Title Morphologic Characteristics of Palatopharyngeal Muscle Author(S)

Morphologic characteristics of palatopharyngeal Title muscle

Author(s) Okuda, S; Abe, S; Kim, HJ; Agematsu, H; Mitarashi, Alternative S; Tamatsu, Y; Ide, Y

Journal Dysphagia, 23(3): 258-266

URL http://hdl.handle.net/10130/1073

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Posted at the Institutional Resources for Unique Collection and Academic Archives at Tokyo Dental College, Available from http://ir.tdc.ac.jp/ Editorial Manager(tm) for Dysphagia Manuscript Draft

Manuscript Number: DYSP193R2

Title: Morphologic Characteristics of Palatopharyngeal Muscle

Article Type: Original Article

Keywords: Palatopharyngeal muscle, palatal muscles, soft palate, swallowing, pharynx, levator muscle of palatine velum, tensor muscle of palatine velum

Corresponding Author: Dr. Shinichi Abe, DDS, Ph,D.

Corresponding Author's Institution: Tokyo Dental College

First Author: Shinpei Okuda, DDS

Order of Authors: Shinpei Okuda, DDS; Shinichi Abe, DDS, Ph,D.; Hee-Jin Kim, DDS, Ph,D.; Hiroko Agematsu, BH, PhD; Satoshi Mitarashi, DDS, PhD; Yuichi Tamatsu, DDS, PhD; Yoshinobu Ide, DDS, PhD Manuscript (must not contain author information)

