What is the Difference Between a Frenulum and Tongue Tie?

Registered Nurse Lactation Consultant performing a gentle infant oral exam.

It’s common for parents to wonder if the little string under their baby’s tongue or lip means something is wrong—but not every frenulum is a problem.

Everyone has a frenulum! A frenulum is a natural fold of tissue that helps anchor a mobile structure to the body—like the tongue or the lip. Just because you can see a frenulum under your baby’s tongue or lip doesn’t mean there’s a tongue tie or lip tie. Many are soft, stretchy, and completely normal.

So What Is a Tongue or Lip Tie?

A tongue tie (or lip tie) only becomes a concern when that tissue is too tight or short, restricting movement and leading to feeding or functional issues. In other words, the appearance of the frenulum alone doesn't mean there's a problem—it must also affect function and cause symptoms.

How We Diagnose Tongue or Lip Tie in Our Clinic

At Pacific Wellness & Lactation, we don’t rely on grading scales alone to diagnose ties. While tools that measure or classify frenula (like “type 1” or “grade 3”) can be helpful, they are not diagnostic on their own.

Tongue Tie (Short Frenulum)

Instead, we use a three-part assessment:

1. Appearance: The frenulum looks short, tight, or restrictive based on a standardized tool.

2. Function: The restriction limits normal movement (like lifting the tongue, extending it, or flanging the lip).

3. Symptoms: The limited function leads to noticeable issues—such as painful latch, poor weight gain, reflux, or speech concerns.

It’s the combination of these three factors—appearance, function, and symptoms—that determines whether a tongue or lip tie is clinically significant.

Lip Tie (Short Maxillary Labial Frenulum)

Symptoms Can Vary

Symptoms differ depending on a child’s age, feeding method, the severity of the restriction, and whether families have tried conservative therapies like bodywork or feeding support. There are a few symptoms that consistently come up when tongue and lip ties are studied in infants.

Evidence Based Signs and symptoms of infant tongue and lip ties include:

- Difficulty nursing/ breastfeeding or bottle feeding

- Painful latch

- Sore nipples (often looking misshapen and flattened after baby unlatches)

- Infant reflux

- Poor milk transfer at breast (baby is not draining breast well)

Additionally we see many babies with ties in our clinic that also have difficulty making and maintaining a seal while nursing at breast or bottle. These babies slip off the breast or bottle frequently, make noises while feeding that sound like smacking or clicking and get fussy through let down or if the flow of milk is too fast. They can leak milk while feeding and are not always satisfied after what seems like a full feeding. Over time we see these babies present with slow weight gain, despite feeding frequently as they appear to have difficulty getting the milk out while nursing.

If you're unsure whether your baby’s frenulum is normal or causing problems, a thorough evaluation from a trained provider can help you get the clarity—and support—you need.

Curious about whether your baby may have a tongue or lip tie? We’re here to help with compassionate, science and evidence-based care.

References:

Baeza, C., Douglas, P., Hazelbaker, A., Kaplan, M., Martinelli, R., Marchesan, I., Murphy, J., Smillie, C. & Watson Genna, C. Incidence and Prevalence of Tongue Tie; Assessment ad Classification of Tongue Tie; Treating Tongue Tie; Posterior Tongue Tie; Complementary Techniques to Address Tongue Tie. Clinical Lactation, September Edition, (2017).  Pages 89-121.

Berry, J, et al. A Double-Blind, Randomized, Controlled Trial of Tongue-Tie Division and Its Immediate Effect on Breastfeeding. BREASTFEEDING MEDICINE Volume 7, Number 3, 2012

Boutsi, E. (2014). The maxillary labial frenum. J Cranio Max Dis, 3:1-2

Buryk, M, et al. Efficacy of Neonatal Release of Ankyloglossia: A Randomized Trial. Pediatrics 2011;128;280

Elad, D, et al. Biomechanics of milk extraction during breast-feeding. PNAS. 2014 Apr 8;111(14):5230-5

Cordray, H., Mahendran, G. N., Tey, C. S., Nemeth, J., Sutcliffe, A., Ingram, J., & Raol, N. (2022). Severity and prevalence of ankyloglossia-associated breastfeeding symptoms: A systematic review and meta-analysis. Acta Paediatrica. https://doi.org/10.1111/apa.16609

Ghaheri BA, Lincoln D, Mai TNT, Mace JC. Objective Improvement After Frenotomy for Posterior Tongue-Tie: A Prospective Randomized Trial. Otolaryngology–Head and Neck Surgery. September 2021. doi:10.1177/01945998211039784

Ghaheri, B., Cole, M., Fausel, S., Chuop, M. & Mace, J. (2016). Breastfeeding improvement following tongue-tie and lip-tie release: A prospective cohort study. Laryngoscope 127(5): 1217-1223. DOI: 10.1002/lary.26306

Geddes, D., & Sakalidis, V.S. (2016) Ultrasound imaging of breastfeeding - a window to the inside: Methodology, normal appearances and application. Journal of Human Lactation, 32(2), 320-349.

Geddes, DT, et al. Frenulotomy for Breastfeeding Infants With Ankyloglossia: Effect on Milk Removal and Sucking Mechanism as Imaged by Ultrasound. Pediatrics 2008;122;e188

Genna, C. W. (2017). Supporting sucking skills in breastfeeding infants (3rd ed.). Jones & Bartlett Learning.

SIEGEL, S.. Aerophagia Induced Reflux in Breastfeeding Infants With Ankyloglossia and Shortened Maxillary Labial Frenula (Tongue and Lip Tie). International Journal of Clinical Pediatrics, North America, 5, apr. 2016.