The anatomical structures involved in chewing and phonation are the same. This means that any functional alterations affecting one system can lead to changes in the other.
Regarding voice production, these structures form the vocal tract and create the resonance system, which is responsible for amplifying and attenuating vocal frequencies, aiding in voice projection. The various possible configurations of the vocal tract, in which sound is filtered according to the nonlinear source-filter theory, significantly impact not only the timbre or “color” of a person’s voice but also the vibratory behavior of the vocal cords.
Mobility restrictions or hyperfunction of any structure involved in speech will have repercussions on the voice, potentially leading to various imbalances in the system.
Let’s examine some vocal dysfunctions caused by morphological or physiological alterations in the stomatognathic system:
Temporomandibular joint (TMJ) disorders: these modify the width, height, and length of the vocal tract. The TMJ is muscularly connected to the laryngeal support muscles and resonance structures. For example, a chronic unilateral chewing pattern alters the rhythm and amplitude of TMJ movement, leading to muscular asymmetries that affect the position and movement of adjacent structures.
Lips: modify the length of the vocal tract.
Suprahyoid muscles: affect laryngeal height, thereby altering the length of the vocal tract.
Tongue alterations: impact resonance space and articulation. The entire muscular chain must be balanced to ensure proper postural alignment, allowing for a natural (euphonic) vocal emission. The tongue is a large, highly mobile, and precise structure, playing a key role in voice quality. When its shape (volume) and position change, the modifications in resonance and voice projection become evident. Its position influences the hyoid bone, which in turn affects laryngeal height, head and neck posture, and other related structures through its extrinsic musculature.
Jaw-lip-larynx relationship: the muscles responsible for jaw opening and closing (geniohyoid, anterior belly of the digastric, and mylohyoid) belong to the suprahyoid muscle group and their activity modifies jaw positioning. When the jaw lowers, the larynx rises, shortening the vocal tract, and vice versa.
Hypertrophy of the pharyngeal and palatine tonsils: reduces and obstructs resonance space.
Velopharyngeal sphincter dysfunction: leads to hyper- or hyponasality and altered oral proprioception.
Tongue-soft palate relationship: these structures are interconnected by various muscles that ensure their coordinated action. Excessive tongue tension or increased tension in the velopharyngeal sphincter muscles restricts the freedom of movement of the other.
An osteopathic evaluation is useful for analyzing and monitoring the anatomical and functional state of these structures over time, ensuring optimal vocal ergonomics and performance.
Valentina Carlile - Osteopath specializing in Osteopathy for Voice and Speech Disorders since 2002. For information and bookings, visit the Contact page.
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