1 2 3 4 5 6 7 Morphologic Characteristics of Palatopharyngeal Muscle 8 9 10 11 Abstract 12 13 In an effort to clarify the morphologic characteristics of the 14 15 palatopharyngeal muscle, we examined the origin, insertion and positional 16 17 relationship with other muscles. The origin of the palatopharyngeal muscle 18 19 was both the oral and nasal sides of the soft palate, being also attached to 20 21 both the palatal aponeurosis and soft palate median. However, in some cases, 22 23 the muscle originated on the nasal side. When the palatopharyngeal muscle 24 25 26 originated from both the oral and nasal sides, it traveled through its 27 28 insertion via the levator muscle of the palatine velum. This insertion was 29 30 seen in a wide area and could be divided into three parts; the pharynx 31 32 anterior, central and posterior walls. In the central pharyngeal wall, 33 34 insertion into the pharyngeal aponeurosis, inferior constrictor pharyngeal 35 36 muscle and esophagus were observed. The present results suggest that the 37 38 palatopharyngeal muscle has a close positional relationship with the levator 39 40 and tensor muscles of the palatine velum, the pharyngeal constrictor 41 42 muscles and the esophagus. 43 44 45 46 Key Words: Palatopharyngeal muscle, palatal muscles, soft palate, 47 48 swallowing, pharynx, levator muscle of palatine velum, tensor muscle of 49 50 palatine velum 51 52 53 54 55 56 57 58 59 60 61 62 63 1 64 65 1 2 3 4 5 6 7 I. Introduction 8 9 Swallowing results from the carefully coordinated movement of 10 11 muscle groups in various many organs, including the oral cavity, soft palate, 12 13 pharynx and esophagus. To better understand swallowing function, it is 14 15 important to understand the morphologic characteristics of the muscle 16 17 groups linking the oral cavity, pharynx and esophagus. 18 19 In current reports on the morphologic characteristics of the muscles 20 21 from the pharynx through esophagus, variations in pharyngeal constrictor 22 23 muscles have been noted. Many of these reports are related to the continuity 24 25 1, 2) 26 of the buccal muscle and pharyngeal raphe variations . Bosma et al. 27 28 reported that pharyngeal raphe tissue at the junction of hypopharynx and 29 3) 30 upper esophagus is replaced with loose connective tissue . Hollinshed also 31 32 reported that the upper esophageal aponeurosis is attached to cricoid 33 34 cartilage 4). These reports clearly indicate a close morphologic relationship 35 36 between the oral cavity, pharynx and esophagus. However, the relationships 37 38 between these organs and the soft palate largely remain unknown. 39 40 With regard to the morphologic characteristics of the muscle groups 41 42 comprising the soft palate, Kuehn et al. 5,6) reported muscle bundle 43 44 arrangements from a functional perspective. However, the relationship at 45 46 the insertion site of the pharynx has not yet been elucidated. Furthermore, 47 48 although there are histopathological reports on the bundle arrangements for 49 50 the muscle groups comprising the soft palate 5,6), no studies have focused on 51 52 the muscle bundles facing the important palatopharyngeal muscle insertion. 53 54 55 Although functional coordination between the soft palate and 56 57 pharynx is necessary during swallowing, swallowing disturbance has been 58 59 reported due to shifts in the timing of muscle motions 7,8). Therefore, detailed 60 61 62 63 2 64 65 1 2 3 4 5 6 7 morphologic observation of running directions and insertion conditions of the 8 9 palatopharyngeal muscle fibers from the soft palate through the pharynx is 10 11 essential for understanding swallowing function. We thus performed 12 13 morphologic observation of the palatopharyngeal muscle fibers with regard 14 15 to running, origin and insertion attachment patterns, and relationships with 16 17 surrounding muscles. 18 19 20 21 II. Materials and methods 22 23 1. Observation materials 24 25 26 A total of twenty Japanese adult cadavers (10 males and 10 females; age 27 28 range, 49-90 years) fixed with neutral buffered 10% formalin solution and 29 30 provided for anatomical practice to the Department of Anatomy at Tokyo 31 32 Dental College were used. Medical records of the cadavers were not available. 33 34 However, on gross inspection, oropharyngeal structures appeared to be 35 36 normal. 37 38 2. Dissection of palatopharyngeal muscle 39 40 After performing sagittal section of the head and neck, the masseter 41 42 muscle, zygomatic arch, part of the mandibular ramus, temporal muscle, 43 44 lateral pterygoid muscle and medial pterygoid muscle were removed. 45 46 Cervical vertebrae localized in the posterior pharynx were also removed. 47 48 With regarding to the soft palate, the palatoglossal muscle was removed and 49 50 the palatopharyngeal muscle was exposed for observation from the oral and 51 52 nasal sides. 