Management of Advanced resorption of residual alveolar ridge

(Flat ridge)(1)

By: Hussein Abd El-hady Hussein Taha

Lecturer of Removable Prosthodontics and Implantology

Faculty of Dentistry – Minia University

The Atrophic

(Flat) Mandibular

Ridge

Flat palate

with shallow

vestibule

Anatomic factors

Age, sex, nutritional deficiency, systemic diseases, loss of

natural teeth.

Biologic Factors

Functional / Prosthodontic factors

Types of bone, size and shape of the ridges

Habits, prosthetic factors

TYPES OF BONE

1. Type of bone: cancellous bone is more prone to

resorption than is cortical bone.

2. Size and shape of the ridge: thin narrow ridges will

resorb more than well-formed broad ridges, as the

force received per unit increased .

Etiology of RRR

I. Anatomic factors

1. Age: RRR generally increases with age.

2. Sex: RRR occurs more in females. This usually

occurs during menopause, as a result of hormonal

disturbances.

3. Nutritional deficiency:

Calcium deficiency, decrease in vitamin C and/or

protein utilization and/or dysfunction of carbohydrate

metabolism, are contributing factors.

II. Biologic / metabolic factors

4.Systemic health: RRR occurs more in

cases such as:

Blood dyscrasis.

Uncontrolled diabetes and other

debilitating diseases that may

cause tissue destruction and reduce

tissue resistance.

II. Biologic / metabolic factors

5.Treatment for certain diseases:

a. Radiation therapy reduces regeneration.

b.Hormonal drugs may have an adverse effect on

the hard and soft tissues.

c. Loss of natural teeth: Extraction of teeth as a

result of severe periodontal disease contributes

to more alveolar atrophy than when teeth are

lost due to caries.

II. Biologic / Metabolic factors

1. Long-term wearing of dentures without serviceability.

2. Improperly constructed dentures with improper vertical

dimension of occlusion, centric relation, non-balanced

occlusion and incomplete coverage of basal seat area.

3. Continuous wearing of the dentures without rest to the

underlying tissues.

4. Porcelain teeth and/or anatomic teeth with high cusp angles

transmit more force to the underlying ridge.

III Prosthodontic factors:

THE ATROPHIC

(FLAT)

MANDIBULAR

RIDGE

FLAT RESIDUAL ALVEOLAR RIDGE

The shape of the ridge provides:

• No resistance to lateral movement of the denture.

• Interference from adjacent musculature Is pronounced.

Reasons for the difficulty:

The clinical problems

Functional Problems

•Instability•The inability of the residual ridge and

its overlying tissues to withstand

masticatory forces

•The Mucosa Overlying The Atrophic Mandibular Ridge Influences A

Patient's Ability To Withstand Loading. The mucosa is sandwiched between the

denture base and the underlying bone so that all the forces generated by the

mandible, during function and parafunction, are transmitted through this

atrophic tissue.

•The mental foramen occupies a more superior position.

•The shallow sulci adversely influence peripheral seal

•The mental foramen occupies a more

superior position.

denture base must be relieved to

prevent nerve compression and

pain.

The shallow sulci adversely influence peripheral seal and in turn

affects retention

Interference from adjacent musculature is pronounced

FLAT PALATE WITH SHALLOW RIDGE• REASON FOR DIFFICULTY:

The denture may be displaced during mastication through lack of

ridge support; the shallow

sulci adversely influence

peripheral seal

The genial tubercles are the origins of

both genioglossus and geniohyoid

muscles, they do not undergo bone

resorption. They can project prominently

in cases of severe bone resorption.

In severe alveolar ridge resorption the

genial tubercles appear on the surface

of the mandible.

One constant, relatively unchanging structure

on the mandibular denture bearing surface is

the retromolar pad.

Advanced resorbed ridge

with projecting

sublingual glands.

Advanced resorbed ridge

with projecting

sublingual glands.

In severe alveolar ridge resorption,

the mylohyoid ridge becomes

prominent and cause pain when

pressure is applied by the denture.

The external oblique ridge runs outside

the buccal shelf bone anteroposteriorly.

it is not involved in resorption

Management of RRR

Prosthetic

Management

With Surgical

Intervention

Prosthetic

Management

Without

Surgical

Intervention

Prosthetic Management With

Surgical Intervention

Vestibuloplasty Ridge

Augmentation

Distraction

Osteogenesis

Implant-

supported

Overdenture

VESTIBULOPLASTY

Obliterated Vestibule

VESTIBULOPLASTY

• It is a surgical procedure designed to restore

alveolar height and/or width by detachment of

buccal and/or labial and lingual tissues. These

tissues are positioned at a lower level to obtain

maximum height of the residual alveolar ridge.

VESTIBULOPLASTY

DISTRACTION OSTEOGENESIS

Distraction Osteogenesis

Distraction Osteogenesis

RIDGE AUGMENTATION

This procedure is used to increase the

height and width of the residual alveolar

ridge. A variety of materials have been

used for this purpose

Ridge Augmentation

A variety of materials have been used for this

purpose:

Autogenous bone from the iliac crest or rib.

Non-autogenous bone.

