Mandibular Implant Overdenture Surgical Guide

Patient presented with severely worn maxillary complete denture opposing a partially dentate mandible with advance chronic periodontal disease.  The patient wanted to keep his teeth if possible.  The teeth were deemed non-restorable and the patient then elected to proceed with a two implant overdenture.  The following describes the basic fundamentals of preparing an adequate surgical guide for a two implant overdenture

Intial presentation with adjustments made to his existing maxillary denture to establish a better occlusal plane.  Acrylic was added to the posterior segments to help restore OVD and better articulation with his existng dentition and for a future interim prosthesis.  Another option might be to fabricate an interim maxillary complete denture.

Interocclusal record obtained to properly mount the patients teeth to aid in fabrication of the interim mandibular denture.

Interim mandibular denture tooth set up in wax.

Processed interim mandibular denture ready for insertion at surgery.

Inserted mandibular interim denture day of surgery

Clear duplicate of mandibular interim denture to be used as a surgical guide.  If implant surgery is to be performed the day of extractions duplicate the interim as soon as it's processed.  If there will be a delay between tooth extraction and implant surgery do not duplicate the interim denture until it has been adequately relined with a soft liner close to the surgical date.

It's important to provide guidelines for your implant surgeon.  This picture depicts removing the lingual flange and lingual portions of the anterior sextant of teeth.  This provides buccal/facial limitation to the implant placement.  Implants directed out the facial or buccal of a prosthesis is not desirable. 

The guide can and should be modified to illustrate the amount of boney reduction required to ensure proper inter-arch space for the prosthesis.   It is recommended that 12 mm of space from the implant platform to the incisal edge be available for proper ovedenture fabrication.  Note: if the patient so desires to progress to a fixed implant prosthesis in the future a minimum of 16 mm of space is required.  This can be accomplished by measuring the proper distance down from the incisal edge of the denture teeth and marking the labial flange of the duplicate denture.  The flange can the be reduced to the measured line.  This allows the surgeon to place the guide in the patients mouth and visually see the amount of required bone reduction required.