Posterior Open Bites: Case Study

Through: Jeffrey W. Horowitz, DMD, FAGD, D-ABDSM, D-ASBA

During your time as a dentist, have you ever encountered posterior open bites?

Here’s a case study about my experience with it.

Posterior Open Bites: Case Study

  • 51-year-old Caucasian female presents for bite consultation, unable to fit teeth or chew properly.
  • Medical history unremarkable except previous TMJ therapy and surgery for hearing loss.
  • No drugs
  • Dento-Facial Exam: The Patient Has No Aesthetic Concerns
  • The patient had orthodontics as a teenager with 4 Bicuspid EXT.
  • The patient developed TMJ pain/popping as an adult and was successfully treated with a mandibular repositioning splint by the last dentist
  • Range of motion good, no pain
  • Dental/Perio Exam: Negative for Pathology
  • Soft tissue examination: within normal limits
posterior open bites

Etiology of Posterior Open Bites

  1. Temporary adjustments to muscle or joint fluid by wearing a repositioning splint.
  2. Temporarily due to acute joint trauma or intracapsular edema.
  3. Temporarily after ortho treatment during “settling”.
  4. Permanent or prolonged postural changes through repositioning of devices that improve joint/disc relationship, muscle harmony or airway function.
  5. Permanent or long-term functional bite narrowing due to orthodontics, overcontoured front teeth or undercontoured/reduced posterior teeth.


Permanent postural change, secondary to improved condyle/disc relationship and improved muscle function.

Initial TMJ/muscle discomfort may have arisen from anterior functional narrowing secondary to
extraction/retraction orthodontic mechanics. (cannot be confirmed)

Facial analysis with Kois Dentofacial analyzer and Panadent articulator showed that the upper posterior right segment and lower posterior left segment had a flat occlusal plane. Can also use stick bite with less precision.


The patient opted for additive restorative rather than orthodontic treatment to close the posterior open bite with equal bilateral simultaneous contact that supports joint and muscle posture.


The patient was successfully treated with a mandibular repositioning splint that improved the joint-disc relationship and created muscle harmony despite open bite.

The bite was repeatable and comfortable. No need to change.

The patient was given the choice of fixed orthodontics or conservative additive restorative treatment to close the posterior open bite in her comfortable adjusted bite relationship/position.

The patient chose additive restorative, performed first with direct composite to “train” occlusion, then completed the case with ceramic onlays and replaced a full-coverage crown.

Posterior segments top right and bottom left restored to flat arches.

Next one: Pits and erosive tooth lesions – what does it mean?

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