Publications by authors named "K F Krey"

33 Publications

Investment casting with FFF (fused filament fabrication)-printed appliances: the intermediate step.

Quintessence Int 2021 Mar 22;0(0). Epub 2021 Mar 22.

Objective: Some modifications of orthodontic appliances such as the rapid maxillary expansion (RME) device with a Hyrax screw or Herbst are fabricated using traditional investment casting (lost-wax casting). This is precise but very labor-intensive. New technologies enable us today to use direct selective laser sintering (SLS) to produce freeform metallic structures. These machines are very expensive and only available in specialized laboratories. The aim of this investigation was to combine fused filament fabrication (FFF) 3D printing with wax-based filaments to produce orthodontic appliances via investment casting.

Method And Materials: For demonstration purposes, a lingual arch, a palatal arch, and an RME appliance were digitally designed based on an intraoral scan. The *.stl files were sliced and printed with a dual-nozzle FFF printer. The object was printed with a wax-based filament especially suited for investment casting, and support structures were printed with water-soluble polyvinyl-alcohol (PVA) filament. The printed objects were cast in metal and finished.

Results: All appliances were successfully cast and polished. They were provisionally placed intraorally. The fit was clinically very good and comparable to traditionally crafted appliances. The printing and handling of the parts made of these special filaments is challenging.

Conclusion: With this experiment, the successful production of investment casting using FFF printing was shown for the first time.
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http://dx.doi.org/10.3290/j.qi.b1098311DOI Listing
March 2021

Is Continuous Eruption Related to Periodontal Changes? A 16-Year Follow-up.

J Dent Res 2021 Mar 3:22034521999363. Epub 2021 Mar 3.

Department of Restorative Dentistry, Periodontology, Endodontology, Preventive Dentistry and Pedodontics, University Medicine Greifswald, Greifswald, Germany.

The aims of this study were to 1) determine if continuous eruption occurs in the maxillary teeth, 2) assess the magnitude of the continuous eruption, and 3) evaluate the effects of continuous eruption on the different periodontal parameters by using data from the population-based cohort of the Study of Health in Pomerania (SHIP). The jaw casts of 140 participants from the baseline (SHIP-0) and 16-y follow-up (SHIP-3) were digitized as 3-dimensional models. Robust reference points were set to match the tooth eruption stage at SHIP-0 and SHIP-3. Reference points were set on the occlusal surface of the contralateral premolar and molar teeth, the palatal fossa of an incisor, and the rugae of the hard palate. Reference points were combined to represent 3 virtual occlusal planes. Continuous eruption was measured as the mean height difference between the 3 planes and rugae fix points at SHIP-0 and SHIP-3. Probing depth, clinical attachment levels, gingiva above the cementoenamel junction (gingival height), and number of missing teeth were clinically assessed in the maxilla. Changes in periodontal variables were regressed onto changes in continuous eruption after adjustment for age, sex, number of filled teeth, and education or tooth wear. Continuous tooth eruption >1 mm over the 16 y was found in 4 of 140 adults and averaged to 0.33 mm, equaling 0.021 mm/y. In the total sample, an increase in continuous eruption was significantly associated with decreases in mean gingival height ( = -0.34; 95% CI, -0.65 to -0.03). In a subsample of participants without tooth loss, continuous eruption was negatively associated with PD. This study confirmed that continuous eruption is clearly detectable and may contribute to lower gingival heights in the maxilla.
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http://dx.doi.org/10.1177/0022034521999363DOI Listing
March 2021

Association between coronal caries and malocclusion in an adult population.

J Orofac Orthop 2020 Dec 18. Epub 2020 Dec 18.

Department of Prosthetic Dentistry, Gerodontology and Biomaterials, University Medicine Greifswald, Walther-Rathenau-Str. 42a, 17475, Greifswald, Germany.

Purpose: Only a few but conflicting results have been reported on the association between malocclusions and caries. We investigated this association using data from the population-based cross-sectional Study of Health in Pomerania (SHIP).

Methods: Sagittal, vertical and transversal intermaxillary relationship, space conditions and sociodemographic parameters of 1210 dentate subjects (median age 30 years, interquartile range 25-35 years) were collected. Caries was assessed with the Decayed-Missing-Filled Surfaces index but analyzed as ordered outcome (four levels: sound, enamel caries, caries, tooth loss) in ordinal multilevel models, taking into account subject, jaw, and tooth level simultaneously.

Results: Anterior open bite ≤3 mm (odds ratio [OR] = 2.08, 95% confidence interval [CI]: 1.19-3.61), increased sagittal overjet of 4-6 mm (OR = 1.31, CI: 1.05-1.64), distal occlusion of ½ premolar width (OR = 1.27, CI: 1.05-1.53) and distal 1 premolar width (OR = 1.31, CI: 1.06-1.63) were associated with adjusted increased odds for a higher outcome level (caries). Anterior spacing (OR = 0.24, CI: 0.17-0.33), posterior spacing, (OR = 0.69, CI: 0.5-0.95), posterior crowding (OR = 0.57, CI: 0.49-0.66) and buccal nonocclusion (OR = 0.54, CI: 0.33-0.87) were associated with a lower outcome level (caries).

Conclusion: The results from this population-based study suggest that a connection between caries and malocclusion exists to a limited extent in young adults. The associations with caries are contradictory for several malocclusion variables. Distal occlusion (OR = 1.31, CI: 1.06-1.63) and related skeletal anomalies displayed positive associations with caries whereas crowding did not. Orthodontic treatment of anterior crowding would probably not interfere with caries experience. These aspects should be considered for patient information and in treatment decisions.
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http://dx.doi.org/10.1007/s00056-020-00271-1DOI Listing
December 2020

Multiloop edgewise archwire technique and denture frame analysis: a systematic review.

Head Face Med 2020 Nov 26;16(1):32. Epub 2020 Nov 26.

Department of Orthodontics and Craniofacial Orthopedics, University Medicine Greifswald, Greifswald, Germany.

