用会厌瓣作为喉功能重建时应注意避免损伤。     

Anatomical routes for cancer invasion of laryngeal cartilages

The larynx is separated into compartments bounded by connective tissue membranes and cartilages. The membranes and cartilages affect the localization and spread of cancer for a while, but invasion eventually occurs. Histological study of the cartilages in the earliest stages of invasion shows cancer cells growing between the collagen bundles where the connective tissue membranes attach to the cartilages. At these points, the collagen bundles pass obliquely through the perichondrium to anchor into the cartilage and bone like Sharpey's fibers. As the cancer cells multiply, they separate the collagen bundles, forming linear passageways through the perichon-drum. This appears to be the mechanism for cartilage invasion. Thus the sites of attachment of the strongest membranes are also the most frequent sites of invasion, i.e., the anterior commissure tendon and the cricothyroid membrane.