PATHOLOGIC TOOTH MIGRATION

DR. SRUTHI K NAIR PG STUDENT

CONTENTS

DEFINITION PREVALENCE FACTORS INFLUENCING TOOTH POSITION TREATMENT PREVENTION CONCLUSION REFERENCES

DEFINITION

Pathologic tooth migration (PTM) refers to tooth displacement that results when the balance among the factors that maintain physiologic tooth position is disturbed by periodontal disease.

most frequently occurs in the anterior region, but posterior teeth may also be affected

in the occlusal or incisal direction is termed extrusion.

PREVALENCE

Prevalence studies of PTM indicate that it is common in periodontal patients.

Martinez-canut et al. 1997 Examined 852 patients who reported with developing diastema A PTM prevalence of 55.8% was found. Towfighi et al. 1997 343 patients with moderate to severe periodontitis were studied

before treatment. A diagnosis of PTM was made by asking the patients if they were

aware of anterior tooth migration in the last 5 years PTM prevalence was 30.03%

Demetriou et al. 1991 gave questionnaires to 330 periodontal patients asking them

about symptoms that motivated them to seek treatment. Tooth migration was listed by 36.96% of the patients.

DRIFTING

Drifting of teeth into the spaces created by unreplaced missing teeth often occurs.

Drifting differs from pathologic migration in that it does not result from destruction of the periodontal tissues.

However, it usually creates conditions that lead to periodontal disease, and thus the initial tooth movement is aggravated by loss of periodontal support.

Drifting generally occurs in a mesial direction, combined with tilting or extrusion beyond the occlusal plane. The premolars frequently drift distally.

Although drifting is a common sequela when missing teeth are not replaced, it does not always occur

Two major factors play a role in maintaining the normal position of the teeth: the health and normal height of the periodontium the forces exerted on the teeth.

FACTORS INFLUENCING TOOTH POSITION

1. DESTRUCTION OF PERIODONTAL SUPPORTING TISSUES

destruction of periodontal tissues plays a significant role in the etiology of PTM.

Selwyn 1973 studied bone loss in 30 patients with periodontal disease

complicated by migrated incisors 30 control patients with periodontal disease whose incisors had not migrated. Statistically, more bone loss was found in the migrated group compared to the non-migrated group

Martinez-Canut et al. studied 852 private practice periodontal patients and found

that PTM was statistically associated with bone loss ,tooth loss and gingival inflammation.

As bone loss increased, the probability of PTM increased from 2.95 to 7.97 times. The authors concluded that no single factor is clearly associated with PTM, but the primary factor is periodontal bone loss.

Towfighi etal. measured attachment loss on 75 pairs of migrated and non-

migrated contralateral teeth in 44 periodontal patients. The mean attachment loss of migrated teeth (4.79 ± 0.28 mm)

was significantly greater (P <0.001) than control non-migrated teeth (3.21 ± 0.18 mm).

The results confirm that periodontal disease destruction of the attachment tissue plays a major role in the etiology of PTM.

Primate studies indicate that a specific part of the periodontium, the transseptal fibers, may play an especially important role in PTM.

They form a chain from tooth to tooth and are thought to help maintain contacts between teeth throughout the arch.

It has been suggested that if the continuity of this chain is broken or weakened by periodontal disease, the balance of forces is upset and displacement of the teeth can occur. (Moss J etal 1982)

FIG 3

Gingival overgrowth caused by severe inflammation or drugs such as phenytoin.

Fu etal. 1997 showed that gingival overgrowth in rats, induced by gastric

feeding of cyclosporin, consistently caused tooth migration.

2. OCCLUSAL FACTORS Posterior bite collapse (PBC) Most common cause of PTM. Unfavourable occlusal changes that occur most frequently

after first molar teeth are lost and not replaced. Results in flaring of anterior teeth.

FAILURE TO REPLACE FIRST MOLAR

The second and third molars tilt, resulting in a decrease in vertical dimension.

The premolars move distally, and the mandibular incisors tilt or drift lingually. While drifting distally, the mandibular premolars lose their intercuspating relationship with the maxillary teeth and may tilt distally.

Anterior overbite is increased. The mandibular incisors strike the maxillary incisors near the gingiva or traumatize the gingiva.

The maxillary incisors are pushed labially and laterally. The anterior teeth extrude because the incisal apposition has

largely disappeared. Diastema are created by the separation of the anterior teeth.

Arch integrity Loss of arch integrity Etiologic factor for PTM. Occlusal forces are distributed to teeth in the arch through

interproximal contacts. If these contacts are destroyed, tooth migration can occur. (Stern etal 1975)

Besides tooth loss other factors that can destroy interproximal contacts include dental caries, faulty restorations, and severe attrition.

Occlusal interferences. Disruptions, such as supraerupted teeth, have been described

as one of the etiologic factors for PTM.Thielman 1971 reported consistent findings of elongation of anterior teeth

diagonally opposite in the dental arch to occlusal interferences. He observed this clinical situation so often that he called this combination of signs Thielman’s Law.

Watkinson and Hathorn 1986 interferences that deflect the mandible anteriorly into the

maxillary incisors as important etiologic factors in PTM. Their observations revealed that these interferences may arise from restorative procedures, but also may be present in the unrestored natural dentition.

