Management of Traumatically Luxated Permanent Teeth: A Retrospective Study

Ivette Landrian Daly: Management of Traumatically Luxated Permanent Teeth: A Retrospective Study (Under the direction of Lorne D. Koroluk) The International Association of Dental Traumatology guidelines state that teeth must be repositioned after luxation injuries, however, the specific method of repositioning has not been specified. The purpose of this study was to compare pulpal and periodontal outcomes of digitally and orthodontically repositioned incisors following extrusive and lateral luxation. The study sample was comprised of 80 (32 females, 48 males) subjects with 126 teeth treated for lateral and extrusive luxation injuries. Forty-one teeth were orthodontically repositioned, 67 teeth digitally repositioned and 18 teeth had mixed treatment. Overall, 35.7% of the teeth required follow up endodontic treatment. Follow up treatment was required in 19.5% of the orthodontically repositioned teeth, 40.3% of the digitally repositioned teeth and 55.6% of the mixed treatment teeth. There was a statistically significant difference in the frequency of follow up endodontic treatment between the three groups; the orthodontically repositioned teeth required less intervention (p=0.02).Master of Scienc

Inheritance patterns of ATCCT repeat interruptions in spinocerebellar ataxia type 10 (SCA10) expansions

<div><p>Spinocerebellar ataxia type 10 (SCA10), an autosomal dominant cerebellar ataxia disorder, is caused by a non-coding ATTCT microsatellite repeat expansion in the ataxin 10 gene. In a subset of SCA10 families, the 5’-end of the repeat expansion contains a complex sequence of penta- and heptanucleotide interruption motifs which is followed by a pure tract of tandem ATCCT repeats of unknown length at its 3’-end. Intriguingly, expansions that carry these interruption motifs correlate with an epileptic seizure phenotype and are unstable despite the theory that interruptions are expected to stabilize expanded repeats. To examine the apparent contradiction of unstable, interruption-positive SCA10 expansion alleles and to determine whether the instability originates outside of the interrupted region, we sequenced approximately 1 kb of the 5’-end of SCA10 expansions using the ATCCT-PCR product in individuals across multiple generations from four SCA10 families. We found that the greatest instability within this region occurred in paternal transmissions of the allele in stretches of pure ATTCT motifs while the intervening interrupted sequences were stable. Overall, the ATCCT interruption changes by only one to three repeat units and therefore cannot account for the instability across the length of the disease allele. We conclude that the AT-rich interruptions locally stabilize the SCA10 expansion at the 5’-end but do not completely abolish instability across the entire span of the expansion. In addition, analysis of the interruption alleles across these families support a parsimonious single origin of the mutation with a shared distant ancestor.</p></div

A minimum spanning network depicting the hypothesized evolution of the ATCCT repeat interruption alleles.

<p>Filled colored circles and numbers correspond to interruption alleles as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175958#pone.0175958.g001" target="_blank">Fig 1</a>. The open blue circle represents a hypothetical allele suggested to exist based on the network. Each bidirectional arrow represents a single repeat unit change between alleles and each arrow notes specific changes. When multiple repeat changes exist between interruption alleles, the order of the repeat changes is not known, i.e. the order of changes between alleles 2 and 3 is not known. The alleles that appear in each family are contained within a red oval and the family (C, M, N, Z) is noted within. The network does not reflect the variation at the distal variable region, theta.</p

The ATCCT repeat interruption is stable through generations.

<p>(A) Schematic of an average length SCA10 expansion allele demonstrating the relative location of the priming sites for the ATCCT PCR amplification and sequencing primers and the relative size of the ATCCT product. White box, ATTCT repeats; hatched black and white box, interruption motifs; green box, presumed pure tract of tandem ATCCT repeat motifs; black box, flanking non-expansion sequences. (B) Detailed schematic of repeat motifs within the ATCCT product. Allele 5 is depicted. White rectangles, ATTCT repeat; orange, ATTTTCT; blue, ATATTCT; green, ATCCT. (C) Seven interruption alleles were observed based on the number of ATTCT repeats observed within each polymorphic stretch (alpha, beta, gamma, delta, epsilon, zeta and eta). (D) SCA10 family pedigrees, only SCA10-positive individuals are shown. Generations are indicated by roman numerals to the left of each pedigree. Square (males) and circles (females) are color-coded by repeat interruption group. Black, undetermined allele; light blue, allele 1; green, allele 2; red, allele 3; yellow, allele 4; grey, allele 5; dark blue, allele 6; tan, allele 7. Numbers below male/female symbols indicate the SCA10 expansion size (in repeat units) determined via Southern blotting; n.d. indicates that the SCA10 expansion size was not determined due to insufficient DNA quality. Thick blue lines, paternal transmissions examined; thick red lines, maternal transmissions examined.</p

Expansion of the Spinocerebellar ataxia type 10 (SCA10) repeat in a patient with Sioux Native American ancestry.

