Tongue-Tie Release in 2026

The Kotlow system also grades the maxillary labial frenulum, commonly called an upper lip tie, on its own Class I to IV scale. Unlike the tongue-tie version, which measures free tongue, the lip-tie classification describes where the frenulum attaches to the gum and palate.

Class I, minimal attachment: the frenulum attaches high in the mucolabial fold, where the inside of the upper lip meets the gum. A relatively minor attachment.

Class II, gingival attachment: the frenulum inserts into the attached gingiva of the upper jaw. More prominent than Class I, but it stops short of the papilla between the upper central incisors.

Class III, papillary attachment: the frenulum reaches the interdental papilla between the upper central incisors. Lifting the lip may reveal a broad or prominent band that puts tension on the gum tissue.

Class IV, papillary-palatal attachment: the frenulum passes through the papilla and extends towards or onto the front of the palate. This is the most extensive attachment in the system, and the one parents usually encounter online as a "Class 4 lip tie".

What Is a Posterior Tongue Tie?

A posterior tongue tie is far less obvious than a classic anterior one.

With an anterior tongue tie, the restricting band runs towards the tip of the tongue and can usually be seen straight away. With a posterior restriction, the tissue doing the restricting sits further back and deeper beneath the tongue, so the tongue can look close to normal when someone simply peers into the baby's mouth.

This is exactly why a tongue-tie assessment has to be more than a visual inspection. Our dentists assess the tongue while it is properly elevated, looking at range of movement and at the anatomy of the tissue underneath. Palpation helps establish how much restriction there is and where it sits.

Where a posterior restriction is suspected, the questions that matter are functional ones:

• Can the tongue elevate far enough?

• Can it stay in contact with the palate?

• Is there side-to-side movement?

• Can the baby cup the tongue?

• Can the baby create and hold suction?

• Does the baby keep losing suction or clicking during a feed?

• Can the baby hold an effective latch?

• Is milk transfer adequate?

The terminology and diagnosis of posterior tongue tie are still debated among clinicians, and definitions are not uniform. For that reason we do not recommend a release on the strength of the label alone. The diagnosis has to hold up clinically.

Classification is one input, not the decision. Our assessment looks at three things together.

• Anatomy. Where does the frenulum attach? For the tongue we may record the restriction using the Kotlow tongue-tie grades. For the upper lip we describe the attachment using the Kotlow Class I to IV lip-tie system.

• Function. Can the tongue lift, extend, move sideways and take part normally in oral function? In an infant, can the baby create and hold suction and use the tongue during a feed? For the lip, is mobility meaningfully restricted?

• Symptoms. What difficulty is actually happening? For a breastfeeding baby that can include latch problems, loss of suction, clicking, long feeds, poor milk transfer, or nipple pain and trauma in the mother.