Background: The Multiloop Edgewise Archwire (MEAW) appliance is an orthodontic treatment method suitable for the therapy of severe types of malocclusions such as open bites or anterior crossbites. The cephalometric Denture Frame Analysis (DFA) provides a supportive diagnostic tool for patient-specific treatment planning concerning the rearrangement of occlusion within the "denture frame". The objective of this study is to give a comprehensive overview of the national and international scientific literature about MEAW and DFA regarding the general therapeutic effects, advantages and limitations.

Methods And Materials: A computerized literature search was performed using four principal medical databases (PubMed/Medline, Google Scholar, Web of Science and Cochrane Central Register of Controlled Trials) and supplemented by manual searching of the references listed in the retrieved articles. The results were screened and assessed following the PRISMA guidelines.

Results: Six hundred seventy-seven full articles were assessed for eligibility. A number of 134 articles went through qualitative analysis and 3 studies were finally involved in comparative synopsis. The findings reveal advantageous characteristics of the MEAW technique such as a high degree of three-dimensional individual tooth control and a comparatively low load deflection rate, causing mostly dentoalveolar changes without significantly influencing the skeletal structures.

Conclusion: Based on current literature, the MEAW technique appears to have several therapeutic benefits and serves as a sufficient alternative treatment method for dentoalveolar compensation, when measures of orthognathic surgery are rejected. Concerning the deficient data basis of available literature and the low level of scientific evidence, further studies are required in order to expand on the knowledge in this subject area. Several aspects like the effectiveness or the long-term stability have to be evaluated more extensively. Moreover, the transferability of the DFA to ethnic groups other than the Asian ethnicity should be examined further.
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http://dx.doi.org/10.1186/s13005-020-00247-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7690140PMC
November 2020

Revealing the Diet of Generalist Insect Predators in Strawberry Fields: Not Only Pests, But Other Predators Beware.

Environ Entomol 2020 12;49(6):1300-1306

Gulf Coast Research and Education Center, University of Florida, Wimauma, FL.

Generalist invertebrate predators contribute to pest management in agriculture, providing an important ecosystem service, particularly in organically managed fields. DNA-based methods to study food webs and feeding interactions in unrestricted field conditions have transformed dietary analysis of generalist predators. In this study, we used MiSeq next-generation sequencing (NGS) technology and universal arthropod primers to investigate the diet of several generalist insect predators collected in commercial organic Florida strawberry fields from November 2017 to March 2018. Of 12 predator insect taxa, Geocoris spp. (Say) (Hemiptera: Geocoridae) was the most abundant early in the growing season (November) and was collected consistently until the end of the season (early March). DNA sequences from 105 predator samples were matched to 44 arthropod families, and of these, 17 were categorized as pest families, 10 as nonpest or nonpredator families, and 17 as predator families. Drosophilidae was the most detected pest family, and Dolichopodidae was the most detected predator family. Prey diversity differed among the predators. Chrysoperla spp. (Neuroptera: Chrysopidae) consumed more prey earlier in the season than did other predators, whereas the other predators consumed a greater diversity of other predators regardless of month. Our results showed a high amount of intraguild predation, but also that predators are contributing to pest suppression in organic strawberries and providing an important biological control service in Florida organic strawberries.
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http://dx.doi.org/10.1093/ee/nvaa125DOI Listing
December 2020

System-Based Approaches to Delineate the Antiviral Innate Immune Landscape.

Viruses 2020 10 21;12(10). Epub 2020 Oct 21.

School of Medicine, Institute of Virology, Technical University of Munich, 81675 Munich, Germany.

Viruses pose substantial challenges for society, economy, healthcare systems, and research. Their distinctive pathologies are based on specific interactions with cellular factors. In order to develop new antiviral treatments, it is of central importance to understand how viruses interact with their host and how infected cells react to the virus on a molecular level. Invading viruses are commonly sensed by components of the innate immune system, which is composed of a highly effective yet complex network of proteins that, in most cases, mediate efficient virus inhibition. Central to this process is the activity of interferons and other cytokines that coordinate the antiviral response. So far, numerous methods have been used to identify how viruses interact with cellular processes and revealed that the innate immune response is highly complex and involves interferon-stimulated genes and their binding partners as functional factors. Novel approaches and careful experimental design, combined with large-scale, high-throughput methods and cutting-edge analysis pipelines, have to be utilized to delineate the antiviral innate immune landscape at a global level. In this review, we describe different currently used screening approaches, how they contributed to our knowledge on virus-host interactions, and essential considerations that have to be taken into account when planning such experiments.
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http://dx.doi.org/10.3390/v12101196DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7589202PMC
October 2020

Organic Farming Sharpens Plant Defenses in the Field.

Front Sustain Food Syst 2020 Jul 17;4. Epub 2020 Jul 17.

Department of Entomology, University of Georgia, Athens, GA, United States.

Plants deploy a variety of chemical and physical defenses to protect themselves against herbivores and pathogens. Organic farming seeks to enhance these responses by improving soil quality, ultimately altering bottom up regulation of plant defenses. While laboratory studies suggest this approach is effective, it remains unclear whether organic agriculture encourages more-active plant defenses under real-world conditions. Working on the farms of cooperating growers, we examined gene expression in the leaves of two potato () varieties, grown on organic vs. conventional farms. For one variety, , we found significantly heightened initiation of genes associated with plant-defense pathways in plants grown in organic vs. conventional fields. Organic fields exhibited lower levels of nitrate in soil and of nitrogen in plant foliage, alongside differences in communities of soil bacteria, suggesting possible links between soil management and observed differences in plant defenses. Additionally, numbers of predatory and phloem-feeding insects were higher in organic than conventional fields. A second potato variety, , which is generally grown using fewer inputs and in poorer-quality soils, exhibited lower overall herbivore and predator numbers, few differences in soil ecology, and no differences in gene-activity in organic and conventional farming systems. Altogether, our results suggest that organic farming has the potential to increase plants' resistance to herbivores, possibly facilitating reduced need for insecticide applications. These benefits appear to be mediated by plant variety and/or farming context.
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http://dx.doi.org/10.3389/fsufs.2020.00097DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7566882PMC
July 2020

FOXO1 promotes HIV latency by suppressing ER stress in T cells.

