Etiology, Diagnosis, Consequences and Treatment of Infraoccluded Primary Molars

Infraocclusion is a condition where teeth are found with their occlusal surface below the adjacent teeth, long after they should have reached occlusion. Many terms have been used to describe this condition; the most commonly used being submergence and ankylosis. Infraocclusion is classified as slight, moderate or severe. Studies have shown the commonness ratio of infraocclusion in kids being 1.3-8.9% with an equal male: female ratio. The frequency of infraocclusion of primary molars of mandible is 10-fold higher in contrast to those of the maxilla. Some studies showed that the first mandibular primary molars are most often affected, but others support the second one. Infraoccluded primary molars appear with an increase in 3 year-old children reaching a peak in 8-9 years of age. The main cause is ankylosis, followed by heredity, trauma, infection and various other theories. However, the etiology is still uncertain. Radiographically, an obliteration of the periodontal ligament can be seen using conventional methods and the CT-method can also be used to reveal greater detail. Clinically, other than submersion, a sharp, solid sound is heard on percussion, in contrast to a softer sound in the normal teeth. Infraoccluded primary teeth can cause occlusal disturbances, tilting of the adjacent teeth, supra-eruption of the antagonists, ectopic eruption or impaction of the successor premolars. A treatment decision must take into account whether there is a permanent successor or not. In the first case, patient monitoring is recommended, because these primary teeth usually exfoliate normally. However, in the second case, the therapeutic approach is not standard. The aim of this review of literature was to elucidate the available evidence concerning infraocclusion, its etiology, diagnosis, clinical characteristics, consequences and treatment.