Velopharyngeal insufficiency (VPI) is a failure of the body's ability to temporarily close the communication between the nasal cavity and the mouth, because of an anatomic dysfunction of the soft palate or of the lateral or posterior wall of the pharynx.

The effect of such a dysfunction leads to functional problems with speech (hypernasality), eating (chewing and swallowing), and breathing. This gap can be treated surgically, although the choice of operational technique is still controversial.

The terms velopharyngeal "incompetence", "inadequacy" and "insufficiency" historically have often been used interchangeably, although they do not necessarily mean the same thing (sense distinctions can be made but sometimes are not). Velopharyngeal insufficiency includes any structural defect of the velum or pharyngeal walls at the level of the nasopharynx with insufficient tissue to accomplish closure, or there is some kind of mechanical interference with closure. It is important that the term insufficiency is used if it is an anatomical defect and not a neurological problem.

Velopharyngeal insufficiency (VPI) can be caused by a variety of disorders (structural, genetic, functional or acquired) and is very often associated with a cleft palate. Abnormal physiological separation of the oropharynx from the nasopharynx can lead to VPI and hypernasality.

A common method to treat Velopharyngeal insufficiency is pharyngeal flap surgery, where tissue from the back of the mouth is used to close part of the gap. Other ways of treating velopharyngeal insufficiency is by placing a posterior nasopharyngeal wall implant (commonly cartilage or collagen) or type of soft palate lengthening procedure (i.e. VY palatoplasty).

While cleft is the most common cause of VPI, other significant etiologies exist. These other causes are outlined in the chart below:

An incorrect diagnosis can lead to insufficient differential management. Most surgeons have their own vision on diagnosis and differential management. If it is thought, for instance, that palatal length is the only variable necessary for achieving normal closure, differential management will be insufficient. Therefore, differential diagnosis is important, because otherwise treatment of the velopharynx may not be appropriate.

There is not one single operative approach to VPI because anatomical structures diverge a lot between individuals. With diagnostic tools the surgeon is able to decide which technique should be used based on the anatomical situation of the individual. The goal of every operation is to achieve the best possible result with the technique assigned to each individual case.

Several methods can be used to diagnose velopharyngeal inadequacy.

The most common complications of the posterior pharyngeal wall flap are hyponasality, nasal obstruction, snoring, and sleep apnea. Rarer complications include flap separation, sinusitis, postoperative bleeding, and aspiration pneumonia. Possible complications of the sphincter pharyngoplasty are snoring, nasal obstruction, difficulty blowing the nose.

Some researches suggest that sphincter pharyngoplasty introduces less hyponasality and obstructive sleep symptoms than the posterior pharyngeal wall flap. Both surgeries have a favourable effect on the function of the Eustachian tube.

The general term for disorders of the velopharyngeal valve is velopharyngeal dysfunction (VPD). It includes three subterms: velopharyngeal insufficiency, velopharyngeal inadequacy, and velopharyngeal mislearning.

- Velopharyngeal insufficiency can be caused by an anatomical abnormality of the throat. It occurs in children with a history of cleft palate or submucous cleft, who have short or otherwise abnormal vela. Velopharyngeal insufficiency can also occur after adenoidectomy.

- Velopharyngeal incompetence is a defective closure of the velopharyngeal valve due to its lack of speed and precision. It is caused by a neurologic disorder or injury (e.g. cerebral palsy or traumatic brain injury).

- Sometimes children present no abnormalities yet still have hypernasal speech: this can be due to velopharyngeal mislearning, indicating that the child has been imitating or has never learned how to use the valve correctly.

Environmental influences may also cause, or interact with genetics to produce, orofacial clefting. An example of how environmental factors might be linked to genetics comes from research on mutations in the gene "PHF8" that cause cleft lip/palate (see above). It was found that PHF8 encodes for a histone lysine demethylase, and is involved in epigenetic regulation. The catalytic activity of PHF8 depends on molecular oxygen, a fact considered important with respect to reports on increased incidence of cleft lip/palate in mice that have been exposed to hypoxia early during pregnancy. In humans, fetal cleft lip and other congenital abnormalities have also been linked to maternal hypoxia, as caused by e.g. maternal smoking, maternal alcohol abuse or some forms of maternal hypertension treatment. Other environmental factors that have been studied include: seasonal causes (such as pesticide exposure); maternal diet and vitamin intake; retinoids — which are members of the vitamin A family; anticonvulsant drugs; nitrate compounds; organic solvents; parental exposure to lead; alcohol; cigarette use; and a number of other psychoactive drugs (e.g. cocaine, crack cocaine, heroin).

Current research continues to investigate the extent to which folic acid can reduce the incidence of clefting.

Cleft lip and palate occurs in about 1 to 2 per 1000 births in the developed world.

Rates for cleft lip with or without cleft palate and cleft palate alone varies within different ethnic groups.

The highest prevalence rates for (CL ± P) are reported for Native Americans and Asians. Africans have the lowest prevalence rates.

