Zhe-Wu Jin1, Ji Hyun Kim2, Masahito Yamamoto3, Yukio Katori4, Hiroshi Abe5, Gen Murakami3,6, Shin-Ichi Abe3. 1. Department of Anatomy, Wuxi School of Medicine, Jiangnan University, Wuxi, China. 2. Department of Anatomy, Jeonbuk National University Medical School, 20 Geunji-ro, Deokjin-gu, Jeonju, 54907, Republic of Korea. 407kk@hanmail.net. 3. Department of Anatomy, Tokyo Dental College, Tokyo, Japan. 4. Department of Otorhinolaryngology and Head and Neck Surgery, Tohoku University School of Medicine, Sendai, Japan. 5. Emeritus Professor of Akita University, Akita, Japan. 6. Division of Internal Medicine, Cupid Clinic, Iwamizawa, Japan.
Abstract
PURPOSE: The constrictor pharyngis superior (CPS) initially develops along the posterior wall of the pharyngeal mucosal tube, whereas, during the early phase, the buccinators (BC) are far anterolateral to the CPS. The process and timing of their meeting during fetal growth have not been determined. METHODS: The topographical relationship between the growing BC and CPS was assessed in histological sections from 22 early- and mid-term fetuses of approximate gestational age (GA) 8-16 weeks, and eight late-term fetuses of approximate GA 31-39 weeks. RESULTS: At 8-9 weeks, the palatopharyngeus appeared to pull the CPS up and forward. Until 11 weeks, the CPS was attached to the hamulus of the pterygoid (pterygopharyngeal part). Until 13 weeks, the CPS extended anterolaterally beyond the hamulus to meet the BC. Some BC muscle fibers originated from the oral mucosa. Notably, by 30 weeks, the CPS-BC interface had become covered by or attached to the palatopharyngeus. Muscle fibers of the palatopharyngeus, however, were thinner than those of the CPS and BC. At and near the interface, BC muscle fibers tended to run along the left-right axis, whereas those of the CPS ran anteroposteriorly. A definite fascia (i.e., a future pterygomandibular raphe) was usually absent between these muscles in fetuses. CONCLUSIONS: The excess anterior growth of the CPS with its subsequent degeneration might cause individual anatomical variations in composite muscle bundles of the palatopharyngeus-CPS complex or palatopharyngeal sphincter. A tensile transduction from the BC to the CPS through the raphe seemed unnecessary for cooperative suckling and swallowing after birth.
PURPOSE: The constrictor pharyngis superior (CPS) initially develops along the posterior wall of the pharyngeal mucosal tube, whereas, during the early phase, the buccinators (BC) are far anterolateral to the CPS. The process and timing of their meeting during fetal growth have not been determined. METHODS: The topographical relationship between the growing BC and CPS was assessed in histological sections from 22 early- and mid-term fetuses of approximate gestational age (GA) 8-16 weeks, and eight late-term fetuses of approximate GA 31-39 weeks. RESULTS: At 8-9 weeks, the palatopharyngeus appeared to pull the CPS up and forward. Until 11 weeks, the CPS was attached to the hamulus of the pterygoid (pterygopharyngeal part). Until 13 weeks, the CPS extended anterolaterally beyond the hamulus to meet the BC. Some BC muscle fibers originated from the oral mucosa. Notably, by 30 weeks, the CPS-BC interface had become covered by or attached to the palatopharyngeus. Muscle fibers of the palatopharyngeus, however, were thinner than those of the CPS and BC. At and near the interface, BC muscle fibers tended to run along the left-right axis, whereas those of the CPS ran anteroposteriorly. A definite fascia (i.e., a future pterygomandibular raphe) was usually absent between these muscles in fetuses. CONCLUSIONS: The excess anterior growth of the CPS with its subsequent degeneration might cause individual anatomical variations in composite muscle bundles of the palatopharyngeus-CPS complex or palatopharyngeal sphincter. A tensile transduction from the BC to the CPS through the raphe seemed unnecessary for cooperative suckling and swallowing after birth.
Authors: Kwang Ho Cho; Hak Seung Lee; Yukio Katori; Jose Francisco Rodríguez-Vázquez; Gen Murakami; Shin-Ichi Abe Journal: Clin Anat Date: 2012-12-17 Impact factor: 2.414
Authors: Peng Ding; Regina Campbell-Malone; Shaina D Holman; Stacey L Lukasik; Takako Fukuhara; Estela M Gierbolini-Norat; Allan J Thexton; Rebecca Z German Journal: Dysphagia Date: 2013-02-16 Impact factor: 3.438
Authors: Jose Francisco Rodríguez-Vázquez; Ji Hyun Kim; Samuel Verdugo-López; Gen Murakami; Kwang Ho Cho; Sachiko Asakawa; Shin-Ichi Abe Journal: J Anat Date: 2011-05-22 Impact factor: 2.610