Overbite
What it looks like: the upper front teeth overlap the lower front teeth more than they should when biting down. A small amount of overlap (2-3 mm vertically) is normal; significant overlap can cause problems.
Why it matters: excessive overbite can wear down the lower incisors over time, contribute to TMJ symptoms, cause palatal tissue irritation when severe, and affect aesthetics.
What causes it: overbite can be dental (the teeth are tilted in a way that creates the overlap, even though the jaws themselves are in a normal position) or skeletal (the jaws themselves are mismatched, often with the upper jaw too far forward or the lower jaw recessed). Each requires different treatment.
How we treat it: dental overbites often respond well to braces or Invisalign alone. Skeletal overbites in children can sometimes be addressed with growth modification before the bones fuse. Skeletal overbites in adults may involve orthodontics combined with MARPE or, in severe cases, coordination with jaw surgery. The treatment plan is matched to the underlying cause.
Underbite
What it looks like: the lower front teeth bite ahead of the upper front teeth — the opposite of normal. The lower jaw appears to project forward; the chin often looks more prominent than it should.
Why it matters: beyond aesthetics, underbites can cause uneven tooth wear, jaw joint stress, difficulty biting and chewing certain foods, and progressive worsening over time if untreated in a growing skeleton.
What causes it: underbites can be dental (the teeth are tilted but the jaws are in a normal position) or skeletal (the lower jaw is genuinely positioned ahead of where it should be, or the upper jaw is underdeveloped). Skeletal underbites are usually genetic — patients often have a family member with the same pattern.
How we treat it: early treatment in growing children can sometimes redirect skeletal underbites using growth modification appliances — a window that closes around adolescence. Mild underbites in adults can sometimes be treated with orthodontics alone. Moderate cases may involve MARPE coordinated with conventional orthodontics. Severe skeletal underbites in adults often require coordinated treatment with oral and maxillofacial surgery for jaw repositioning.
Crossbite
What it looks like: one or more upper teeth bite inside (closer to the tongue than) the corresponding lower teeth instead of outside them. Crossbites can be in the front (anterior crossbite) or in the back (posterior crossbite). Posterior crossbites are more common.
Why it matters: crossbites can cause asymmetric jaw growth in children, uneven tooth wear, TMJ symptoms, and progressive worsening over time. Posterior crossbites are also a red flag for an underlying narrow upper palate — which can have airway implications.
What causes it: the most common cause of a posterior crossbite is a narrow upper jaw (maxilla). The upper teeth follow the position of the upper jaw, so when the maxilla is narrower than the mandible, the upper teeth end up biting inside the lower ones. Anterior crossbites are usually about tooth angulation or a developing Class III skeletal pattern.
How we treat it: posterior crossbites in children typically respond beautifully to palatal expansion — a routine, gentle treatment in growing kids. In adults, the same condition usually requires MARPE for skeletal expansion without surgery. Anterior crossbites are often correctable with braces, Invisalign, or growth modification depending on age and underlying cause. More about MARPE →
Open Bite
What it looks like: when the back teeth are closed together, the upper and lower front teeth don't touch — there's a gap between them, sometimes large enough to see through.
Why it matters: patients with anterior open bites often have difficulty biting through food with their front teeth, struggle with certain speech sounds, and have unequal wear on the back teeth. Open bites also have a strong association with airway and tongue posture issues that deserve evaluation.
What causes it: common causes include prolonged thumb-sucking or pacifier habits in children that prevented the front teeth from coming together; tongue thrust patterns; airway issues that push the tongue into a forward, low resting position; and skeletal jaw growth patterns where the vertical dimension of the face has become excessive.
How we treat it: habit-related open bites in growing children often respond to habit interruption appliances combined with growth guidance. Airway-driven open bites require coordinated treatment — orthodontic correction of the bite plus addressing the underlying airway component. Severe skeletal open bites in adults sometimes require coordination with oral and maxillofacial surgery for jaw repositioning. Identifying the cause is the critical first step.
