Misaligned Teeth Research Articles

Editor's Comment and Q&A: Effect of arch form on the fabrication of working archwires

<h3>Introduction</h3> Previous studies have shown that most practitioners plan to maintain intercanine and intermolar widths during orthodontic treatment with fixed appliances. The aim of this study was to determine whether this was put into practice by clinicians during the latter stages of orthodontic treatment with fixed appliances. <h3>Methods</h3> This 2-part investigation was a laboratory-based measurement study at Bristol Dental Hospital, United Kingdom, from 2005 to 2007. Using standardized maxillary and mandibular study models with identical intermolar and intercanine widths but with differing degrees of tooth misalignment, 30 clinicians were asked to fabricate final working archwires according to their normal clinical practice. Then the intercanine and intermolar widths of the archwires were measured. In the second part of the study, the same intra-arch dimensions were measured directly from 50 pretreatment and posttreatment patient study models obtained from a subsample of 10 of the clinicians. <h3>Results</h3> The intercanine and intermolar widths measured on the adapted archwires from the standardized study models showed wide variations in the results, even though the intercanine and intermolar widths of the models were identical. Data from 50 treated patients also showed that, in most, there were wide variations in intercanine and intermolar widths between the patients' pretreatment and posttreatment study models. <h3>Conclusions</h3> Although most clinicians aim to maintain the pretreatment arch form, this study shows that this is often not transferred to clinical practice.

Effect of arch form on the fabrication of working archwires

Previous studies have shown that most practitioners plan to maintain intercanine and intermolar widths during orthodontic treatment with fixed appliances. The aim of this study was to determine whether this was put into practice by clinicians during the latter stages of orthodontic treatment with fixed appliances. This 2-part investigation was a laboratory-based measurement study at Bristol Dental Hospital, United Kingdom, from 2005 to 2007. Using standardized maxillary and mandibular study models with identical intermolar and intercanine widths but with differing degrees of tooth misalignment, 30 clinicians were asked to fabricate final working archwires according to their normal clinical practice. Then the intercanine and intermolar widths of the archwires were measured. In the second part of the study, the same intra-arch dimensions were measured directly from 50 pretreatment and posttreatment patient study models obtained from a subsample of 10 of the clinicians. The intercanine and intermolar widths measured on the adapted archwires from the standardized study models showed wide variations in the results, even though the intercanine and intermolar widths of the models were identical. Data from 50 treated patients also showed that, in most, there were wide variations in intercanine and intermolar widths between the patients' pretreatment and posttreatment study models. Although most clinicians aim to maintain the pretreatment arch form, this study shows that this is often not transferred to clinical practice.

Percepción y hábitos de salud bucodental en niños y adolescentes de Navarra, 2007

To determine the self-perception of oral health levels and the need for treatment, hygienic habits and frequency of visits to the dentist amongst schoolchildren in Navarre. The population of the study was aged 6, 12 and 14 years. The sample was obtained from schools teaching 1st and 6th year in Primary Education and 2nd year in Compulsory Secondary Education. The data was gathered through self-answering questionnaires. Ninety-two percent of 6 and 12 year olds, and 82.9% of 14 year olds are satisfied with their oral health. Thirteen point one percent of 12 year olds and 19.3% of 14 year olds are dissatisfied, above all with misaligned teeth. Approximately one-third think they need some treatment, above all fillings at age 6 and orthodontics at 12 and 14 years. Nearly two-thirds say they brush their teeth more than once a day and between 80 and 90% say they have visited the dentist in the last year. More than 75% of those responsible for the schoolchildren aged 6 and 12 years make a positive evaluation of the contributions of the child dental care program (PADI) and more than 95% are satisfied with the care given by PADI dentists to their children. Sex, average residence and socioeconomic level barely influence the perception of health, frequency of brushing teeth or need for treatment. The study reveals that the subjective perception of oral health is good and that one-third of those surveyed think they need some type of treatment. It is very positive that they majority say that they have been to the dentist in the last year and that they brush their teeth more than once a day, which is an improvement on the results of previous studies.

