How Bite Height Affects Your Smile
When patients think about dentures or rebuilding worn teeth, they usually focus on the teeth themselves — how white they are, how straight they look, or how natural they appear. But one of the most important factors influencing how a smile looks is something most patients have never heard of: the vertical dimension of the bite.
Dentists call this the occlusal vertical dimension (OVD). It refers to the distance between the upper and lower jaws when the teeth come together.
This measurement affects how your lips, teeth, and facial proportions appear when you smile.
Why Bite Height Changes Over Time
Over time, teeth can wear down, break, or be lost. When this happens, the height of the bite can gradually decrease.
This may cause:
- a shorter lower face
- compressed or thinner-looking lips
- the chin appearing closer to the nose
- deeper folds around the mouth
Many patients describe this appearance as a collapsed or aged look. Restoring the correct bite height is an important goal when making dentures or rebuilding worn teeth.
Research on Bite Height and the Smile
In research that I conducted studying how bite height affects smiling, we evaluated how the lips and teeth change appearance as vertical dimension is gradually increased in small increments. Participants were photographed smiling at each position, and measurements were taken to track changes.
The study found several consistent effects:
The space between the lips increases.
As the vertical dimension increases, the opening between the upper and lower lips during a smile becomes larger.
More lower teeth become visible.
Increasing the bite height allows the lower lip to move slightly downward during a smile, making more of the lower teeth visible.
The total visible tooth area increases.
The overall display zone of the smile — the area where teeth show — also expands with increasing vertical dimension.
The width of the smile stays about the same.
Interestingly, the corners of the mouth remain in a similar position. The width of the smile does not change significantly.
This means that bite height mainly affects the vertical proportions of the smile rather than its horizontal width.
What This Means for Denture Patients
For patients receiving dentures, the dentist must recreate the correct bite height from the beginning — there are no remaining natural teeth to use as reference.
If the bite is set too low, the face can appear collapsed and aged. If the bite is set too high, the teeth may look too prominent, or the lips may have difficulty closing comfortably.
The goal is to find a bite height that restores a natural, harmonious balance between the teeth, lips, and facial proportions.
Finding the Right Balance
Dentists evaluate several factors to determine the correct vertical dimension:
- facial proportions and measurements
- lip position when smiling and speaking
- comfort of the jaw muscles
- tooth display during normal speech
- the overall relationship between the nose and chin
In some cases, trial dentures or temporary appliances are used to test a new bite height before the final dentures are made.
A Natural Smile Is More Than Just Teeth
A natural smile depends on many elements working together — teeth, lips, jaw position, and facial proportions. The vertical dimension of the bite is one of the key factors that helps maintain this balance.
When dentures restore proper bite height, patients often notice improvements not just in chewing and comfort, but also in the appearance of their smile and the youthfulness of their facial profile.