A tongue-tied baby’s tongue often looks heart-shaped or notched at the tip when lifted or crying. This happens because a short, tight band of tissue under the tongue (called the frenulum) connects too close to the tip, pulling it down and restricting movement. Tongue tie affects roughly 4 to 16 percent of newborns and is nearly twice as common in boys as in girls.
Not every tongue tie looks the same, though. Some are immediately obvious, while others hide beneath the surface and can only be detected by touch. Here’s what to look for.
The Classic Heart-Shaped Tongue
The most recognizable sign of tongue tie is a visible notch or dip at the front of the tongue when your baby tries to lift it or cries. Instead of coming to a smooth, rounded point, the tongue’s tip gets pulled into a V or heart shape. This happens because the frenulum attaches at or very near the tip, tethering it to the floor of the mouth. You may also notice the tongue looks shorter than expected or seems unable to extend past the lower gum line.
In some babies, the frenulum itself is easy to see: a thin, translucent strip of tissue running from the underside of the tongue straight down to the gum ridge. When the tissue is especially tight, the tongue may look flat or square rather than pointed, and you might see the edges of the tongue curl up while the center stays pinned down.
Anterior vs. Posterior Tongue Tie
Tongue ties are grouped into four types based on where the frenulum attaches, and they look quite different from one another.
Types 1 and 2 are called anterior tongue ties. In a Type 1, the frenulum is thin and elastic but anchors the very tip of the tongue to the gum ridge, producing that classic heart shape. In a Type 2, the attachment sits 2 to 4 millimeters behind the tip, still close enough to visibly restrict movement. Both are relatively easy to spot just by looking under the tongue.
Types 3 and 4 are posterior tongue ties, and they’re harder to identify. A Type 3 tie involves a thick, stiff band of tissue anchoring the middle of the tongue’s underside to the floor of the mouth. The tongue may look normal at first glance, but it won’t lift well. A Type 4 tie is the most hidden: the frenulum is buried under the mucous membrane and often can’t be seen at all. It can only be detected by running a finger along the floor of the baby’s mouth and feeling tight, fibrous bands beneath the surface. Sometimes the floor of the mouth looks shiny or thickened in that area, but that’s a subtle sign even professionals can miss.
Signs of a Posterior Tie
Because posterior ties aren’t visible in the same way, you’re more likely to notice them through what the tongue does rather than what it looks like. Watch for a dimple on the top surface of the tongue when your baby tries to move it, especially during crying or feeding. The tongue may rise at its edges but not at the center, creating a bowl shape that collapses under effort. If the tip of the tongue can’t reach the roof of the mouth when your baby opens wide, that’s another clue.
What You’ll Notice During Feeding
Many parents first suspect tongue tie not by looking at the tongue itself, but because of what happens at the breast or bottle. A tied tongue can’t extend, cup, or wave properly, which disrupts the seal and suction a baby needs to feed efficiently.
Common feeding signs include:
- Clicking or smacking sounds as the baby repeatedly loses and regains the latch
- Sliding off the nipple frequently, even when the baby seems hungry and eager
- Long, exhausting feeds that don’t seem to satisfy the baby
- Poor weight gain despite frequent nursing sessions
- Excessive gas or fussiness from swallowing air during a shallow latch
One telling sign shows up on the nursing parent’s body rather than the baby’s. After a feed, the nipple may come out flattened, creased with a visible line, or shaped like a new tube of lipstick with an angled tip. This “lipstick shape” happens because the baby is compressing the nipple against the hard palate instead of drawing it deeply into the mouth, which is what a full range of tongue motion allows.
How Tongue Tie Is Assessed
Pediatricians and lactation consultants often use a structured scoring system called the Hazelbaker Assessment Tool, which evaluates both how the tongue looks and how it moves. On the appearance side, the tool scores five things: the shape of the tongue tip when lifted (round is normal, heart-shaped suggests restriction), the elasticity of the frenulum, its length, and where it attaches to both the tongue and the lower gum ridge. A frenulum that attaches well behind the tip and sits on the floor of the mouth, away from the gum ridge, scores highest.
The functional side tests seven movements: whether the tongue can move side to side, lift to the middle of the mouth, extend past the lower lip, spread wide, form a firm cup shape, and produce a smooth wave-like motion from front to back during sucking. Frequent “snapback,” where the tongue loses suction and snaps down repeatedly, is a red flag. A perfect functional score is 14. Scores below 11 indicate impaired function, and treatment is typically recommended when both the appearance and function scores are low.
What a Normal Frenulum Looks Like
Every baby has a lingual frenulum. It’s a normal part of oral anatomy. In a typical mouth, the frenulum attaches about 1 centimeter behind the tongue tip and connects to the floor of the mouth well below the gum ridge. This gives the tongue plenty of slack to lift, extend, and move freely. A short or visible frenulum alone doesn’t mean a baby is tongue-tied. The distinction comes down to whether the frenulum actually restricts movement enough to cause problems. A baby whose tongue can lift to the roof of the mouth, extend over the lower lip, and move side to side freely likely has normal function, even if the frenulum looks prominent.
Checking at Home
You can do a basic visual check by gently encouraging your baby to open wide, either during crying or by lightly stroking the lower lip. Look at the tongue’s shape: does the tip round out naturally, or does it pull into a notch? Try to see under the tongue for a visible band of tissue. If your baby will tolerate it, you can also slide a clean finger along the floor of the mouth just behind the lower gum ridge, feeling for a tight string or thick cord of tissue.
Pay attention to movement. Can the tongue extend past the lower gum? Can it reach upward toward the palate when the mouth is open? Does it move side to side? A tongue that stays low in the mouth, humps up in the back instead of the front, or can only reach the gums is showing restricted motion. These functional signs matter as much as, and sometimes more than, the visual appearance, especially with posterior ties that don’t always look abnormal on the surface.