FURCATION INVOLVEMENT

VIBHA

SHARMA FINAL YEAR

INTRODUCTION DEFINITION: it refers to commonly occuring

conditions in which the bifurcations and trifurcations of multi-rooted teeth are invaded by the disease process.

Area of complex anatomic morphology that may be difficult or impossible to debride.

The presence of furcation involvement is one clinical finding that can lead to a diagnosis of advanced periodontitis and potentially to a less favorable prognosis for the affected tooth or teeth.

ETIOLOGIC FACTORS OF FURCATION INVOLVEMENT

Bacterial plaque and its the inflammatory consequences resulting from its long term presence.

The extent of the attachment loss required to produce furcation defects depends upon :

Local anatomic factors Local developmental anomalies

Local anatomic factors Root trunk length Root length Root form Inter radicular

dimension Anatomy of

furcation

Root trunk length Portion of the root between cemento-enamel

junction and the separation of the roots. Teeth may have very short root trunks

moderate root trunk length or roots that may be fused to a point near the apex

When the root trunk is short the furcation will become involved early in the disease process.

When the root trunk is long the furcation will be invaded later but will be more difficult for instrumentation.

ROOT LENGTH It is directly related to quantity of

attachment supporting the tooth

Teeth with long root trunks and short roots may have lost a majority of their support by the time the furcation becomes affected.

Teeth with long roots and short to moderate root trunk are more readily treated because sufficient attachment remains to meet functional demands.

Root form

All root surfaces facing the furcation exhibit some degree of concavity or depression in an occluso-apical direction.

This may make instrumentation for plaque removal and root planing almost impossible but these concavity increases the attachment area of the tooth and produce a root shape that is resistant to torque.

It is common in mesiobuccal root of maxillary first molar and mesial root of mandibular first and second molar.

INTERRADICULAR DIMENSION Closely approximated or fused

roots can preclude adequate instrumentation during scaling, root planing and surgery.

Teeth with widely separated roots present more treatment options and are more readily treated.

ANATOMY OF FURCATION

The presence of bifurcational ridges, a concavity in the dome and accessory canals complicate the treatment and periodontal maintenance.

LOCAL DEVELOPMENTAL ANOMALIES

CERVICAL ENAMEL PROJECTIONS

They occur on 8.6% to 28.6% of molars.

They favor plaque accumulation and must be removed to facilitate scaling and root planing.

Classification Classified by Masters and Hoskins in 1964

as:

Grade I: the enamel projection extends from the cemento-enamel junction of the tooth towards the furcation entrance.

Grade II: the enamel projection approaches the entrance to the furcation . It does enter the furcation , and therefore no horizontal component is present.

Grade III : the enamel projection extends horizontally into the furcation.

CLASSIFICATION A number of systems have been

developed to classify furcation involvement.

Among these systems are those developed by Glickman(1958), Heins and Canter(1968), Easely and Drannon (1969), Hamp,Nyman and Lindhe(1975) and Tarnow and Fletcher(1984).

GLICKMAN’S CLASSIFICATION

One of the most widely used system.

Grade I : it is the incipient or early stage of furcation involvement.

The pocket is suprabony and primarily affects the soft tissues.

Early bone loss may have occurred with an increase in probing depth but no radiographic changes are found.

Grade II It can affect one or more of the

furcations of the same tooth. The furcation lesion is

essentially a cul-de-sac with a definite horizontal component.

If multiple defects are present, they do not communicate with each other because a portion of the alveolar bone remains attached to the tooth.

Vertical bone loss may be present.

The radiograph may or may not depict the grade II furcation involvement.

Grade III In grade III furcations, the

inter-radicular bone is completely lost but the facial or lingual surfaces are occluded by gingival tissues.

Therefore, the furcation involvement can not be seen clinically.

If the radiographs are taken with proper angulation and the roots are divergent, the lesion will appear as a radiolucent area between the roots.

Grade IV In grade IV furcation the

interdental bone is destroyed, and the soft tissues have receded apically so that the furcation opening is clinically visible.

A tunnel therefore exists between the roots of such an affected tooth.

Thus the periodontal probe passes readily from one aspect of tooth to the other.

Easely and Drennan’s classification This provides information relative to vertical

component of furcation involvement.

Class I: incipient involvement in which the fluting coronal to the furcation involvement is affected but there is no definite horizontal component to the furca.

Class II: Type 1- a definite horizontal loss of attachment into the furcation, but the pattern of bone loss is essentially horizontal.

There is no definite buccal or lingual ledge of the bone. Type2- there is a buccal or lingual bony ledge and a

definite vertical component to attachment loss.

Class III: A through and through loss of

attachment in the furcation . As with class II furcation defects ,

the pattern of attachment loss may be:

1. horizontal 2. vertical

Hamp, Lindhe and Nyman classification

Based on the probing depth.

Class I - Furcation defect is less than 3 mm is depth. Class II - Furcation defect is at least 3 mm in depth

(and thus, in general, surpassing half of the buccolingual thickness of the tooth) but not through-and-through (i.e. there is still some interradicular bone attached to the angle of the furcation. The furcation defect is thus a cul-de-sac.