Past Performance Based on Future Results, and: The End of Cause and Effect, and: When We Were Rich

158 RACHEL ZUCKER PAST PERFORMANCE BASED ON FUTURE RESULTS There we were asset striping, engaging in unbridled naked short selling, while the big swinging dicks got by on greater fool theory. Stock boys going down on Franny and Freddy in murky corners of the market while Morgan, Lehman, and Merrill woke up to find themselves a Texas hedge away from the pink sheets. Longs were down and shorts were up but, what the fuck—we were prime brokered, we were counter partied, we were outperforming. Gold Kist is still an attractive risk. Helen of Troy sells to Target and Walmart, two brutal negotiators, and our favorite pick has a near-monopoly on misaligned teeth. So, come on, let’s pump and dump and pump and dump. Sell on the rumor and buy on the news. Our shorts are compellingly vulnerable. Our current exposure is high. We’re holding our holdings, except when we swap. We still seek volatility and bottoms, and, under the avalanche of bad paper, offer ample opportunity. 159 THE END OF CAUSE AND EFFECT Forgive us for raising this while you’re dealing with important issues in the Middle East, but could you clarify for us, sir, exactly what your relationship was with Ms. Lewinsky? There is a ~ between fiber and ?. Estrogen and. Water ~ a&sociation. co&nection. a&filliation the nature of the relationship co~relation between heart disease & colorectal cancer & aluminum & plastic & libido & medicine & : : : you [baby] sleep me fucked (pornograph) no sleep gamete hospital no whining , boy cycle re New York normal [childhood] & shhhhhhhhhhhhh email stupid houseplants others / family allergens anti- & & coagulants blood pact family mites misery other RACHEL ZUCKER 160 [nettles] states : : forgive ness cessity ’s ’s ’s-fights mine turn taking notebook sleep making : : dinner / love / your brother crazy dreams waking want other men ’s more “s”’s history New York other citys air quality time park children germ states play boroughs under ground cry-it-out night-waking(s) outlook five day new repelling forecast (by) products 1/2 lives wicking non-degradable made material eternal all ill will will existential waking spousal filial outlast & us & you & baby state : : of desire of mind of despair of disrepair of the nation war apartment grace disaster of emergency of need of [an & makes two anythings co&nected but doesn’t cause] [peanut butter & [jelly] anaphalactic] shock the nature of the relationship [epi] of the relationship [epic] night serial prophylactic I did not have did not have did not have [breasts and hands] 161 WHEN WE WERE RICH We hardly had sex. I bet celebrities didn’t either. We bought cage-free, grain-fed eggs instead and found solace in fine dining. We paid our hip, chaste nanny well and insured the lives of those we loved. We met with school psychologists when nothing was wrong and summered where the ocean shocked our cerebral offspring. Otherwise we discussed the diversity and toxicity of our urban epicenter in smug and terrified tones. Foreigners wanted to kill us and buy our overvalued real estate. We bemoaned the demise of Humanism, Liberalism, Intellectualism, over microgreens and grass-fed brisket. We were fat or over-exercised by half-naked trainers who confessed celibacy between motivational tirades. We wore “mensch” and “homebirth mama” T-shirts and practiced armchair activism between episodes of meticulous television. At night we snored or suffered insomnia unaided by our extensive knowledge of herbs, tonics, tinctures and decoctions. We helped women have the births they wanted or high school students get into elite colleges. We combined apartments and adopted endangered animals on the internet. We had stars named after our sons and ran into Philip Roth in Central Park and in Zabar’s where we bought smoked fish even though the sable is better at Barney Greengrass. That was when we were rich but didn’t know it, didn’t know what we were missing. Now we’re fucked. Every night. RACHEL ZUCKER ...

Siblings with the adult-onset slowly progressive type of pantothenate kinase-associated neurodegeneration and a novel mutation, Ile346Ser, in PANK2: Clinical features and 99mTc-ECD brain perfusion SPECT findings

Pantothenate kinase-associated neurodegeneration (PKAN), formerly known as Hallervorden–Spatz syndrome (HSS), is an autosomal recessive neurodegenerative disorder characterized by iron accumulation in the brain. Mutations in the pantothenate kinase 2 ( PANK2) gene are known to be responsible for PKAN. Several studies have revealed correlations between clinical phenotypes and particular PANK2 mutations. The adult-onset slowly progressive type of PKAN with PANK2 mutations is very rare. In this report, we describe siblings with the adult-onset slowly progressive type of PKAN with a novel mutation, Ile346Ser, in PANK2. The siblings had the same mutation in PANK2 and had common clinical signs such as misalignment of teeth, a high arched palate, hollow feet, a slight cognitive decline, and an apparent executive dysfunction, although they showed different patterns of movement disorders. Thus, even if PKAN patients have identical mutations, it is likely that they will present with different types of movement disorders. Brain perfusion single photon emission computed tomography in both patients showed decreased regional cerebral blood flow in the bilateral frontoparietal lobes, the globus pallidus, the striatum, and around the ventriculus quartus. Cardiac uptake of [ 123I] meta-iodobenzylguanidine was normal in both patients. Analysis of genotype–phenotype correlations and the elucidation of mutational effects on pantothenate kinase 2 function, expression, and structure are important for understanding the mechanisms of PKAN.

