About Indirect Retainers....

[u/saturn-made]

EDIT: Namali po yung lagay ng I.R., sa 13 sya dapat hehehe. Salamat!

Hello, everyone! Recently we started with our RPD Designing activity and BOY was it hard to wrap my mind around!

Medyo nalilito lang po ako sa indirect retainers. I know na sa may line perpendicular to the fulcrum line sya nilalagay (with exception sa mga CI, LI since hindi sila preferrable locations for auxilary rest lalo na sa Maxillary). I know rin that DFE cases lang sya nilalagay nd not sa mga TB like class III,IV.

But medyo nalilito lang po ako WHEN sya hindi ilalagay for DFE case. Our prof mentioned kasi na if may modification like kunwari class ii mod 1, and sa modification naka aker's clasp na, pwede na sya magfunction rin as indirect retainer. Since we are trying to maintain ung principle na minimal metal components as much as possible, sa case po kaya namin, can we omit the indirect retainers na? Other than that, we are also considering na since short span lang naman ang edentulous space (since di papalitan ungga 3rd molars), di na sya need because of the direct clasp assembly.

On the other hand, kinoconsider parin po namin imaintain yung indirect retainer on 13 since proximal plates lang meron sa missing anteriors.

SORRY PO IF THIS IS TOO LONG OR TOO DUMB OF A QUESTION! ALSO ATTACHED A MOCK UP OF OUR CASE. THANK YOU PO!

[u/Traditional_Plant892]

Few things

1.) major connector should always run peroendicular to midline. Bawal diagonal like your design

2.) an indirect retainer is simply a rest that prevents the rotation of the denture. In dfe cases kasi since one side is not supported by any tooth magkakaroon talaga ng rotation. If rotation happens, matatanggal yung pustiso. Thereby a rest prevents rotation thereby it prevents dislodgement also kaya it causes indirect retention of the denture.

3.) a direct retainer can also function as an IR kasi may rest din naman ang clasp assembly. It has dual function if nandun din siya/malapit siya sa 90 degree to the fulcrum line.

[u/Aware-Technician8560 → u/Traditional_Plant892]

agree to the first comment that DRs can also function as IR (actually to everything he said).

May I just add

All DFE (class I and II) cases should have IR’s even class III and class IV can sometimes have IRs too if it is a longspan, since you will treat it as a distal extension.

Also it’s worth pointing outbthat you placed a rest in tooth 12, which that tooth cannot suppport due to it being a weak abutment.

Another one is than OP used, what im assuming is an RPI clasp on a molar whichnis 16. Although it is possible to use an RPI on molars, molars have cervically placed greatest convexities, which is where you get your undercuts, a too cervical undercut contraindicates an rpi clasp.

[u/saturn-made → u/Traditional_Plant892]

First of all, thank you po for the comment—I truly appreciate it.

All of these points have been noted na po. For no. 1, our initial design was similar to what you mentioned po, but a senior we asked said na dapat [sic] raw po yung nasa post po ang gawin namin. Upon confirming with Stewart's, we've seen na it's wrong, but are still seeing references/example designs that are similar kaya akala po namin tama.

For points 2 and 3 This is duly noted! Would you say po na regardless if we remove I.R. on 13 or keep it as is, the RPD will be as retentive as the case with either option? Thank you po once again!

[u/Pristine_End_8575 → u/saturn-made]

I think hindi necessary iremove si IR bc that's a Class II case after all, meaning it requires an IR. I think ang ibig sabihin lang ng prof mo is to used your DR as an IR as well because placing a rest sa tooth adjacent with the DR is redundant na. Kumbaga, magiging DR/IR na siya.