What Is A Cleft Lip?

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Introduction

Close-up of young woman's face and lips
PhotoAlto/Milena Boniek/PhotoAlto Agency RF Collections/Getty Images

A cleft lip is one of the most common facial anomalies treated by plastic surgeons. Cleft lip is distressing for parents, as they don’t want their child to feel self-conscious or to be the focus of ridicule.

A cleft lip is a gap in the upper lip. Why does it occur? During fetal development, nasal and lip elements do not come together properly. Cleft lips vary in their degree of severity.

Cleft lip has historically been referred to as "hare lip." This moniker came about because of the natural split that is present in the upper lip of rabbits/hares. The term hare lip is no longer used in the medical community as it is viewed as derogatory.

A cleft lip is different from a cleft palate. A cleft lip affects the upper lip, whereas a cleft palate is a gap in the roof of the mouth. Not all individuals with cleft lips have a cleft palate. And not all individuals with a cleft palate have a cleft lip. It is possible for an individual to have both a cleft lip and a cleft palate.

In this article, you will learn the names of the parts of a normal lip. Knowing what a normal lip looks like will help you better understand what parts of the lip are abnormal in a cleft lip. You will also learn about the different types of cleft lips – unilateral versus bilateral, complete versus incomplete. Unilateral means the lip has a cleft on one side. Bilateral means there is a cleft on both sides. Complete indicates that the cleft extends from the lip all the way into the nose. Incomplete involves the lip but spares the nose.

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Normal Lip Anatomy

normal lip anatomy
Anatomy of the Normal Lip. Lisa Stirling / Getty Images

Normal Lip Anatomy

To understand the abnormalities of a cleft lip defect, it's necessary to understand what a normal lip looks like. Normal anatomy consists of an upper and lower lip. Cleft lip affects the upper lip. The upper lip has several components.

  • White roll: The white roll is a prominent ridge just above where the lip skin meets the facial skin.
  • Vermillion: The vermillion is the pigmented part of the lip. The color ranges from red to brown based on the pigmentation of the individual. It has a dry component (visible when lips are closed) and a wet component (visible when the lips are parted).
  • Philtral Columns: The vertical pillars that extend from the lips to the nose. The inferior/lower aspect of the philtral columns makes the peaks of the upper lip. The superior/upper aspect makes up the nasal sill, the floor of the nostril.
  • Philtral Dimple: The hollow or depression between the two philtral columns.
  • Cupid’s Bow: The curvature at the central part of the white roll. It is flanked by two peaks on either side. The peaks are the lower portion of the philtral columns.
  • Orbicularis Oris: The orbicularis oris muscle surrounds the lips. The muscle is important in providing the ability to speak, eat and drink normally. If an incomplete cleft is less than two-thirds of the lip height, some muscle fibers may cross the cleft. In more severe clefts, there is a complete disruption of the muscle fibers.
  • Nasal Sill: The nasal sill makes up the bottom or the floor of the nostril. The nasal sill is missing in some forms of cleft lip.
  • Simonart’s Band: A bridge of skin that crosses the bottom of the nostril on the cleft side of a cleft lip. A Simonart's band gives the appearance of an intact nasal sill.
  • Alar Rim: The alar rim is the part of the nose the surrounds the nostril.

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Microform Cleft Lip

Microform Cleft Lip
Microform cleft lip is the mildest form of cleft lip. It may appears as a barely imperceptable notch or as a scar of the philtral column. Photo © Millicent Odunze, M.D., M.P.H.

A microform cleft lip (also known as a "forme fruste") is the mildest version of a cleft lip, and is categorized as an incomplete cleft.

A microform cleft lip does not have the obvious cleft appearance of the other clefts. It may simply appear as a vertical scar from the lip to the nose. There may be a notch in the vermillion border and the nose may be affected. While a microform cleft may not be obvious, there may still be a problem with functionality. There is some disruption of the continuity of the orbicularis oris muscle. This may cause eating and drinking issues as well as speech issues.

The nose is usually normal with a microform cleft deformity.

The actor, Joaquin Phoenix, has a microform cleft lip. It appears as if he has a surgical scar from repair of a cleft lip. In actuality, that is his natural appearance.

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Unilateral Complete Cleft Lip

Unilateral Complete Cleft Lip
Left-sided Unilateral Complete Cleft Lip. Photo © Millicent Odunze, M.D., M.P.H.

