I am doing an implant supported mandibular fixed partial denture for an elderly edentulous patient. My oral surgeon has placed 8 regular platform implant fixtures in the first molar, second premolar,canine and lateral incisor sites. My oral surgeon advised me to do a single piece metal framework extending around the arch from second molar to second molar. My dental laboratory technician recommended that I make the metal framework in 3-separate segments – one anterior, two posterior. He claims that the mandible flexes and changes dimension in function. Which should I do?
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Hello
The mandible does flex. However one factor is what are you making the final prosthesis out of: porcelain or bar with wrap around acrylic?? Another question that will place a factor is what the patient has in the opposing arch?
The full horseshoe wrap around works great! I have done many of these. You should have no problem with doing a one piece.
However, the man to ask is Dr. Carl Misch…he will provide you with some great feedback on this.
mandibular flex is so often forgotten……
Interesting how the original implants were placed in front of the mental nerve and reduced the concern.
hi,
ur lab has advised u correctly.
the mandibular flexion is a very established factor and has more effect as you progress posteriorly into the molar region.
and it should always be taken into consideration ahenever u make a full arch rehabilitation in the mandible.
it has nothing to do with the opposing arch and is due to the pull of the perioral musculature,it flexes even when the mouth is opened.
u have enough implants to do the prosthesis in 3 pieces so go ahead.
if u have enough implants it is better to do the prosthesis in 2-3 segments as it also aids a simpler maintainence in terms of time and expense, if at all the prosthesis has to be retreived at a later date, as u have to remove only the segment where there is a problem.
i hv done many cases with single frame & acrylic facings with no prbs in 10 yrs follow ups.u will have to do that only because ur oral surgeon has put the implant in 1st molar & 2nd pm.for a good 3 piece , it would hv been better to choose 2nd molar & 1st pm region to avoid cantelever movements (though these site are difficult)for post pieces.for ant piece canine to canine ,i see no prb.prosthetic part should be planned & discussed with lab technician & surgeon before placing implants.to avoid bad effects of mandibular flexure movements u may choose pin & slot joint at first pm ,which allows for movement if any.
but is’nt flex typically in the area between the 2 premolars, if that is true where is the best place to put the anterior implant: 1st or 2nd premolar position?
My initial thought would be you don’t need 14 teeth. a 6-6 occlusion would be sufficient to avoid any distal cantilever. Also I agree that with porcelain on gold you will get distortion of the framework from porcelain shrinkage if it is on one piece unless you ‘post-ceramic solder’. Using acrylic/composite would avoid that problem. As kiran has said making it in 3 sections will help with maintenance and retrievability if any section has to be removed.
Hi ,
My thought is, if you doing cement retained prosthesis better to split them, as single piece bridge would get lose often .If screw retained single frame work,splinted implants will overcome the mandibular flexure. Done quite a few Hybrid denture for mandible past 5 years and no complications so far.
In my mind it would be more correct from a technical and hygiene point of view to make a 3-piece construction: molar plus premolar from both sides and canines plus incisors in the frontal area
Make it a one piece framework. Splinted implants are always stronger.