Asymmetric eruption and delayed development of permanent mandibular canine on an 11-year-old patient

The patient was assessed on an undergraduate paediatric clinic at Peninsula Dental school, where the permanent right mandibular canine was noted to be unerupted despite the contralateral being erupted. Further clinical examination showed that the maxillary permanent canines were still unerupted, but within normal eruption range, while the maxillary right permanent lateral incisor was microdont. Radiographic examination, with an orthopantomogram (OPG), revealed a full permanent dentition, including the developing maxillary third molars while the mandibular third molar crypts were present. Maxillary canines appeared to be well positioned permanent left mandibular lateral incisor, and the permanent left mandibular canine were fully erupted, whereas the permanent right mandibular lateral incisor and permanent right mandibular canine were unerupted and with delayed root formation. The primary right mandibular lateral incisor, which was mobile, and the primary right mandibular canine were still present. When comparing this radiograph to the previous one which was taken in 2023, it was noted that although the permanent right mandibular lateral incisor and the permanent right mandibular canine showed evidence of further development, this was still limited, especially for the canine, and not in line with expectations according to the patient’s age and their general dental development. The case was discussed on clinic from an orthodontic and paediatric dental point of view and advice was sought from senior members of the team, as appropriate. It was subsequently agreed to monitor the root development of the mandibular right permanent canine and that of the mandibular permanent lateral incisor with cone beam computerised tomography (CBCT) (1) in six months or an OPG (2) in a year’s time, while we also monitor the eruption of the permanent right mandibular lateral incisor with no intervention at present being necessary, as the primary right mandibular lateral incisor is mobile and possibly close to exfoliation.

References: 1. Hodges R J, Atchison K A, White S C. Impact of cone-beam computed tomography on orthodontic diagnosis and treatment planning. Am J Orthod Dentofacial Orthop. 2013; 143(5):665-74. 2. College of General Dentistry. Selection criteria for dental radiography. 2004. Available at https://cgdent.uk/wp-content/uploads/securepdfs/FGDP-SCDR-ALL-Web.pdf (Accessed 06/12/2025).