Submerged deciduous teeth

Definition The affected teeth do not come to the level of adjacent normal occluding teeth or submerged teeth are always 0.5mm or more below the intact marginal ridges of the adjacent teeth Occurs after eruption/emergence of teeth in the oral cavity due to a “failure in eruption”

Causative Factors Exact etiology : controversial might be caused ankylosis, impaction, absence of a permanent successor, gaps in the periodontal membrane, trauma, infection, failure bone growth, abnormal tongue pressure Trauma Damage dental follicle / developing PDL Disrupt the eruption of the tooth & become ankylosed Most commonly affected – mandibular E, then D

Prevalence 1.3% - 38.5% based on pt age frequently in middle mix dentition; 8-9 yr old 10 times more in primary than permanent mostly mandibular 2nd primary molar followed by mandibular 1st primary molar

Complications Malocclusion Retention and delayed resorption of deciduous roots thus preventing eruption of permenant teeth If the permanent successor is absent, loss of dental arch space is likely a midline discrepancy may occur because the mesiodistal width of the primary submerged tooth is greater than that of the contralateral premolar overeruption of the opposing teeth and tilting of the adjacent teeth can occur Insufficient development of width and height of supporting bone Increased risk of caries

Diagnosis Clinical examination reveals that the primary tooth is below the level of the occlusal plane Tapping the tooth reveals an abnormal percussive “cracked teacup” sound if there is ankylosis, the tooth is immobile Rx - show lack of a well-defined PDL and lamina dura space and fusion of the root with bone Depression in the marginal bone surrounding the submerged teeth, and often the permanent successor is lacking

Management Depends on whether the tooth are If tooth is not ankylosed Ankylosed (mostly) or not permanent successor is present or absent If tooth is not ankylosed waiting for normal exfoliation has been suggested 6 to 12 months relative to the unaffected contralateral tooth If the premolar is present, spontaneous eruption is possible

Extraction is recommended if there is a progressive To prevent tipping of the adjacent tooth & overeruption of the opposing tooth restoration of the occlusal surface is recommended eg. stainless steel crown or composite resin buildup Extraction is recommended if there is a progressive deep infraocclusion below the gingival margin, severe tipping ectopic eruption of the permanent successor formation of caries and abscess

If the permanent successor is absent, the decision to extract depends on : Condition of the tooth Amount of root support Degree of occlusion and Patient’s preference If a malocclusion exists, referred to an orthodontist for evaluation, as extraction of the nonankylosed submerged tooth may influence future orthodontic treatment