53 54 55 3. Observation region 56 57 1) Origin of palatopharyngeal muscle 58 59 We investigated the presence of the palatopharyngeal muscle origin 60 61 62 63 3 64 65 1 2 3 4 5 6 7 through the oral and nasal directions. The locus relationship between the 8 9 palatopharyngeal muscle and the levator muscle of palatine velum was also 10 11 observed through the oral and nasal directions. Classification was performed 12 13 based on the oral side locus relationship, followed by observation of the nasal 14 15 side locus relationship of each part. 16 17 2) Insertion of palatopharyngeal muscle 18 19 Confluence of the palatopharyngeal muscle with the salpingopharyngeus 20 21 muscle is already known 9). Moreover, some reports have considered the 22 23 salpingopharyngeus muscle to be part of the palatopharyngeal muscle 10). 24 25 11) 26 This makes distinction of the two muscles difficult . Therefore, we excluded 27 28 cases having a salpingopharyngeus muscle. 29 30 As insertion of the palatopharyngeal muscle covers a large area of the 31 32 hypopharynx, morphologic observation was performed by dividing the 33 34 palatopharyngeal muscle into 3 regions; anterior, posterior and central. 35 36 37 38 III. Results 39 40 1) Origin of palatopharyngeal muscle 41 42 (1) Observation from oral side 43 44 Two regions of the palatopharyngeal muscle origin were seen on the oral 45 46 side. Origin from the posterior of the palatine aponeurosis (Oral Tendineus 47 48 (OT); 20 out of 20 cases) was observed, and origin with interlacing fibers at 49 50 the median portion of the soft palate from the contralateral 51 52 palatopharyngeal muscle were seen (Oral Median (OM); 20 out of 20 cases). 53 54 55 On the oral side, OT and OM were seen in all cases (Fig. 1). 56 57 (2) Observation from nasal side 58 59 Two regions of the palatopharyngeal muscle origin were seen on the nasal 60 61 62 63 4 64 65 1 2 3 4 5 6 7 side. Origin from the posterior of the palatine aponeurosis (Nasal Tendineus 8 9 (NT); 14 out of 20 cases) and at the median portion of the soft palate, and 10 11 origin with interlacing fibers from the contralateral palatopharyngeal 12 13 muscle (Nasal Median (NM); 17 out of 20 cases) were observed. 14 15 NT did was not seen the posterior palatine aponeurosis area. Rather, it 16 17 was observed in a narrow area of the palatine aponeurosis medial to the 18 19 vertical section of the levator muscle of the palatine velum (vertical muscle 20 21 bundles running from the temporal bone to the soft palate) (Fig. 2). Moreover, 22 23 insertion from the posterior palatine aponeurosis near the hamulus 24 25 26 pterygoideus lateral to the vertical section of the levator muscle of palatine 27 28 velum was observed (Fig. 3) 29 30 2) Positional relationship with levator muscle of palatine velum 31 32 (1) Observation from oral side 33 34 The palatopharyngeal muscle at the oral side (MOP) originated at the 35 36 posterior (OT) and median (OM) parts of the palatine aponeurosis. From the 37 38 positional relationship of MOP with the levator muscle of the palatine velum, 39 40 two types were observed: 41 42 Type 1: MOP running through the anterior part of the oral side of the 43 44 levator muscle of the palatine velum (17 out of 20 cases). 45 46 Type 2: MOP covering all the levator muscle of the palatine velum on the 47 48 oral side (3 out of 20 cases) (Fig. 4). 49 50 (2) Observation from nasal side 51 52 The palatopharyngeal muscle at the nasal side (MNP) originated at 53 54 55 the posterior (NT) and median (NM) palatine aponeurosis. 56 57 The two types (O1 and O2) classified on observation of the oral side 58 59 were also examined from the nasal side. 60 61 62 63 5 64 65 1 2 3 4 5 6 7 Observation of O1 from the nasal side (MOP running through the 8 9 anterior part of the oral side of the levator muscle of the palatine velum) 10 11 revealed two subtypes according to the positional relationship of MNP with 12 13 the levator muscle of the palatine velum. These are: 14 15 N1a type; MNP running through the nasal side of the levator muscle 16 17 of the palatine velum (12 out of 17 cases). 18 19 N1b type; MNP interlacing with the levator muscle of the palatine 20 21 velum (5 out of 17 cases) (Fig. 5). 22 23 Nasal side observation of O2 (muscle bundle MOP covering all the levator 24 25 26 muscle of palatine velum) revealed depletion of MNP (Fig. 6) 27 28 3) Insertion of palatopharyngeal muscle 29 30 Because the palatopharyngeal and salpingopharyngeus muscles run 31 32 vertically to the hypopharynx after merging at the lower portion of the 33 34 palatopharyngeal arch, distinction between the two parts is difficult. Thus, 35 36 we observed the insertion of the palatopharyngeal muscle in cases with 37 38 depletion of the salpingopharyngeus muscle (15 out of 20 cases) (Fig. 7). 