Application of shape memory polyurethane in orthodontic

A shape memory polymer wire for orthodontic application was prepared by melt-spinning of polyurethane block copolymer (PU) which was synthesized in a two-step process from a reaction of 4,4'-methylene bis(phenylisocyanate), poly(ε-caprolactone)diol (PCL), and 1,4-butanediol. An orthodontic test using the PU wire was carried out in an orthodontic model with a metal bracket. High shape recovery force of 70 gf for PU wire at 40 wt% hard segment content could be preserved for even 1 month after a shape recovery force test at a constant temperature of 50°C. The shape recovery force decreased exponentially during the initial 2 h, but reached an equilibrium shape recovery force of 50 gf after about 20 days. It was found that this shape recovery force was sufficient to correct misaligned teeth in the orthodontic test. The shape memory PU wire possesses strong potential as a novel orthodontic appliance with esthetically appealing appearance.

Hurler syndrome or Morquio syndrome: Intelligence required for diagnosing the case

Dear Sir, I have read with interest the article by Das et al.,[1] in which they have described a child with Hurler syndrome (MPS I), diagnosed on the basis of the clinical findings and radiological examination. In Hurler syndrome, the diagnosis is made between 6-24 months in the presence of hepatosplenomegaly, skeletal deformity, coarse facial features, corneal clouding, joint stiffness, and short stature. Hearing loss is common and developmental delay, with moderate mental retardation, is present.[2] Morquio syndrome, on the other hand, is characterized by short-trunk dwarfism, corneal deposits, skeletal dysplasia, and preservation of intelligence. Extraskeletal manifestations may include hepatomegaly, cardiac valvular lesions, and small teeth with caries formation.[2,3] The author has not mentioned the status of mental development or the results of echocardiography. In my opinion, this may be a patient with Morquio syndrome in view of the presence of hepatomegaly, cardiac valvular lesion, swollen alveolar ridges and gums with misaligned teeth, cloudy corneas, skeletal dysplasia, normal auditory functions, and normal intelligence.

Metric analysis of the hard palate in children with Down syndrome - a comparative study

The hard palate is viewed as playing an important role in the passive articulation of speech. Its probable role in the defective articulation of speech in individuals with Down syndrome has been examined in the present study. In individuals with Down syndrome, the hard palate is highly arched, constricted, and narrow and stair type with malformed misaligned teeth and a large and fissured tongue. As a result good palato-lingual contact is not achieved, with resulting defective articulation. Using orthodontic and prosthodontic principles could modify this situation, i.e. the anatomy of the hard palate. The altered palatal contour may give better placing to the tongue, leading to improved palato-lingual contact and articulation. The dimensional parameters measured were: average linear width (AVL), average curvilinear width (AVCL), average height (AVH) at different planes; average antero-posterior length (AAP), average volume (V), palatal arch length (PAL), and palatal index (PI). The findings were compared with those of controls of the same age and sex. The AVL, AVCL, AAP, PAL, V and PI values of patients with Down syndrome were found to be less than the corresponding values of controls and the average height values of patients with Down syndrome were greater than the corresponding values of controls. Statistical significance was observed in all measurements between the controls and the patients with Down syndrome, especially in those concerning the height and the volume of the oral cavity. Observations from this study have suggested that prostheses might be designed to modify the palatal anatomy and produce better articulation in people with Down syndrome.

Odontogenic Keratocysts Arise from Quiescent Epithelial Rests and Are Associated with Deregulated Hedgehog Signaling in Mice and Humans

Odontogenic keratocysts in humans are aggressive, noninflammatory jaw cysts that may harbor PTCH1 mutations, leading to constitutive activity of the embryonic Hedgehog (Hh) signaling pathway. We show here that epithelial expression of the Hh transcriptional effector Gli2 is sufficient for highly penetrant keratocyst development in transgenic mice. Mouse and human keratocysts expressed similar markers, leading to tooth misalignment, bone remodeling, and craniofacial abnormalities. We detected Hh target gene expression in epithelial cells lining keratocysts from both species, implicating deregulated Hh signaling in their development. Most mouse keratocysts arose from rests of Malassez--quiescent, residual embryonic epithelial cells that remain embedded in the periodontal ligament surrounding mature teeth. In Gli2-expressing mice, these rests were stimulated to proliferate, stratify, and form a differentiated squamous epithelium. The frequent development of keratocysts in Gli2-expressing mice supports the idea that GLI transcription factor activity mediates pathological responses to deregulated Hh signaling in humans. Moreover, Gli2-mediated reactivation of quiescent epithelial rests to form keratocysts indicates that these cells retain the capacity to function as progenitor cells on activation by an appropriate developmental signal.

