[Implant restoration for patients with congenital missing teeth].

OBJECTIVE: To evaluate the treatment plan, clinical outcome and related problems in patients with congenital missing teeth. METHODS: From November 2000 to February 2009, thirty seven patients with congenital missing teeth underwent thorough diagnostic workup, treatment planning and an interdisciplinary approach to ensure optimal treatment in Department of Implant Dentistry, Peking University, School and Hospital of Stomatology. A standard follow-up protocol was conducted for all the patients. RESULTS: The enrolled cases in this study were classified in to 3 types: single tooth missing, multiple teeth missing and edentulous. Among them single tooth missing was found in 21 cases, multiple teeth missing was found in 12 cases and 4 cases were edentulous. 120 implants were placed and restored in 37 patients with the mean follow-up 39.3 months (10-109 months) after prosthetic functioning. Two implants lost after function about 6 months and the remaining implants functioned well until the last review. No adverse complications such as pain and nerve trauma was observed and the mean bone resorption was 1.91 mm. CONCLUSION: An interdisciplinary approach ensures optimal treatment for patients with congenital missing teeth. Implant restorations provide an alternative way with predictable clinical results.

Oral manifestations of lamellar ichthyosis in association with rickets.

Lamellar ichthyosis (LI) is a rare genetic condition that affects the skin, with an incidence of less than 1:300 000 in different parts of the world. This report describes a case of a 5-year-old girl with LI and rickets presenting with premature loss of 51, 52, 61, 62 and 71, grade II mobility in 72, 73, 81, 82 and 83 along with loss of supporting bone with 53, 63, 72, 73, 82 and 83. This is the first report describing oral manifestations of this combination of LI and rickets.

[Novel mutations of PAX9 gene in Chinese patients with oligodontia].

OBJECTIVE: To investigate the mutational characteristics of PAX9 gene in Chinese patients with congenital oligodontia and thus to provide a molecular basis for studying the pathogenesis of oligodontia. METHODS: Thirteen individuals with oligodontia and 9 healthy individuals, from 4 unrelated autosomal dominant families, and 16 sporadic patients with hypodontia in China, as well as 196 healthy control individuals (without oligodontia or hypodontia) were screened. Congenital absence of teeth was confirmed by panoramic X-ray analysis. Mutations of PAX9 gene were detected using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. After the finding of abnormal SSCP bands, analysis was carried out with DNA sequencing. RESULTS: PCR-SSCP detected SSCP bands alteration in exon2 of PAX9 gene in two unrelated families. Sequencing of PAX9 gene revealed a novel frameshift mutation (109InsG) and a novel missense mutation (C139T). All the affected members of each family were heterozygous for the mutations. In sporadic patients and the other two families, no similar sequence changes in PAX9 gene were found. CONCLUSIONS: The results extend the spectrum of mutations in PAX9 gene associated with oligodontia. The novel mutations will play an important role in gene diagnosis of oligodontia.