39 40 On observation from the intrapharyngeal side, the palatopharyngeal 41 42 muscle comprising the palatopharyngeal arch, the muscle bundle originating 43 44 from the oral side of the soft palate (MOP) and the muscle bundle originating 45 46 from the nasal side of the soft palate (MNP) interlaced, merged and extended 47 48 like a fan running downward, and finally inserted into a wide area in the 49 50 pharynx wall. These muscles exhibited 2 layers; a superficial layer (luminal 51 52 side) mainly composed of MNP, and a deep layer (outer wall side) composed 53 54 55 of MOP (Fig. 8). 56 57 (1) Insertion observation of anterior part 58 59 In the anterior part of the pharynx, both the palatopharyngeal muscle 60 61 62 63 6 64 65 1 2 3 4 5 6 7 and the stylopharyngeus muscle were observed. The stylopharyngeus muscle 8 9 ran in the anteroinferior direction of the deep layer of the palatopharyngeal 10 11 muscle. However, in some cases, the distinction between the 12 13 palatopharyngeal muscle and the stylopharyngeus muscle was clear (5 out of 14 15 15 cases), while in other cases, the distinction between the palatopharyngeal 16 17 muscle and the stylopharyngeus muscle was not clear due to confluence of 18 19 the two muscles (10 out of 15 cases). 20 21 With regard to the 5 cases in which distinction between the 22 23 palatopharyngeal muscle and the stylopharyngeus muscle was possible, 24 25 26 insertion of the palatopharyngeal muscle into the piriform fossa and into the 27 28 posterior border of the thyroid cartilage was seen in 2 cases, while insertion 29 30 into the posterior border of the thyroid cartilage was seen in 3 cases (Fig. 9). 31 32 However, in all 10 cases showing confluence of the palatopharyngeal muscle 33 34 with the stylopharyngeus muscle, insertion into the posterior border of the 35 36 thyroid cartilage was seen (Fig. 10). Insertion into the piriform fossa was not 37 38 clearly observed due to the difficulty in distinguishing the palatopharyngeal 39 40 muscle from the stylopharyngeus muscle. When the palatopharyngeal 41 42 muscle inserted into the anterior part, the muscle bundle (MOP) tended to 43 44 originate on the oral side. 45 46 (2) Insertion observation of posterior part 47 48 In the posterior pharynx, the palatopharyngeal muscle inserted into the 49 50 pharyngeal raphe. 51 52 The muscle bundle originating on the oral side (MOP) inserted at a 53 54 55 higher point than the muscle bundle originating on the nasal side (MNP) 56 57 (Fig. 8). 58 59 The muscle bundle originating from the posterior palatine aponeurosis of 60 61 62 63 7 64 65 1 2 3 4 5 6 7 the hamulus pterygoideus origin on the nasal side (NP; Fig. 3), part of the 8 9 muscle bundle within the soft palate, merged with MOP and ran along the 10 11 pharyngeal wall outer surface in the posterior direction. This muscle bundle 12 13 inserted into the superior part of the pharyngeal raphe (pharyngeal luminal 14 15 side) located in the superficial layer (Fig. 11). 16 17 (3) Insertion observation of central part 18 19 The palatopharyngeal muscle inserted into the central pharynx had 3 20 21 types. 22 23 Type 1: Muscle bundle inserted into the pharyngeal aponeurosis (10 out 24 25 26 of 15 cases; Fig. 12). 27 28 Type 2: Muscle bundle inserted into the pharyngeal aponeurosis and 29 30 interlaced with the horizontal running inferior constrictor pharyngeal 31 32 muscle (4 out of 15 cases; Fig. 13). 33 34 Type 3: Muscle bundle inserted into the pharyngeal aponeurosis and ran 35 36 horizontally through the esophageal inner circular muscle layer of the 37 38 luminal side (1 out of 15 cases; Fig. 14). 39 40 However, all tissues at the superior part of the esophagus were dissected. 41 42 As a result, the fibers in the esophagus could be examined, but the insertion 43 44 conditions could not be observed. The muscle bundle originating from the 45 46 oral side (MOP) and the muscle bundle originating from the nasal side 47 48 (MNP) could not be distinguished due to the confluence and interlacing. 49 50 51 52 IV. Discussion 53 54 55 Although classical textbooks describe the origin of the 56 57 palatopharyngeal muscle as being in the hard palate and palatine 58 59 aponeurosis 9), 12-14), the present study found the muscle to originate in the 60 61 62 63 8 64 65 1 2 3 4 5 6 7 palatine aponeurosis, but not in the hard palate. The palatopharyngeal 8 9 muscle originated from the palatine aponeurosis and the median part of soft 10 11 palate on both the oral and nasal side. The palatine aponeurosis is reported 12 13 to comprise the anterior part of the soft palate through reciprocal merging of 14 15 the contralateral tensor muscle of palatine velum with the ipsilateral tensor 16 17 muscle of palatine velum after its tendon turns around the hamulus 18 19 pterygoideus 15). 