Nat Microbiol 2020 09 15;5(9):1144-1157. Epub 2020 Jun 15.

Gladstone Institute of Virology and Immunology, Gladstone Institutes, San Francisco, CA, USA.

Quiescence is a hallmark of CD4 T cells latently infected with human immunodeficiency virus 1 (HIV-1). While reversing this quiescence is an effective approach to reactivate latent HIV from T cells in culture, it can cause deleterious cytokine dysregulation in patients. As a key regulator of T-cell quiescence, FOXO1 promotes latency and suppresses productive HIV infection. We report that, in resting T cells, FOXO1 inhibition impaired autophagy and induced endoplasmic reticulum (ER) stress, thereby activating two associated transcription factors: activating transcription factor 4 (ATF4) and nuclear factor of activated T cells (NFAT). Both factors associate with HIV chromatin and are necessary for HIV reactivation. Indeed, inhibition of protein kinase R-like ER kinase, an ER stress sensor that can mediate the induction of ATF4, and calcineurin, a calcium-dependent regulator of NFAT, synergistically suppressed HIV reactivation induced by FOXO1 inhibition. Thus, our studies uncover a link of FOXO1, ER stress and HIV infection that could be therapeutically exploited to selectively reverse T-cell quiescence and reduce the size of the latent viral reservoir.
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http://dx.doi.org/10.1038/s41564-020-0742-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7483895PMC
September 2020

Effect of self-assembling peptide P-4 on orthodontic treatment-induced carious lesions.

Sci Rep 2020 04 22;10(1):6819. Epub 2020 Apr 22.

Dental school of the University Medicine Greifswald, Department of Prosthodontics, Greifswald, Germany.

This study aimed to evaluate the effect of self-assembling peptide P-4 (SAP) in the therapy of initial smooth surface caries (white spot lesions, WSL) following orthodontic multibracket treatment. Twenty-three patients (13f/10m; average age 15.4 years) with at least two teeth with WSL were recruited for the randomised controlled clinical trial with split-mouth design. In opposite to the control teeth, the test teeth were treated with SAP on Day 0. The primary endpoint was the impedance measurement of WSL using customised tray to ensure reproducibility of the measurement location. The secondary endpoint was the morphometric measurement of WSL using a semi-automated approach to determine the WSL size in mm. Treatment effects were adjusted for site-specific baseline values using mixed models adapted from the cross-over design. Test WSL showed a mean baseline impedance value of 46.7, which decreased to 21.1, 18.4, and 19.7 after 45, 90, and 180 days, respectively. Control WSL showed a mean baseline value of 42.0, which decreased to 35.0, 29.5, and 33.7, respectively. The overall treatment contrast was -13.7 (95% CI: -19.6 - -7.7; p < 0.001). For the secondary endpoint, the test WSL size decreased from 8.8 at baseline to 6.5 after 180 days. The control WSL decreased from 6.8 to 5.7, respectively. The related treatment contrast was -1.0 in favour of test WSL (95% CI: -1.6 - -0.5; p = 0.004). The treatment of initial carious lesions with self-assembling peptide P-4 leads to superior remineralisation of the subsurface lesions compared with the control teeth.
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http://dx.doi.org/10.1038/s41598-020-63633-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7176635PMC
April 2020

Does craniofacial morphology affect third molars impaction? Results from a population-based study in northeastern Germany.

PLoS One 2019 22;14(11):e0225444. Epub 2019 Nov 22.

Department of Prosthodontics, Gerodontology and Biomaterials, University Medicine Greifswald, Greifswald, Germany.

Objectives: It is still not clear why impaction of third molars occurs. Craniofacial morphology and facial parameters have been discussed to be strong predictors for third molar impaction. Thus, this study aimed to investigate the effect of craniofacial morphology on erupted or impacted third molars in a German population sample.

Materials And Methods: Erupted and impacted third molars in 2,484 participants from the Study of Health in Pomerania were assessed by whole-body magnetic resonance imaging. Markers of facial morphology were determined in 619 individuals of those participants in whose 421 participants (16.7%) had at least one impacted third molar. Craniofacial morphology was estimated as linear measurements and was associated in a cross-sectional study design with impacted and erupted third molars by multinomial logistic regression models. Erupted third molars were used as reference outcome category and regression models were adjusted for age and sex.

Results: Maximum Cranial Width (Eurion-Eurion distance) was significantly associated with impacted third molars (RR: 1.079; 95% confidence interval 1.028-1.132). This association was even more pronounced in the mandible. Individuals with a lower total anterior facial height (Nasion-Menton distance) and a lower facial index also have an increased risk for impacted third molars in the mandible (RR 0.953; 95% confidence interval 0.913-0.996 and RR: 0.943; 95% confidence interval 0.894-0.995). No significant associations of third molar status with facial width (Zygion-Zygion distance), and sagittal cranial dimension (Nasion-Sella distance; Sella-Basion distance) were observed.

Conclusion: Individuals with an increased maximal cranial width have a higher risk for impaction of third molars in the mandible and in the maxilla. Individuals with a lower anterior total anterior facial height and lower facial index also have an increased risk for third molars impaction in the mandible. These findings could help orthodontic dentists, oral surgeons and oral and maxillofacial surgeons in decision-making for third molars removal in their treatment. These findings highlight the necessity of an additional analysis of the maximal cranial width by the Eurion- Eurion distance.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0225444PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6874347PMC
March 2020

Organic Soils Control Beetle Survival While Competitors Limit Aphid Population Growth.

Environ Entomol 2019 12;48(6):1323-1330

Department of Entomology, Washington State University, Pullman, WA.