Spinocerebellar ataxia type 10 (SCA10), an autosomal dominant cerebellar ataxia, is caused by the expansion of the non-coding ATTCT pentanucleotide repeat in the ATAXIN 10 gene. To date, all cases of SCA10 are restricted to patients with ancestral ties to Latin American countries. Here, we report on a SCA10 patient with Sioux Native American ancestry and no reported Hispanic or Latino heritage. Neurological exam findings revealed impaired gait with mild, age-consistent cerebellar atrophy and no evidence of epileptic seizures. The age at onset for this patient, at 83 years of age, is the latest documented for SCA10 patients and is suggestive of a reduced penetrance allele in his family. Southern blot analysis showed an SCA10 expanded allele of 1400 repeats. Established SNPs surrounding the SCA10 locus showed a disease haplotype consistent with the previously described "SCA10 haplotype". This case suggests that the SCA10 expansion represents an early mutation event that possibly occurred during the initial peopling of the Americas

SMRT sequencing results summary.

<p>^§as estimated by gel electrophoresis of cloned expansion fragment excised from plasmid backbone.</p><p>^<b>¶</b><b>As compared with Sanger sequencing.</b></p><p>*Alignment based on reference genome sequence (NC_000022.11; GI: 568815576, Region: 45794523..45796589) using LALIGN.</p><p>^as determined by counting motif blocks in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135906#pone.0135906.g002" target="_blank">Fig 2</a>. Rpts, repeats; nts, nucleotides; bp, base pairs</p><p>SMRT sequencing results summary.</p

pJAZZ-OCmin vector.

<p>The telN gene and several non-essential genes from phage N15 (purple boxes) were deleted from the vector pJAZZ-OC. repA, cB: replication protein genes; Cam^r, chloramphenicol resistance; T, terminator. Closed terminal hairpin structures are indicated by black circles.</p

SCA10 expansion templates for SMRT sequencing.

<p>(A) PCR amplification of the SCA10 expansion from gDNA extracted from blood lymphocytes (Subjects A and B) or from somatic cell hybrid lines (subject C). Lanes are cropped from non-adjacent lanes of the same gel. The full gel is shown is <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135906#pone.0135906.s001" target="_blank">S1 Fig</a>. Arrows indicate the size of bands that were excised for cloning and sequencing (subject A, the 6.5 kb band; subject B, the 5.9 kb band; subject C, the 4.7 kb band) (B) Purified template from cloned PCR products in Fig 1A for SMRT sequencing. L: 1 kb ladder (New England Biolabs). The full gels are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135906#pone.0135906.s002" target="_blank">S2 Fig</a>.</p

Schematic representations of the repeat expansions.

<p>(A) SCA10 expansion in subject A. (B) SCA10 expansion in subject B. (C) SCA10 expansion in subject C. Rectangles represent sequence motifs, as indicated by the color key, in the 5’ (upper left) to 3’ (lower right) direction. Black rectangles indicate unverified motifs described further in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0135906#pone.0135906.g003" target="_blank">Fig 3B</a> and are indicated as follows: A: ATTTCT, ATTTCT; B: ATTTCT, A, ATTTCT, A, ATTCCT, TAC, ATTTCT, A, ATT, ACTTCT, ATTCA, ATTTCT, ATTTCT, T, ACTTTCT, TCTTTCT, ATTT, ATTTCT, ATCT, ATTTCT, ATTTCT, ATTTCT, ATTTCT, ATTTCT, T, ATCC, ATTC, ATTTCC, C, ATTTCC, TTCCC, ATTTCC, CATCC, ATTTCC, C, C, C, C, ATTC, ATTTCC, ATTCC; C: ATCT, ATCT, ATCT, AT, ATCT, T, ATC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, C, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, ATC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, ATCC, C</p

Proportion of repeat motifs in SCA10 expansions.

<p>Proportions are calculated as the percentage of nucleotides of each motifs divided by the total number of nucleotides for each expansion. Motifs present in SMRT sequence results that are verified by Sanger sequencing methods (“shotgun”) comprise the majority of motifs seen (A) while some motifs are unverified (B). Green, SMRT sequencing results from subject A; Green hatched, random shotgun sequencing results from subject A; Blue, SMRT sequencing results from subject B; Red, SMRT sequencing result from subject C; Red hatched, random shotgun sequencing results from subject C.</p