20 21 Although depletion of the palatine aponeurosis origin and the soft 22 23 palate median region was not seen on the oral side, unilateral or bilateral 24 25 26 sparseness of the origin was observed on the nasal side, thus suggesting a 27 28 developmental difference from the oral side. The palatopharyngeal muscle 29 30 originates from the surface of the palatine aponeurosis on oral and nasal 31 32 sides, and exhibits a morphologic origin, for example, holding the posterior 33 34 part of the palatine aponeurosis from both the oral and nasal sides. Our 35 36 results suggest that joining of the insertion of the palatine velum tensor 37 38 muscle with the palatopharyngeal muscle originating from the palatine 39 40 aponeurosis occurs in the sequential function of mastication and swallowing 41 42 movements. 43 44 With regard to the positional relationship between the 45 46 palatopharyngeal muscle and the levator muscle of the palatine velum, 47 48 Shimokawa et al. reported that the levator muscle of palatine velum was 49 50 held by the palatopharyngeal muscle 16). However, the detailed positional 51 52 relationship of the two muscles has not yet been reported. In the present 53 54 55 research, muscle bundles originating from the oral and nasal sides of the 56 57 palatopharyngeal muscle passed along the oral and nasal sides of the levator 58 59 muscle of the palatine velum. In cases with a depleted nasal side origin and 60 61 62 63 9 64 65 1 2 3 4 5 6 7 palatopharyngeal muscle, the origin of the median part on the oral side 8 9 exhibited an attachment hiding the levator muscle of the palatine velum. 10 11 Thus, the palatopharyngeal muscle held the levator muscle of the palatine 12 13 velum, and despite the deficient bundle on the nasal side, it merges with the 14 15 levator muscle of palatine velum in the oral side. Thus, movement of the soft 16 17 palate, such as elevation and descending is performed smoothly. Moreover, 18 19 the palatopharyngeal muscle originated from a limited region of the 20 21 posterior palatine aponeurosis, and inserted into the pharyngeal raphe after 22 23 posteriorly passing the superficial layer of the superior constrictor 24 25 26 pharyngeal muscle. The palatine aponeurosis was localized laterally to the 27 28 horizontal section of the levator muscle of palatine velum observed on the 29 30 nasal side of the soft palate. 31 32 Whillis reported that part of the superior constrictor pharyngeal 33 34 muscle was located in the soft palate and described this as the 35 36 palatopharyngeal sphincter 17). However, our results showed that part of the 37 38 muscle bundle of the transverse section of the palatopharyngeal muscle 39 40 merged with the muscle bundle on the oral side and ran inferiorly along the 41 42 pharynx luminal wall. The distinction between the palatopharyngeal muscle 43 44 and the superior constrictor pharyngeal muscle in the vicinity of the 45 46 hamulus pterygoideus was largely clear. The transverse part of the 47 48 palatopharyngeal muscle passed from the soft palate through the pharyngeal 49 50 raphe and superficial layer of the superior constrictor pharyngeal muscle. 51 52 This suggests that it participates in forming Passavant’s ridge in the 53 54 11) 55 superior pharynx during nasopharyngeal closure . The palatopharyngeal 56 57 muscle also participates in closure of the nasopharynx by supporting the 58 59 elevation of the soft palate by the palatine velum levator muscle, and 60 61 62 63 10 64 65 1 2 3 4 5 6 7 antero-posterior protrusion of the posterior pharynx wall by the superior 8 9 constrictor pharyngeal muscle11). 10 11 Classical textbooks mention that the palatopharyngeal muscle 12 13 inserts into the thyroid cartilage, the pharynx lateral wall and the 14 15 pharyngeal raphe 9), 12-14). It has also been reported that part of the muscle 16 17 bundle inserts into the piriform fossa 18) or the esophagus 14). However, 18 19 Cassel et al.19) revised the classical description by separating vertically 20 21 running fibers from the soft palate to the larynx and inferior pharynx as the 22 23 palatothyroideus, and horizontal muscle fibers running from the soft palate 24 25 26 laterally and posteriorly into the superior pharynx as the true 27 28 palatopharyngeal muscle. Thus, there are different opinions regarding the 29 30 insertion of the palatopharyngeal muscle. 