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Aim: This paper reports on the use of early introduction of a specific parental presence/absence (PPA) behavioural technique to manage the initially uncooperative child. Methods: Using a prospective design, 440 healthy children aged 3 to 10 years visited a paediatric dental practice within 33 months. Children exhibiting initially Frankl 'negative' and 'definitely negative' behaviour were empathically offered parental presence only if they were cooperative. Otherwise, the parent stepped out until behaviour improvement. Statistics: t-tests and Chi-square tests were used to compare characteristics of initially cooperative and uncooperative children, as well as proportions of parents who were asked to leave the surgery. The technique's success was assessed by a one sample binomial test. RESULTS: 75 of the children presented as Frankl either 'negative' (30) or 'definitely negative' (45) at their first visit; 70 (93.3%, p< 0.001) responded to the PPA technique by displaying positive behaviour as their first visit progressed. 38 responded without the need to ask the parent to exit the practice room, while the other 32 responded only after their parent exited. 52 children had additional appointments, and 8 required an application of PPA at a second appointment; all children cooperated in all subsequent appointments. Conclusion: Early and empathic application of the PPA technique appears very successful in managing initially uncooperative child patients, suggesting that a randomised controlled trial of the technique is warranted. [ABSTRACT FROM AUTHOR]

Background: Burkitt lymphoma (BL) is an aggressive non-Hodgkin lymphoma (NHL), subdivided into endemic, sporadic, and immunodeficiency-associated forms. While jaw lesions are common in endemic BL, they are infrequent in sporadic cases, only rarely constituting the first manifestation of the disease. The aim of this study is to present a rare pediatric case of sporadic BL first manifesting as gingival swellings and tooth hypermobility and provide a review of all the published sporadic BL case reports as the first sign of disease. Case report: An 11-year-old Caucasian female was referred for the evaluation of hypermobility of posterior lower teeth, associated with painful gingival swellings of 20 days duration. Clinical examination revealed right facial asymmetry and bilateral prominent swellings of the posterior lower gingiva. A panoramic radiograph revealed ill-defined radiolucent lesions in the posterior mandible bilaterally. On computed tomography, soft-tissue masses were identified along the mandibular ramus extending into the maxillary sinus bilaterally. The histopathologic and immunohistochemical analyses of the lesions led to a diagnosis of Burkitt lymphoma (BL). The patient underwent a full staging work-up, revealing bone marrow involvement and widespread disease. A multi-chemotherapy regimen was initiated with the regression of oral lesions and symptoms within a few weeks and complete disease remission after nine chemotherapy cycles. The patient remains free of disease 11 years later. Conclusions: This case underscores the critical importance of the timely diagnosis and life-saving referral of rapidly growing jaw lesions, which may represent the first sign of an underlying lymphoreticular malignancy with aggressive course, such as BL.

This paper presents the diagnosis and management of a rare case of bulbous exophytic malformation of three permanent mandibular incisors. An 8-year-old Caucasian girl presented with concerns on the appearance of these teeth. Medical history was noncontributory, and there was no recall of relevant past trauma. Upon clinical examination, 3 permanent mandibular incisors exhibited hard bulbous protuberances in the crown's middle and cervical areas. Radiographic examination assisted by dental computed tomography revealed that these were continuous with the tooth structure, contained no pulpal tissue, and the teeth displayed normal root development. They were excised and the teeth were restored with a thin composite facing. They remained asymptomatic with acceptable esthetics for 4 years. Scanning electron microscopy and histology of the biopsied hard tissue revealed a nonhomogeneous structure resembling anomalously intertwined enamel with predentin and dentin. The etiology of this disturbance of dental development remains unknown.

To address the functions of FGFR2 and FGFR3 signaling during mandibular skeletogenesis, we over-expressed in the developing chick mandible, replication-competent retroviruses carrying truncated FGFR2c or FGFR3c that function as dominant negative receptors (RCAS-dnFGFR2 and RCAS-dnFGFR3). Injection of RCAS-dnFGFR3 between HH15 and 20 led to reduced proliferation, increased apoptosis, and decreased differentiation of chondroblasts in Meckel's cartilage. These changes resulted in the formation of a hypoplastic mandibular process and truncated Meckel's cartilage. This treatment also affected the proliferation and survival of osteoprogenitor cells in osteogenic condensations, leading to the absence of five mandibular bones on the injected side. Injection of RCAS-dnFGFR2 between HH15 and 20 or RCAS-dnFGFR3 at HH26 did not affect the morphogenesis of Meckel's cartilage but resulted in truncations of the mandibular bones. RCAS-dnFGFR3 affected the proliferation and survival of the cells within the periosteum and osteoblasts. Together these results demonstrate that FGFR3 signaling is required for the elongation of Meckel's cartilage and FGFR2 and FGFR3 have roles during intramembranous ossification of mandibular bones.

