Incidence and clinical risk factors associated with the development of labial protuberances after orthodontic treatment

•Hard, nodular labial protuberances (LPs) because of differential alveolar bone modeling are occasionally noted after orthodontic treatment.•The incidence rate of developing notable LPs after orthodontic treatment was 3.2%.•Adult males and those undergoing orthodontic extraction have a higher risk of developing LPs.•Clinicians should be aware that distinct LPs may develop when large amounts of incisal retraction are planned in adults.