Simple approach for correcting an entrapped ectopic permanent mandibular first molar caused by poor marginal adaptation of a preformed metal crown on an adjacent primary second molar: a case report with a 5-year follow-up.

Ectopic eruption of the permanent first molar can lead to malocclusion if left untreated. Despite several reported etiologic factors and treatment options, ectopic eruption caused by an improper restoration on an adjacent tooth and a simple solution have never been documented. Case report: An 8-year-old boy presented with an entrapped ectopic permanent mandibular first molar under the poorly adapted margin of a preformed metal crown (PMC) on the adjacent primary second molar. Replacement with a PMC that had well-contoured margins followed by inserting a separating module between the proximal contact of the two teeth resulted in successful management of this situation in 1 month. Conclusion: This simple approach with good interdisciplinary communication is practical for correcting eruption problems due to a poorly adapted PMC, with long-term satisfactory results. To avoid subsequent malocclusion and unnecessary treatments, dental practitioners must be vigilant when manipulating PMCs and assessing the marginal adaptation prior to their cementation.