31 32 In the present study, the palatopharyngeal muscle originating from 33 34 the oral side mainly inserted into the posterior border of the thyroid cartilage 35 36 (part also inserted into the piriform fossa) and into a wide area from superior 37 38 to inferior region of the pharyngeal raphe. The muscle bundles originating 39 40 from the nasal side inserted into the pharyngeal aponeurosis (part also 41 42 inserted into posterior border of the thyroid cartilage) and into a narrow area 43 44 from the middle to inferior region of the pharyngeal raphe. This suggests 45 46 that even when the palatopharyngeal muscle originating from the nasal side 47 48 is depleted, the palatopharyngeal muscle originating from the oral side 49 50 inserts into a wide area to compensate for this deficiency, thereby 51 52 maintaining normal swallowing function. Moreover, insertion into the 53 54 55 pharyngeal raphe in the median pharynx, interlacing of the 56 57 palatopharyngeal muscle bundle with the inferior pharyngeal constrictor 58 59 muscle, and its longitudinal running down the luminal side of the esophageal 60 61 62 63 11 64 65 1 2 3 4 5 6 7 inner circular muscle layer all suggest that the palatopharyngeal muscle 8 9 supports the sequential swallowing process from the pharyngeal phase to 10 11 esophageal phase. 12 13 The results of the present study suggest that the palatopharyngeal 14 15 muscle has a close topographic relationship with the levator muscle of the 16 17 palatine velum, the tensor muscle of the palatine velum, the pharyngeal 18 19 constrictor muscles and the esophagus, and that it is involved in sequential 20 21 swallowing function during the pharyngeal stage, as well as the oral and 22 23 esophageal stages. 24 25 26 27 28 Acknowledgements 29 30 These studies were supported by Grants-in-Aid for Scientific Research (No. 31 32 19592131: Shinichi Abe) from the Ministry of Education, Culture, Sports, 33 34 Science and Technology (MEXT) of Japan, by the Foundation of Japan 35 36 Medical Association, by Oral Health Science Center Grant HRC7 (Shinichi 37 38 Abe) from Tokyo Dental College, and by a “High-Tech Research Center” 39 40 Project for Private Universities matching fund subsidy from MEXT, 41 42 2006-2011. 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 12 64 65 1 2 3 4 5 6 7 Figure legends 8 9 Fig. 1. Origin on oral side. 10 11 Oral Tendineus (OT): Origin of the palatal aponeurosis posterior border on 12 13 the oral side, Oral Median (OM): Origin of the soft palate median part, PB: 14 15 Palatal bone, PA: Palatal aponeurosis, LVP: Levator muscle of the palatine 16 17 velum (crossing internal part of the soft palate), UV: Uvula, SPC: Superior 18 19 pharyngeal constrictor muscle, MOP: Palatopharyngeal muscle originating 20 21 on the oral side, MNP: Palatopharyngeal muscle originating on the nasal 22 23 side. 24 25 26 Fig. 2. Origin on nasal side. 27 28 Nasal Tendineus (NT): Origin of the palatal aponeurosis on the nasal side, 29 30 Nasal Median (NM): Origin of soft palate median part, LVP: Levator muscle 31 32 of the palatine velum (longitudinal fibers lying from origin to soft palate), 33 34 UV: Uvula, SPC: Superior pharyngeal constrictor muscle, TVP: Tensor 35 36 muscle of palatine velum, PA: Palatal aponeurosis, MOP: Palatopharyngeal 37 38 muscle originating on oral side, MNP: Palatopharyngeal muscle originating 39 40 on nasal side. To observe origin of NM median part on the nasal side, part of 41 42 the musculus uvulae, which is localized superficially, was removed. 43 44 45 46 Fig. 3. Origin was posterior of the palatal aponeurosis near the hamulus 47 48 pterygoideus (NP). 49 50 Part of the NP muscle bundle merged with the MOP within the soft palate. 51 52 Asterisks: Palatopharyngeal muscle originating from NP, Arrows: Hamulus 53 54 55 pterygoideus, PB: Palatine bone, LVP (1): Levator muscle of the palatine 56 57 velum (longitudinal fibers lying from temporal bone to soft palate), LVP (2): 58 59 Levator muscle of palatine velum (crossing fibers into soft palate), UV: Uvula, 60 61 62 63 13 64 65 1 2 3 4 5 6 7 TVP: Tensor muscle of palatine velum PA: Palatine aponeurosis, MOP: 8 9 Palatopharyngeal muscle originating on oral side, MNP: Palatopharyngeal 10 11 muscle originating on nasal side, SPC: Superior pharyngeal constrictor 12 13 muscle. 14 15 16 17 Fig. 4. Positional relationship of palatopharyngeal muscle with levator 18 19 muscle of the palatine velum on oral side. 20 21 O1 type: MOP passes anterior of the levator muscle of palatine velum, O2 22 23 type: MOP covers the levator muscle of palatine velum, MOP: 24 25 26 Palatopharyngeal muscle originating on oral side, LVP: Levator muscle of 27 28 the palatine velum, MNP: Palatopharyngeal muscle originating on nasal 29 30 side. 31 32 33 34 Fig. 5. Observation of O1 type on nasal side. 35 36 N1a: Palatopharyngeal muscle on the nasal side (MNP) passes through the 37 38 nasal side of the levator muscle of palatine velum, N1b: Palatopharyngeal 39 40 muscle on the nasal side (MNP) interlaces with the levator muscle of 41 42 palatine velum, Dotted line: Path of levator muscle of the palatine velum on 43 44 nasal side, Black arrow: Interlacing with levator muscle of the palatine 45 46 velum, MNP: Palatopharyngeal muscle originating on nasal side, LVP: 47 48 Levator muscle of the palatine velum, ATC: Auditory tube cartilage, UV: 49 50 Uvula, T: Tongue. 