Many people wonder why their upper front teeth seem to disappear when they talk or smile. There are several potential reasons this occurs, most of which are natural variations in facial structure and not a medical concern. However, in some cases lack of visible upper teeth can indicate an orthodontic issue or be seen as unsightly. Understanding the various causes and available solutions can help you decide if treatment is worthwhile for showing more of your smile.
When are the upper teeth normally visible?
Under normal conditions, a reasonable amount of the upper front teeth should be visible when a person’s mouth is relaxed, such as when listening or in repose. Typically, about 2-4mm of tooth length is revealed along the gumline. When smiling or laughing, the full crown length of the upper front teeth is exposed.
However, there is significant diversity in how much of the maxillary central and lateral incisors show at rest among the population. The degree of visibility depends on the size and shape of the upper jaw, the length and position of the upper lip, gum exposure, lip muscle strength, and several other factors.
What Structural Factors Influence Tooth Exposure?
The key anatomical elements that impact how much of the upper anterior teeth are revealed include:
Lip Length and Thickness
- A shorter upper lip that overlaps more tooth surface tends to conceal the upper incisors and canine crowns.
- Thicker, fuller lips offer more tissue to cover the enameled portions of the teeth.
- Longer and thinner lips reveal more of the maxillary central incisors at rest.
Amount of Gingival Showing
- A “gummy smile” with excessive gingival exposure when smiling blocks visibility of the teeth.
- In contrast, minimal gum and more tooth can be seen in a “toothsome smile.”
Upper Jaw Positioning
- An underdeveloped or retruded maxilla (upper jaw) leads to less tooth exposure.
- With a normal positioned or protrusive upper jaw, the teeth are more visible.
Vertical Maxillo-Mandibular Relations
- Open bite – increased vertical overlap reveals more upper incisors.
- Deep bite (overbite) – decreased vertical overlap hides upper teeth.
Horizontal Maxillo-Mandibular Relations
- Normal overjet shows upper incisors ahead of lower teeth.
- Excessive overjet increases visibility.
- Edge to edge incisor positioning reduces exposure.
Tooth Shape and Position
- Small, narrow, or uneven teeth are more easily covered.
- Broad, long, symmetrical upper incisors are naturally more visible.
- Malpositioned teeth located too far posteriorly are obscured.
Causes of Reduced Tooth Visibility
There are several potential reasons someone’s upper front teeth may not be visible when speaking or at rest:
1. Short Upper Lip
A shorter than average upper lip that does not adequately expose the teeth is a common cause. The upper lip length from base of nose to vermillion border is generally around 20-22mm in females and 22-24mm in males. A shorter upper lip covers more tooth surface.
2. Low Smile Line
The smile line is delineated by the upper border of tooth exposure when smiling. An unusually low smile line means less tooth and more gingiva are displayed. Ideal smile line reveals 1-2mm of gingiva above the maxillary centrals.
3. Deep Overbite
Excessive overlap of the upper incisors over the lower teeth when biting, termed a deep bite or overbite, can wholly obstruct the upper front teeth from view with the jaws closed.
4. Small Teeth
Teeth of shorter crown length or narrower mesiodistal width can more easily be covered by the upper lip. Central incisors are normally 10-11mm long.
5. Upper Lip Hyperfunction
Constant contraction of the lip elevator muscles when speaking can overly elevate the upper lip, masking teeth exposure. This habit can develop from psychological factors or compensation for structural imbalances.
6. Anterior Tongue Posture
Resting the tongue against the anterior teeth instead of the palate when at rest can block their visibility. This oral posture is commonly seen.
7. Jaw Misalignment
Improper growth or positioning of the maxilla and/or mandible affects how much tooth is revealed. Common issues include retruded maxilla, overjet, underbite, asymmetry.
8. Combination of Factors
In many cases, short lip length coupled with deep overbite, small teeth, and lip muscle hyperfunction collectively obscure visibility of the upper front teeth.
Should Lack of Visible Upper Teeth Be Corrected?
The amount of upper tooth exposed is primarily an aesthetic concern. However, in some cases there are functional or psychological indications for increasing tooth visibility:
- Speech impediments – Excessive elevation and tension of lip muscles during speech can affect articulation. Speech pathology may help.
- Tooth wear – Lack of lip seal from short upper lip can lead to tooth erosion. Evaluating dental and skeletal factors is needed.
