Tongue-Tie Grading: Coryllos, ATLFF and What the Scores Mean

Quick answer

Tongue-tie grading is the systematic assessment of an abnormally tight lingual frenulum's appearance and functional impact. The Coryllos system (Classes I-IV) describes the frenulum's visible attachment point, while the ATLFF (Assessment Tool for Lingual Frenulum Function) scores functional mobility. A higher ATLFF score indicates greater restriction. Understanding these grades helps clarify the diagnosis and informs discussions about potential frenectomy for tongue-tie.

At a glance

• Class I in the Coryllos system attaches at the tongue tip.
• Class IV describes a submucosal, or "posterior," tongue-tie.
• The ATLFF assesses 5 functional criteria, scored from 0 to 2.
• A total ATLFF score of 11-12 is considered normal infant function.
• Grading is typically a visual and physical exam taking just a few minutes.
• No single grade automatically dictates treatment; function is the primary guide.

What is tongue-tie grading?

Tongue-tie grading is the clinical process of classifying an ankyloglossia (tongue-tie) based on its anatomical appearance and functional limitations. It provides a common language for healthcare providers to describe the severity of the restriction. The two most common frameworks are the Coryllos anatomical classification and the Hazelbaker Assessment Tool for Lingual Frenulum Function (ATLFF). These tools help move beyond a simple "yes or no" diagnosis to a more nuanced understanding of how the tie might be affecting activities like breastfeeding, speech, or oral hygiene.

The Coryllos classification system

Developed by Dr. Alexander Coryllos, this system categorizes tongue-tie based on where the lingual frenulum is visibly attached to the tongue and floor of the mouth. It's a straightforward anatomical scale.

Coryllos Class	Frenulum Attachment Point
Class I	Attaches to the tip of the tongue.
Class II	Attaches 2-4 millimeters behind the tongue tip.
Class III	Attaches to the mid-tongue, at or near the base of the mouth.
Class IV	Attaches against the base of the mouth; often a thick, submucosal "posterior" tie.

While useful, a limitation of the Coryllos system is that it doesn't directly measure function. A Class I tie may cause significant problems, while a Class IV tie might allow for reasonable mobility. This is why functional assessment is critical.

The ATLFF functional assessment

The Assessment Tool for Lingual Frenulum Function (ATLFF), created by Dr. Alison Hazelbaker, evaluates how the tongue actually moves. It is often considered the gold standard for functional assessment in infants. The provider scores several items:

1. Appearance Items: These include tongue lift, elasticity of the frenulum, and the tongue's shape at rest.
2. Function Items: These assess the most critical movements, such as the tongue's extension, lift, and spread, as well as its cupping and peristaltic motion during a suck.

Each item is scored from 0 to 2, with 0 indicating severe impairment and 2 indicating optimal function. The scores are totaled. A functional score of 11-12 is generally considered within normal limits, while lower scores indicate increasing levels of dysfunction that may contribute to issues like poor weight gain or nipple pain.

Posterior vs. anterior tongue-tie in grading

This is a key distinction often clarified by grading systems. An anterior tongue-tie (typically Coryllos Class I or II) is visibly attached near or at the tongue tip. A posterior tongue-tie (often Class III or IV) is thicker, tighter, and attaches further back under the tongue's surface; it may not be immediately visible without lifting the tongue. The difference between anterior and posterior ties is crucial because posterior ties can be missed but still cause severe functional problems. Both types are assessed using the same ATLFF functional criteria.

How a tongue-tie assessment is performed

A clinical assessment for grading a tongue-tie typically follows these steps:

1. History Review: The provider discusses feeding difficulties, symptoms in baby, speech concerns, or other oral issues.
2. Visual Inspection: The provider looks inside the mouth to locate the frenulum's attachment point (Coryllos class).
3. Physical Maneuvers: Using gloved hands, the provider lifts the tongue to assess its full range of motion, elasticity, and strength, scoring the ATLFF criteria.
4. Functional Observation: For infants, this may involve observing a breastfeeding session. For older children or adults, specific tongue movements are tested.
5. Scoring & Discussion: The provider tallies the scores, explains the findings, and discusses whether the restriction is significant enough to consider a release procedure.

