What does “Dental midline discrepancy” mean?
A dental midline discrepancy means that the centres of the upper and lower front teeth do not align with each other, or that a dental midline does not align with the facial reference midline. First distinguish which references differ, then assess tooth alignment, jaw relationships and jaw movement during closure together.
Define the reference centres and examination conditions
Check the centres between the upper and lower front teeth separately from the facial reference midline. Tooth inclination and face or jaw position can change how the difference appears, so measurements need defined references. Lines on a single photograph cannot establish the cause or required treatment movement.
Distinguish tooth position from functional jaw movement
Assess differences in dental space and alignment alongside jaw relationships. Check whether the jaw moves sideways during closure to avoid an interfering tooth contact, distinguishing a difference in tooth position from a functional jaw shift. Crossbite and the overall bite are also considered.
Weigh the goals and limitations against the whole bite
Ask why the midline would be changed and how movement could affect the bite, teeth and gums, rather than considering only how far it should move. Discuss feasible options such as limited movement, comprehensive orthodontics or observation, and differences that may remain. Orthodontics alone cannot guarantee complete facial symmetry.
Frequently Asked Questions
Do different upper and lower dental midlines mean asymmetric facial bones?
Not necessarily. Tooth positions, functional jaw movement and skeletal relationships need to be assessed separately.
Must even a small difference be corrected completely?
Not always. Goals are set by considering function, desired changes, the overall bite and tissue condition, and treatment risks and limitations.
Checking midline references and movement goals
Learn what the term means and how it relates to your dental condition.
- Sufficient understanding
Which midline differs from which reference?
Explanation and evidenceAsk about upper and lower incisors and facial references, tooth inclination, space, jaw movement and necessary records.
Houston Methodist: Assessment of dental and facial centres and jaw symmetry - A choice suited to your condition
How would changing the midline affect the overall bite?
Explanation and evidenceConfirm movement scope and contacts with other teeth, tissue risks, alternatives including observation and differences that may remain.
British Orthodontic Society: Comprehensive assessment, alternatives, risks and retention for limited orthodontics
Further reading and references
Further reading
References
- Houston Methodist: Assessment of dental and facial centres and jaw symmetryhoustonmethodist.org (opens in a new tab)
- AAPD: Developing dentition, bite assessment and staged treatment (2024 revision)aapd.org (opens in a new tab)
- British Orthodontic Society: Comprehensive assessment, alternatives, risks and retention for limited orthodonticsbos.org.uk (opens in a new tab)
