Orthodontic management of a migrated maxillary central incisor with a secondary occlusal trauma

Introduction: Normal or excessive occlusal forces exerted on teeth with a reduced periodontal support might result in a secondary occlusal trauma. This type of injury is diagnosed based on histological changes in the periodontium. Multiple clinical and radiographic indicators are, therefore, required as surrogates to assist the presumptive diagnosis of a (secondary) occlusal trauma. Case Presentation: In this case report, the diagnosis, management, and the 1-year follow-up of a secondary occlusal trauma of a maxillary central incisor are described. The occlusal relationship was rehabilitated with fixed orthodontic appliances and was further stabilized with both fixed and removable retainers. Conclusions: A combined periodontal-orthodontic approach for a secondary occlusal trauma allows the rehabilitation of periodontal, occlusal, and esthetic parameters. Twelve months after the end of the active orthodontic treatment, a combination of fixed and removable retainers showed to be effective in retaining the treatment outcome

The in vitro remineralizing effect of CPP-ACP and CPP-ACPF after 6 and 12 weeks on initial caries lesion

Objective: The aim of this in vitro study was to determine the effects of remineralization promoting agents containing casein phosphopeptidestabilized amorphous calcium phosphate (CPP-ACP), or CPP-ACP in combination with fluoride (CPP-ACPF) on artificial white spot lesions (WSLs) after 6 and 12 weeks. Methodology: White spot lesions were created on 123 sectioned premolars (246 specimens) with a demineralization solution during a 96 hours pH-cycling regime. Two experimental groups were created: a CPP-ACP group (Tooth MousseTM), and a CPP-ACPF group (Mi Paste PlusTM). Additionally, two control groups were created, one using only a conventional toothpaste (1450 ppm fluoride) and another one without any working agents. All teeth were also daily brushed with the conventional toothpaste except the second control group. Tooth MousseTM and Mi Paste PlusTM were applied for 180 seconds every day. The volume of demineralization was measured with transverse microradiography. Six lesion characteristics regarding the lesion depth and mineral content of WSLs were also determined. Results: The application of CPP-ACP and CPP-ACPF had a significant regenerative effect on the WSLs. Compared to Control group 1 and 2 the volume of demineralization after 6 weeks decreased significantly for CPP-ACP (respectively p<0.001 and p<0.001) and CPP-ACPF (respectively p=0.001 and p=0.003). The same trend was observed after 12 weeks. For the CPP-ACPF group, WSL dimensions decreased significantly between 6 and 12 weeks follow-up (p=0.012). The lesion depth reduced significantly after application of CPP-ACP and CPP-ACPF but increased significantly in the Control groups. Mineral content increased for CPP-ACP and CPP-ACPF after an application period of 12 weeks, but this was only significant for CPP-ACP. Conclusions: Long-term use of CPP-ACP and CPP-ACPF in combination with a conventional tooth paste shows beneficial effects in the recovery of in vitro subsurface caries lesions

Ownership and control in a competitive industry

We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry profits are maximized within a symmetric two product monopoly, the investor attains this only in exceptional cases. Instead, she sometimes acquires a noncontrolling stake. Or she invests asymmetrically rather than pursuing a full takeover if she acquires a controlling one. Generally, she invests indirectly if she only wants to affect the product market outcome, and directly if acquiring shares is profitable per se. --differentiated products,separation of ownership and control,private benefits of control

Orofaciale clefts: beoordeling van groei en behandelingsuitkomst

status: publishe

An esthetic evaluation of unilateral canine substitution for a missing maxillary lateral incisor

Objectives: The aim of this study is to determine whether variation in size, morphology, and color of a unilateral substituted maxillary canine has influence on the dentogingival attractiveness perceived by dental professionals and laypeople. Materials and Methods: A frontal clinical photograph of a patient with unilateral canine substitution was used as standard picture. Five different series were created by modification of following parameters with a raster graphics editor (Photoshop CS 6): (1) width, (2) color, (3) gingival margin height, and (4) crown tip morphology of the substituted canine and (5) the gingival margin height of the neighboring first premolar. For each parameter, the photograph deviating the most from the standard photograph, was combined into a final series. Four groups of examiners (orthodontists, periodontists, dentists, and laypeople) were asked to rank the photographs from most to least attractive. Results: One hundred seventy-four examiners ranked the photographs in order of attractiveness. Overall, a darker canine color (mean rank 4.361.03) and a more pronounced canine tip morphology (mean rank 3.471.11) were significantly ranked as most unattractive (P<.05). The gingival height of the neighboring premolar was ranked as least unattractive by all groups of examiners (mean rank 1.30 +/- 0.74). Conclusions: Darker canine color and a pronounced tip morphology of a substituted canine are rated as the most unattractive by dental professionals and laypeople. CLINICAL SIGNIFICANCE: The present study showed that the canine color and crown tip morphology are important parameters when considering unilateral canine substitution, both for professionals and laypeople. There is a general preference in favor of canines with a light color and a reduced incisal tip

