What is a Cleft Palate and Lip?

A cleft lip and/or cleft palate is a medical condition in which babies are born with defects causing their lips or palates not to fuse properly.

The upper jaw and middle face (including the nose) are usually formed and fused together during the 6-8th week of pregnancy. During this time, any malformation or mistake happening during this fusion may lead to a cleft lip and palate.

Therefore, cleft lip and palate is failure of fusion between the two sides of the lip or palate. The word “cleft” literally means a “split”, or a “division”.

What is a Cleft Palate and Lip

The condition can affect either the lip, the palate, or both the lip and the palate.

So cleft lip and palate can usually be categorized as:

  1. Cleft lip alone (more common in boys)
  2. Cleft palate alone (more common in girls)
  3. Cleft lip and palate together

Additionally, it can be located on one side of the face (known as a unilateral cleft lip and palate), or on both sides of the face (known as a bilateral cleft lip and palate).

What is a Cleft Palate?

The palate is the scientific name for the roof of the mouth.

It’s the whole area beginning directly from the gums at the back of your upper front largest 2 teeth (the central incisors), all the way back to the uvula. A cleft palate can occur anywhere along this area.

Normally as the embryo is forming, the palate forms on the right side and the left side and fuses in the middle. Failure of fusion anywhere along this line can cause a cleft palate.

Both the front and back parts of the palate can be split. Sometimes the uvula on its own is split as well.

What is a Cleft Lip?

A cleft lip is failure of fusion of the tissues that form the upper lip during the 6th week of embryological life. The condition only affects the upper lip, and not the lower lip.

The extent of a cleft lip may differ greatly within individuals, from a small slit in the upper lip, to a whole division reaching all the way up to the nose.

It can either be either unilateral (affecting one side) or bilateral (affecting both sides of the lip). Usually the left side is more commonly affected by a unilateral cleft lip.

Causes of Cleft Lip and Palate

Cleft lip and/or palate is quite a common medical birth defect, and has an occurrence of around 1-2 per 1000 births (1).

The exact cause of cleft lip and palate is still unknown, however it’s most likely a mixture of genetic and environmental factors.

Though there is still a lot more research to be conducted in this field in order to develop closing answers with sufficient evidence, there does seem to be a clear family link in those born with cleft lip and palate.

Some factors during pregnancy seem to have a direct effect on the incidence of cleft lip and palate. Research has suggested that the following may impact the development of cleft lip and palate:

What may cause a cleft palate and lip to form during pregnancy

  • Maternal Smoking:

Smoking during pregnancy is incredibly tactless and dangerous, in addition to many other birth defects, it may increase the likelihood of cleft lip and palate.

  • Drinking Alcohol:

Similar to smoking, drinking alcohol when pregnant is strongly discouraged, especially during the first trimester, and is directly related to embryo development of cleft lip and palate.

  • Certain medicines:

Women who are on certain anti-epileptic drugs, such as Phenytoin, are at a higher risk of having babies born with cleft lip and palate.

What problems can a cleft lip and palate cause?

Feeding problems

The most important problem for babies with a cleft lip and especially palate defect, is struggling to feed.

Babies with a cleft palate find it challenging to breastfeed, or feed from a bottle, as their ability to suck is affected, as well as the fact that they swallow a lot of air and this causes food regurgitation.

Usually, a bottle with a special nipple is manufactured for such cases to make sure that babies can feed comfortably and are not at a risk of malnutrition.

It’s important for babies with a cleft lip and/or palate to have regular checkups with a doctor to make sure that their growth is normal and that they’re receiving adequate nutrition.

Dental problems

There are several dental anomalies and abnormalities associated with cleft lip and palate.

Children with a cleft palate and/or lip have have an increased chance of developing extra (supernumerary) teeth, or of having missing teeth (hypodontia).

It’s also very likely for them to have delayed eruption of teeth, meaning that teeth may erupt at later age than the normal.

Other problems

Children affected with cleft lip or palate have distinct speech problems. In fact, disturbance in speech is a determining factor in a clinical diagnosis for small submucosal palatal clefts. In addition to troubles enunciating certain words, the voice usually sounds really nasal, this is because the palate is not adequately preventing air from leaking out of the nose. This also causes nasal discharge to sometimes leak out while speaking.

Children with cleft lip and palate have also reported experiencing hearing loss. This is because of a fluid buildup in the middle ear, leading to infection.

Cleft lip and palate repair

Thankfully cleft lip and palate surgery does exist, and with proper treatment and time results can be extremely well.

Depending on the case, in general, treatment of a cleft lip and palate involves several surgeries, bone grating, and most likely orthodontics.

The degree of cleft lip and palate repair will vary depending on the severity of the case, but most of the times, a large team will be involved in the repair process. In addition to the paediatrician, there will be a cleft specialist oral & maxillofacial surgeon, an ENT surgeon, an orthodontist, a speech therapist, and possibly even a psychologist.

Cleft Lip Surgery

Cleft lip surgery can take place during the 3rd-6th month of a baby’s life.

Cleft lip surgery has excellent results, and most parents are usually satisfied with the results and minimal scarring.

Cleft Palate Surgery

Cleft palate surgery occurs during the 9th-12th month of age.

During cleft palate repair, doctors connect muscles and tissues of the palate, joining them together and closing the cleft.


Due to the above two surgeries, some skeletal changes might occur in children with cleft lip and palate.

Most commonly the lower jaw (the mandible) is larger, and more protruded than the upper jaw.On the other hand, the maxilla (upper jaw) will usually be smaller and lacking in bone.

Orthodontic treatment is usually indicated for children with cleft lip and palate, as early as when the first adult tooth erupts (around 6 years of age).

Usually an orthodontic appliance is worn to expand the upper jaw in time for the adult teeth to have enough room to emerge.

Alveolar bone graft

Some cleft and lip palate cases require orthodontic grafting because there is insufficient alveolar bone, and this will negatively impact teeth attempting to erupt – most importantly the canine.

Therefore, at around 10 years of age, children with cleft lip and palate may need to undergo bone grafting to increase the amount of bone in the upper jaw.

The bone is usually taken from the iliac crest (near the hips) and is planted in the upper jaw of the child. This ensures that the upper jaw has enough bone and support for adult teeth to grow properly, and also aids in the complete closure between the nasal cavity and the mouth.

Orthognathic Surgery (Orthodontic Surgery)

After the child has grown into an adult and is over 21 years of age. If there is still clear malocclusion and there is a clear facial deformity that they are not pleased with, the option of orthognathic surgery becomes available to them.

In this procedure, the patient needs to wear traditional braces for a set period of time, and then they undergo surgery in which the position of their jaws can be altered by a maxillo-facial surgeon.



Written by Dr. Khaled Mahmoud

Khaled Mahmoud completed his dental education and obtained his Bachelor of Dental Surgery (BDS) in 2017. His interests lie in cosmetic dentistry and non-surgical facial aesthetics. He is active in dental research, contemporary cosmetic materials and techniques, and has been a member of numerous public health outreach programs.