Soil chemistry and microbial diversity can impact the vigor and nutritive qualities of plants, as well as plants' ability to deploy anti-herbivore defenses. Soil qualities often vary dramatically on organic versus conventional farms, reflecting the many differences in soil management practices between these farming systems. We examined soil-mediated effects on herbivore performance by growing potato plants (Solanum tuberosum L.) in soils collected from organic or conventional commercial farm fields, and then exposing these plants to herbivory by green peach aphids (Myzus persicae Sulzer, Hemiptera: Aphididae) and/or Colorado potato beetles (Leptinotarsa decemlineata Say, Coleoptera: Chrysomelidae). Responses of the two potato pests varied dramatically. Survivorship of Colorado potato beetles was almost 3× higher on plants grown in organic than in conventional soils, but was unaffected by the presence of aphids. In contrast, aphid colony growth was twice as rapid when aphids were reared alone rather than with Colorado potato beetles, but was unaffected by soil type. We saw no obvious differences in soil nutrients when comparing organic and conventional soils. However, we saw a higher diversity of bacteria in organic soils, and potato plants grown in this soil had a lower carbon concentration in foliar tissue. In summary, the herbivore species differed in their susceptibility to soil- versus competitor-mediated effects, and these differences may be driven by microbe-mediated changes in host plant quality. Our results suggest that soil-mediated effects on pest growth can depend on herbivore species and community composition, and that soil management strategies that promote plant health may also increase host quality for pests.
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http://dx.doi.org/10.1093/ee/nvz100DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6885743PMC
December 2019

Three Release Rates of (Hemiptera: Miridae) for Management of (Hemiptera: Aleyrodidae) on Greenhouse Tomato.

Insects 2019 Jul 19;10(7). Epub 2019 Jul 19.

USDA-ARS, 5230 Konnowac Pass Road, Wapato, WA 98951, USA.

The sweetpotato whitefly, , is a pest of greenhouse-grown tomato. Restrictions on insecticides in enclosed structures and the presence of commercial pollinators limit the options for the chemical control of whiteflies in greenhouses, increasing the importance of biological controls. is a zoophytophagous mirid predator native to North America. Three release rates of were evaluated on greenhouse tomato for control of the sweetpotato whitefly. The release rates were one, two or three adult per tomato plant each week for three weeks in cages containing four tomato plants and one mullein banker plant. There were fewer whitefly eggs in cages receiving predators than untreated cages one week after the third release, and fewer whitefly nymphs in cages receiving predators two weeks after the third release. There were no statistical differences in whitefly eggs or nymphs among predator release treatments. The highest release rate resulted in a 60% reduction in whitefly nymphs. Forty-two days after the first predator releases, there were no differences among release treatments in the number of . Our results indicate that can contribute management of on greenhouse tomato, but that it may be insufficient as a sole strategy.
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http://dx.doi.org/10.3390/insects10070213DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6681358PMC
July 2019

New insights in the link between malocclusion and periodontal disease.

J Clin Periodontol 2019 02;46(2):144-159

Department of Prosthetic Dentistry, Gerodontology and Biomaterials, University Medicine Greifswald, Greifswald, Germany.

Aim: We aimed to investigate associations between malocclusions and periodontal disease by comparing it to that of smoking in subjects recruited from the population-based cross-sectional study "Study of Health in Pomerania."

Materials And Methods: Sagittal intermaxillary relationship, variables of malocclusion and socio-demographic parameters of 1,202 dentate subjects, 20-39 years of age, were selected. Probing depth (PD) and attachment loss (AL) were assessed at four sites by tooth in a half-mouth design. Analyses were performed with multilevel models on subject, jaw and tooth level.

Results: Distal occlusion determined in the canine region, ectopic position of canines, anterior spacing, deep anterior overbite and increased sagittal overjet were associated with AL (p-value <0.05). Associations between malocclusions and PD: deep anterior overbite with gingival contact (odds ratio [OR] = 1.40, 95% CI: 1.08-1.82; p-value = 0.0101) and anterior crossbite (OR = 1.75, 95% CI: 1.29-2.38; p-value = 0.0003). Regarding crowding, only severe anterior crowding was compatible with a moderate to large association with PD (OR = 1.93, 95% CI: 0.89-4.20). Compared to smoking, the overall effect of malocclusions was about one half for AL and one-third for PD.

Conclusion: Malocclusions or morphologic parameters were associated with periodontal disease.
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http://dx.doi.org/10.1111/jcpe.13062DOI Listing
February 2019

Fully digital workflow for presurgical orthodontic plate in cleft lip and palate patients.

Int J Comput Dent 2018;21(3):251-259

Objective: In most cases, according to our treatment concept, a presurgical orthodontic treatment (POT) is performed on patients with cleft lip and palate (CLP). The aim of this case report is to demonstrate a completely digital workflow for the production of a palate plate.

Materials And Methods: For the assessment of the maxillary arch, a digital impression of the jaw was made on two patients with an intraoral scanner (Cerec Omnicam Ortho). After reconstruction of a virtual model from the scan data, appropriate areas of the jaw could be blocked out and a plate constructed. This was printed with a DLP three-dimensional (3D) printer (SHERA EcoPrint D30) with class IIa biocompatible material. After minor surface finishing, the plates could be incorporated in the patients' mouths.

Results: The scans could be performed in a short time without affecting the very young patients. All clinically relevant areas for the production and digital measurement of the models could be recorded. The plates showed an extremely good fit, and there were no differences in wear compared with a conventionally manufactured plate.

Conclusion: For the first time, a risk-free digital impression of the edentulous jaw in CLP babies with a subsequently completely digitally constructed and 3D-printed palatal plate could be shown.
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June 2019

Assessment of vaccine wastage rates, missed opportunities, and related knowledge, attitudes and practices during introduction of a second dose of measles-containing vaccine into Cambodia's national immunization program.

Vaccine 2018 07 19;36(30):4517-4524. Epub 2018 Jun 19.

UNICEF, New York, NY, USA.

Introduction: Missed opportunities for vaccination (MOV) can result in inadequate protection against disease. Although healthcare provider reluctance to open multi-dose, lyophilized vaccine vials (particularly the measles-containing vaccine [MCV]) for every eligible child due to concerns about wasting vaccine is a known reason for MOV, little is known about providers' related attitudes and practices.