Class III - Furcation defect encompassing the entire width of the tooth so that no bone is attached to the angle of the furcation

CLINICAL FEATURES CLINICALLY The mandibular first molars -most common

sites Maxillary premolars -least common. The denuded furcation may be visible

clinically or covered by the wall of the pocket.

Associated with suprabony and infrabony pockets.

Periodontal abscess. Root caries and tooth mobility.

MICROSCOPICALLY In its early stages, there is a widening of

periodontal space with cellular and inflammatory fluid exudation, followed by epithelial proliferation into the furcation area from the adjoining pocket.

Extension of inflammation into the bone leads to the resorption and reduction in bone height.

The bone destructive pattern may produce horizontal loss, or there may be angular osseous defects associated with infrabony pockets.

DIAGNOSIS

Earlier the recognition – simpler the treatment

Thorough clinical examination

Careful probing – To determine the

presence and extent of furcation involvement ,

The position of attachment relative to the furca,

The extent and configuration of the furcation defect.

Factors contributing to the development of furcation defect and affecting the treatment outcome include:

i. The morphology of the affected toothii. The position of the tooth relative to the

adjacent teeth.iii. The local anatomy of the alveolar bone.iv. The configuration of any bony defects.v. The presence and extent of other dental

diseases.

TREATMENT

The objectives of furcation therapy are:

To facilitate maintenance. To prevent further attachment loss. To obliterate the furcation defects

as a periodontal maintenance problem.

Therapeutic classes of furcation defects

Class I: early defects- These defects are amenable to conservative

periodontal therapy. Oral hygiene, scaling and root planing are

effective. Any thick overhanging margins of restorations,

facial grooves, or CEP’s should be eliminated by odontoplasty, recountouring and replacement.

The resolution of inflammation and subsequent repair of the periodontal ligament and bone are usually sufficient to restore periodontal health.

CLASS II: Once a horizontal component to the

furcation has developed , therapy becomes more complicated.

Shallow horizontal involvement without significant vertical bone loss usually responds favorably to localized flap procedures with odontoplasty and osteoplasty.

Isolated deep class II furcations may respond to flap procedures with osteoplasty and odntoplasty and regeneration procedures.

This reduces the dome of the furcation and alters gingival contours to facilitate patient’s plaque removal.

Classes II to IV : Advanced defects. Non surgical treatment is usually

ineffective because the ability to instrument the tooth surfaces adequately is compromised.

Periodontal surgery, endodontic therapy and restoration of the tooth may be required to retain the tooth.

SURGICAL DEBRIDEMENT OF FURCATIONS

The most elementary surgical method -periodontal flap procedure.

Provides access and visibility to the furcation. This facilitates the thorough removal of

plaque, calculus and any other bacterial contaminants from the root surface of the furcation.

If the bony resorption is of a horizontal nature without a significant intrabony component, thorough debridement will result in resolution of the inflammation and potentially to a diminishment of pocket depth.

ODONTOPLASTY AND OSTEOPLASTY Provides a means of further altering the

physical dimension of the furcation defect in advanced situations.

Odontoplasty provides a means of reducing the intermediate bifurcation ridge and the extent of dome over the furcation,thereby reducing the volume of furcation defect.

Osteoplasty does the same for any bony deformity.

This results in a shallow furcation area, which facilitates the patient’s ability to remove the plaque during oral hygiene.

The efficacy of the debridement procedures is generally limited to the buccal and lingual furcations of the mandibular molars; the buccal furcations of maxillary molars with early to moderate degrees of involvement; and those furcations where aberrations in root/furcation morphology and significant osseous defects are absent.

ROOT RESECTION Definition: process by which one or more

roots of a tooth are removed at the level of furcation while leaving the crown and remaining roots in function.

Objective -obliteration of the furcation as a problem in periodontal maintenance.

Indications Severe vertical bone loss on one root of a

multirooted tooth not amenable to regeneration/reattachment.

Furcation invasion not correctable by odontoplasty. Proximal furcation invasion on combination with

root approximation. Furcation invasion that is not maintainable. Periodontally involved abutment teeth with a

hopeless prognosis associated with one root. Vertical or horizontal root fracture. Uncorrectable root dehiscence. When endodontic therapy is impossible on one root

of a multirooted tooth.

Contraindications Advanced bone loss with an unfavorable crown to root

ratio. Fused roots that can not be separated. If an endodontically inoperable canal would be retained. If the remaining root(s) would be inadequate to serve as

a prosthetic abutment. If indicated splinting can not be performed. When periodontal support after resection is inadequate

to withstand normal occlusal forces. Inability to create a good post surgical gingival

enviornment. If socioeconomic conditions preclude necessary

treatment procedures. In the presence of inadequate oral hygiene.

Which root to remove and why?

Remove the root(s) that will eliminate the furcation and allow the production of a maintainable architecture on the remaining roots.

Remove the root with greatest amount of bone and attachment loss.

Remove the root that best contributes to the elimination of the periodontal problems on adjacent teeth.

