Background and objectives: Stage IV grade C localized periodontitis (pre-puberal localized aggressive periodontitis/LPP) is a rare form of inflammatory periodontal disease occurring in clinically healthy individuals (no/small calculus/dental plaque traces), due a hyper-aggressive auto-immune response to high amounts of bacteria present in the oral cavity.
Case presentation: This case report describes a 4-year-old Caucasian girl with localized gingival inflammation and advanced bone loss around the temporary lower left canine. The first diagnostic assumption was hypophosphatasia, and the patient was sent for further genetic and metabolic investigations (which turned out to be negative). The LPP diagnosis was made during the family's summer holidays due to her parents' concerns about persistent gingival inflammation and tooth mobility.
Results: The diagnosis of LPP was supported by clinical oral examination results, earlier X-rays, earlier blood tests, and a periodontal bacterial test. The treatment was limited to avoid spreading inflammation to other teeth (via topical antibiotic treatment) due to our limited time frame, while the main problem of excessive amounts of periodontal bacteria in the oral cavity was not addressed. The tooth was eventually lost.
Conclusions: The ability to early recognize radiological and clinical LPP signs correlated with understanding of its pathological auto-immune mechanism is extremely important for expanding treatment options, since bone preservation and reducing amounts of bacteria are strictly correlated with therapeutic speed.
Keywords: bone loss; diagnosis; hypophosphatasia; juvenile aggressive periodontitis; periodontal pocket; temporary dentition.