Incidence is the number of new cases of a disorder or condition identified in a specific time period. Prevalence is the number of individuals who are living with the disorder or condition in a given time period.
Given the various etiologies and presentations of resonance disorders, overall incidence and prevalence are unknown. Incidence and prevalence estimates for one cause of resonance disorders—VPD—is reported in the literature for the following disorders and conditions.
References below are made to both VPD and velopharyngeal insufficiency; for clarification between terms, see Classification of Velopharyngeal Dysfunction.
- Cleft palate is the condition most commonly associated with VPD (Kummer, Marshall, & Wilson, 2015). Overall, up to 30% of individuals who have undergone cleft palate repair experience continued velopharyngeal insufficiency (Ha, Koh, Moon, Jung, & Oh, 2015; Phua & de Chalain, 2008; Witt, Wahlen, Marsh, Grames, & Pilgram, 1998; Zhao et al., 2012).
- Submucous cleft palate presents with velopharyngeal insufficiency in about 10% to 35% of cases (Nasser, Fedorowicz, Newton, & Nouri, 2008; Weatherly-White, Sakura, Brenner, Steward, & Ott, 1972; Ysunza et al., 2001).
- Pierre Robin sequence (PRS) typically presents with a wide U-shaped cleft palate, among other aerodigestive tract abnormalities. Resonance disorders are common; however, evidence is mixed as to whether individuals with PRS experience different rates of postsurgical velopharyngeal insufficiency than do individuals with cleft palate alone (Filip et al., 2015; Goudy, Ingraham, & Canady, 2011).
- Genetic syndromes are often associated with resonance disorders, but the extent of the relationship is difficult to determine given frequently co-occurring voice, cognitive, and/or hearing impairments (van Borsel, 2004).
- 22q11.2 deletion syndrome (also known as velo-cardio-facial syndrome, DiGeorge syndrome, Shprintzen syndrome, and Sedláčková syndrome) is the most common genetic cause of congenital VPD (Kirschner, 2005); velopharyngeal insufficiency is present in about 75% of individuals (Crockett, Goudy, Chinnadurai, & Wootten, 2014; Kirschner, 2005; Shprintzen & Golding-Kushner, 2008).
- Other conditions associated with VPD
- Dysarthria may or may not present with resonance issues, most typically related to discoordination of velopharyngeal valving, prolonged vowel productions that are often accompanied by hypernasality, and neurologic effects on the musculature of the palate and pharynx. VPD “is frequently, but not universally, associated with dysarthria” (Yorkston, Beukelman, Strand, & Hakel, 2010, p. 203).
- Adenoidectomy may result in persistent VPD in about 1 in 1,500 to 1 in 10,000 patients (Biavati, Rocha-Worley, & Wiet, 2017); this may require surgical or prosthetic management. VPD is persistent when it lasts beyond several weeks (Biavati et al., 2017; Willging & Kummer, 2014).
- Uvulopalatopharyngoplasty, a common procedure for the correction of obstructive sleep apnea, is associated with velopharyngeal insufficiency as a long-term complication in about 8% of individuals (Tang, Salapatas, Bonzelaar, & Friedman, 2017).
- Hearing loss is associated with hypernasality, hyponasality, or mixed resonance. Children with cochlear implants may have less disordered resonance than those with hearing aids (Baudonck, Van Lierde, D'haeseleer, & Dhooge, 2015; Fletcher, Mahfuzh, & Hendarmin, 1999; Sebastian, Sreedevi, Lepcha, & Mathew, 2015).