Our laboratory and others have shown that overexpression of Dlx5 stimulates osteoblast differentiation. Dlx5(-/-)/Dlx6(-/-) mice have more severe craniofacial and limb defects than Dlx5(-/-), some of which are potentially due to defects in osteoblast maturation. We wished to investigate the degree to which other Dlx genes compensate for the lack of Dlx5, thus allowing normal development of the majority of skeletal elements in Dlx5(-/-) mice. Dlx gene expression in cells from different stages of the osteoblast lineage isolated by FACS sorting showed that Dlx2, Dlx5 and Dlx6 are expressed most strongly in less mature osteoblasts, whereas Dlx3 is very highly expressed in differentiated osteoblasts and osteocytes. In situ hybridization and Northern blot analysis demonstrated the presence of endogenous Dlx3 mRNA within osteoblasts and osteocytes. Dlx3 strongly upregulates osteoblastic markers with a potency comparable to Dlx5. Cloned chick or mouse Dlx6 showed stimulatory effects on osteoblast differentiation. Our results suggest that Dlx2 and Dlx6 have the potential to stimulate osteoblastic differentiation and may compensate for the absence of Dlx5 to produce relatively normal osteoblastic differentiation in Dlx5 knockout mice, while Dlx3 may play a distinct role in late stage osteoblast differentiation and osteocyte function.

Objective: To examine the functions of FGF/FGFR signaling during mandibular skeletogenesis in ovo., Design: We examined the effects of inhibition of FGF signaling during mandibular skeletogenesis by overexpressing replication-competent RCAS virus encoding a truncated form of FGFR3 in the chicken mandibular process between stages 17 and 26., Results: Injection of RCAS-dnFGFR3 into the developing mandible resulted in abnormalities in a stage- and region-dependent manner. Injection at early stages of development resulted in the truncation of Meckel's cartilage, severely reduced outgrowth of the mandibular process and absence of five of the mandibular bones. Injection at later stages did not affect the outgrowth of the mandibular process and Meckel's cartilage but resulted in abnormalities in mandibular osteogenesis in a region-specific manner. The bones in the more caudal region were frequently truncated whereas bones in the more rostral regions such as dentary and splenial bones were frequently absent., Conclusion: Together these experiments have revealed essential roles for FGF/FGFR signaling in the elongation of Meckel's cartilage, development of osteogenic condensations and appositional growth of mandibular bones.

Our laboratory and others have shown that a homeodomain protein binding site plays an important role in transcription of the Collal gene in osteoblasts. This suggests that homeodomain proteins have an important role in osteoblast differentiation. We have investigated the role of Dlx5 in osteoblastic differentiation. In situ hybridization studies indicated that Dlx5 is expressed in chick calvarial osteoblasts (cCOB) in vivo. Northern blot analysis indicated that Dlx5 expression in cultured cCOBs is induced concurrently with osteoblastic markers. To study the effect of overexpression of Dlx5 on osteoblast differentiation, we infected primary osteoblast cultures from 15-day-old embryonal chicken calvaria with replication competent retroviral vectors [RCASBP(A)] expressing Dlx5 or control replication competent avian splice acceptor brianhightiter polymerase subtype A [RCASBP(A)]. Expression of Collal, osteopontin, alkaline phosphatase, and osteocalcin messenger RNA (mRNA) occurred sooner and at higher levels in cultures infected with RCASBP(A)DLX5 than in RCASBP(A)-infected cultures. Mineralization of Dlx5-expressing cultures was evident by days 12-14, and RCAS-infected control osteoblasts did not begin to mineralize until day 17. Dlx5 also stimulated osteoblastic differentiation of calvarial cells that do not normally undergo osteoblastic differentiation in vitro. Our results suggest that Dlx5 plays an important role in inducing calvarial osteoblast differentiation.