- Native Americans: 3.74/1000

- Japanese: 0.82/1000 to 3.36/1000

- Chinese: 1.45/1000 to 4.04/1000

- Caucasians: 1.43/1000 to 1.86/1000

- Latin Americans: 1.04/1000

- Africans: 0.18/1000 to 1.67/1000

Rate of occurrence of CPO is similar for Caucasians, Africans, North American natives, Japanese and Chinese. The trait is dominant.

It caused about 4,000 deaths globally in 2010 down from 8,400 in 1990.

Prevalence of "cleft uvula" has varied from .02% to 18.8% with the highest numbers found among Chippewa and Navajo and the lowest generally in Africans.

Individuals with Nager syndrome typically have the malformations of the auricle, external auditory canal, and middle ear, including the ossicles. These malformations were found in 80% of individuals with Nager syndrome. Inner ear malformations, however, are not typically seen in this population. Middle ear disease is common among individuals with Nager syndrome. Chronic otitis media and Eustachian tube deformity can result in conductive hearing loss. For this reason, early detection and treatment for middle ear disease is crucial in this population. Sensorineural hearing loss is not a typical characteristic of Nager syndrome; however, a subset of individuals present with a mixed hearing loss, due to a progressive sensorineural component combined with the typical conductive hearing loss (Herrman "et al.", 2005).

Hearing loss with craniofacial syndromes is a common occurrence. Many of these multianomaly disorders involve structural malformations of the outer or middle ear, making a significant hearing loss highly likely.

Thoracic insufficiency syndrome is the inability of the thorax to support normal respiration. It is frequently associated with chest and/or spinal abnormalities. Treatment options are limited, but include supportive pulmonary care and surgical options (thoracoplasty and/or implantation of vertical expandable prosthetic titanium rib (VEPTR) devices).

Many studies indicate the effect of a "fight or flight" response on the body that happens with each apneic event is what increases health risks and consequences in OSA. The fight or flight response causes many hormonal changes in the body; those changes, coupled with the low oxygen saturation level of the blood, cause damage to the body over time.

Without treatment, the sleep deprivation and lack of oxygen caused by sleep apnea increases health risks such as cardiovascular disease, aortic disease (e.g. aortic aneurysm), high blood pressure, stroke, diabetes, clinical depression, weight gain and obesity.

The most serious consequence of untreated OSA is to the heart. Persons with sleep apnea have a 30% higher risk of heart attack or death than those unaffected. In severe and prolonged cases, increased in pulmonary pressures are transmitted to the right side of the heart. This can result in a severe form of congestive heart failure known as "cor pulmonale". Dyastolic function of the heart also becomes affected. One prospective study showed patients with OSA, compared with healthy controls, initially had statistically significant increases in vascular endothelial growth factor (P=.003) and significantly lower levels of nitrite-nitrate (P=.008), which might be pathogenic factors in the cardiovascular complications of OSA. These factors reversed to normal levels after 12 weeks of treatment by CPAP, but further long-term trials are needed to assess the impact of this therapy.

Elevated arterial pressure (i.e., hypertension) can be a consequence of OSA syndrome. When hypertension is caused by OSA, it is distinctive in that, unlike most cases (so-called essential hypertension), the readings do "not" drop significantly when the individual is sleeping (non-dipper) or even increase (inverted dipper).

Lujan–Fryns syndrome is a rare X-linked dominant syndrome, and is therefore more common in males than females. Its prevalence within the general population has not yet been determined.

Exophoria is particularly common in infancy and childhood, and increases with age.

The prognosis of tricuspid insufficiency is less favorable for males than females. Furthermore, increased tricuspid insufficiency (regurgitation) severity is an indication of a poorer prognosis according to Nath, et al. It is also important to note that since tricuspid insufficiency most often arises from left heart failure or pulmonary hypertension, the person's prognosis is usually dictated by the prognosis of the latter conditions and not by the tricuspid insufficiency "per se".

Old age is often accompanied by muscular and neurological loss of muscle tone of the upper airway. Decreased muscle tone is also temporarily caused by chemical depressants; alcoholic drinks and sedative medications being the most common. The permanent premature muscular tonal loss in the upper airway may be precipitated by traumatic brain injury, neuromuscular disorders, or poor adherence to chemical and or speech therapy treatments.

Individuals with decreased muscle tone and increased soft tissue around the airway, and structural features that give rise to a narrowed airway are at high risk for OSA. Men, in which the anatomy is typified by increased mass in the torso and neck, are at increased risk of developing sleep apnea, especially through middle age and later. Women suffer typically less frequently and to a lesser degree than do men, owing partially to physiology, but possibly also to differential levels of progesterone. Prevalence in post-menopausal women approaches that of men in the same age range. Women are at greater risk for developing OSA during pregnancy.

OSA also appears to have a genetic component; those with a family history of it are more likely to develop it themselves. Lifestyle factors such as smoking may also increase the chances of developing OSA as the chemical irritants in smoke tend to inflame the soft tissue of the upper airway and promote fluid retention, both of which can result in narrowing of the upper airway. An individual may also experience or exacerbate OSA with the consumption of alcohol, sedatives, or any other medication that increases sleepiness as most of these drugs are also muscle relaxants.