- Social confidence – Some feel self-conscious about hidden teeth when smiling, public speaking, etc. Cosmetic options may increase confidence.
- Orthodontic correction – Misaligned jaws, overjet, overbite may improve with orthodontic treatment or orthognathic surgery.
- Esthetic concerns – Small, uneven, or yellowed teeth are seen as less attractive. Esthetic procedures can be done.
- Job factors – Actors, media personalities, politicians may favor enhanced dental esthetics and request cosmetic treatment.
The risks and costs of procedures to increase tooth exposure must be carefully weighed against the benefits for each individual patient.
What Treatment Options Can Show More Tooth?
If inadequate visible maxillary anterior teeth bothers you aesthetically or functionally, there are several treatment options available:
Dental Solutions
- Tooth lengthening or bonding
- Porcelain veneers or crowns
- Selective enameloplasty
- Gingivectomy for excessive gums
- Botulinum toxin injections – Limit muscle pull on upper lip
Myofunctional Therapy
- Lip strength training – Strengthen orbicularis oris muscle
- Speech therapy – Modify speech patterns
- Improve tongue rest posture
Less Invasive Procedures
- Upper lip laser resurfacing – Reduce lip traction on teeth
- Dermal fillers – Augment lip length
- Upper lip chemical peel – Reduce upper lip height
Surgical Approaches
Orthognathic Surgery
- Maxillary advancement – Bring upper jaw forward
- Mandibular setback – Move lower jaw backwards
Soft Tissue Surgery
- Lip repositioning surgery – Decrease lip coverage of teeth
- Bullhorn lip lift – Raise central part of upper lip
- Direct lip lift – Remove strip of skin above lip to raise it
- Rhinoplasty – Alter nose size or shape to impact lip position
Muscle Surgery
- Myotomy – Cut lip elevator muscles to limit upper lip elevation
The optimal treatment plan depends on careful diagnosis of the specific dental and skeletal factors causing inadequate visible maxillary teeth for each patient. More conservative approaches are usually attempted first, with more complex surgical options reserved for severe cases with significant functional impacts.
FAQs about Lack of Visible Upper Teeth
Is it normal for my top front teeth not to be visible?
It is rather common for the upper front teeth not to show very much or at all at rest. Exactly how much tooth exposure is visible varies widely based on skeletal structure, dental factors, lip shape, overbite measurements and other elements. Some visibility of the upper central incisors is ideal, but a lack of visible maxillary teeth is not necessarily outside the range of normal variation.
What causes the top teeth to disappear when talking?
Excessive elevation or tension of the upper lip muscles when speaking is a key reason maxillary front teeth seem to disappear during speech. Other possible causes include a naturally short upper lip, increased overbite, small teeth size, and improper tongue posture resting against the front teeth. Targeted myofunctional therapy may help modify these habits long term.
Is surgery a good option for making my top teeth show?
For mild lack of visible maxillary teeth, nonsurgical options like lip retraining exercises, Botox lip relaxants or veneers often suffice. In severe cases with marked jaw discrepancies, combined orthodontic treatment and orthognathic surgery may be recommended. This would require moving the jaws into better alignment to allow the upper incisors to be revealed. Lip lifts and other soft tissue procedures are a last resort for stubborn cases.
Can I train my lip muscles to show more upper teeth?
With conscious effort and special exercises, you can sometimes re-train the orbicularis oris muscle and modify speech patterns to reduce upper lip tension and show more maxillary tooth structure without surgery. However, this takes diligence. A speech pathologist can suggest exercises to relax the upper lip and highlight the anterior teeth more during speech and smiling.
When should I see a dentist about invisible top teeth?
Consult a dentist or orthodontist if you have any speech or dental/orthodontic health concerns related to hidden upper teeth. They can pinpoint any problematic overbite, small teeth, or jaw growth issues. If the lack of visible maxillary teeth is simply cosmetic, a dentist can still advise you on available options based on your particular anatomy.
Conclusion
The upper front teeth commonly do not show much at rest or when speaking. A short upper lip, deep overbite, small teeth, and lip hyperfunction during speech can all contribute to concealing the upper incisors. While not always problematic, increasing tooth exposure can sometimes improve speech, dental function or simply enhance smile esthetics. A variety of nonsurgical and surgical options exist to show more upper tooth structure. Consulting dental professionals helps determine appropriate solutions for each individual situation.