What the scores mean for treatment

A grading score alone does not mandate surgery. Treatment decisions are based on a combination of factors:

• Functional Score: A low ATLFF score, indicating poor mobility, is a stronger indicator for intervention than anatomical class alone.
• Presence of Symptoms: Is the tie causing documented problems like ineffective feeding, speech articulation errors, or dental issues?
• Failed Conservative Management: For infants, have issues persisted despite help from a lactation consultant? For speech, has therapy plateaued?

The grades provide objective data to inform this decision. For example, a provider may be more likely to recommend a frenectomy for an infant with a Class IV tie and an ATLFF score of 6 who is failing to gain weight, compared to an infant with a Class II tie and a score of 10 who is feeding well.

Who performs tongue-tie grading?

Several types of trained professionals can assess and grade a tongue-tie:

• Lactation Consultants (IBCLCs): Often the first to identify functional feeding problems and refer for a formal assessment.
• Pediatricians & Pediatric Dentists: Can perform clinical exams and diagnose ankyloglossia.
• ENTs (Otolaryngologists) & Oral Surgeons: Specialists who frequently diagnose and treat tongue-tie, especially for complex cases or older patients.
• Speech-Language Pathologists: Assess functional impact on speech and swallowing.

It is common for a team approach to be used, especially for infants, involving both a lactation consultant and a pediatrician.

Next steps after a tongue-tie diagnosis

If you or your child receives a tongue-tie grade indicating a significant restriction, here are the recommended next steps:

1. Seek a Comprehensive Evaluation: Ensure the grading included both anatomical (Coryllos) and functional (ATLFF) components.
2. Consult with a Treatment Provider: Schedule a consultation with a qualified dentist, ENT, or oral surgeon who performs frenectomies to discuss the findings.
3. Ask Informed Questions: Inquire about the provider's experience, the recommended procedure type, and what the recovery entails.
4. Review All Options: Understand the potential benefits and risks of treatment versus continued monitoring or therapy.
5. Get a Second Opinion if Needed: If you have doubts, it is reasonable to seek another evaluation from a different qualified provider.

Frequently Asked Questions

What is the most common tongue-tie grade?

There is no definitive statistic, but Class II and Class IV (posterior) tongue-ties are frequently diagnosed in clinical practice. The prevalence of different grades varies widely across studies.

Does a higher Coryllos class mean a worse tongue-tie?

Not necessarily. While Class III and IV ties are often more restrictive, the functional impact (measured by the ATLFF) is more important than the anatomical class alone for determining severity.

Can a posterior tongue-tie (Class IV) be missed?

Yes. Because it is often hidden under a mucosal covering, a posterior tie can be easily overlooked without a skilled assessment that involves lifting the tongue to feel for tension.

What ATLFF score requires a frenectomy?

There is no universal cutoff score. A frenectomy is typically considered when the ATLFF score indicates significant dysfunction and that dysfunction is linked to clinical symptoms like feeding failure, pain, or speech delay.

Do adults get graded for tongue-tie?

Yes. The same principles of anatomical and functional assessment apply. Clinicians will evaluate the frenulum's appearance and test tongue range of motion relevant to speech, swallowing, and oral rest posture.

If the grade is mild, should we still consider treatment?

Treatment for a mildly graded tie is only considered if it is clearly causing functional problems that have not responded to other therapies, such as speech therapy for articulation or persistent feeding difficulties.

References

1. Coryllos, E. V., Genna, C. W., & Salloum, A. C. (2004). Congenital tongue-tie and its impact on breastfeeding. American Academy of Pediatrics Section on Breastfeeding.
2. Hazelbaker, A. K. (1993). The Assessment Tool for Lingual Frenulum Function (ATLFF). Pacific Oaks College.
3. American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS). Clinical Consensus Statement: Ankyloglossia in Children.
4. Mayo Clinic. Ankyloglossia (Tongue-Tie): Diagnosis and Treatment.
5. NHS UK. Tongue-tie in babies.

Medical disclaimer

This article is for informational purposes only and is not medical advice. It does not establish a doctor-patient relationship. You should always consult with a qualified healthcare provider for diagnosis, treatment, and advice tailored to your individual health circumstances. Never disregard professional medical advice or delay seeking it because of something you have read here. Reviewed by the frenectomyguide.com editorial team · Last updated 2026-10-31.