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This case report describes a patient with severe (11-mm) mandibular anterior crowding who received periodontally accelerated osteogenic orthodontics (PAOO) nonextraction treatment, showing 5-year follow-up. A 15-year-old female presented with severe dental crowding, Angle Class I skeletal and molar relationships and a Class II canine relationship, and excessive overjet and overbite. Following fixed-appliance placement (0.022-inch, MBT prescription), full-thickness periosteal flaps beyond the tooth apices were raised bilaterally from the second molars in both arches, and selective decortication of cortical bone was performed on the facial and lingual sides using a surgical tool. Bone grafting material, comprised of a mixture of demineralized freeze-dried bone allograft (DFDBA) and bovine bone (Bio Oss, Geistlich), was placed at the corticotomy sites. The patient was seen every 2 weeks after the surgery for orthodontic adjustments; the total active orthodontic treatment time was 9 months. Limits of tooth movement (the scope of treatment) were increased by the bone-graft augmentation. At the 5-year follow-up, cephalometric comparisons to baseline conditions showed dramatic incisor changes and stable dentoalveolar effects. This case demonstrates the efficacy of PAOO as a useful adjunct orthodontic strategy for adult patients who require treatment of severe crowding, ie, treatment that would be considered unreasonable if conventional orthodontics were employed. When conventional orthodontics cannot achieve the treatment goal and orthognathic surgery is not feasible, PAOO expands the scope of conventional orthodontic treatment in the adult 2-fold to 3-fold in most spatial dimensions. [ABSTRACT FROM AUTHOR]

Suggests that practical and emancipatory knowledge (Habermas, 1971) have been underemphasized in dental curriculum, and that until they are fostered, visions of competency and the joining of theory and practice will be difficult to achieve. Highlights strategies to foster such knowledge within competency-based curricula: problem-based learning and case methods, heuristic strategies, reflective practica, journals, reflective storytelling, and performance-based assessment. (EV)

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Ni-dependent carbon monoxide dehydrogenases (Ni-CODHs) are a diverse family of enzymes that catalyze reversible CO:C[O.sub.2] oxidoreductase activity in acetogens, methanogens, and some CO-using bacteria. Crystallography of Ni-CODHs from CO-using bacteria and acetogens has revealed the overall fold of the Ni-CODH core and has suggested structures for the C cluster that mediates CO:C[O.sub.2] interconversion. Despite these advances, the mechanism of CO oxidation has remained elusive. Herein, we report the structure of a distinct class of Ni-CODH from methanogenic archaea: the [[alpha].sub.2][[epsilon].sub.2] component from the [[alpha].sub.8][[beta].sub.8][[gamma].sub.8][[delta].sub.8][[epsilon].sub.8] CODH/acetyl-CoA decarbonylase/ synthase complex, an enzyme responsible for the majority of biogenic methane production on Earth. The structure of this Ni-CODH component provides support for a hitherto unobserved state in which both CO and [H.sub.2]O/O[H.sup.-] bind to the Ni and the exogenous FCII iron of the C cluster, respectively, and offers insight into the structures and functional roles of the [epsilon]-subunit and FeS domain not present in nonmethanogenic Ni-CODHs. carbon dioxide | carbon monoxide | oxidoreductase | acetate | methanogenesis

Research reveals that methanogenesis from tri-, di-, and monomethylamine is mediated by three different methyltransferases in the archaeal bacteria. Results indicate that genes encoding the enzymes exhibit in-frame amber codons.