Remove the root with the greatest number of anatomic problems such as severe curvature, developmental grooves, root flutings, or accessory and multiple root canals.

Remove the root that least complicates future periodontal maintenance.

HEMISECTION Definition: splitting of a two rooted tooth

into two separate portions. Also called bicuspidization or separation as

it changes the molar into two separate roots.

It is most likely to be performed on mandibular molars with buccal and lingual class II or III furcation involvements.

Molars with advanced bone loss in the interproximal and interradicular zones are not good candidates for hemisection.

The retention of both molar roots can complicate the restoration of the tooth, since it may be virtually impossible to finish margins or to provide an adequate embrasure between the two roots for effective oral hygiene and maintenance.

Therefore orthodontic separation of the roots is commonly required to allow restoration with adequate embrasure form.

The root resection/ hemisection procedure

The most commonly root resection is the distobuccal root of maxillary first molar.

After appropriate local anesthesia , a full-thickness mucoperiosteal flap is elevated.

The flap should provide adequate access for visualisation and instrumentation and to minimise trauma during operation.

After debridement the resection of the root begins with the exposure of the furcation on the root to be removed.

The removal of a small amount of facial or palatal bone may be required to provide access for elevation and facilitate root removal

A cut is then directed from just apical to the contact point of the tooth, through the tooth, to the facial and distal orifices of the furcation.

This cut is made with a high speed surgical length fissure or cross-cut fissure carbide bur.

For hemisection a vertically oriented cut is made faciolingually through the buccal and lingual developmental grooves of the tooth, through the pulp chamber and through the furcation.

If a vital root resection is to be performed, a more horizontal cut through the root is made.

An oblique cut exposes a large surface area of radicular pulp/ dental pulp chamber which can lead to post-operative pain and can complicate the performance of endodontics.

After sectioning , the root is elevated from its socket.

Care should be taken not to traumatise bone on remaining roots or to damage adjacent tooth.

Removal of root provides visibility to the furcation aspects of remaining roots and simplifies the debridement of furcation.

If necessary, odontoplasty can also be performed.

Patients with advanced periodontitis commonly have root resection performed in conjunction with other surgical procedures.

The bony lesions that may be present on adjacent teeth are then treated using resective or regenerative therapies.

After resection the flaps are approximated to cover any grafted tissues or to slightly cover the bony margins around the tooth.

Sutures are then placed to maintain the position of the flaps.

The area may or may not be covered with surgical dressing.

The removal of a root alters the distribution of occlusal forces on the remaining roots, so the occlusion of the teeth should be evaluated and if necessary adjust the occlusion.

TUNNELING

Definition: process of deliberately removing bone from the furcation to produce an open tunnel through the furcation.

It is an alternative to root resection and hemisection, used to treat class II and III furcation involvement in two rooted teeth such as mandibular molars.

The rationale for this is to provide ready access for a variety of home care instruments to be passed through furca to remove dental plaque.

There are a number of potential problems associated:

Only a few molars have roots sufficiently long or widely divergent to allow tunneling and the establishment of local anatomy that is readily maintained.

Soft tissues tend to rebound and obstruct the furcation.

Many patients are unwilling or unable to perform the home care procedures necessary to keep furcation free of plaque.

Regeneration A variety of materials and techniques have been

proposed. Among these are bone autografts, xenografts and allografts, and alloplastic materials designed as either bone substitutes or biologic barriers.

These materials have been applied to the treatment of molar furcations and other periodontal defects.

In 1969, Robinson described the use of osseous coagulum which is a mixture of autogenous bone, connective tissue and blood elements.

In this procedure after thorough debridement of the affected area, the patient’s own bone collected during osteoplasty and ostectomy is placed into the bony defect and covered by a surgically reflected flap.

Guided tissue regeneration procedures

Since 1988, the resorbable and non resorbable barrier membranes have been used to treat molar furcation defects.

These membranes are used to isolate the furcation and exclude soft tissue elements so that healing will be accomplished by elements from the periodontal ligament and adjacent alveolar bone.

Earlier, e-PTFEE(Teflon) membrane was used. subsequent to advent of e-PTFEE membranes, a variety

of resorbable membranes collagen, dermis or synthetic polymers were developed for GTR or GBR purposes.

The GTR procedure is technique sensitive and requires more than average clinical skills.

It is most successful in the intrabony portion of the defect and is best applied to class II furcations.

It is least successful in class III or Glickman grade IV furcation deformities.

Therefore , these procedures are indicated for teeth when other treatment approaches are not likely to be successful.

EXTRACTION• The extraction of teeth with through and

through furcation defects(class III and IV) and advanced attachment loss may be the most appropriate therapy for some patients.

• This is particularly true for individuals who: Can not or will not perform adequate plaque

control Have a high level of caries activity. Will not commit to a suitable maintenance

program. Have socioeconomic factors that may preclude

more complex therapies.

PROGNOSIS OF ROOT RESECTION/ HEMISECTION

The success rate is quite high when resections are preceded by careful diagnosis and the procedures are appropriately performed.

The primary cause of failure are root fracture, caries, endodontic complications, cement washouts, restorative failures, and periodontal attachment loss.