Methods: In 100 randomly selected health facilities and 24 districts of Cambodia, we surveyed healthcare providers and their district supervisors regarding routine vaccine administration and wastage knowledge and practices, and child caregivers (five per facility) regarding MOV. Vaccine stock management data covering six months were reviewed to calculate facility and district level wastage rates and vaccine usage patterns for six vaccines, including a recently introduced second dose of MCV (MCV2).

Results: Response rates were 100/100 (100%) among facility staff, 48/48 (100%) among district staff, and 436/500 (87%) among caregivers. Mean facility-level wastage rates varied from 4% for single-dose diphtheria-tetanus-pertussis-hepatitis B-Haemophilus influenzae type b vaccine to 60% for 10-dose MCV; district-level wastage rates for all vaccines were 0%. Some vaccines had lower wastage rates in large facilities compared to small facilities. The mean MCV wastage rate was the same before and immediately after MCV2 introduction. Providers reported waiting for a mean of two children prior to opening an MCV vial, and 71% of providers reported offering MCV vaccination less frequently during scheduled vaccination sessions than other vaccines. Less than 5% of caregivers reported that their child had been turned away for vaccination, most frequently (65%) for MCV.

Discussion: Although the MCV wastage rate in our study was in line with national targets, providers reported waiting for more than one child before opening an MCV vial, contrary to vaccine management guidelines. Future research should explore the causal links between provider practices related to vaccine wastage and their impact on vaccination coverage.
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http://dx.doi.org/10.1016/j.vaccine.2018.06.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6032508PMC
July 2018

Three-dimensional morphology of first molars in relation to ethnicity and the occurrence of cleft lip and palate.

PLoS One 2017 9;12(10):e0185472. Epub 2017 Oct 9.

Department of Orthodontics, Center for Dental, Oral and Craniomandibular Sciences, University Medicine Greifswald, Greifswald, Germany.

Objectives: This study aims to describe morphological peculiarities of maxillary and mandibular first molars in Europeans, Asians and Europeans with cleft lip and palate.

Material And Methods: Reflex microscopy was used to obtain three-dimensional morphometric landmarks from 40 models (11 Europeans and 13 Asians without cleft lip and palate, 16 Europeans with unilateral cleft lip and palate). The cases were examined using traditional morphometry and geometric morphometry, and visualized using thin-plate splines.

Results: Classic morphometry showed no right/left differences in the study groups and no significant differences with regard to the cleft side in patients with cleft lip and palate. In Asians, a significantly greater mesiodistal width was found. Geometric morphometry showed an enlarged centroid size in Asians (maxilla and mandible). In cleft patients, the cleft site did not appear to impact the morphology of first molars.

Conclusion: Unilateral clefting did not affect the size and shape of molars; however, characteristic ethnicity-based differences were in fact identified. The results are relevant for orthodontic treatment with preadjusted appliances, and prosthetic CAD/CAM restorations.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0185472PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5633149PMC
October 2017

A completely CAD/CAM individual transmission device for electronic mandible movement registration.

Int J Comput Dent 2017;20(2):193-199

The connection of a device for the registration of mandibular movements depends on the coupling of the teeth with a paraocclusal adapter. This is normally done by individualizing a prefabricated metal support, either directly on the patient or in the dental laboratory. The goal was to create an individual paraocclusal adapter by means of additive computer-assisted design/computer-assisted manufacturing (CAD/CAM) procedures, and to test it clinically. Starting from intraoral scans of the maxillary and mandibular teeth, an individual paraocclusal adapter was constructed by combining an adapter piece adapted to the tooth and jaw shape with a prefabricated standard part. This article describes step by step the design using the 3D CAD software, up until production by means of 3D printing. Initial clinical experience is also discussed.
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August 2017

3D-printed orthodontic brackets - proof of concept.

Int J Comput Dent 2016;19(4):351-362

Today, orthodontic treatment with fixed appliances is usually carried out using preprogrammed straight-wire brackets made of metal or ceramics.

Objective: The goal of this study was to determine the possibility of clinically implementing a fully digital workflow with individually designed and three-dimensionally printed (3D-printed) brackets.

Materials And Methods: Edgewise brackets were designed using computer-aided design (CAD) software for demonstration purposes. After segmentation of the malocclusion model generated based on intraoral scan data, the brackets were digitally positioned on the teeth and a target occlusion model created. The thus-defined tooth position was used to generate a template for an individualized arch form in the horizontal plane. The base contours of the brackets were modified to match the shape of the tooth surfaces, and a positioning guide (fabricated beforehand) was used to ensure that the brackets were bonded at the correct angle and position. The brackets, positioning guide, and retainer splint, digitally designed on the target occlusion model, were 3D printed using a Digital Light Processing (DLP) 3D printer. The archwires were individually pre-bent using the template.

Results: In the treatment sequence, it was shown for the first time that, in principle, it is possible to perform treatment with an individualized 3D-printed brackets system by using the proposed fully digital workflow. Technical aspects of the system, problems encountered in treatment, and possible future developments are discussed in this article.
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March 2017

Estimating effects of craniofacial morphology on gingival recession and clinical attachment loss.

J Clin Periodontol 2017 Apr 18;44(4):363-371. Epub 2017 Feb 18.

Department of Prosthodontics, Gerodontology and Biomaterials, University Medicine Greifswald, Greifswald, Germany.

Objectives: Evidence on possible associations between facial morphology, attachment loss and gingival recession is lacking. We analysed whether the facial type, which can be described by the ratio of facial width and length (facial index), is related to periodontal loss of attachment, hypothesizing that a broad face might be associated with less gingival recession (GR) and less clinical attachment loss (CAL) than a long face.

Materials And Methods: Data from the 11-year follow-up of the population-based Study of Health in Pomerania were used. Periodontal loss of attachment was assessed by GR and CAL. Linear regression models, adjusted for age and gender, were used to assess associations between specific landmark based distances extracted from magnetic resonance imaging head scans and clinically assessed GR or CAL (N = 556).

Results: Analysing all teeth, a higher maximum cranial width was associated with a lower mean GR (B = -0.016, 95% CI: -0.030; -0.003, p = 0.02) and a lower mean CAL (B = -0.023, 95% CI: -0.040; -0.005, p = 0.01). Moreover, a long narrow face was significantly associated with increased mean GR and CAL (facial index, P for trend = 0.02 and p = 0.01, respectively). Observed associations were more pronounced for incisors and canines than for premolars and molars.