A unilateral cleft lip only affects one side of the upper lip. Two-thirds of the Cupid’s bow, one philtral column and the philtral dimple are preserved on the noncleft/normal side. The cleft extends all the way from the lip to the nose in a complete cleft lip. The orbicularis oris muscle is not in continuity in a complete cleft lip. Instead of encircling the mouth, the muscle inserts into the base of the nose on both sides of the cleft. This disruption creates difficulty speaking, eating and drinking.

The nose is distorted with a cleft lip deformity. The nostril is widened and the floor of the nostril is missing in a complete cleft lip deformity.

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Unilateral Incomplete Cleft Lip

Unilateral Complete Cleft Lip
Left Unilateral Incomplete Cleft Lip. Photo © Millicent Odunze, M.D., M.P.H.

A unilateral cleft lip has clefting of the lip on one side only. There is a normal philtral column, Cupid's bow and philtral dimple on the side without a cleft. What makes it different from a complete cleft lip is that some orbicularis muscle fibers may cross the cleft. Incomplete cleft lips can take on a variety of appearances. There may be just a small gap or cleft in the vermillion or it may slightly extend into the skin above the lip or extend almost to the nostril.

As with a complete cleft lip deformity, the nose has some distortion. The distortion is usually to a lesser degree. The nostril may be widened, but the floor of the nostril is intact. Additionally, there is a bridge of tissue at the base of the nostril on the cleft side. This is known as a Simonart’s band.

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Bilateral Complete Cleft Lip

bilateral complete cleft lip
Bilateral Complete Cleft Lip. Photo © Millicent Odunze, M.D., M.P.H.

Bilateral Complete Cleft Lip

A bilateral complete cleft lip affects both the right and left sides of the lip. There are no philtral columns, no philtral dimple, and there is no orbicularis muscle in the central segment. On both sides, the cleft extends from the vermillion to the nostril. The lack of continuity in the muscle makes clear speech difficult for these individuals. Feeding can be more difficult.

There is nasal distortion with a bilateral complete cleft lip. Both alar rims are widened, the nasal sills are missing and the nose takes on a flattened appearance.

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Bilateral Incomplete Cleft Lip

bilateral incomplete cleft lip
Bilateral Incomplete Cleft Lip. Photo © Millicent Odunze, M.D., M.P.H.

Bilateral Incomplete Cleft Lip

A bilateral cleft lip has a gap on both sides of the upper lip. Just like with a bilateral complete cleft lip, the philtral columns are affected. To what degree depends on how far up the cleft extends from the vermillion. There may be some orbicularis muscle intact. The nostril sills are intact. The philtral dimple is intact.

In a bilateral incomplete cleft lip deformity, the nose is affected, although not to the same degree as with a bilateral complete cleft lip deformity. In those individuals with a bilateral cleft lip deformity, one side may be an incomplete deformity and the other side a complete deformity.

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Mixed Bilateral Incomplete and Complete Cleft Lip

Right side is a complete cleft lip and the left side is an incomplete cleft lip.
Bilateral Cleft Lip: Right side is a complete cleft lip and the left side is an incomplete cleft lip. Photo © Millicent Odunze, M.D., M.P.H.

In those who have a bilateral cleft lip, one side may be an incomplete cleft lip and the other side a complete cleft lip deformity. An incomplete cleft lip may be barely imperceptible.

Sources:

Boutros SG, Cutting C. Bilateral Cleft Lip. In: McCarthy JG, RD Galiano, Boutros SG, eds. Current Therapy in Plastic Surgery, 1st Ed. Philadelphia: Elsevier, Inc, 2006.

Boutros SG, Cutting C. Unilateral Cleft Lip. In: McCarthy JG, RD Galiano, Boutros SG, eds. Current Therapy in Plastic Surgery, 1st Ed. Philadelphia: Elsevier, Inc, 2006.

Gosman, AA. Cleft Lip. In: Janis JE, ed. Essentials of Plastic Surgery. St. Louis: Quality Medical Publishing, Inc., 2007.

Hopper RA, Cutting C, Grayson B. Cleft Lip and Palate. In: Thorne CH, Beasely RW, Aston SJ, Bartlett SP, Gurtner GC, Spear S, eds. Grabb and Smith’s Plastic Surgery, 6th ed. Philadelphia: Lippincott, 2007.

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