The superiorly based pharyngeal flap with Z-plasty. Surgery and Speech

Abstract

Cleft of the lip, the alveolar process and the palate (CLP) is the most common congenital malformation of the head. Whereas the cleft lip is a malformation that affects aesthetics, cleft palate is a malformation that affects function. Functional disorders due to a palatal cleft include problems of nutrition, swallowing, breathing and grimacing. Moreover, speech and voice quality are commonly affected. Speech and voice disorders may persist after repair of the palatal cleft. Speech is primarily affected by hypernasality or increased nasal resonance as well as nasal air escape, and secondarily by misarticulations, decreased intelligibility and hoarseness. Hypernasality and nasal air escape are commonly treated by surgery, while misarticulations and hoarseness are treated by speech therapy.

The superiorly based posterior pharyngeal wall flap with a Z-plasty to cover the wound surface of the flap is one of the surgical techniques that can be used to treat hypernasality in speech due to velopharyngeal insufficiency. Velopharyngeal insufficiency occurs when the soft palate is unable to separate the oropharynx from the nasopharynx. Hypernasality is one of the parameters that may influence intelligibility of speech. As speech is the cornerstone of social integration and peer acceptance, the ultimate goal of the flap operation is to obtain speech with a normal nasal resonance and with a pleasing quality. However, if after pharyngeal flap surgery speech outcome with regard to hypernasality is disappointing, revisional surgery is usually performed in order to obtain a more favourable outcome. The incidence of revisional surgery may be used as a measure to describe speech outcome after pharyngeal flap surgery. To assess speech before and after pharyngeal flap surgery, as well perceptual judgment as instrumental measures can be performed. In clinical situation, the perceptual impression is the first tool used to judge the severity of the abnormalities in speech before and after therapy. For scientific reasons it is important to know the reliability of the perceptual judgment. Unfortunately, the current research points out that the reliability of this perceptual judgment is only moderate. For a more objective support for diagnosis and decision making for therapy, instruments to measure hypernasality in speech have been developed. One of these instruments is the Nasometer®. The nasometer claims to provide measures which are based on physiology. During standardized speech, nasal acoustic energy is measured separately from oral acoustic energy. The ratio of acoustic energy proceeding from the nasal cavity and the total acoustic energy is used as a measure for nasal resonance. The correlation between the perceptual judgment and the instrumental measure is an important issue. From the current research appears that the correlation between perception and nasometry is only moderate, probably meaning that measurement by nasometry and judgment by perception reflects different dimensions of speech. Therefore, acoustic nasometry must not be considered as a substitute for the perceptual judgment, but as a tool to quantify nasal resonance before and after therapy as part of a multidimensional diagnostic process (beside aerodynamics, imaging and self-evaluation).