ABSTRACT
INTRODUCTION: Skeletal maturation assessment has a great role in many health professions especially in Orthodontics & Dentofacial Orthopedics. Functional appliances have proved to be more effective when used at the peak of mandibular growth, rather than before. AIM: The aim of this study was to evaluate whether the calcification stages of permanent maxillary canine are useful to assess skeletal maturity. MATERIALS AND METHODS: In this cross-sectional study, samples were derived from panoramic radiographs and lateral cephalograms of 300 subjects (137 males and 163 females) with their age ranging from 9 to 18 years. Dental maturity {Demirjian Index (DI)} and skeletal maturity {Cervical Stages (CS)} were assessed from radiographs. The Pearson chi-square test (χ2) and Sakoda adjusted Pearson contingency coefficient (C*) were calculated to determine the correlation between DI and CS. RESULTS: A highly significant association (C* = 0.851, p<.001for males and 0.879, p<.001 for females) was found between DI and CS. DI stage E coincided with CS2 (pre-peak of pubertal growth spurt) & DI stage F coincided with CS3 (peak of pubertal growth spurt) for all the subjects. DI stage H corresponded to CS5 and CS6 (end of peak of pubertal growth spurt). CONCLUSION: A highly significant association was found between DI and CS. Maxillary canine DI stages could be useful to assess skeletal maturity.
ABSTRACT
The conserved SecYEG protein-conducting channel and the accessory proteins SecDF-YajC and YidC constitute the bacterial holo-translocon (HTL), capable of protein-secretion and membrane-protein insertion. By employing an integrative approach combining small-angle neutron scattering (SANS), low-resolution electron microscopy and biophysical analyses we determined the arrangement of the proteins and lipids within the super-complex. The results guided the placement of X-ray structures of individual HTL components and allowed the proposal of a model of the functional translocon. Their arrangement around a central lipid-containing pool conveys an unexpected, but compelling mechanism for membrane-protein insertion. The periplasmic domains of YidC and SecD are poised at the protein-channel exit-site of SecY, presumably to aid the emergence of translocating polypeptides. The SecY lateral gate for membrane-insertion is adjacent to the membrane 'insertase' YidC. Absolute-scale SANS employing a novel contrast-match-point analysis revealed a dynamic complex adopting open and compact configurations around an adaptable central lipid-filled chamber, wherein polytopic membrane-proteins could fold, sheltered from aggregation and proteolysis.
Subject(s)
Escherichia coli Proteins/chemistry , Escherichia coli/chemistry , Membrane Transport Proteins/chemistry , SEC Translocation Channels/chemistry , Binding Sites , Cloning, Molecular , Cryoelectron Microscopy , Escherichia coli/genetics , Escherichia coli/metabolism , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Gene Expression , Genetic Vectors/chemistry , Genetic Vectors/metabolism , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Methanocaldococcus/chemistry , Methanocaldococcus/genetics , Methanocaldococcus/metabolism , Models, Molecular , Neutron Diffraction , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Protein Transport , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , SEC Translocation Channels/genetics , SEC Translocation Channels/metabolism , Scattering, Small Angle , Structural Homology, Protein , Substrate Specificity , Thermus thermophilus/chemistry , Thermus thermophilus/genetics , Thermus thermophilus/metabolismABSTRACT
Patients with deep bites or crossbites often need temporary bite opening to prevent mandibular brackets from being sheared off and to allow unobstructed tooth movement. Here we present a simple auxiliary occlusal extension for temporary bite opening to correct an anterior crossbite. The bite plane is hygienic, less intrusive to the tongue space and prevents supra-eruption of the adjacent as well as opposing teeth.
Subject(s)
Malocclusion/complications , Malocclusion/therapy , Occlusal Splints , Overbite/complications , Adolescent , Humans , Orthodontic Appliances, Removable , Overbite/therapy , Vertical DimensionABSTRACT
Borderline and mild skeletal Class III relationships in adult patients are usually treated by orthodontic camouflage. Reasonably rood results have been achieved with nonsurgical teatment of anterior crossbite. Class III malocclusion may be associated with mandibular prognathism, maxillary retrognathism, or both. Class III maxillary retrognathism generally involves anterior crossbite, which must be opened if upper labial brackets are to be bonded. If multiple teeth are in crossbite, after opening the bite usual step is to ligate forward or advancement arch made of 0.018" or 0.020" stainless steel or NiTi wire main arch that must be kept separated 2 mm from the slot ofupper incisor braces. Two stops or omegas are made 1 mm mesial to the tubes of the molar bands that will impede main arch from slipping,and in this manner the arch will push the anterior teeth forward Here we have fabricated a modified multiple loop protrusion arch to correct an anterior crossbite with severe crowding that was not amenable to correct by advancement arches.
Subject(s)
Malocclusion, Angle Class III/therapy , Orthodontic Appliance Design , Orthodontic Wires , Adolescent , Dental Arch/pathology , Female , Humans , Incisor/pathology , Maxilla/pathology , Overbite/therapy , Tooth Movement Techniques/instrumentationABSTRACT
We have investigated the magnetic properties of four recently synthesized stable TMM-type nitroxide diradicals. Four new diradicals are proposed by tailoring one of the species in such a way that both conjugation and planarity increase. As a remarkable consequence, the intramolecular ferromagnetic exchange interaction was found to be quite high in the proposed radicals. The calculated coupling constants were in the range of +102 to +140 cm-1. The MO and spin density analysis are provided to interpret the exchange interactions. We observed the existence of intramolecular pi-pi-interactions for the species 2. This slightly increased the J value by shortening the length of the spacer between the two spin sources.