Conclusion: This study revealed craniofacial morphology, specifically the cranial width and the facial index, as a putative risk factor for periodontal loss of attachment.
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http://dx.doi.org/10.1111/jcpe.12661DOI Listing
April 2017

Tutankhamun's Dentition: The Pharaoh and his Teeth.

Braz Dent J 2015 Nov-Dec;26(6):701-4

Department of Orthodontics, University Hospital of Greifswald, Greifswald, Germany.

Tutankhamun was a Pharaoh of the 18th Dynasty (New Kingdom) in ancient Egypt. Medical and radiological investigations of his skull revealed details about the jaw and teeth status of the mummy. Regarding the jaw relation, a maxillary prognathism, a mandibular retrognathism and micrognathism have been discussed previously. A cephalometric analysis was performed using a lateral skull X-ray and a review of the literature regarding King Tutankhamun´s mummy. The results imply diagnosis of mandibular retrognathism. Furthermore, third molar retention and an incomplete, single cleft palate are present.
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http://dx.doi.org/10.1590/0103-6440201300431DOI Listing
February 2017

Three-dimensional analysis of maxillary development in patients with unilateral cleft lip and palate during the first six years of life.

J Orofac Orthop 2015 Sep;76(5):391-404

Department of Orthodontics and Orofacial Orthopedics, Center for Dentistry and Oral and Maxillofacial Surgery, Universitätsmedizin Greifswald, University Medicine Greifswald, Rotgerberstr. 8, 17475, Greifswald, Germany.

Objectives: The purpose of this work was to analyse early upper-jaw development in patients with unilateral cleft lip and palate (UCLP) treated using two different concepts and to compare shape and size developments between these two groups and a group of noncleft patients.

Materials And Methods: A total of 204 maxillary casts available for this study from 50 UCLP patients were analyzed for upper-jaw development based on three-dimensional measurements performed with a Reflex Microscope from birth up to 71 months of age. Thirty-five of these 50 patients were part of an early treatment group (two-stage cleft closure with single-stage palatoplasty at an age of 10-14 months) and 15 were part of a late treatment group (two-stage cleft closure with palatoplasty at an age of 4-7 years). The control group included 39 casts of 17 noncleft patients.

Results: Analysis of shape and size between the patients in the three groups yielded statistically significant differences between the cleft and the noncleft patients. In both treatment groups, we made observations typically associated with cleft formation like lateralization, asymmetry of the greater and lesser cleft segments, and pronounced vertical deviations of the segments. Viewed in all dimensions, however, the patients in the early treatment group approached the control group more closely, although a statistically significant difference was still observed.

Conclusion: Our results suggest that the timing of hard-palate closure is not a decisive factor for upper-jaw development. Intrinsic factors (initial cleft width, presence of tooth buds) and the surgeon's skills appear to have a much more defining role.
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http://dx.doi.org/10.1007/s00056-015-0299-zDOI Listing
September 2015

Morphology of open bite.

J Orofac Orthop 2015 May;76(3):213-24

Department of Orthodontics and Orofacial Orthopedics, Center for Dental, Oral and Craniomandibular Sciences, University Medicine Greifswald, Rotgerberstr. 8, 17475, Greifswald, Germany,

Objectives: The purpose of this work was to define and illustrate the skeletal morphology of open-bite patients against the background of sagittal jaw relationships on the basis of lateral cephalograms.

Materials And Methods: Lateral cephalograms of 197 untreated adults were analyzed in dental imaging software (Onyx Ceph 3™; Image Instruments, Chemnitz, Germany). Four groups were formed based on vertical (Index scores) and sagittal (individualized ANB values) parameters. Ninety-nine patients were defined as the control group due to their neutral sagittal and vertical relationships. The remaining patients were found by their vertical relationships to represent open-bite cases and were divided by their sagittal relationships into three study groups: neutral (Class I, n = 34), distal (Class II, n = 26), and mesial (Class III, n = 38). A geometric morphometric approach was used to analyze the x,y-coordinates of 28 skeletal landmarks on each cephalogram. Relative size was captured based on centroid size (CS). The shape-determining factors in the groups were compared by permutation testing after Procrustes transformation, and intergroup differences were visualized in the form of thin-plate splines.

Results: While size (CS) was significantly increased in the Class III group, the other two groups were not different from the control group. After Procrustes transformation, characteristic and invariably significant (p < 0.001) differences in shape were detected. Neutral (Class I) open bite involved compression in the mandibular ramus and the upper anterior facial third, including vertical expansion in the lower molar and anterior nasal spine areas. Mesial (Class III) open bite was associated with pronounced vertical and sagittal size reductions in the upper posterior segments and reduced lengths of the mandibular ramus. Distal (Class II) open bite involved expansion in the pterygoid area and compression in the mandibular ramus.

Conclusion: Open bite is not a homogeneous group. Our geometric techniques of morphometric analysis revealed typical patterns, thus, confirming the differences observed by traditional morphometry. True skeletal overdevelopment appears to be present only in open-bite cases having a mesial jaw relationship. All open-bite groups have in common that the mandibular ramus is compressed, but marked differences are seen in terms of vertical development of the maxilla. This differentiated view of open-bite cases should be taken into consideration during individual etiology assessment and treatment planning.
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http://dx.doi.org/10.1007/s00056-015-0290-8DOI Listing
May 2015

Pubertal status of children and adolescents during orthodontic treatment.

J Orofac Orthop 2013 May 8;74(3):257-64. Epub 2013 May 8.

Department of Orthodontics, University of Leipzig, Leipzig, Germany.

Objective: Most orthodontic therapy in Germany takes place during puberty. However, since boys and girls experience puberty very differently, we can expect differences in their pubertal status when undergoing orthodontic therapy. In this study we addressed the stages of pubertal development in male and female children and adolescents undergoing orthodontic treatment.