A number of features involving the heart have been noted in several LFS cases, the most significant being dilation of the aortic root, a section of the ascending aorta. Aortic root dilation (enlargement) is associated with a greatly increased risk of dissection of the aortic wall, resulting in aortic aneurysm. As this presents a possible life-threatening consequence of LFS, routine cardiac evaluation methods such as echocardiogram are implemented when the disorder is first diagnosed, along with MRI scans of the brain to screen for suspected agenesis of the corpus callosum. Additional effects on the heart that have been reported with LFS are ventricular and atrial septal defect.

Exophoria can be caused by several factors, which include:

- Refractive errors - distance and near deviation approximately equal.

- Divergence excess - exodeviation is more than 15 dioptres greater for distance than near deviation.

- Convergence insufficiency - near exodeviation greater than distance deviation.

These can be due to nerve, muscle, or congenital problems, or due to mechanical anomalies. Unlike exotropia, fusion is possible in this condition, causing diplopia to be uncommon.

Accommodative insufficiency (AI) involves the inability of the eye to focus properly on an object. AI is generally considered separate from presbyopia, but mechanically both conditions represent a difficulty engaging the near vision system (accommodation) to see near objects clearly. However, AI is the term used for a patient where normal near vision is expected, whereas presbyopia is specifically the loss of accommodation due to age. Approximately 80 percent of children diagnosed with convergence excess also demonstrate AI, a relationship attributed to the accommodative convergence.

Jaw claudication is pain in the jaw associated with chewing. It is a classic symptom of Giant-cell arteritis, but can be confused with symptoms of Temporomandibular joint disease, Rheumatoid arthritis of the temporomandibular joint, Myasthenia gravis, tumors of the Parotid gland, or occlusion or stenosis of the External carotid artery. The term is derived by analogy from claudication of the leg, where pain is caused by arterial insufficiency.

Johanson–Blizzard syndrome (JBS) is a rare, sometimes fatal autosomal recessive multisystem congenital disorder featuring abnormal development of the pancreas, nose and scalp, with mental retardation, hearing loss and growth failure. It is sometimes described as a form of ectodermal dysplasia.

The disorder is especially noted for causing profound developmental errors and exocrine dysfunction of the pancreas, and it is considered to be an inherited pancreatic disease.

The most prominent effect of JBS is pancreatic exocrine insufficiency. Varying degrees of decreased secretion of lipases, pancreatic juices such as trypsin, trypsinogen and others, as well as malabsorption of fats and disruptions of glucagon secretion and its response to hypoglycemia caused by insulin activity are major concerns when JBS is diagnosed. Associated with developmental errors, impaired apoptosis, and both prenatal and chronic inflammatory damage, necrosis and fibrosis of the pancreatic acini (clusters of pancreatic exocrine gland tissue, where secretion of pancreatic juice and related enzymes occurs), pancreatic exocrine insufficiency in JBS can additionally stem from congenital replacement of the acini with fatty tissue. Near total replacement of the entire pancreas with fatty tissue has also been reported. This is a progressive, sometimes fatal consequence of the disorder.

In treating pulmonary insufficiency, it should be determined if pulmonary hypertension is causing the problem to therefore begin the most appropriate therapy as soon as possible (primary pulmonary hypertension or secondary pulmonary hypertension due to thromboembolism). Furthermore, pulmonary insufficiency is generally treated by addressing the underlying condition, in certain cases, the pulmonary valve may be surgically replaced.

Majewski's polydactyly syndrome, also known as polydactyly with neonatal chondrodystrophy type I, short rib-polydactyly syndrome type II, and short rib-polydactyly syndrome, is a lethal form of neonatal dwarfism characterized by osteochondrodysplasia (skeletal abnormalities in the development of bone and cartilage) with a narrow thorax, polysyndactyly, disproportionately short tibiae, thorax dysplasia, hypoplastic lungs and respiratory insufficiency. Associated anomalies include protruding abdomen, brachydactyly, peculiar faces, hypoplastic epiglottis, cardiovascular defects, renal cysts, and also genital anomalies. Death occurs before or at birth.

The disease is inherited in an autosomal recessive pattern.

It was characterized in 1971.

In medicine, pulsus bisferiens, also bisferious pulse or biphasic pulse, is a sign where, on palpation of the pulse, a double peak per cardiac cycle can be appreciated. "Bisferious" means striking twice. Classically, it is detected when aortic insufficiency exists in association with aortic stenosis, but may also be found in isolated but severe aortic insufficiency, and hypertrophic obstructive cardiomyopathy.

Normally, arterial pulses are best felt in radial arteries but character is better assessed in carotid artery. Pulsus bisferiens is best felt in brachial and femoral arteries. Another pulse which can be confused with bisferiens is pulsus alternans which is felt better in peripheral arteries. The first lift is due to "percussion wave"(P) and the second lift is due to tidal wave (T).

- If P>T - AR>AS

- If T>P - AS>AR

Characteristic causes:

1. Aortic regurgitation (AR)

2. Aortic regurgitation with Aortic Stenosis (AR+AS)

3. Hypertrophic cardiomyopathy