PIEZOGRAPHIC PROSTHESIS

PIEZOGRAPHIC PROSTHESIS

1. Introduction: In 1728, Fauchart said: “We must take into account the shape and modeling of the external and internal surfaces of the prostheses to avoid hindering the tongue and cheeks in their functions”
2. Definition: the word piezography comes from the Greek Piezein: To press.    Graphein: To sculpt.

P. KLEIN: is the first to have brought this term to the field of dentistry. According to this author, piezography is the result of the modeling of a plastic material by the dynamics of the organs limiting a virtual or real space, where the material is introduced.
 Piezography is a sculpture by muscular forces that compress or embrace muscle masses acting like the hands of a sculptor.

For A. NABID, piezography is the three-dimensional reproduction of the prosthetic space of the totally edentulous person.

Principle: Pinching effect between two muscle groups exerting antagonistic pressures (tongue & buccinato-labial strap)

3. Goals :
   1. Making functional mandibular impressions
   2. Modeling of polished surfaces of prostheses
   3. Physiological determination of the prosthetic occlusion plane  
   4. Determination of the prosthetic volume as well as the volume of dental elements 
   5. Obtain stable and functional prostheses adapted to the muscular dynamics specific to each individual.
4. Clinical form of the piezographic impression:
   1. Analytical Piezography:  This is an impression intended for the study of the pressure exerted on the prostheses by the buccinato-labio-lingual strap.

                          Indication  :

– Control of the position of polished surfaces and dental elements in the premolar and molar areas .

-Allows you to check whether the existing prosthesis fits correctly in the prosthetic corridor .

2. Prosthetic piezography: 
   1. Definition  : Intended to determine the prosthetic corridor.
   2. Indication: 
      1. Total bimaxillary or unimaxillary edentulism, with significant bone resorption, resulting in weak, flat, or even negative ridges (cl III, cl IV according to Landa)
      2. Total bimaxillary edentulation in patients with a very large tongue that has invaded the prosthetic space 
      3. In patients with facial paralysis, or with orofacial asymmetries.
      4. Upper total prosthesis with a lower partial prosthesis cl I KA when the patient has a bothersome gag reflex.
      5. Mandibular prosthesis on implants.
3. Piezographic techniques: piezographic imprint techniques are presented in two techniques depending on the modeling function used: 

The function	Phonation	Swallowing
Authors	P. Klein	Heath Et Schiesser, Beressin, Nabid
Benefits	oral function most generating unbalancing horizontal forces the tongue moves with extreme capacity function most developed by its daily duration moderately affected by edentulism possibility of using upper occlusion models	simpler technique materials used easy to handle more stable model during printing wide field of indication since it also targets the deaf and dumb, mentally ill.
Disadvantages	limited indicationmore complicated techniquelonger completion time	inability to use the upper occlusion model. risk of crushing the impression against the upper ridge

6. Piezographic Phonemes:

The phonemes chosen for modeling must simultaneously solicit the activity of the two antagonistic muscular poles, the tongue and the buccinato-labial strap. 

-Consonants: (S, R) (DE, TE) (DA, TA in Arabic) (PE, ME)

-Vowels: ioe (or in Arabic)

7. Piezographic Materials: 
   1. Features : 

• Easy handling
• Stability
• Loyalty
• sufficiently slow plasticity time
• irreversible….

2. Suggested materials:

• Delayed setting resins
• Dense thiocols
• High viscosity delayed setting silicones “  Xantopren Fonction”

8. Piezographic Techniques: 
   1. Mandibular piezography:

-Creation of a stable impression tray base  : it is made of self-polymerizing resin on a primary model from a primary impression or according to Klein who describes a pre-impression without an impression tray taken with Thiocol.

        -Different recording phases : KLEIN Phonetic Technique

a/First buccinator (jugal) modeling:

-We start laterally (Right or Left) by injecting the material on the base and spreading the tongue.

-The patient is asked to repeat the phonemes: “SIS” 6 times and “SO” once (the buccinator region)

-The phonation is continued until the material hardens.

-Avoid swallowing.

– Eliminate excess.

b/2nd jugal modeling  : IDEM for the opposite side.

c/3rd jugal modeling: the first partial buccinator piezography is rejected because it is possible that the tongue will tend to push back the resin at the beginning. The 3rd ^modeling is carried out in better conditions than the first time, because the 2nd ^modeling is in place.

d/ Previous modeling:

• Lingual modeling: “TE” and “DE”
• Vestibular modeling: “ME” and “PE” 

– Note  : recording without upper model and the position of the patient’s head is that taken in a normal conversation

1. Determination of POP: Linguo-mandibular reference

• Vestibular side: bottom of the groove (horizontal fiber of the buccinator)
• Lingual side: papillated-depapillated mucosal junction of the tongue at rest
• Previously: the plane // the lip; it meets aesthetic requirements.

2. Secondary Imprint: formwork and casting
3. Duplicate of the piezography: Before demolding the secondary impression of the vestibular and lingual keys in heavy silicone or plaster are made 

• Remove the keys. The imprint is demolded. 
• The keys are repositioned
• The resulting prosthetic space is cast with wax

4. Recording of intermaxillary reports:

• Lower piezographic model: POP is already set.
• Upper model: determination of the DV (phonetics)

5. Assembly and balancing: Balanced non-geared assembly, Flat without compensation curve.
6. Semi Maxillary Piezography:

-Creation of a stable base in auto resin (2mm)

-Search for a pre DV (minimum phonetic space): 3 cones on model then phonation of (SIS – SIR)

-Modeling of the posterior wall : resin injected around the cones: lateral movement, swallowing, etc.

-Recording of the anterior prosthetic space: “injected fluid delayed setting resin”

• 1st ^time   : Internal face: Te – De “Ta – Da in Arabic”
• 2nd ^time : Vestibular face “ the bilabials” “ME – MI”

3. Conclusion

The principle of piezography is to make an impression that respects the paraprosthetic organs both at rest and in function in order to obtain a prosthesis that is as stable as possible. 

PIEZOGRAPHIC PROSTHESIS

  Early cavities in children need to be treated promptly.
Dental veneers cover imperfections such as stains or cracks.
Misaligned teeth can cause difficulty chewing.
Dental implants provide a stable solution to replace missing teeth.
Antiseptic mouthwashes reduce bacteria that cause bad breath.
Decayed baby teeth can affect the health of permanent teeth.
A soft-bristled toothbrush preserves enamel and gums.
 

PIEZOGRAPHIC PROSTHESIS