Mouth and Pharynx Deformities
The following Oropharyngeal deformities are usually associated with the Cleft lip/palate. Such as: The Robin sequence, macroglossia, ankyloglossia, epignathus, lingual thyroid, and a few other conditions which are briefly discussed in this section.
Robin sequence

The Robin sequence includes cleft palate (CP), a small mouth, and retrognathia. Retrognathism results in a functional abnormality of the tongue musculature that manifests with airway obstruction during sleep, as the tongue falls posteriorly. In addition to the respiratory difficulties, feeding difficulties can result in a failure to thrive.

The severity of airway compromise dictates management. In mild cases, conservative treatment consists of placing the patient in a prone position and intensive monitoring. Surgery is indicated if no improvement occurs after 7 days. Surgery involves either tracheostomy or repositioning of the tongue.

Macroglossia

Congenital macroglossia may be secondary to tumors (eg, dermoids), muscular hypertrophy or hyperplasia (Beckwith-Wiedemann syndrome), or hemihypertrophy. Vascular malformation is a common cause of macroglossia.[11] Macroglossia may interfere with speech or deglutition. In addition, the exposed tongue can become dry, cracked, and ulcerated. Oral hygiene and drooling can be problematic.

Lymphangiomas are the most common vascular malformations of the tongue. Surgical biopsy or relatively minor trauma to the patient with lymphangioma can result in massive swelling, with difficulty in closing the mouth or, at times, airway compromise. Increased swelling can occur with superimposed lymphangitis. Early in life, conservative treatment is recommended; this includes the avoidance of trauma and the prompt use of antibiotics at the first sign of infection. Surgery is usually delayed until the child is older (4-5 y) to decrease the likelihood of postoperative airway problems.

Macroglossia is a feature of Down syndrome. The etiology is believed to be a reactive hypertrophy due to muscular hypotonia. The combination of macroglossia and a small oral cavity in these patients results in glossoptosis. Partial glossectomy is usually successful in returning the tongue to the oral cavity and in removing this visible stigma of mental retardation.

Macroglossia can also be associated with a few syndromes, such as Treacher Collins (mandibulofacial dysostosis or Franceschetti-Zwahlen- Klein) syndrome.

Ankyloglossia

Ankyloglossia is due to the presence of a frenulum tethering the tip of the tongue to the floor of the mouth. The commonly used term to describe ankyloglossia is tongue-tied. Problems with articulation may affect sounds that require placement of the tongue on the upper incisor teeth, as in the /th/ sound. In Spanish-speaking persons with this condition, rolling of the tongue to produce the /r/ sound is particularly difficult.

Surgical intervention is indicated for articulation problems and for feeding difficulties (poor suckling), dental problems (spreading of the lower incisor teeth), or requests by the patient's parents. Release may involve simple division of the involved band of tissue or a Z-plasty lengthening procedure. Injury to the Wharton duct should be avoided.

Epignathus
Epignathi are rare teratomas that histologically contain tissue of all 3 germ- cell lines.[12] Patients usually present at birth with a mass that protrudes through the mouth and compromises the airway (see the image below). Grossly, the tumor is covered with skin and mucosa and appears to arise from the palate or pharynx, filling the oral cavity. These masses are thought to arise from pluripotential stem cells from the Rathke pouch region.

Prenatal ultrasonography usually demonstrates the mass protruding from the fetal face. The differential diagnosis should include hairy polyps, encephaloceles, gliomas, and dermoids.

Management involves emergently securing an airway by intubation or formal tracheostomy. A magnetic resonance image (MRI) (or computed tomography [CT] scan) is required before surgical intervention to rule out an encephalocele or intracranial extension of the lesion. Once the extent of the mass is adequately determined, the tumor can be excised through the oral cavity.

Lingual thyroid

A lingual thyroid is due to the undescended thyroid at the tongue base. Common symptoms include dysphagia; dysphonia; and, occasionally, dyspnea. Thyroid ultrasonography has replaced radioisotope thyroid scanning in the evaluation of the amount of active thyroid tissue present.

Management depends on functional and metabolic factors. If the patient is euthyroid, observation with careful follow-up is advised. Suppressive thyroid hormone therapy should be initiated if a hypothyroid status develops. If the lingual swelling increases, surgical excision with replacement therapy is indicated.

Other conditions

Lip pits represent vestigial remnants of the lateral sulci of the mandible at the 7.5- to 12.5-mm stage of the embryo. In van der Woude syndrome (an autosomal dominant syndrome with 90% penetrance), lip pits are paramedian and usually bilateral. They vary in depth from a few millimeters to 3 centimeters or more. A communication may exist with the minor salivary glands of the lower lip. Lip pits may also occur in popliteal pterygium syndrome and in aganglionic megacolon with cleft lip and palate (CLP).