51 52 53 54 55 Fig. 6. Observation of O2 type on nasal side. 56 57 The palatopharyngeal muscle on the nasal side (MNP) was deficient. 58 59 MOP: Palatopharyngeal muscle originating on oral side, LVP: Levator 60 61 62 63 14 64 65 1 2 3 4 5 6 7 muscle of the palatine velum, ATC: Auditory tube cartilage, UV: Uvula, T: 8 9 Tongue. 10 11 12 13 Fig. 7. Relationship between palatopharyngeal muscle and 14 15 salpingopharyngeal muscle. 16 17 A: Merged with salpingopharyngeal muscle (5 out of 20 cases), B: 18 19 Salpingopharyngeal muscle is deficient (15 out of 20 cases), PP: 20 21 Palatopharyngeal muscle, SP: Salpingopharyngeal muscle, ATC: Auditory 22 23 tube cartilage, LVP: Levator muscle of the palatine velum, UV: Uvula, T: 24 25 26 Tongue. 27 28 29 30 Fig. 8. Distribution of palatopharyngeal muscle originating on oral side 31 32 (MOP) and palatopharyngeal muscle originating on nasal side (MNP). 33 34 MOP runs in a deeper layer than MNP. 35 36 Dark gray area: MNP, Light gray and dark gray areas: MOP, ST: 37 38 Stylopharyngeal muscle (runs in a deeper layer than MOP), SPC: Superior 39 40 pharyngeal constrictor muscle (runs in a deeper layer than MOP), ATC: 41 42 Auditory tube cartilage, LVP: Levator muscle of the palatine velum, TVP: 43 44 Tensor muscle of the palatine velum, TC: Thyroid cartilage, PA: Pharyngeal 45 46 aponeurosis, EP: Epiglottis, LA: Larynx, PR: Pharyngeal raphe. 47 48 49 50 Fig. 9. Cases in which distinction between the palatopharyngeal and 51 52 stylopharyngeal muscles was possible. 53 54 55 A: Palatopharyngeal muscle inserts into the piriform fossa and posterior 56 57 border of the thyroid cartilage (2 out of 5 cases), B: Cases with insertion into 58 59 the posterior border of the thyroid cartilage (3 out of 5 cases), PP: 60 61 62 63 15 64 65 1 2 3 4 5 6 7 Palatopharyngeal muscle, ST: Stylopharyngeal muscle (runs in a deeper 8 9 layer than the palatopharyngeal muscle), T: Tongue, EP: Epiglottis, TC: 10 11 Thyroid cartilage. 12 13 14 15 Fig. 10. Confluence of palatopharyngeal muscle with stylopharyngeal 16 17 muscle. 18 19 PP: Palatopharyngeal muscle, ST: Stylopharyngeal muscle (runs in a deeper 20 21 layer than the palatopharyngeal muscle), T: Tongue, EP: Epiglottis, LA: 22 23 Larynx, TC: Thyroid cartilage. 24 25 26 27 28 Fig. 11. Traveling and insertion of muscle bundle originating from NP. 29 30 White arrows: Muscle bundle from OP crosses, Dotted line: Pharyngeal 31 32 raphe, PA: Palatine aponeurosis, LVP: Levator muscle of the palatine velum 33 34 (longitudinal fibers from origin into soft palate), MNP: Palatopharyngeal 35 36 muscle originating on nasal side, PPA: Palatopharyngeal arch, UV: Uvula, T: 37 38 Tongue. 39 40 41 42 Fig. 12. Type I (Palatopharyngeal muscle bundle inserts into pharyngeal 43 44 aponeurosis). 45 46 PP: Palatopharyngeal muscle, TC: Thyroid cartilage, PA: Pharyngeal 47 48 aponeurosis, EP: Epiglottis, LA: Larynx, PR: Pharyngeal raphe, TR: Trachea, 49 50 ES: Esophagus. 51 52 53 54 55 Fig. 13. Type II (Palatopharyngeal muscle inserts after interlacing with the 56 57 inferior pharyngeal constrictor muscle). 58 59 Black arrow: Palatopharyngeal muscle crosses into the inferior pharyngeal 60 61 62 63 16 64 65 1 2 3 4 5 6 7 constrictor muscle, IPC: Inferior pharyngeal constrictor muscle, PP: 8 9 Palatopharyngeal muscle, EP: Epiglottis, LA: Larynx, TC: Thyroid cartilage. 10 11 12 13 Fig. 14. Type III (Palatopharyngeal muscle passes through the surface of the 14 15 esophagus inner circular muscle). 16 17 PP: Palatopharyngeal muscle, ES: Esophagus, EP: Epiglottis, LA: Larynx, 18 19 TC: Thyroid cartilage, TR: Trachea. 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 17 64 65 1 2 3 4 5 6 7 V. References 8 9 10 11 1. 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J Whillis (1930): A note of the muscles of the palate and the superior 18 19 constrictor; J Anat, 65: 92-95 20 21 22 23 18. Ohtsuka K, Tomita H, Murakami G (2002): Anatomy of the tonsillar Bed 24 25 26 – topographical relationship between the palatine tonsil and the lingual 27 28 branch of the glossopharyngeal nerve; Acta Otolaryngol Suppl 546: 99-109 29 30 31 32 19. Cassell MD, Moon JB, Elkadi H (1990): Anatomy and physiology of the 33 34 velopharynx; In J. Bardach & H. L. Morris (eds.), Multidisciplinary 35 36 Management of Cleft Lip and Palate. Philadelphia: W. B. Saunders Co., pp. 37 38 366-377 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 20 64 65 Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image Figure Click here to download high resolution image * Title Page with ALL Author Contact Information