Subjects And Methods: A total of 1011 individuals were randomly selected from a population-based representative sample of school students aged 10-18 years in the German city of Halle/Saale. This cohort was evaluated for the prevalence of orthodontic treatment and--using a modified German version of the Pubertal Development Scale--for pubertal status. An orthodontic subgroup of these boys and girls was analyzed for age distribution and pubertal stage (χ(2) test).

Results: The orthodontic subgroup included 296 boys and girls (accounting for 29.3% of the total sample), 50% of whom (n=148) had already attained advanced stages of pubertal development. Broken down by gender, we observed advanced stages in 60% of the girls versus 38% of the boys (p<0.001). However, this gender-specific difference was not reflected in the orthodontic subgroup's age distribution (p>0.05). Irrespective of gender, most subjects undergoing orthodontic treatment were 12 or 13 years old.

Conclusion: Boys and girls in Germany undergo orthodontic treatment at the same age. Given the delayed onset of puberty in boys, most are still pre-pubertal, whereas most girls have reached an advanced stage of puberty by the time they undergo treatment--a discrepancy that could have therapeutic implications.
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http://dx.doi.org/10.1007/s00056-013-0145-0DOI Listing
May 2013

Frequency of orthodontic treatment in German children and adolescents: influence of age, gender, and socio-economic status.

Eur J Orthod 2012 Apr 12;34(2):152-7. Epub 2011 Apr 12.

Department of Orthodontics, School of Dentistry, University of Leipzig, Nuernberger Strasse 57, 04103 Leipzig, Germany.

Orthodontic treatment is a common dental procedure in developed countries. However, the frequency and factors associated with treatment demand are different between countries. The aim of this study was to examine the frequency of orthodontic treatment in German children and adolescents and to analyse the influence of age, gender, and socio-economic status (SES; education and region) on the frequency of treatment. Subjects in a random population sample of 1538 German children and adolescents, aged 11-14 years, were interviewed at home in the autumn of 2008 regarding current orthodontic treatment and associated factors. Approximately one-third (33.5 per cent) of the subjects interviewed were undergoing orthodontic treatment at that time. In a multivariable logistic regression model, the likelihood of receiving orthodontic treatment was higher for girls [odds ratio (OR) = 1.32, 95 per cent confidence interval (CI): 1.06-1.65], for high school pupils (OR = 1.19, 95 per cent CI: 1.06-1.34), and for children and adolescents living in the western part of Germany (OR = 1.45, 95 per cent CI: 1.00-2.08) and increased with age (OR = 1.13 per year, 95 per cent CI: 1.02-1.25). Subjects undergoing orthodontic treatment more often received prophylactic measures (OR = 2.06, 95 per cent CI: 1.63-2.59) compared with those not currently receiving orthodontic treatment. The frequency of orthodontic treatment in Germany largely depends on gender and SES.
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http://dx.doi.org/10.1093/ejo/cjq155DOI Listing
April 2012

Studies on the craniofacial morphology of adult cleft patients using euclidean distance matrix analysis (EDMA): a cephalometric study.

J Orofac Orthop 2009 Sep 9;70(5):396-406. Epub 2009 Dec 9.

Department of Orthodontics and Pediatric Dentistry, Friedrich Louis Hesse Center for Dentistry and Oral Medicine, University of Leipzig, Leipzig, Germany.

Objective: The aim of this study was to compare the craniofacial morphology of a group of orthognathic adults to adult patients with unilateral cleft lip and palate who had undergone delayed cleft closure.

Patients And Methods: Lateral cephalograms of 38 adult patients with unilateral cleft lip and palate (cleft group) were submitted for cephalometric analysis with Onyx Ceph((R)) and the x-y coordinates compared to measurements from a reference group of 103 untreated orthognathic adults (non-cleft group). Comparison was based on the cephalometric variables, and a Euclidean distance matrix analysis (EDMA) was applied to identify morphological differences, and describe their size and location.

Results: Cephalometric analysis revealed a mesial basal jaw relationship with a retrognathic craniofacial morphology in the cohort with unilateral cleft. EDMA revealed an increase in the vertical distances between A-Pog, ANS-Pog and N-Or. Deficits in the sagittal and vertical distances of the midface (S-ANS, Ba-A) were more pronounced. Differences in the mandibular morphology were also apparent (Ba-Go).

Conclusions: Key morphological characteristics of cleft patients are pronounced underdevelopment of the midface in vertical and sagittal dimensions, as well as shortening and clockwise rotation of the mandible. Therefore, bimaxillary procedures should be con- sidered for the purposes of surgical correction, rather than correction of the maxillary position alone.
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http://dx.doi.org/10.1007/s00056-009-9920-3DOI Listing
September 2009

In vitro analysis of laboratory-processed and CAD/CAM-generated occlusal onlay surfaces.

Int J Prosthodont 2009 Nov-Dec;22(6):620-2

Department of Prosthodontics, RWTH Aachen University Aachen, Germany.

The purpose of this study was to evaluate the occlusion of all-ceramic onlay surfaces generated with a laboratory (LAB) and computer-aided design/computer-assisted manufacturing (COMP) system. The treatment of the mandibular left first molar was simulated on 16 casts. A minimum of three static contacts and their localization were defined beforehand (MIN3). The occlusal contacts obtained (CORR) were analyzed and the mean quotients (MIN3/CORR) for COMP- and LAB-processed restorations were calculated (1.06 +/- 0.17 and 1.03 +/- 0.13, respectively). The Wilcoxon signed ranks test revealed no significant differences (P <.05).
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February 2010

Three-dimensional analysis of the deciduous dentition of patients with bilateral cleft lip and palate and delayed cleft closure.

J Orofac Orthop 2009 May 31;70(3):237-46. Epub 2009 May 31.

Department of Orthodontics, University of Leipzig, Leipzig, Germany.

Objective: The objective of this study was to describe the three-dimensional morphology of the maxilla of patients with bilateral cleft lip and palate treated by a delayed cleft closure in the deciduous dentition. They were compared to a eugnathic control group.

