Augmentation pharyngoplasty is a kind of plastic surgery

Plastic surgery

Plastic surgery is a medical specialty concerned with the correction or restoration of form and function. Though cosmetic or aesthetic surgery is the best-known kind of plastic surgery, most plastic surgery is not cosmetic: plastic surgery includes many types of reconstructive surgery, hand...

 for the pharynx

Pharynx

The human pharynx is the part of the throat situated immediately posterior to the mouth and nasal cavity, and anterior to the esophagus and larynx. The human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx , and the laryngopharynx...

 (soft tissue at the back of the mouth) when the tissue at the back of the mouth is not able to close properly. It is typically used to correct speech problems in children with cleft palate. It may also be used to correct problems from a tonsillectomy

Tonsillectomy

A tonsillectomy is a 3,000-year-old surgical procedure in which the tonsils are removed from either side of the throat. The procedure is performed in response to cases of repeated occurrence of acute tonsillitis or adenoiditis, obstructive sleep apnea, nasal airway obstruction, snoring, or...

 or because of degenerative diseases. After the surgery, patients have an easier time pronouncing certain sounds, such as 'p' and 't', and the voice may have a less nasal sound.

In this surgery, the posterior pharyngeal wall is moved forward, making it similar to an adenoid

Adenoid

Adenoids are a mass of lymphoid tissue situated posterior to the nasal cavity, in the roof of the nasopharynx, where the nose blends into the throat....

 pad and closing the small gap that interferes with clear speech.
Several techniques have been used including: rearranging the soft tissue

Soft tissue

In anatomy, the term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body, not being bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes , and muscles, nerves and blood vessels .It is sometimes...

, implanting cartilage

Cartilage

Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...

 and injection

Injection (medicine)

An injection is an infusion method of putting fluid into the body, usually with a hollow needle and a syringe which is pierced through the skin to a sufficient depth for the material to be forced into the body...

 or implant

Implant (medicine)

An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue...

ing different types of synthetic materials: (Peterson-Falzone et al., 2001)

• Soft tissue advancement: Passavant (1862), attempted to advance the soft tissue of the posterior pharyngeal wall by suturing two palatopharyngeal muscles in the middle to exemplify Passavant’s ridge. Later, he tried to create this ridge by folding a flap of pharyngeal mucosa upon itself. This type of surgery is best for patients with velopharyngeal defect
  Soft palate
  The soft palate is the soft tissue constituting the back of the roof of the mouth. The soft palate is distinguished from the hard palate at the front of the mouth in that it does not contain bone....
  
  s. (Peterson-Falzone et al., 2001)

• Cartilage implants: material, (usually from the patient’s rib), is implanted to create an anterior projection on the pharyngeal wall. Most of the time, the success rate is low because the surgeons could not get a large enough sample from the ribs to stay in place in the pharyngeal wall. Later, several surgeons only performed this surgery on patients with openings 5 mm wide or less. The ten patients in this study no longer experience hypernasality or audible nasal emissions
  Insufflation
  In religious and magical practice, insufflation and exsufflation are ritual acts of blowing, breathing, hissing, or puffing that signify variously expulsion or renunciation of evil or of the devil , or infilling or blessing with good .In historical Christian practice, such blowing appears most...
  
  . Another study was done under the same circumstances (20 patients with gaps 1-3 mm), and had a much lower success rate. (Peterson-Falzone et al., 2001) Pg 320-321

• Synthetic materials: synthetic materials used to augment the posterior pharyngeal wall include: silicone
  Silicone
  Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications , cookware, and insulation....
  
   (Silastic) (Blocksma, 1963), Teflon (Ward et al. 1966, Smith & McCabe, 1977), Proplast (Wolford et al. 1989), and collagen
  Collagen
  Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...
  
  . Many of these procedures were abandoned because results were unpredictable, there were post operative complications or the Food and Drug Administration
  Food and Drug Administration
  The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
  
  imposed restrictions. Overall these procedures were deemed undesirable in the long term. (Peterson-Falzone et al., 2001)