Mandibular swellings associated with impacted and submerged teeth might be the tip of the iceberg and mimic those caused by odontogenic infection, especially in early childhood.

A 6-year-old girl presented with right persistent mandibular swelling. She was treated by an oral surgeon for seven months with multiple courses of oral antibiotics and, subsequently, surgical extraction under general anaesthesia of her submerged right mandibular second deciduous molar as the offending cause.

On physical examination she had multiple smooth-edged café au lait macules, axillary freckling and bilateral multiple iris Lisch nodules. Extraoral examination revealed mild facial asymmetry and painless, firm, hard right mandibular swelling (fig 1). There was no associated lymph node involvement. Intraoral examination showed buccolingual alveolar enlargement distal to her right mandibular deciduous canine with apparently normal mucosal colour and consistency. Panoramic radiographs demonstrated right mandibular body altered bone trabecular pattern with increased radiopacity, widened inferior alveolar canal, enlarged and inferiorly displaced mandibular foramen (fig 2). Histopathological examination of the affected area confirmed the presence of intraosseous neurofibromatosis without mucosal involvement. Examination of her family members showed her father and other siblings were affected with signs and symptoms of neurofibromatosis type 1 (NF1).

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Figure 1

Intraoral view of the right posterior mandibular area with buccolingual alveolar enlargement and apparently normal overlying mucosa.

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Figure 2

(A) Panoramic radiograph 8 months earlier with submerged right mandibular second deciduous molar (white arrow) and characteristic radiographic features showing increased bone density, widened inferior alveolar nerve canal and enlarged inferiorly displaced mandibular foramen. (B) Panoramic radiograph at presentation with her extracted deciduous molar.

For our patient, dento-oral treatment is now limited to rehabilitate her functional dental occlusion in the affected side by orthodontic space maintainer and definitive treatment might need a combined surgical, orthodontic and prosthodontic treatment, which should be delayed until the pubertal growth spurt has ended.

NF1 is an autosomal dominantly inherited neurocutaneous disorder with a minimum prevalence of 1/4000–5000.1 Intraosseous neurofibromas are rarely associated with NF1 and are more commonly solitary lesions.2 These lesions might be misdiagnosed as odontogenic abscess.3 Due to increased bone density in mandibular osseous NF1, these lesions will often be associated with impacted or non-erupted teeth.2 In our patient, the mandibular alveolar swelling together with the radiographic altered bone trabecular pattern and the associated impacted primary molar gave the false impression that the swelling was due to odontogenic abscess caused by the primary molar that led to its impaction. The characteristic bony radiographic features combined with histopathological findings should differentiate mandibular intraosseous neurofibromatosis from mandibular swellings caused by odontogenic abscesses.