Conclusion: Aspiration and stricture common side effects dose limits established for larynx and inferior pharyngeal constrictors.No stricture if mean inferior pharyngeal constrictor dose <54 Gy smoking correlated significantly. No aspiration if mean larynx dose <48 Gy or mean inferior pharyngeal constrictor dose <54 Gy. Outcome: Clinically significant aspiration 32% and stricture 37%.96 patients with H&N cancers, 85% definitive RT vs 15% postop RT. Harvard 2008 (2004-2006) PMID 18468812 - 'Dose to larynx predicts for swallowing complications after intensity-modulated radiotherapy.' (Caglar HB, Int J Radiat Oncol Biol Phys.Conclusion: Dose to larynx and pharyngeal constrictors predicted long-term swallowing complications.Predictors for pharyngoesophageal stricture: superior pharyngeal constrictor V65 >33%, middle pharyngeal constrictor V65 > 75%.Dose volume constraints for anterior oral cavity (V30 41 Gy, larynx V60 >24%, inferior pharyngeal constrictor V60 >12%.MDACC 2012 PMID 20646872 - 'Candidate dosimetric predictors of long-term swallowing dysfunction after oropharyngeal intensity-modulated radiotherapy.' (Schwartz DL, Int J Radiat Oncol Biol Phys.Front Page: Radiation Oncology | RTOG Trials | Randomized Trials.The fiber arrangement suggested that, besides constriction of the pharynx, the ascending and descending fibers of the middle constrictor can act as an elevator muscle, and the irregular attachments could affect the functions of the muscles and vessels. The ascending and descending fibers rarely reached the top of the pharynx and the thyroid cartilage, respectively. The three groups were inserted into the pharyngeal raphe, and the descending fibers joined the longitudinal pharyngeal muscles. Some fibers attached to the hyoglossus, occasionally to the stylohyoid and the posterior belly of the digastric, but seldom to the lingual artery and the triticeal cartilage in the thyrohyoid ligament.

The posteroinferior group fanned out from the posterior part of the greater horn, while the middle constrictor arose internally to the hyoglossus some fibers often passed externally, and their fibers sometimes intersected around the lingual artery, which ran between them. The middle group ascended posterosuperiorly from the greater horn and fanned out. The anterosuperior group ascended posterosuperiorly from the ligament and the lesser horn and fanned out. The middle constrictor arose from the stylohyoid ligament and the hyoid bone, and its fibers were divided into three overlapping groups. The gross anatomies of the pharyngeal and neighboring muscles were examined in 41 cadavers. This study investigated the attachments of the middle constrictor to clarify its configuration and re-examine its functions. Such arrangements make the interrelationships among pharyngeal muscles complicated.

The pharyngeal muscles overlap each other and some of their parts have different areas of origin.

Pharyngeal constrictor