Most gaps between the front teeth cause no harm, and plenty of people keep theirs for life. What a dentist wants to know first is why the space is there, because a gap that has been present since childhood means something quite different from one that has opened up in the last year or two. The reason behind the space also decides which way of closing it will stay closed.
Dentists call the space a diastema. It most often sits between the two upper front teeth, where it is easy to notice in photos, and it can be anything from a hairline to several millimetres wide.
In young children a gap is often part of normal growth
When the adult front teeth first come through, a space between them is common. As the adult canines erupt a few years later, they often push the front teeth together and the gap narrows or disappears. A review in Dental Update (Abraham and Kamath, 2014) notes that because a gap can be part of normal development, deciding whether to step in early is not always straightforward, and that larger gaps are the ones more likely to benefit from earlier treatment. For most children with a small midline space, watching it at regular check-ups is enough.
In adults the picture is different. A gap that is still there after all the adult teeth have come through usually stays unless the teeth are moved or reshaped.
A new or widening gap in an adult needs a check first
If you notice a space appearing where there was none, or an old gap getting wider, book a check before thinking about cosmetic options. Gum disease can destroy the bone that supports the teeth, and teeth with less support can drift and fan out. Bleeding gums, gums pulling back from the teeth, or a tooth that feels loose alongside a new gap all point in this direction. In that case the gums are treated first; closing the space comes later, if at all, once they are stable. You can read more about this in our article on how gum disease progresses.
Why the gap is there changes how it is closed
Several things can leave space between the front teeth, and more than one may be involved for the same person.
Teeth that are small for the jaw
This is a common reason. When the teeth take up less room than the jaw provides, they spread out and spaces form. Tooth size and jaw size are largely inherited, which is why gaps often run in families. Upper lateral incisors (the teeth either side of the two front teeth) that are narrow or peg-shaped, or missing altogether, are a common version of this.
A low or thick lip frenum
The frenum is the fold of tissue joining the inside of the upper lip to the gum above the front teeth. When it is thick or attaches low, between the teeth, it can be part of the reason a gap forms or reopens. A systematic review in Quintessence International (Delli and colleagues, 2013) found that an enlarged frenum may play a role in midline gaps and that orthodontists often suggest reducing it after the teeth have been brought together. Whether that is needed is decided case by case after an examination.
An extra tooth or other hidden cause
Occasionally an extra tooth sitting in the bone between the front roots, or another problem below the gum, keeps the teeth apart. These cannot be seen in the mirror, which is one reason an X-ray is usually part of the assessment.
Habits and tongue position
Long-term thumb or dummy sucking, and a tongue that presses forward against the front teeth when swallowing, can tip the upper front teeth outward and apart. These matter most while the adult teeth are still settling.
Adding to the teeth or moving them
All of the ways to close a gap fall into two groups. Some add material to the teeth to fill the space. Others move the teeth themselves so they meet.
Filling the space with bonding or veneers
Composite bonding adds tooth-coloured resin to the sides of the teeth, shaped by hand and hardened with a light. For a small gap it can usually be done in one visit, often with little or no drilling. Resin can stain and chip over the years, so it may need polishing or repair from time to time. Our comparison of composite bonding and veneers and our guide to edge bonding go into more detail.
Porcelain veneers cover the front of the teeth and can change their width, shape and colour at the same time, which suits people who want more than the gap changed. They usually involve removing a thin layer of enamel, so they are a long-term commitment. See how long veneers last for what to expect over time.
The limit with both is proportion. Making two front teeth wider to fill a large gap can leave them looking oversized, so these options suit small spaces best.
Moving the teeth with aligners or braces
Clear aligners and fixed braces bring the teeth together rather than covering the space, and they suit moderate or larger gaps, or cases where other teeth also need straightening. Treatment time depends on how far the teeth need to move and on what else is being corrected. Lumi's dentists provide both clear aligners and braces; our articles on clear aligner options and Invisalign costs cover these in more depth.
Sometimes the best result comes from combining the two: moving the teeth part of the way, then using bonding to fine-tune the shape of narrow teeth.
Keeping a closed gap closed
Teeth that have been moved together tend to drift back toward where they were. A retainer, worn as instructed after aligners or braces, is what holds them. Many dentists use a thin wire bonded behind the front teeth for midline gaps because they are prone to reopening. Not wearing a retainer is a common reason a closed gap comes back.
Bonding and veneers do not need a retainer because nothing has been moved, but they still need looking after with daily cleaning and regular check-ups.
Typical market costs
These are general market ranges seen across Australian practices, not Lumi fees. Your own cost depends on the size of the gap, how many teeth are involved and what else is being treated.
| Option | Typical market range | Usually suits |
|---|---|---|
| Composite bonding | $250 to $800 per tooth | Small gaps |
| Porcelain veneers | $1,500 to $2,500 per tooth | Gaps along with shape or colour concerns |
| Clear aligners or braces | Varies widely with the case | Moderate or larger gaps, or crowding elsewhere |
A midline gap usually involves two teeth, so bonding is often quoted for both. Some health funds with extras cover pay part of some treatments. Our smile makeover cost guide looks at how options are combined when several teeth are involved.
Common questions
Is it fine to leave a gap alone?
Yes, if it does not bother you and there is no gum problem, missing tooth or other cause that needs attention. Closing a gap is usually a personal choice.
Does closing a gap hurt?
Bonding is usually comfortable and often needs no anaesthetic. Aligners and braces can make the teeth feel tender for a few days after each change as they move.
Will my child's gap close by itself?
Often, yes, once the adult canines come through. Your child's dentist or OHT can keep an eye on it at check-ups and let you know if anything else is keeping the teeth apart.
Talk to us about your gap
If you would like to know why your gap is there and which options make sense for it, the team at our Melrose Park practice can examine your teeth and gums and explain the choices, including composite bonding. Consults for cosmetic and aligner treatment are free; see our current offers for details.
This article is general information and is not a substitute for personalised dental advice. Always consult a registered dental practitioner about your individual circumstances.