Assessment modalities of non-ionizing three-dimensional images for the quantification of facial morphology, symmetry, and appearance in cleft lip and palate : a systematic review

The use non-ionizing three-dimensional (3D) imaging in cleft lip and palate is an emerging field, but properly designed methods for the assessment of these images are not well established. Therefore, the aim of this study was to review the current literature on the modalities of assessment of non-ionizing 3D images for the quantification of facial morphology, symmetry, and appearance in cleft lip and palate, and to assess the method error of these modalities. A systematic literature search was conducted using MEDLINE (PubMed), Cochrane Central Register of Controlled Trials, Web of Science, and Embase. Cross-sectional studies with prospective or retrospective data collection, using non-ionizing 3D imaging, with a subjective or objective outcome assessment and including at least 10 cleft lip and/or palate patients were considered eligible. Overall, 1767 unique studies were identified and 33 met the inclusion criteria. The images were objectively assessed using elementary measurements and comprehensive statistical methods for superimposition, shape description, and structuring. Subjective assessment was performed using a Likert-type scale or visual analogue scale. It can be concluded that non-ionizing 3D images are widely used in cleft research, but 3D analysis of the images is often methodologically suboptimal. Researchers must fully utilize the content of 3D images to quantify morphology, symmetry, and appearance

The evaluation of the transport medium for extracted premolars prior to cryopreservation : a systematic literature review

Prior to cryopreservation, a tooth is transported from a contaminated oral environment to the tooth bank. Our objective was to identify all studies reporting or investigating a transport protocol prior to the cryopreservation of teeth, in terms of decontamination of the subjects. The systematic literature search (1970-2017) was based on MEDLINE via PubMed, Web of Science and the Cochrane Library. The reference lists of the included studies and the Science Citation Index were used for hand searching (snowballing). Only studies reporting the transport conditions of the transplant were included. Language restrictions for English, Dutch or French were applied. The search led to 14 eligible studies. Almost all studies were laboratory studies, so the methodological quality of evidence was low. The majority of the included studies was performed by only five different research groups and the number of subjects varied between 1 and 120 teeth. In general, the teeth were stored in a tissue culture medium supplemented with fetal calf serum and/or different combinations of antibiotics and/or antimycotics. The teeth were transported cooled (4 A degrees C) or at room temperature, for a period of time not exceeding 24 h. Only three studies reported the irrigation of the teeth with phosphate buffered saline prior to the transport. The optimisation of the decontamination during transport was investigated in three studies (from 1971, 1980 and 1982). It was concluded that the literature on this topic is scarce, and the decontamination protocol for teeth, prior to cryopreservation has not been validated recently

Translocation Frequencies Measured in Patients One Year after Radioactive Iodine Therapy for Thyrotoxicosis

PURPOSE: To investigate the incidence of translocations induced by iodine-131 therapy in thyrotoxicosis patients 1 year after the administration of the radiolabelled compound. MATERIALS AND METHODS: Tricolour FISH with whole-chromosome-specific probes for chromosomes 2, 4 and 8 was used for scoring translocations. From the genomic translocation frequencies, derived using the Lucas formula, equivalent whole-body doses were calculated, based on the in vitro (60)Co gamma-ray dose-response curve. RESULTS: A total of 101 translocations were observed in 4864 metaphases, 63% being of the two-way type. In the control group used for obtaining dose-response data, nine translocations were observed in 5278 metaphases, 55% being two-way translocations. No correlation was found between the observed frequency of translocations and administered radioactivity. Using the in vitro dose-response, an estimated average dose for the group of nine patients of 0.79 +/- 0.22Gy was obtained. Compared with frequencies following the assumption that the involvement of a particular chromosome in a two-break exchange-type aberration is proportional to its DNA content, chromosome 4 was more frequently involved and chromosomes 2 and 8 less frequently involved in chromosomal rearrangements. CONCLUSION: This study shows that (131)I therapy for thyrotoxicosis patients induced translocations, especially in chromosome 4, which could be detected 1 year after the administration of the radiolabelled compound