Prescribing Optimised Tooth Position

• Natural dentition:

  • Genetic factors - tooth size, shape, jaw dimensions
  • Environmental factors - oral and perio-oral muscles
  • Extrinsic factors - sucking habits
  • Other habits/hobbies
• Putting prosthetic teeth where natural teeth once were:

  • Resorption
  • Angulation
  • Alveolar support in relation to occlusion and tooth position
  • Patient expectations
• Prosthetic dentition:

  • Patient factors
  • "Nice straight white teeth" - designer smile
  • "I don't want anyone to know I have false teeth" - naturalistic
  • Environmental factors
  • The opinion of the first person to see them with their new teeth has disproportionate impact
  • What looks good in the shop may not be comfortable
• Soft tissue support:

  • Incisal level
  • Position of buccal teeth
  • Matching mandibular to maxillary
  • Vertical relation

  
• Check your perspective when assessing soft tissue support.

  
• OVD (occlusal-vertical dimension):

  • OVD should provide an appropriate freeway space
  • Freeway space can be assessed by looking and listening
  • Confirmation of freeway space may be aided by use of some crude means of demonstrating the space
  • Closure along retruded arc into centric relation
  • Achieving a retruded contact on our record blocks at the chosen appropriate OVD
  • The technician sets up teeth to this presentation so that RCP and ICP coincide
• How to choose what teeth to prescribe:

  • Face shape - matches tooth morphology
  • Gender - a male or female looking dentition
  • Height - taller people may have bigger teeth
• Look for clues when choosing what teeth to prescribe:

  • Current dentures
  • Photographs of pt's natural teeth
  • Close family members with similar appearance
  • Partners' opinions
  • Try to be guided by the pt
  • Advise but don't dictate - if an eighty year old wants bleached white teeth then let them have them
• Registration and recording jaw relations:

  • How do the maxillary and mandibular arches relate to each other
  • In the sagittal plane/coronal plane/antero-posteriorly
  • How do we reproduce this (reliably)?
  • For an edentulous person this is the most difficult aspect of clinical dentistry
• Comfort, fit and extension, shade and mould:

  • Maxillary record block
  • Lip support, incisal level, occlusal plane, buccal corridors
  • Mandibular record block
  • Even contact with maxillary block, buccal corridors, occlusal plane, incisal level, lip support
  • Occlusal relationship
  • RFH (resting face height) - OVD (occlusal-vertical dimension) = FWS (freeway space)
  • Does it look right
  • CR - centric relation - condylar hinge axis
  • Retruded arc of closure
  • Transfer it to the laboratory
  • Prescription form