A lip tie is a condition where the tissue connecting the upper lip to the gum ridge is unusually tight or short, restricting the lip’s natural movement. A “tie” occurs when its structure limits the lip’s ability to lift, curl, or flange outward. The restriction caused by a lip tie can interfere with crucial oral functions, particularly feeding in infants, and may also pose challenges for oral hygiene later in life.
Anatomy: Locating the Maxillary Frenulum
The maxillary labial frenulum is the small fold of tissue found centrally behind the upper lip. It connects the underside of the lip directly to the upper gum, or alveolar ridge, typically situated between the two upper front teeth. To inspect this area, gently lift the upper lip upward toward the nose, often described as “rolling” the lip back. This action exposes the frenulum, allowing assessment of its length and flexibility. A normal frenulum is thin and allows the lip to move freely.
The Defining Visual Characteristics
A lip tie is visually defined by the physical characteristics of the restrictive frenulum. When the lip is lifted, the tissue often appears visibly thick, rigid, or abnormally taut. Instead of a delicate, flexible band, a lip tie may look like a prominent web or a fibrous cord. The attachment point on the gum ridge may sit unusually low, close to the edge where teeth will erupt, or even extend onto the palate. This low or thick attachment physically tethers the lip, preventing it from fully lifting or curling outward.
Understanding Lip Tie Classification
The severity of a lip tie is described using a four-grade classification system based on the frenulum’s attachment location.
Grade I (Mucosal Tie)
This tie attaches high near the junction of the lip and the gum line. It often causes no functional restriction.
Grade II (Gingival Tie)
The Grade II tie inserts lower onto the gum tissue itself.
Grade III (Papillary Tie)
The frenulum extends to the area where the upper front teeth will emerge, attaching into the interdental papilla. The tissue is positioned between the central incisors.
Grade IV (Papilla-Penetrating Tie)
This is the most extensive grade, where the tissue extends between the teeth, sometimes crossing the bone and reaching toward the hard palate. This lower attachment point demonstrates maximum tethering and is associated with significant limitation in lip mobility.
Functional Indicators Visible to Parents
A lip tie can be identified by immediately observable functional limitations. One telling sign is blanching, where the gum tissue at the frenulum’s attachment point turns white when the upper lip is gently lifted. This whitening indicates excessive tension and a restrictive pull on the gum line. During feeding, an infant’s upper lip may not be able to “flange” or curl outward to create a proper seal, remaining tucked inward against the gum ridge. When an infant cries forcefully, the upper lip may pull so tightly that it creates a distinct V-shape indentation, further demonstrating the restriction.