A treatment decision-making model for infraoccluded primary molars

S. L. EKIM & S. HATIBOVIC-KOFMAN

International Journal of Paediatric Dentistry 2001; 11: 340–346

The objective

• to clarify the literature’s findings and provide guidelines for decision-making during the long-term treatment planning of infraoccludedprimary molars.

Definition

Infraocclusion is a clinical term describing a tooth depressed below the occlusal plane.

Other terms used and create a sense of confusion :-

Submergence, secondary retention, ankylosis, impaction, reimpactionand incomplete eruption.

Aetiology

• By far, dental ankyloses is thought to be the major aetiologicalmechanism of infraocclusion.

Prevalence

• Studies report prevalence rates of infraocclusion to be from 1.3% to 8.9% of the population with a significantly higher incidence between siblings

• Primary mandibular molars are affected more than 10 times as often as primary maxillary molars.

Radiographic presentation

• Limited

• Radiographs are two-dimensional and that ankylosis can be microscopical

• Studies found :-

• Osteoid tissue deposited in the furcation area.

• teeth without successors showed ankylosis in the vicinity of the apex

Clinical presentation

• It tends to be bilateral with cases of with multiple instances of ankylosis, showing similar degrees of infraocclusion.

Classification :-

• ‘slight’ :- between the occlusal surface and the interproximal contact

• ‘moderate’ :- being within the occlusal-gingival dimensions of the interproximal contact point.

• ‘severe’ :- being anywhere below the interproximal contact point.

• A high-pitched tone on percussion - inconsistent diagnostic tool, heard

when at least 20% of the root surface is ankylosed.

• loss of mobility only occurs when more than 10% of the root surface is ankylosed

• Observing extensive root resorption on an immobile tooth is very suggestive

of ankyloses.

• Most infraoccluded primary molars with a permanent successor have been shown to exfoliate normally by the erupting successor resorbing the area of fusion .

• However, extensive bony ankylosis may prevent normal exfoliation, causing future alignment problems .

• Studies note a 6 month delay as an acceptable exfoliation schedule for ankylosed primary molars and that degree of infraocclusion is not related to amount of delay.

Other clinical signs

• Incomplete alveolar process development.

• lack of normal mesial drift.

• non-response to orthodontic forces.

• Retained primary teeth without a successor.

• a depressed tooth with tipping adjacent teeth.

• supereruption of opposing teeth.

• lateral open bite .

• higher frequency of crossbites.

The date of onset can be determined using Darlingand Levers estimation patterns :-

Treatment decision-making model of infraoccluded primary molars without successors.

potential for ridge defects

Treatment decision-making model for infroccludedprimary molars with successors :-