The outcomes of auto-transplanted premolars in the anterior maxilla following traumatic dental injuries.

BACKGROUND/AIMS: Tooth auto-transplantation is a treatment option, which is often not considered to replace anterior maxillary incisors in children and adolescents. There are multiple prognostic factors that may influence the outcomes of premolar auto-transplantation, but there is limited evidence from human studies. The aim of this study was to report the outcomes of auto-transplanted premolars in the anterior maxilla following traumatic dental injuries (TDIs) and to identify their prognostic factors. MATERIALS AND METHODS: The clinical records of patients who had premolars transplanted in the anterior maxilla following TDI, with appropriate radiographs and a minimal of 1-year follow-up, were reviewed retrospectively. A specific data extraction form was developed, tested and used to collect information for the prognostic factors and outcomes. RESULTS: The cohort included 120 patients with 144 auto-transplanted premolars. The mean age was 12.2 years (±2.0), and the mean observation period was 3.7 years (±1.8). The success rate was 80%, and the survival rate was 93%. Unfavourable outcomes included external replacement resorption in 12.5%, uncontrolled external inflammatory resorption in 2.7%, and both resorption types in 4.9% of teeth. Periodontal healing was significantly associated with donor tooth root maturity, graft handling at the time of surgery including ease of donor tooth extraction and placement at the recipient sites, recipient site alveolar bone status, and post-operative transplant mobility. Seventy-four teeth (53.4%) were immature at the time of transplantation where pulp revascularisation was anticipated, and 52 (70%) of those had radiographic and clinical signs of pulp healing. Pulp healing was significantly related to donor tooth eruption stage, ease of extraction of donor tooth, and ease of placement in the recipient site. CONCLUSIONS: Good outcomes were observed for premolar teeth auto-transplanted in the anterior maxilla. The main prognostic factors were ease of extraction of donor tooth and ease of placement in the recipient sites and donor tooth root maturity.

Immunocytochemical characterization of primary teeth pulp stem cells from three stages of resorption in serum-free medium.

BACKGROUND/AIMS: Dental pulp stem cells from primary teeth cultured in serum-free conditions may have clinical use for the repair and regeneration of teeth as well as other complex tissues and organs. The aim of this study was to test the change in the stem cell markers expression/ stem cell population in human primary pulp cells at the different stages of root resorption. METHODS: Caries-free human primary canines at defined stages of physiological root resorption were included (n = 9). In vitro cultures were established in xeno-free, serum-free Essential 8™ medium with human truncated vitronectin for cell attachment. An embryonic stem cell line (GENEA002) was used as a positive control. The expression of embryonic stem cell markers (Oct4, Nanog and Sox2), neural crest stem cell markers (nestin and Dlx2) and mesenchymal stem cell surface markers (CD90, CD73 and CD105) were investigated by immunocytochemistry. Mesenchymal stem cell markers CD105, CD73 and CD90 and haematopoietic markers: CD45, CD34, CD11b, CD19 and HLA-DR were quantified with flow cytometry. RESULTS: The early neural progenitor markers nestin and Dlx2 were detected in most serum-free cultured dental pulp stem cells, regardless of the tooth resorption stage from which they were harvested. Only isolated cells were found that expressed the embryonic stem cell transcription factors Oct4A, Nanog and Sox2, and in the late stages of resorption, no Oct4A was detected. The majority expressed the mesenchymal stem cell markers CD90, CD73 and CD105. Flow cytometry found positive signals for CD90 > 97.3%, CD73 > 99.6% and CD105 > 82.5%, with no detectable differences between resorption stages. CONCLUSIONS: This study identified populations of dental pulp cells in vitro with markers characteristically associated with embryonic stem cells, neural crest-derived cells and mesenchymal stem cells. Flow cytometry found CD105 expressed at lower levels than CD90 and CD73. The consistency of stem cell marker expression in cells cultured from teeth at different resorption stages suggests that pre-exfoliated primary teeth that are free of caries may provide a convenient source of multipotent stem cells for use in regenerative medicine.

Effects of zoledronic acid and geranylgeraniol on angiogenic gene expression in primary human osteoclasts.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious complication associated with bisphosphonate treatment. Zoledronic acid (ZA) is a commonly used bisphosphonate due to its effectiveness in increasing bone density and reducing skeletal events, with evidence that it alters angiogenesis. Replacement of the mevalonate pathway using geranylgeraniol (GGOH) was studied to determine the effects of ZA on angiogenic gene expression in primary human osteoclasts. Osteoclast cultures were generated from peripheral blood mononuclear cells of three patients using the peripheral blood mononuclear cell isolation. These cells were phenotyped by phase-contrast microscopy, tartrate-resistant acid phosphatase staining, and pit assays. Primary osteoclasts were found to express a number of key angiogenic molecules at very high levels. Gene expression levels for 84 human angiogenic factors were determined using PCR arrays. Three genes with significant fold regulation (FR) in response to ZA were as follows: tumor necrosis factor (FR = +2.57, P = 0.050), CXCL9 (FR = +39.48, P = 0.028), and CXCL10 (FR = +18.52, P = 0.0009). The co-addition of geranylgeraniol with ZA resulted in the significant down-regulation of these three genes along with CCL2, TGFBR1, ENG, and CXCL1. GGOH reversed the gene changes induced by ZA and may offer a promising treatment for BRONJ.

Amelogenesis imperfecta--multidisciplinary management from eruption to adulthood. Review and case report.

Amelogenesis imperfecta (AI) is a group of hereditary conditions that affect enamel formation. It is associated with a high morbidity for the patients and may present major restorative and sometimes orthodontic challenges for the dental team. Early recognition followed by appropriate preventive and restorative care is essential in the successful management of AI. A multidisciplinary approach with careful planning from early childhood will maximise the treatment options available for the permanent dentition and optimise the final outcome. In this case, a team consisting of two paediatric dentists, an orthodontist, a restorative dentist, and an oral and maxillofacial surgeon were involved in the management of the patient over a 12-year period. Treatment included preventive advice, interim composite restorations, two phases of orthodontic treatment, orthognathic surgery and placement of cast crowns. The patient is extremely happy with the result.

Novel dental anomalies associated with congenital contractural arachnodactyly: a case report.

Congenital contractural arachnodactyly (CCA) is an inherited disorder of connective tissue similar to Marfan's syndrome. The craniofacial and oral features of a young girl with CCA are described. The patient has the typical features of CCA as well as some additional dental anomalies which have not previously been reported with this syndrome. These include banded pitted enamel hypoplasia and hypomineralization, long, spindly tapered roots, and pulp canal obliteration with multiple pulp stones. Dentists must be aware of the clinical features of a patient's syndrome to determine whether there are implications for dental treatment such as a need for antibiotic prophylaxis. It is important to exclude Marfan's syndrome as a differential diagnosis for CCA because the former has more associated complications and a less favorable prognosis.