The small fold of tissue that connects your upper or lower lip to the gum is called a labial frenulum (sometimes spelled “frenum”). Nearly everyone has one under the upper lip and another under the lower lip, though the upper one tends to be more prominent and more often noticed. It is a mucosal fold made mostly of connective tissue, and while it seems like a minor piece of anatomy, it has attracted serious attention from dentists, pediatricians, and even forensic specialists for a range of reasons that go well beyond its modest size.
What the Frenulum Actually Is
If you pull your upper lip outward in front of a mirror, the thin vertical band of tissue running from the inside of the lip down to the gum above your front teeth is the superior labial frenulum. A similar band connects the lower lip to the gum below the front teeth. An anatomical and histological study confirmed that the superior labial frenulum is a mucosal fold between the gingival mucosa and alveolar mucosa, with connective tissue underneath it.
Despite how it looks, the frenulum is not a single type of tissue everywhere in the mouth. The upper and lower labial frenula differ from each other, and both differ from the buccal frenula found further back in the cheeks. Dissection studies have shown that the labial frenulum is formed by taut connective tissue, while the buccal frenulum is shaped partly by the borders of facial muscles and connective tissue together. Even the upper and lower labial versions are not identical: the tissue under the upper one is thin and taut, while the tissue under the lower one is thicker and flatter, filling the space between the chin muscles on either side.
The frenulum under the tongue, called the lingual frenulum, is a related but separate structure. When people talk about “tongue-tie,” they are referring to an unusually short or tight lingual frenulum. “Lip tie” is the corresponding term for the labial version. All these frenula share the basic design of a mucosal fold reinforced with connective tissue, but each has its own anatomy and clinical relevance.
How It Forms and Changes Over Time
The maxillary frenulum originates during fetal development as a remnant of structures called tectolabial bands, which help shape the upper lip and palate in the embryo. After the baby teeth start erupting, these bands leave behind the fold of tissue we recognize as the frenulum. In addition to tight connective tissue, the structure sometimes contains occasional skeletal muscle fibers woven through it.
In newborns, the frenulum often attaches quite close to the top of the gum ridge. A study of healthy newborns found that the average distance from the edge of the gum ridge to where the frenulum attaches was only about 1.5 millimeters, with the frenulum stretching to roughly 5 millimeters in length when pulled taut. As a child grows and the permanent teeth come in, the frenulum typically recedes upward, moving away from the teeth and becoming less prominent. This is one reason pediatric dentists often advise waiting before deciding whether a child’s frenulum needs any intervention: what looks tight or low at age two may resolve on its own by the time the adult teeth arrive.
Does It Actually Do Anything?
The frenulum’s role is modest but real. It helps stabilize the upper lip against the gum, limiting how far the lip can pull away from the teeth. Think of it as a soft tether rather than a structural beam. You would not miss it if it were surgically removed, but while it is there, it provides a small amount of anchorage.
A thick or elongated frenulum can restrict upper lip movement, which in theory could affect feeding or even certain speech sounds that require the lip to curl outward or upward. However, the clinical evidence connecting a prominent frenulum to significant functional problems is weaker than many parents are led to believe, a point worth exploring in more detail.
The Lip Tie Debate in Infants
Over the past decade, “lip tie” has become a common concern among parents of newborns who struggle with breastfeeding. The idea is straightforward: if the frenulum is too tight or thick, the baby cannot flange the upper lip properly, making it hard to latch. Lactation consultants, pediatricians, and ear-nose-throat specialists have debated the significance of this diagnosis vigorously, and the evidence does not clearly support the alarm.
A study of over 260 healthy newborns found that about a quarter had thick upper lip frenula and roughly 9 percent showed remarkable tightness when the lip was turned upward. Yet the researchers found no association between any of these upper lip findings and breastfeeding problems. A separate observational cohort study reached a similar conclusion, finding that a tethered labial frenulum was not associated with an increase in breastfeeding disturbances or oral disorders, and that mothers of babies with prominent frenula actually reported less breastfeeding discomfort than the control group.
