Treatment of intercalary edentulism

Treatment of intercalary edentulism

Treatment for partial edentulism involves not only replacing the missing teeth but also preserving the remaining teeth .

Definition of intercalary edentulous classes

According to Kennedy and Applegate, four classes are defined:

• Class III : concerns cases of bilateral intercalated edentulism (without loss of canine).
• Class IV : anterior intercalated edentulism on either side of the midline.
• Class V : bilateral intercalated edentulism with loss of at least one canine.
• Class VI : unilateral intercalated edentulism.

• Treatment of intercalary edentulism

2.1 Pre-prosthetic treatment

Parallelizer study:

Production of the temporary acrylic prosthesis

Restoration of the oral cavity by other dental disciplines

2.2 Prosthetic treatment proper

In intercalary edentulousness, the treatment of choice remains the joint prosthesis. The PPAC is designed in case of impossibility of realizing a fixed bridge for one of the following reasons:

• Significant extent of the toothless crest.
• Significant resorption of the ridges.
• Reduced periodontium requiring increased dental and osteomucosal support.
• The patient’s financial possibilities.

Typical chassis layout

1. Class III typical chassis layout

	Upper jaw	Lower jaw
Main connection	* a double spacer: Its half-reed section, its thickness is 02mm *A narrow palatal plate	– a lingual bar: in the shape of a ½ pear -Lingual band when clinical imperatives require it
The hooks	ACKERS hooks placed on the 4 teeth bordering the gap and ensuring the connection.	The same hooks used at the upper arch level
The saddles	Two retention grids	Two retention grids.

Class IV chassis layout

     Anterior toothlessness poses several problems:

* Aesthetic problem: centripedal resorption of the maxillary àteeth will be mounted outside the crest.

* Biomechanical problem: anterior axis of rotation

During the incision, the forces exerted on the incisal edges posteriorly dislodge the prosthesis from these bearing surfaces.

This results in a reversal movement around the axis of rotation which brings together the front cleats.

Moment of action = force x distance

Moment of reaction > Moment of action

Moment of reaction = 2resistance x DISTANCE

Move the rear anchors back sufficiently                

          – Significantly reduce the force required on the anterior abutment teeth in order to avoid tipping of the prosthesis                                    -place posterior stabilizing hooks.

Treatment of intercalary edentulism

* Functional problem:

The incisal guide being removed, its restoration by the prosthesis reduces the incision gesture by an end-to-end assembly.

	Upper jaw	Lower maxilla
Main connection	* double palatal bar: reduced edentulism * solid plaque: significant edentulism	-lingual bar: connected to the saddle anteriorly – lingual strip
The hooks	Previously: Ackers hook Posteriorly: Reverse Ackers on the most posterior teeth.	Previously: Ackers Later: BONWILL double hooks.
The saddles	An anterior retention grid	idem

1. Class V chassis layout: The problems posed by this class are:

    *Biomechanical problem

The incisor limiting the edentulism does not constitute sufficient support àfor a saddle in mesial extension + the presence of a diagonal axis of rotation.

*Occlusal problem

                The absence of the canine will disrupt the guidance of the mandible in diduction, consequently we will opt for a group function on the side where the canine is missing.

	Upper jaw	Lower jaw
Main connection	Full palatal plate.	Lingual bar or lingual strip.
Hooks	* On the side of the canine loss: Ackers hook or Ring. *On the side opposite the missing canine: 2 Ackers on the teeth bordering the edentulousness and an inverted Ackers on the most posterior tooth.	* On the side of the loss of the canine: idem. *on the side opposite the missing canine: -Ackers on the abutment teeth. – Ackers on the most posterior tooth. *Indirect support: Continuous Kennedy hook height: 02 mm, thickness: 01 mm
The saddles	2 retention grids	idem

Treatment of intercalary edentulism

Class VI chassis layout

	Upper jaw	Lower jaw
Main connection	* narrow palatine plate	A lingual bar or lingual strip
hooks	*Edentulous side: 2 Ackers hooks on the teeth bordering the edentulous area, in the presence of an isolated posterior tooth: Ring hook. * Opposite side to the toothing a double Bonwill hook to balance the saddle on the opposite side.	idem
The saddles	A retention grid	idem

1. Trying on the framework in the mouth

• Check the insertion axis.
• The intimacy of the framework with the dental structures.
• Reciprocity of action.
• The frame must not compress the mucosa.
• No interference from occlusion cleats.

1. Occlusion recording

1. Functional test: It is important to check:
2. Stability, phonation, aesthetics, occlusal contacts in static and dynamic

iiii. The appetizer:

• Post-prosthetic treatment
• The patient should be reviewed after delivery of the prosthesis, hard and soft tissues should be examined.
• Rebasing of the stool may be necessary, particularly in cases of extensive anterior edentulism.

Conclusion

The practitioner should keep in mind the various design principles that would lead to a perfect realization of the cast prosthesis and thus to its biological integration.

Treatment of intercalary edentulism