Crowding
What it looks like: there's not enough room in the dental arch for all the teeth to fit properly. Teeth overlap, rotate, get pushed out of alignment, or in severe cases, get blocked from coming in entirely.
Why it matters: crowded teeth are harder to clean — leading to higher rates of decay and gum disease over time. Severe crowding can also indicate underlying skeletal issues that have airway or growth implications.
What causes it: crowding is essentially a space problem — the arches developed narrower than they needed to be for the size of the teeth, or the teeth came in larger than the arches could accommodate. The underlying driver is often the same muscle balance issue described in the spacing section — but in the opposite direction. When the tongue rests low in the mouth instead of against the palate (often tied to airway issues, mouth breathing, or tongue posture habits), the upper arch doesn't get the natural outward pressure it needs to develop wide enough during growth. The result is a narrow arch and teeth that don't have room. This is one reason early airway-focused evaluation matters for kids: addressing tongue posture during growth can prevent crowding later.
In adults, late crowding (lower front teeth shifting in your 30s and 40s) can also occur from natural arch narrowing over time.
How we treat it: three general approaches. Alignment within available space when the teeth can fit with rotation correction alone. Expansion to create more space — palatal expansion in growing children, MARPE in adults, or arch development using Damon Ultima mechanics. Extractions to create space when there's genuinely not enough room. The digital workflow we use lets us evaluate each case carefully and often find non-extraction solutions in cases that historically would have required them. More about our digital workflow →
Spacing — gaps between teeth
What it looks like: visible gaps between teeth — most commonly between the front two teeth (called a diastema) but possible anywhere along the arch.
Why it matters: spacing is usually a cosmetic concern more than a functional one, though large gaps can affect speech and bite stability. Some patients want their gaps closed; others have lived with them happily for decades and don't want them touched. Both are valid.
What causes it — the part most patients haven't heard: spacing (and crowding) come down to muscle balance. The position of your teeth at rest is held by a balance of forces — the tongue pushing outward from the inside, the lips and cheeks pushing inward from the outside. As long as that balance is intact, teeth stay where they belong.
The most common cause of spacing is tongue thrust — a swallowing and resting pattern where the tongue pushes forward against the front teeth instead of up against the roof of the mouth. Normally, when you swallow, the tongue should travel up against the palate. In tongue thrust, it travels forward and pushes against the back of the front teeth, hundreds of times a day. The tongue is one of the strongest muscle systems in the body — it consistently overpowers the lips' ability to push back — and the front teeth get progressively pushed outward, opening up the spaces you see in the mirror. Tongue thrust is often tied to airway issues, mouth breathing, and tongue posture habits.
Less common contributors include teeth that are genuinely smaller than the arch can accommodate, missing teeth that have allowed adjacent teeth to drift, and in the case of a front-teeth gap (diastema), a low-attached labial frenulum (the small piece of tissue connecting the upper lip to the gum) that physically prevents the two front teeth from coming together.
How we treat it: orthodontic alignment can close the spaces — either braces or Invisalign works well for the tooth-movement portion. But here's the critical point: if tongue thrust is the underlying cause, the spaces will reopen after treatment unless the tongue pattern is addressed. We routinely coordinate with myofunctional therapy to retrain tongue posture — getting the tongue resting against the palate and swallowing upward rather than forward. For cases where a restricted frenulum is the issue, we coordinate with a general dentist or oral surgeon for a frenectomy before or alongside orthodontic work. For cases caused by missing teeth, we coordinate with restorative dentistry for an implant or bridge after orthodontics has prepared the space.
What if I have more than one of these?
Most cases involve more than one bite issue. A patient with crowding often has rotation. A patient with a crossbite often has crowding too. A patient with an overbite frequently has a Class II skeletal pattern with airway implications. Real cases are usually combinations.
The advantage of the digital workflow we use is that the treatment plan addresses all the contributing factors in coordinated sequence — not treating each problem in isolation. At your consultation we'll lay out what's happening in your specific case, what the priority order of treatment is, and what the final result will look like.