The difficulty is that “lip tie” lacks a universally agreed-upon definition. Multiple classification systems exist for grading the frenulum, and they do not agree with each other particularly well. A study comparing classification scales found that even a novel three-point system achieved only moderate agreement among different raters, outperforming the older Kotlow and Stanford systems, which had even lower reliability. When clinicians cannot consistently agree on what counts as a problematic frenulum, the diagnosis is going to be inconsistent too. Parents who are told their baby has a lip tie by one provider may hear something completely different from another.
When the Frenulum Affects Your Teeth
The most established dental concern about the labial frenulum is its relationship to a gap between the two upper front teeth, known as a midline diastema. Not every gap is caused by the frenulum, and not every prominent frenulum causes a gap. But certain types of frenulum attachment are more likely to be involved.
A systematic review of available evidence found that two specific subtypes of frenulum, the papillary type and the papillary penetrating type, are associated with midline diastema. These subtypes attach lower on the gum, closer to or even between the front teeth, where they can physically interfere with the teeth coming together. A cross-sectional study confirmed this, showing that papillary and papillary penetrating frenula were significantly associated with midline diastema. If your frenulum attaches higher up on the gum, well away from the teeth, it is much less likely to contribute to a gap.
Beyond spacing, an unusually positioned frenulum can also pull on the gum tissue itself. When a frenulum exerts traction on the gum margin, it can contribute to gum recession around the front teeth. This is more of a concern in adults than in children, and it is not common, but it is one of the reasons a dentist or periodontist might recommend surgical modification of the frenulum even outside the context of a gap.
Frenectomy and What It Involves
A frenectomy is the surgical procedure to release or remove part of the frenulum. It can be performed with a scalpel, surgical scissors, or a laser, and it is typically a quick procedure done under local anesthesia. In infants, it is sometimes done in the office with minimal anesthesia, though the decision to do it at all is where the real debate lies.
A randomized controlled trial comparing diode laser and scalpel frenectomy in infants (for tongue-tie, a related procedure with similar technique) found that both methods led to significant functional improvements and weight gain, with no major differences between the two approaches. At one week, the scalpel group showed slightly better breastfeeding scores, but by later follow-ups the groups converged. Both groups experienced reduced pain and progressive healing over time. While this trial focused on tongue-tie specifically, the surgical principles and healing patterns for labial frenectomy are similar.
After a frenectomy, many providers recommend post-operative stretching exercises to prevent the tissue from reattaching. A survey of healthcare professionals found that about 70 percent release buccal ties (if needed) at the same time as tongue-ties, and roughly three-quarters recommend post-operative stretches as necessary for good healing. Whether those stretches truly make a difference is still debated, and the experience can be stressful for both parent and baby.
For older children and adults, the main reasons for frenectomy are a persistent gap between the front teeth that is not closing with orthodontic treatment, gum recession being worsened by the frenulum’s pull, or preparation for dentures. The procedure in adults is straightforward and heals within a couple of weeks.
The Frenulum and Dentures
If you wear or are considering a full upper denture, the frenulum matters in a way you might not expect. The denture needs a notch or relief cut into the area where the frenulum attaches, because the frenulum moves every time you talk, eat, or make facial expressions. If the denture does not accommodate the frenulum properly, the repeated movement creates stress on the denture base.
Research has shown that the height of the labial frenulum significantly affects the stresses and strains on a maxillary complete denture, particularly along the midline and at the incisive papilla behind the front teeth. A higher frenulum attachment means more stress on the denture in that region. Over time, this can cause cracking or outright fracture of the denture along the midline, a common and frustrating failure point. Dentists sometimes recommend frenectomy before fitting a complete upper denture specifically to reduce this risk.
A Torn Frenulum and What It Means
The frenulum is thin and relatively fragile, so it can tear from direct trauma to the mouth. In young children, this can happen from a fall, a bump, or being hit in the face with a toy. It bleeds noticeably but usually heals on its own without treatment.
