Background: Dental abnormalities of tooth number in development of the permanent dentition are quite common; however combined occurrence of hypodontia and hyperdontia is a rare phenomenon, especially when it occurs in the same dental arch and in a non-syndromic situation.
Case report: A 15½-year-old non-syndromic male with missing mandibular central incisors and an erupted mandibular mesiodens presented for dental treatment. Intra-oral examination showed reddish, soft, oedematous marginal gingivitis of the molars with absence of stippling. Hard tissue examination revealed the absence of mandibular central incisors bilaterally and presence of a microdont conical shaped supernumerary tooth in the midline. The morphology of clinical crowns of the mandibular incisors and absence of spacing between incisors and canines determined a diagnosis of congenitally missing central incisors.
Treatment: To ensure optimum function and aesthetics, the patient was advised to have aesthetic rehabilitation for mandibular anterior teeth, but he refused the treatment. Complete scaling and restorations for 16 and 26 were performed.
Follow-up: The patient was followed every 6 months for two years to assess his oral health status. Oral health remains good but aesthetic restorations have continued to be refused.
Conclusion: This is only the fifth case reported in the dental literature, where the two anomalies manifest in the anterior region of the mandible.