Morphologic Characteristics of Palatopharyngeal Muscle

Shinpei Okuda, DDS1, Shinichi Abe, DDS, PhD1,2, Hee-Jin Kim, DDS, PhD3,

Hiroko Agematsu BH, PhD1, Satoshi Mitarashi, DDS, PhD1, Yuichi Tamatsu,

DDS, PhD4, and Yoshinobu Ide, DDS, PhD1

1Department of Anatomy, Tokyo Dental College, Chiba-city , Chiba , Japan,

2Oral Health Science Center HRC7, Tokyo Dental College 1-2-2 Masago,

Mihama-ku, Chiba-City 261-8502, Japan

3Division in Anatomy & Developmental Biology, Department of Oral Biology,

College of Dentistry, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu,

120-752 SEOUL, KOREA

4Department of Neurology Gross Anatomy, Kagoshima University Graduate

School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima

890-8520, Japan

Correspondence to: Shinichi Abe, DDS, PhD,

Department of Anatomy,

Tokyo Dental College,

１ － 2 － 2 Masago,Mihama-ku, Chiba-city,

Chiba ,261－8502 , Japan

E-mail : [email protected]

1 * Response to Reviewer Comments (must not contain author information)

September 25, 2007 Bronwyn Jones Editor-in-Chief Dysphagia

Dear Professor Bronwyn Jones

Re: Dysphagia - Decision on Manuscript "Morphologic Characteristics of Palatopharyngeal Muscle during Swallowing Function"

Thank you very much for reviewing our manuscript. I am sending herewith the english-check revisions to our manuscript.

With kind regards,

Shinichi Abe, DDS, PhD, Department of Anatomy,

Tokyo Dental College, １ － 2 － 2

Masago,Mihama-ku, Chiba-city,

Chiba, 261－8502, Japan

E-mail: [email protected]