A torn labial frenulum in a young child, especially an infant, has long been discussed in the medical literature as a potential indicator of physical abuse, particularly from forced bottle-feeding or a blow to the mouth. However, the evidence on this point is more nuanced than many clinicians assume. A systematic review published in Archives of Disease in Childhood found that while a torn labial frenulum is widely regarded as a hallmark of abuse, the current literature does not support diagnosing abuse based on a torn frenulum in isolation. A separate systematic review of orofacial injuries in abused children confirmed that torn frenula do appear among the injuries seen in physical abuse cases, alongside facial bruises, burns, and dental fractures, but no single oral injury by itself proves abuse.
The practical point for parents: if your toddler tears their frenulum in a fall, it is not an emergency and does not require stitches in most cases. The tissue heals quickly. But if a healthcare provider notices a torn frenulum in a child and there is no clear accidental explanation, they are trained to consider it alongside other findings as part of a broader assessment.
Missing or Extra Frenula as Medical Clues
Most of the time, having a prominent or a barely visible frenulum is just normal variation. But in some cases, the absence of a frenulum or the presence of extra ones can signal an underlying genetic condition. This is niche territory, but it is worth knowing about because these associations can be diagnostically useful.
Ehlers-Danlos syndrome, a group of connective tissue disorders, provides one of the more striking examples. A study of French patients found that absence of the inferior labial frenulum (the one under the lower lip) had a specificity of 99 percent for the condition, meaning that almost no one without Ehlers-Danlos was missing it. Among those with the vascular type of Ehlers-Danlos, 65 percent were missing the inferior labial frenulum. The lingual frenulum under the tongue showed a similar pattern, with absence having 98 percent specificity. These are not screening tests you would use on the general population, but if a clinician already suspects Ehlers-Danlos, checking for a missing frenulum is a quick and free bedside assessment.
On the other end of the spectrum, some genetic conditions feature extra or overgrown frenula. A review of syndromic conditions and oral frena found that Ellis-van Creveld syndrome and oral-facial-digital syndrome typically present with frenulum overgrowth, while Pallister-Hall syndrome and Opitz C syndrome are associated with abnormal extra frenula. By contrast, holoprosencephaly, a brain development disorder, is strongly associated with absence of the superior labial frenulum. A study found that 88 percent of holoprosencephaly cases were missing the upper labial frenulum regardless of how severe the other craniofacial features were, making it useful as a diagnostic sign even in mild cases.
Can the Frenulum Affect Speech?
This question comes up frequently, and the honest answer is that the labial frenulum plays a much smaller role in speech than the lingual frenulum (under the tongue). Tongue mobility matters enormously for articulation, which is why tongue-tie can genuinely affect pronunciation. Lip mobility matters less for most speech sounds, and the frenulum would need to be exceptionally restrictive to interfere.
That said, a thick or elongated maxillary frenulum can restrict upper lip movement enough to affect sounds that rely on lip rounding or protrusion, and some clinical reviews note speech impairment as a potential consequence of a significantly abnormal frenulum. In practice, speech pathologists rarely identify the labial frenulum as the primary cause of a speech problem. If a child has articulation difficulties, the tongue, palate, and hearing are all investigated well before anyone looks at the upper lip frenulum.
Variations That Are Completely Normal
Frenulum anatomy varies widely from person to person, and most of that variation is entirely harmless. Some people have a thick, visible frenulum that attaches close to the teeth. Others have one so thin and high that they barely notice it. In the same newborn study mentioned earlier, the researchers found a broad spread in every measurement they took, from frenulum length to thickness to how much of the gum it covered. This range is expected, and it shrinks as a diagnostic concern with age as the frenulum naturally recedes.
Color changes, small bumps, or mild soreness of the frenulum are also usually benign. The tissue can become irritated from aggressive tooth brushing, orthodontic appliances rubbing against it, or even spicy food. An ulcer or sore on the frenulum that does not heal within two weeks, however, deserves a look from a dentist or doctor, just as any non-healing oral sore would.
One thing worth keeping in mind is that if you had a frenulum torn or released at some point, it may or may not have fully grown back. Frenulum tissue can partially reattach after injury, which is why post-frenectomy stretching exercises are recommended. Some people who tore their frenulum as children find that the tissue healed into a slightly different shape or became less prominent, and they go through life with no issues at all.