Hydroxyapatite, (in the granular or block form)

which is injected through one or more

subperiosteal tunnels to build up sufficient

height of the residual ridge.

Ridge Augmentation

SURGICAL MANAGEMENT

Contouring the genial tubercles:

This is done to provide for an extension in the

sublingual flange of the mandibular denture.

SURGICAL MANAGEMENT

In severe alveolar ridge resorption,

the mylohyoid ridge becomes

prominent and causes pain when

pressure is applied by the denture.

Outside the buccal shelf, a ridge runs

anteroposterior which is called the

external oblique ridge. It is not involved in

resorption.

IMPLANT-SUPPORTED

OVERDENTURE

IMPLANT-SUPPORTED OVERDENTURE

Implant-Tissue Supported

IMPLANT-SUPPORTED OVERDENTURE

Implant-Tissue Supported

IMPLANT-SUPPORTED OVERDENTURE

Implant-Tissue Supported

HOW TO OVERCOME THE PROBLEMS

The primary consideration for a continued success of the denture is

Proper diagnosis and full use of every factor, which favor success for this

denture,

Maximum base extension within functional anatomical limits (distributed forces

over the largest possible area of supporting structures and the force per unit

area kept at minimum.)

Reduction of the forces to which the denture is subject

The polished surface: The creation of the correct form of the polished

surfaces,

The fitting surface: Good impressions that yield an accurate fit

spreading the bite load out over the entire ridge.

The border Extension: Proper denture border lengths that allow for free

movement of musculature and tissue attachments.

Tooth Position:

Molars that are placed proximate to the center of the ridge so as

not to create a teeter totter action when chewing.

Correct vertical placement of teeth. Teeth that are placed too high

off a lower ridge will create more leverage to rock the

denture.

Occlusion:

A reduced occlusal table,

An appropriate vertical dimension and

A balanced occlusion and free articulation creating an

uniform application of bite force down on to your ridge.

Dental implants: these may be the only solution for some

patients when the first five components have been met and the

patient still struggles with retention.

IMPRESSION MAKING

AN IDEAL IMPRESSION SHOULD PROVIDE:

• MAXIMUM EXTENSION Without muscle impingement.

• INTIMATE CONTACT With the tissue area covered.

• Proper form of THE BORDERS Including the posterior border of the

maxillary denture.

• PROPER RELIEF Of hard and sensitive areas.

IMPRESSION TECHNIQUES

• PRIMARY IMPRESSIONS

CONVENTIONAL TECHNIQUES

•DEFINITIVE IMPRESSIONS

I- muco-compressive imp. Techniques

II- butterfly technique.

III- dynamic impression technique

IV- functional techniques

•The primary impressions should accurately record clinical relevant

landmarks of the edentulous mouth without excessive tissue

distortion .

•The basic functions of primary impression is to outline support and

to provide the basis of a primary cast on which a customised or

'special' tray is made.

Primary impressions

PRELIMINARY IMPRESSIONSTHEY ARE MADE USING READY MADE STOCK TRAYS OF DIFFERENT SIZES.

(TRAYS FOR COMPLETELY EDENTULOUS HAVE ROUNDED FLOOR AND SHORT FLANGES(

PERFORATED TRAYS ALGINATE

NON-PERFORATED IMPRESSION COMPOUND

The lower impression tray is inserted in

the patient's mouth with the operator

sitting or standing in front of the patient

.

The lower impression tray should be

rotated into the mouth, with the cheek

retracted by the operator's finger.

Selection of lower stock tray

Modify the tray with impression compound, pink wax or

autopolymerising acrylic as appropriate, to improve adaptation and

extension

FUNCTIONAL MOVEMENTS FOR BORDER MOLDING

Compound should be softened in a

warm water bath, and then kneaded

between the operator's finger before

use.

The compound for the lower

impression tray should be rolled into

a sausage shape and placed within the

tray.

LOWER IMPRESSION

It should then be molded with the

fingers to the approximate shape

of the final denture.

Any defects in the impression may be

locally softened the compound with

alcohol torch, then tempering in hot

water and reseat the tray in patient

mouth.

Impression re-inserted

in

patient’s mouth

moulded with the fingers to

the approximate shape of the

final denture.

The compound for the upper

impression should be rolled into a

ball placed in the center of the

impression tray

UPPER IMRESSION

The impression tray should be

seated gently in patient mouth

and ask the patient to sucks in

the cheeks, pull down the lips

and move the mandible from

side to side.

The impression is chilled

in cold water and then

inspected for defects.

The completed lower and

upper impressions

Well-formed impression of (lower) lingual sulcus area

Deficiencies of lower impressions in the

retromolar pads and the functional

forms of the floor of the mouth and

the retromylohyoid fossae result in an

unstable denture.

One of the problems faced by a technician when an underextended

impression has been made of the posterior lingual pouch (arrowed)

Two well-formed impressions using a

hydrocolloid material

The occlusal table proved to be a problem because the

wide posterior teeth presented lingual undercuts. In

addition, the length of the table, extending over the

ascending portion of the ridge, adversely affected denture

stability.

Sincerely :

Dr. Hussein A. Hady Hussein