Posterior pharyngeal flap surgery is the most commonly used operation to restore velopharyngeal competence (i.e., develop a functional seal between the vocal and the oral cavity), and therefore correct hypernasality and nasal air escape (Ysunza et al., 2002).
Posterior pharyngeal flaps can be based superiorly or inferiorly and the velum can be split transversely or along the midline (Lideman-Boshki et al., 2005).
Pharyngolasties correcting hypernasal speech can be traced back as far as the 19th century when Passavant first explored palatopexy in a 23-year-old female (Hall et al., 1991).
In 1928, Rosenthal used an inferiorly based posterior pharyngeal flap in combination with a modified von Langenbeck palatoplasty in primary surgery for cleft palate repair.
Taking a different approach, Padgett (1930) utilized a superiorly based flap for cleft palate patients whose primary surgical repair had been unsuccessful (Sloan, 2000).
In the 1970s, Hogan and Shprintzen advanced posterior pharyngeal flaps, leading to an increased success rate in the elimination of VPI.
Consistent with Warren’s aerodynamic data, Hogan advocated that the velopharyngeal opening be no greater than 4 mm in diameter because a larger gap would most likely result in hypernasal speech (Peterson-Falzone et al., 2001).
The patient’s pattern of VP closure is one aspect that is taken take into consideration by doctors in deciding whether pharyngeal flap surgery is the appropriate method of treatment (Armour et al., 2005).
When planning pharyngeal flap surgery, it is imperative for the doctor to match the postoperative structure to the preoperative movements in order for an adequate seal to be achieved (Ysunza et al., 2002).
However, with thorough preoperative planning, pharyngeal flap surgery can be just as effective in eliminating VPI in adults as it is in children (Hall et al., 1991).
Some of the issues associated with this compromise include: narrowing of the nasal and oral airway secondary to edema, impeding of the nasopharynx by the flap itself, anatomical changes in which the oropharynx becomes smaller, and decreased respiratory drive following general anaesthesia.
Pharyngeal flap surgery may be able to improve speech performance in children or adults with a cleft palate who have velopharyngeal insufficiency.
In addition to speech improvements, pharyngeal flap surgery may help eliminate hypernasality, nasal turbulence, and facial grimacing (Tonz et al., 2002).
The outcomes of pharyngeal flap surgery vary among each individual in regards to improvements in hyponasality, hypernasality, nasal turbulence, voice quality, articulation, and intelligibility (Tonz et al., 2002; Liedman-Boshki et al., 2005).
Patients who undergo pharyngeal flap surgery encounter the risk of never breathing through their nose again, which could create abnormal speech (i.e., denasal resonance) (Witt et al., 1998).
It is common that individuals who have to undergo a second surgery could develop secondary speech problems, more specifically compensatory articulation and resonance disorders.
There are higher rates of surgical failure in children with a history of perinatal upper airway obstruction, such as those with Robin sequence (Witt et al., 1998).