Patients And Methods: Thirty-two study casts of complete bilateral cleft lip and palate from the archive of the former Wolfgang-Rosenthal Clinic Thallwitz were scanned in three-dimensions and compared to an equally large eugnathic control group. The mean age of the study group was 4.92 years, and that of the control group 5.02 years. Dimensions were recorded using a reflex microscope according to specific landmarks.

Results: The study group exhibited transversal anterior compression and posterior over-development of the dental arch. We observed conspicuously more frequent, marked inward rotation of the left lateral segment together with broadly-scattered data. We were unable to establish a correlation between the anterior and posterior dental arch widths. In the sagittal dimension, the mean position of the premaxilla was in no way different than that of the control group. Vertically we noted a difference in the level between the premaxilla and lateral segments. The premaxilla was situated significantly more caudally than the lateral segments.

Conclusions: Even when cleft palate closure is delayed, the result is maxillary constriction and vertical deviation of the cleft segments. The large individual scatter of deviations demands a greatly individualized, differentiated concept for later maxillary development.
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http://dx.doi.org/10.1007/s00056-009-8814-8DOI Listing
May 2009

Morphometric analysis of facial profile in adults.

J Orofac Orthop 2008 Nov 11;69(6):424-36. Epub 2008 Nov 11.

Poliklinik für Kieferorthopädie, Zentrum für Zahn-, Mund- und Kieferheilkunde, Universität Leipzig, Leipzig, Germany.

Aim: Are centroid size, principal component analysis (PCA) and thin-plate splines (TPS) sufficient for determining facial morphology? Is it possible to identify relationships between cranial morphology, gender and facial profile?

Material And Methods: Profile photos of 110 adult patients were measured according to A.M. Schwarz landmarks using Onyx Ceph. Centroid size was calculated from x and y-coordinates. After Procrustes transformation, a principal component analysis for identifying major components of facial morphology was performed and the results visualized using thin-plate splines. At the same time, lateral cephalograms of all patients were analyzed according to Hasund.

Results: There were significant differences in centroid size betweeen male and female patients. Only the vertical skeletal structure had an impact on centroid size. Six components (PC1 to PC6) were identified using PCA. They were responsible for 86.5% of the variance. PC1 (33.9%) described scaling along an axis from Porion to chin. PC2 (28.6%) characterized the vertical dimensions of the lower face. Significant differences were only apparent between males and females in PC3 and PC4. In terms of cephalometric parameters, PC2 and PC3 differed in the vertical, and PC1 und PC2 in the sagittal configuration.

Conclusions: The analyses presented here suffice for describing facial morphology qualitatively and quantitatively as demonstrated by this example. Separating size from shape is useful for investigating therapeutically and growth-related morphological changes. It is difficult to draw conclusions about skeletal parameters.
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http://dx.doi.org/10.1007/s00056-008-8803-3DOI Listing
November 2008

Changes in arch form following surgically-assisted rapid maxillary expansion (SRME).

J Orofac Orthop 2008 May;69(3):177-88

Department of Orthodontics, Dental School, University of Leipzig, Germany.

Background And Aim: Surgically-assisted rapid maxillary expansion is a frequently employed procedure for expanding the maxilla in adults to treat pronounced transversal discrepancies of the upper jaw. Several studies have shown how the position of the anchorage teeth changes due to SRME. However, there is little detailed information available on the transversal movement of each tooth, its change in inclination and subsequent alterations of the arch length, width and sagittal arch form.

Material And Methods: In our study we investigated those changes in 31 patient casts after SRME, following the active phase, and after a 3-month retention period whereby the Hyrax appliance remained blocked in situ. The casts were examined using a 3-dimensional reflex microscope.

Results: After active treatment the second molars moved 28% less than the amount of total expansion. At 9.6 degrees (first bicuspid) and 11.6 degrees (first molar), the anchorage teeth were also more buccally tipped than the second molars (7.4 degrees ). Unlike with conventional maxillary expansion, the measured increase in arch length here corresponded to the amount of anchorage teeth expansion. The sagittal arch decreased significantly during the retention phase in those teeth in front of and behind the anchorage teeth. Three months later we found that only 68% of the original expansion had occurred in the canines and second molars. The inclination of the teeth decreased slightly but significantly. We observed an only temporary increase in the sagittal dimension after appliance activation. There was an average loss of 0.83 mm at the end of the retention phase. Moreover, the anterior dental arch length only experienced a 50% increase in space over the expansion achieved initially.

Conclusion: To minimize relapse rates in cases of severe crowding, we recommend that the canines and second molars be included in the appliance.
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http://dx.doi.org/10.1007/s00056-008-0738-1DOI Listing
May 2008

Potential and limits of achieving neutral occlusion in patients with clefts of lip, alveolus and palate.

J Craniomaxillofac Surg 2006 Sep;34 Suppl 2:67-72

Department of Orthodontics, Preventive and Pediatric Dentistry, E.-M.-Arndt University, Greifswald, Germany.

Introduction: Therapy of cleft patients aims to control bone growth and tooth development so as to ensure a secure occlusion with good function. This paper aims to uncover the potential and limits of achieving neutral occlusion in patients with clefts of lip, alveolus and palate. Two treatment approaches are presented and compared with respect to the best long-term results.

Patients And Methods: The first method implies occlusal rehabilitation using maximum intermaxillary orthodontic fixation with the Jasper Jumper. Thus, orthodontic dental-alveolar compensation of the anomaly is obtained. The second method represents orthognathic surgery to achieve ideal intermaxillary relations and a neutral occlusion. Two patients are described - one each for both treatment regimens.

Discussion: The methods presented are meant to illustrate possible options for sagittal jaw development/movement in patient management. Orthodontic treatment has to rely on cooperation with maxillofacial surgery to achieve a neutral occlusion. Optimal management is ensured by a combination of both orthodontic and maxillofacial therapy. The orthodontic and surgical techniques for managing unilateral or bilateral clefts are continuously being further developed.

Conclusion: Although orthodontic treatment can achieve good neutral occlusion in some patients, there are limitations and surgical measures may become necessary.
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http://dx.doi.org/10.1016/S1010-5182(06)60015-2DOI Listing
September 2006