Muscular origins of the levator veli palatini muscle: Documenting anatomical variation and resolving five centuries of conflicting accounts.

Histologic sections from nine temporal bones with eustachian tubes (ETs) attached were analyzed with a computer-aided three-dimensional reconstruction method to determine the curvature and tilt of the ET and the anatomic relationships between the medial lamina of the ET cartilage, the levator veli palatini muscle (LVPM), and Rosenmüller's fossa. It was found that the ET is convex superomedially and is tilted medially. The LVPM is located inferolateral to the inferior margin of the medial lamina of the anterior ET cartilage. The LVPM is inferior to the medial lamina of the posterior ET cartilage. These findings suggest that the LVPM opens the anterior cartilaginous portion of the ET by rotating the medial lamina with increased dimension of the muscle body when it contracts. Rosenmüller's fossa extends along the ET with rich lymphoid tissues as far as approximately one half the total length of the ET and very close to the skull base.

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.

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. 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/). Ten normal healthy adults (five men, five women) between 21 and 53 years of age and free of oropharyngeal abnormalities. Two-dimensional spin echo static images and dynamic fast gradient echo images of the levator muscle in both the sagittal and oblique/coronal planes. 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. 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.

To provide detailed descriptions of contraction-induced morphometric changes in the extravelar segments of the levator veli palatini (LVP) muscle using 3-dimensional (3-D) magnetic resonance imaging (MRI). Three-dimensional MRI data were acquired at rest and during "silent /i/" from 4 singers. During silent /i/, participants voluntarily sustained velar elevation while breathing orally for the entire scan time. Focusing on the extravelar segments, LVP length, angle of the muscle origin, and cross-sectional area (CSA), measurements were obtained and compared between tasks. Three of the 4 participants exhibited the expected patterns of change following concentric contraction of the LVP muscle. Consistent changes from the resting to the contracted state included reductions in LVP length by 13.5% and angle of the muscle origin by 9.8%, as well as increases in CSAs by 22.1%, on average. This study presented high-resolution data of the LVP muscle behavior with the first in vivo 3-D measurements of the contracted LVP muscle, which can be useful for the validation of computational models that aim at describing biomechanical properties of the LVP muscle in future research. The active behavior of the extravelar LVP muscle also provides some insight on optimal LVP muscle geometry to consider during cleft palate repair.

After palatoplasty, incomplete velopharyngeal closure in speech articulation sometimes persists, despite restoration of deglutition function. The levator veli palatini (LVP) is believed to be significantly involved with velopharyngeal function in articulation; however, the development and innervation of LVP remain obscure. The development of LVP in human embryos and fetuses has not been systematically analyzed using the Carnegie stage (CS) to standardize documentation of development. The anlage of LVP starts to develop at CS 21 beneath the aperture of the auditory tube (AT) to the pharynx. At CS 23, LVP runs along AT over its full length, as evidenced by three-dimensional image reconstruction. In the fetal stage, the lesser palatine nerve (LPN) is in contact with LVP. The positional relationship between LVP and AT three-dimensionally, suggesting that LVP might be derived from the second branchial arch. Based on histological evidence, we hypothesize that motor components from the facial nerve may run along LPN, believed to be purely sensory. The multiple innervation of LVP by LPN and pharyngeal plexus may explain the postpalatoplasty discrepancy between the partial impairment in articulation vs. the functional restoration of deglutition. That is, the contribution of LPN is greater in articulation than in deglutition.

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.

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.

The endoscopic prelacrimal recess approach to the paramedian middle cranial base: An anatomical study

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).

Anatomical features of the middle ear and auditory tube (AT) in the house musk shrew, Suncus murinus, were examined by dissection and light microscopy. The tensor veli palatini (TVP) and tensor tympani (TT) have no connections with the wall or cartilage of the AT although they are connected by the intermediate tendon. None of the levator veli palatini (LVP) muscle bundles are attached to the AT. The salpingopharyngeus (SA) alone has its origin on the caudal edge of the tubal cartilage. The origin extends to the pharyngeal two thirds of the cartilage. The SA originates perpendicular to the AT and runs caudomedialward. Some SA muscle bundles intermingle with those of the palatopharyngeus to end on the dorsal wall of the pharynx. The observations provide no evidence that the TVP, LVP and TT have any role in AT function. The only muscle affecting the AT function in S. murinus is the SA, and it would be the AT dilator.

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.

Fetal development of the cartilage of the pharyngotympanic tube (PTT) is characterized by its late start. We examined semiserial histological sections of 20 human fetuses at 14-18 weeks of gestation. As controls, we also observed sections of 5 large fetuses at around 30 weeks. At and around 14 weeks, the tubal cartilage first appeared in the posterior side of the pharyngeal opening of the PTT. The levator veli palatini muscle used a mucosal fold containing the initial cartilage for its downward path to the palate. Moreover, the cartilage is a limited hard attachment for the muscle. Therefore, the PTT and its cartilage seemed to play a critical role in early development of levator veli muscle. In contrast, the cartilage developed so that it extended laterally, along a fascia-like structure that connected with the tensor tympani muscle. This muscle appeared to exert mechanical stress on the initial cartilage. The internal carotid artery was exposed to a loose tissue facing the tubal cartilage. In large fetuses, this loose tissue was occupied by an inferior extension of the temporal bone to cover the artery. This later-developing anterior wall of the carotid canal provided the final bony origin of the levator veli palatini muscle. The tubal cartilage seemed to determine the anterior and inferior margins of the canal. Consequently, the tubal cartilage development seemed to be accelerated by a surrounding muscle, and conversely, the cartilage was likely to determine the other muscular and bony structures.

View Supplementary Video 1 Laryngoscope, 2020

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 nonnasal 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 point...

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. Retrospective histopathologic case review and comparison with an age-matched control. Elizabeth McCullough Knowles Otopathology Laboratory, University of Pittsburgh School of Medicine, Pittsburgh, Pa. 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. 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.