Commissural lip pits occur more frequently than other lip pits and are not related to the syndromes just described. Their prevalence is estimated to be 1 case per 300 white persons and 1 case per 48 black persons.

Micrognathia could be associated with numerous syndromes and conditions, such as an adducted thumb, atelosteogenesis (types I and III); cerebrocostomandibular findings; the Robin sequence; and Aase-Smith, Chitayat-Azouz, chromosome 3 dup 3p, chromosome 4 partial del 4p, chromosome 7 term del 7q, Say, and Shprintzen (velocardiofacial) syndromes.

Embryology

In facial morphogenesis, neural crest cells migrate into the facial region, where they form the skeletal and connective tissue and all dental tissues except the enamel. Vascular endothelium and muscle are of mesodermal origin.[4]

The upper lip is derived from medial nasal and maxillary processes. Failure of merging between the medial nasal and maxillary processes at 5 weeks' gestation, on one or both sides, results in cleft lip. Cleft lip usually occurs at the junction between the central and lateral parts of the upper lip on either side. The cleft may affect only the upper lip, or it may extend more deeply into the maxilla and the primary palate. (Cleft of the primary palate includes cleft lip and cleft of the alveolus.) If the fusion of palatal shelves is impaired also, the cleft lip is accompanied by cleft palate, forming the cleft lip and palate abnormality.

  • Cleft palate is a partial or total lack of fusion of palatal shelves. It can occur in numerous ways:
  • Defective growth of palatal shelves
  • Failure of the shelves to attain a horizontal position
  • Lack of contact between shelves
  • Rupture after fusion of shelves

The secondary palate develops from the right and left palatal processes. Fusion of palatal shelves begins at 8 weeks' gestation and continues usually until 12 weeks' gestation. One hypothesis is that a threshold is noted beyond which delayed movement of palatal shelves does not allow closure to take place, and this results in a cleft palate.

Cleft lip can be easily diagnosed by performing ultrasonography in the second trimester of pregnancy when the position of the fetal face is located correctly (see Media files 6-7).

Bilateral cleft lip on ultrasound. 

Median cleft lip on ultrasound. 

Usually, diagnosing a cleft palate with ultrasonography is not possible; however, an experienced physician or technician may catch an atypical movement of the fetal tongue in a lateral view. In the case of a large cleft palate, the tongue moves up into an open space (cleft) in the roof of the oral cavity. Three-dimensional imaging has been introduced to prenatal ultrasonography diagnostics of cleft anomalies and appears to be promising for recognizing a cleft palate in a fetus.
Etiology

Generally, facial clefting results when medial, lateral, and maxillary nasal processes on either left, right or both sides of the forming craniofacial complex do not fuse completely. Early embryonic changes (during the fourth and tenth weeks of gestation) may result in clefting. Suspected causes include: 1) environmental insults (i.e. maternal diseases, chemotherapy, radiation, alcohol, excess retinoic acid and anticonvulsant medications); or 2) genetic factors.

Researchers have identified some of the genes involved in regulating craniofacial development. The Human Genome Project hopes to ultimately identify all the genes that make us human. This should help us to better understand the genetic causes of cleft lip and palate.

Factors that increase the chance of congenital malformations include: 1) pregnancies in women older than 35; 2) teenaged pregnancies; and 3) increased consumption of teratogens during early months of pregnancy (Slavkin 1992).

The good news is that ultrasound, amniocentesis and molecular genetic techniques can be used to detect common congenital malformations, including cleft lip, early. Advances in surgical techniques and growth factors also help correct problems associated with cleft lip or cleft palate. Cleft lip is usually less serious than cleft palate. A post-pubescent male may choose to grow a mustache to hide the external scar that remains after childhood surgery has closed the cleft lip. Unfortunately, this easy cosmetic option is not available to females.

About 22 percent of facial clefting has a genetic origin. Again, most cleft lips with or without cleft palate are produced by environmental insults (teratogens such as alcohol, retinoic acid, maternal illness, protein/calorie malnutrition during pregnancy) interacting with one or more genes. There is increased risk for congenital malformations because of maternal age at the time of pregnancy.

Additional risk factors include lack of prenatal care during pregnancy, cigarette smoking, lack of a balanced diet and the chronic use of non- prescribed drugs or substance abuse. If parents without a cleft have a child with a cleft, the chance that a subsequent baby will have a cleft is only two to four percent. If either parent has a cleft, the relative risks become about four to five percent for having a baby with a cleft. If both parents have clefts, the risks are much greater (Slavkin 1992).

In addition to the required tissue repair, children with cleft lip and palate may have difficulty hearing or speaking clearly. Thanks to professionals including dentists, surgeons, and teachers, prognosis is very good. Patients with isolated cleft lip usually do not have trouble with feeding. However, infants with cleft lip and palate don't have adequate suction to draw milk through a nipple. Methods have been developed to enhance maternal bonding during the feeding of newborn and very young infants.

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