Gaps Between Teeth: Why They Happen and How They Are Closed
For adults with a gap between their teeth (diastema): why gaps form, tooth position versus tooth size, when a gap can signal gum disease, black triangles, how gaps are closed, why closed gaps can reopen, fee list prices and common questions. The core point: the cause decides the fix.
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Clinically reviewed by Dr Ibraheem Ijaz, dentist · GDC 301711
Medical disclaimer: This page is for general information only. It does not replace an examination or treatment by a dentist.
This page is reviewed by Dr Ibraheem Ijaz, the practice's principal dentist and a General Dental Practitioner (GDC 301711). His qualifications: BDS, BSc (Hons), MSc (Leeds), PG Dip Implant Dentistry, PG Cert Restorative and Aesthetic Dentistry.
What is a diastema?
A diastema is a gap between two teeth; a gap between the two upper front teeth is a midline diastema. If you want it closed, its cause decides which option works.
Why do gaps between teeth form?
Gaps between teeth have several possible causes, and they can combine. A 2025 study of Saudi adults aged 18 to 30 who had not sought orthodontic treatment found the main contributors to a midline diastema were a shifted midline, a long labial frenum (the fold joining the upper lip to the gum) and small teeth. Developmental causes include:
- Small teeth (microdontia), which NHS hospital guidance says often result in gaps between the teeth.
- Teeth that never developed (hypodontia, about 5% of people), where neighbouring teeth usually drift into the space and leave unevenly sized gaps.
Is your gap caused by tooth position or tooth size?
A diastema comes from where the teeth sit, how big they are, or both, and that decides between moving teeth and adding to them. Normal-sized teeth that are spaced out or off-centre are a position problem, which moving them with clear aligners or braces can treat. Teeth too small for the space are a tooth size discrepancy, which widening them with tooth-coloured composite can treat.
Can a gap between teeth be a sign of gum disease?
Sometimes, yes: in periodontitis, the more advanced form of gum disease, front teeth can drift and a diastema can open. A 2016 study of 314 patients with periodontitis found teeth drifting out of position in 35 of them, and in none with mild periodontitis. European guidance on the most severe stage of periodontitis says drifted teeth need further treatment after active gum treatment is complete.
NHS guidance says to see a dentist if your gums bleed when you brush your teeth or eat hard foods, your gums are painful and swollen, or you have bad breath. Ask for an urgent dentist appointment if you or your child has gum disease and other symptoms such as very sore and swollen gums, teeth becoming loose or falling out, ulcers or red patches in your mouth, or a lump in your mouth or on your lip.
If you do not have a dentist or cannot get an emergency appointment, call 111.
Our page on how gum disease develops covers the condition.
To ask about closing a gap between your teeth, book online or call 0114 288 2121.
What are black triangles between teeth?
Black triangles are dark spaces at the gum line between teeth, where gum no longer fills the space below the contact point. Unlike a diastema, the teeth still touch above them. A 2001 study found them in 38% of 337 adults after orthodontic treatment. Our page on receding gums covers gum shrinking back. A 2025 review says black triangles remain difficult to correct by surgical or restorative means. Black triangle closure is among the practice's cosmetic treatments.
How are gaps between teeth closed?
Gaps are closed by moving the teeth, adding to them, or both, and the choice follows the cause of the diastema.
| Option | Mainly suits a gap from | What keeps the result |
|---|---|---|
| Aligners or braces (move teeth) | Position: spacing, shifted midline | Retainers, long term |
| Composite bonding (adds to the sides) | Size: small or narrow teeth | Composite upkeep and repair |
| Composite veneers (cover the front) | Size: small or narrow teeth | Composite upkeep and repair |
| Moving teeth, then adding composite | Both position and size | Retainers and composite upkeep |
Composite does not move teeth, and in a 7-year study of direct composite its failures were fractures and colour mismatch. Our page on bonding or clear aligners for gaps compares the two, and our page on spacing between teeth covers wider spacing.
Which options does the practice offer?
Options at the practice include gap closure with composite bonding, and composite veneers, provided by our cosmetic dentists, and clear aligners and fixed metal, ceramic and lingual braces, provided by our dentists. Composite bonding and composite veneers are planned with a trial mock-up in the mouth before you commit. Read more about closing gaps with composite bonding and straightening teeth with removable aligners.
Can a closed gap open again?
Yes, a gap closed by moving the teeth can reopen. BOS guidance says almost every patient who has had orthodontic treatment needs retainers, because teeth tend to move back towards where they were (relapse) and may move unpredictably with age. In a 1999 follow-up of 96 patients treated for a midline diastema, 49% had relapsed 4 to 9 years on, counting a measurable space, retreatment or a retainer still worn to hold it. A wider starting gap and a family member with a similar gap were the significant risk factors.
Our page on keeping your teeth in their new position covers retainers.
How much does closing a gap cost?
The cost of closing a diastema depends on the option and how many teeth are involved. The practice's current fee list gives these prices:
- Composite bonding: from £300 per tooth
- Clear aligners: from £1,495 per arch
The fee list says all its prices are “from” prices, based on individual clinical needs. The fee list does not say whether these lines cover composite veneers, black triangle closure or fixed braces.
Frequently asked questions
Can a gap between teeth be closed without braces?
Yes, when the diastema comes from tooth size rather than position. Composite bonding widens the teeth without moving them, and direct composite bonding at the practice usually needs no drilling and no injection. If the teeth are spaced apart or off-centre, moving them treats the cause, and clear aligners can do that without fixed braces.
Is the frenum the reason for my gap?
It can be one reason. An NHS hospital's hypodontia guidance says a large frenum can contribute to a gap between the two front teeth, and removing it is sometimes part of an overall treatment plan. In one study, an abnormal frenum came with wider gaps but was not linked to relapse.
What happens if I stop wearing my retainer?
Your teeth can move back towards where they were, so a closed gap can reopen. BOS guidance says that without retainers teeth will go crooked again and the work of treatment is lost, and it advises having brace treatment only if you are happy to wear retainers afterwards.
Are braces for gaps available on the NHS?
Usually only for under-18s. NHS guidance says braces are usually only free on the NHS for people under 18 who have a problem with their teeth, depending on how the teeth affect day-to-day life. It lists large gaps among reasons for braces. Adults usually pay.
How long does it take to close a gap by moving the teeth?
It depends on how far the teeth need to move. With clear aligners, small front-tooth corrections can take a matter of months and fuller treatment often 12 months or more; your 3D plan shows the planned length first. NHS guidance says fixed braces usually take 1 to 2 years.
Book a consultation.
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You can book online or by phone, 8am to 8pm, Monday to Sunday. For other concerns, such as a chipped front tooth, you can browse this section. Our page on improving how your teeth look covers cosmetic dentistry as a whole, and patients describe the practice in our patient reviews.
334 Manchester Road
Deepcar, Sheffield S36 2RH
0114 288 2121
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