Orthodontic treatment with a series of removable appliances

In the United States, the demand for straight white teeth has never been more important to patients. Crowded, poorly aligned teeth are not esthetically pleasing and are difficult to keep clean. However, until recently, the process of straightening the teeth typically has involved appliances involving bands, brackets and wires that also can be difficult to clean. The desire for a cosmetic solution to misaligned teeth has led to an increase in the number of patients seeking veneers, crowns and other laboratory-fabricated cosmetic restorations. Some clinicians are not aware that there are other ways to align teeth without either significant enamel reduction or conspicuous fixed orthodontic appliances. An alternative method of treatment, involving a series of clear removable appliances, circumvents this shortcoming and enables tooth alignment while avoiding deterioration in the cosmetics of the smile during treatment. This article describes a method of treatment, Invisalign (Align Technology, Santa Clara, Calif.), that clinicians can use in conjunction with 3-D computer models to accomplish the esthetic and oral hygiene objectives during and after treatment. The authors present three case reports, all involving a chief concern of crowding. The first case involved treatment of both arches by interproximal reduction, alignment of teeth and leveling the curve of Spee. The second case involved treatment of both arches by proclination, expansion and minor interproximal reduction. The final case shows relief of lower-arch crowding via lower-incisor extraction. In addition to satisfying the patient's chief concern of desiring straight teeth, this method of treatment satisfies additional objectives of esthetic treatment and esthetic results with significant oral hygiene benefits. Clinicians can address a patient's chief concern effectively without requiring an inventory of appliances (such as bands, brackets, wires and instruments). Furthermore, the use of 3-D computer models can give clinicians additional information to make more complete decisions regarding treatment.

Fibre reinforced thermoplastic composites for dentistry

Clinical implementation of fibre-reinforced composites (FRCs) for treatment of misaligned teeth requires a stability of the material under stress in a moist environment. The performance of the material is strongly dependent on its resistance to hydrolytic deterioration of the components. Of particular concern are the quality and durability of the interfaces between the fibres and the matrix. Scanning electron microscopy (SEM) was utilized to evaluate qualitatively the effect of water immersion on the interfaces between constituents in a variety of E-glass fibre-reinforced thermoplastics. A particular series of organosilane-coated fibres embedded in polycarbonate (PC) were chosen for further quantitative study of the residual shear strength of the interfaces using an embedded-single-fibre test. Annealed PC and maleated polypropylene (MPP) reinforced with bare E-glass fibres have an appropriate combination of mechanical properties and environmental stability for potential orthodontic applications. The usual sizing agents used for commercial E-glass fibres interfere with the bonding of the fibres to the matrix and the usual silane treatments used to promote bonding could lead to problems of hydrolytic stability under extreme conditions of stress and moisture.

Melnick–Needles syndrome (osteodysplasty) in an older male–report of a case and a review of the literature

In 1966 Melnick and Needles reported on a previously undiagnosed bone dysplasia. The diagnosis was based on characteristic radiographic findings: a delay in closure of the anterior fontanel, i.e. sclerosis of the skull base and mastoids. The long tubular bones are bowed with cortical irregularities and metaphyseal flaring. The ribs also show cortical irregularities and have a ribbonlike or wavy appearance. The vertebral bodies show an increase in height with a decrease in antero-posterior measurement and anterior scalloping. A decrease in disk space is also present. The pelvis has a typical constricted appearance with flaring of the iliac crest and tapering of the ischial and pubic bones. The clinical signs include exophthalmos, full prominent cheeks, mild hypertelorism, micrognatia, large ears and misaligned teeth. Females are affected almost exclusively and inheritance is in an X-linked dominant pattern. The condition is lethal in males born from Melnick–Needles syndrome (MNS) mothers (Donnenfeld, 1987). Three male patients (born from normal parents) are reported to have reached the age of 3 years. We present the case of an 11-year-old boy, the oldest living male patient documented so far.

Analytical and Experimental Investigation of Magnetic Support Systems. Part II: Experimental Investigation

An experimental apparatus was developed for measuring forces and fluxes in the gap between magnetic surfaces. A test program, conducted for both aligned and misaligned teeth, showed very good agreement between the analytical expressions, developed in a companion paper and the present test results. This agreement was found to prevail even at relatively high flux levels and a high degree of misalignment.