Protrusive pattern of masticationYaffe etal.1992 studied a group of 27 patients with a protrusive pattern of

function. These patients had anterior attrition and 16 had flaring of the incisors. The investigators suggest that this protrusive pattern of mastication should be considered an etiologic factor for anterior PTM.

Bruxism Bruxism forces are known to damage the dental attachment

apparatus. Also, it is known that bruxism can result in abnormal occlusal forces that are frequent and of long duration.

bruxism in some patients can act as an unfavorable orthodontic force to cause PTM. Bruxism as an etiologic factor for PTM does not seem to be evidence based, however. Parafunctional occlusal habits have been listed as a contributing factor for PTM. (shifman etal. 1998)

Parafunctional habits have been reported as a prognostic factor associated with tooth loss and so, in this way, may indirectly be a factor in PTM.

Soft Tissue Pressure of the Tongue, Cheek, and Lips Orthodontic research has confirmed that soft tissue

forces of the tongue, cheek, and lips can move teeth, especially after loss of periodontal support.(Proffit 1978)

Forces as light as 1.0 gram, produced by the facial muscles when at rest, are sufficient to initiate displacement of incisors.

Tongue and lip pressures vary greatly, but tongue pressures are usually several times greater than lip or cheek pressures.

forces of the tongue, cheek, and lips, together with the forces of the periodontal tissues, are the most important factors that determine tooth position.

Periodontal and Periapical Inflammation As early as 1933, Hirschfeld described pathologic drifting of

teeth resulting from pressure of inflammatory tissue in periodontal pockets.

Subsequent case reports and case series mentioned this phenomenon and often described the tooth

movement in a direction opposite to the deepest part of the pockets.

Sutton 1985 proposed a theory that hydrodynamic and hydrostatic forces

within the blood vessels and inflamed tissues in the periodontal pocket may account for abnormal tooth migration.

animal research showing that inflamed gingiva displays an increase in interstitial fluid pressure, due to an increase in capillary filtration.(Del fabbro etal 2001)

The extravasation of fluid into the interstitial tissue causes a rise in interstitial hydraulic pressure. Vascular permeability and blood flow of the gingiva are known to increase during gingival inflammation.

Extrusive Forces It is known that eruption forces are small, in the range of 2 to

10 grams and are present throughout life. As an erupting tooth emerges from the gingiva and moves

toward occlusal contact, movement is rapid (in the order of 0.3 to 0.5 mm per week).

In adulthood, the velocity of eruption is much slower.

From an animal study it appears that the major eruptive force is localized within the periodontal membrane. Eruption forces are thought to be generated either from contraction of collagen as it matures or traction from contractile fibroblasts.

since extrusion of incisors is a very common form of PTM, eruptive forces may play a very important role as a contributing factor in PTM.

Habits Oral habits of patients may affect tooth position and have

been associated with pathologic tooth migration. Habits that have been associated with PTM include lip and

tongue habits, finger nail biting, thumb sucking, pipe smoking, and playing wind instruments.

In considering oral habits as a contributing etiologic factor in PTM, it is important to remember that duration of force in tooth movement is more important than force magnitude. The greater the duration of the habit, the greater potential to move teeth.

TREATMENT

Treatment of severe PTM often involves orthodontic therapy that is preceded by non-surgical and surgical periodontal therapy and prosthodontic treatment. (Duncan 1997)

When PTM is in initial stages and localized, the treatment may be greatly simplified for the patient.

Correction of pathologic tooth migration

Extraction and replacement of migrated teeth

when migration is very severe

Spontaneous correction of

the early stages of

PTM following

periodontal therapy

Limited or adjunctive orthodontic

therapy

Conventional orthodontic

treatment.

Many case reports describing reactive positioning or spontaneous correction of pathologic migration following periodontal treatment.

These reports indicate migrated teeth sometimes move back to their normal position following non-surgical perioontal treatment alone or in some instances when combined with surgical methods.

Gaumet et al. studied 16 patients with 33 diastema sites of anterior teeth that

had developed in the last 5 years. Study concluded that if a recently formed diastema of anterior teeth associated with periodontal disease is ≤1 mm in dimension, closure is predictable after periodontal therapy.

Spontaneous correction of PTM include patients with severe gingival overgrowth.

When enlarged tissue is removed surgically in some cases migrated tooth move back into a more normal position.

When PTM is in the early stages, periodontal therapy alone is sometimes effective in producing spontaneous correction of the migration. This correction has been reported after non-surgical and surgical treatment.

Light intrusive orthodontic forces are effective in treating extrusion and flaring if inflammation is controlled during all phases of treatment.

Most patients with PTM have moderate to severe periodontitis. Several studies describe successful orthodontic treatment in these patients if inflammation is controlled.

PREVENTING PTM

Control of periodontal disease- most effective method to prevent

Treatment of occlusal factors and habits. Early detection

CONCLUSION

Severe PTM has significant psychological effects and treatment is expensive and time consuming, the importance of prevention appears great.

Based on prevalence findings, PTM needs more attention in dental research, especially regarding etiology, prevention, and treatment.

REFERENCES

Carranza’s Clinical Periodontology, 10th Edition.

Clinical Periodontology and Implant Dentistry, Lindhe, 4th Edition.

Pathologic Tooth Migration .Michael A. Brunsvold. J periodontol 2005

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