Pavlína Černochová

Root resorption associated with ectopically erupting maxillary permanent canines: a computed tomography study

The aims of this retrospective computed tomography (CT) study were to determine the occurrence of severe root resorption involving the pulpal canal of adjacent permanent teeth associated with ectopically erupting canines, and to verify the existence of related factors. The sample consisted of 255 consecutive patients (159 females and 96 males, mean age 18.4 and 16.8 years, respectively). Three hundred and thirty-four ectopic maxillary canines and adjacent teeth were analysed using CT images. Statistical significance was evaluated with chi-square and Fishers exact tests. The results showed that severe root resorption of adjacent permanent teeth occurred in 17.7 per cent of ectopic canines and was equally common in females and males. Severe root resorption affected 12.6 per cent of the lateral incisors, 4.8 per cent of the first premolars, and 2.1 per cent of the central incisors. No relationship was found between the type or side of ectopic eruption, inclination of the longitudinal axis of the ectopic canine and the occurrence of severe root resorption. A significant relationship was found between a bucco-lingual position of the ectopic canine and root resorption (P < 0.05). Root resorption mainly occurred in the apical third (57.6 per cent) and apical and middle thirds (27.1 per cent). A significant relationship existed between the occurrence of root resorption and complete loss of space for the erupting canine (P < 0.05). No association was found between alignment of the upper permanent incisor and root resorption. A widened dental follicle occurred in 15 per cent of ectopic canines but did not cause root resorption of the adjacent permanent teeth. Since root resorption is asymptomatic, early detection by radiographic examination is essential for correct diagnosis and treatment.

IL1 gene polymorphisms in relation to external apical root resorption concurrent with orthodontia

OBJECTIVE External apical root resorption (EARR) is permanent shortening of the end of the tooth root. It is a common clinical complication of orthodontic treatment. Polymorphisms in the interleukin 1 (IL1) gene cluster have been related to an increased EARR risk. The aim of this study was to analyze possible associations of IL1 gene variants with EARR in Czech population. SUBJECTS AND METHODS In this case-control study, 32 patients with EARR (age 15.0 ± 4.1 years) and 74 controls (age 15.2 ± 5.3 years) were genotyped using PCR-based methods for IL1A (-889C/T), IL1B (+3953C/T), and IL1RN [IL1 receptor antagonist, variable number tandem repeat (VNTR)] gene polymorphisms. RESULTS While no statistical significant differences in the IL1A and IL1B genotype, allele and reconstructed IL1 haplotype frequencies between patients with EARR and controls were found, marginally significant differences were observed in the frequencies of IL1RN variant (P = 0.05 for *22 genotype and P = 0.06 for a short (2) allele). In addition, significant associations between IL1RN*12, *22 genotypes and the short (2) allele and EARR were identified in the subgroup of girls (P = 0.04 and P = 0.02, P = 0.02). CONCLUSIONS Although no significant role of IL1A (-889C/T) and IL1B (+3953C/T) variants in EARR was confirmed, IL1RN VNTR may be associated with EARR, especially in girls.

Dentoskeletal characteristics in patients with palatally and buccally displaced maxillary permanent canines

The aim of this retrospective study was to analyse dentoskeletal characteristics in patients with eruption disturbances of the maxillary permanent canines. Pre-treatment panoramic radiographs and lateral cephalograms of 636 consecutive orthodontic patients were assessed. The control group included 456 patients with physiologically erupted maxillary permanent canines (261 females and 195 males, mean age 12.6 and 12.4 years, respectively). The other groups comprised 144 subjects with palatally displaced canines (PDCs) (92 females and 52 males, mean age 14.2 and 14.7 years, respectively) and 36 patients with buccally displaced canines (BDCs) (16 females and 20 males, mean age 12.4 and 12.8 years, respectively). The selected dentoskeletal parameters were compared with classic cephalometric norms using the method of analysis of variance, chi-square, and Fishers exact tests. The PDC patients showed a significantly more prognathic maxilla, a significantly more frequent occurrence of skeletal class I, retroinclination of maxillary central incisors, hypodivergent relationship, and mandibular anteriorotation and less frequent posteriorotation. A significantly more frequent retrognathic maxilla and skeletal class III and less frequent retroinclination of the maxillary central incisors were found in the BDC patients. The results of this study indicate the existence of different facial morphology and more likely also etiopathogenesis of eruption disturbances of the canines in the PDC and BDC patients.

A screen of a large Czech cohort of oligodontia patients implicates a novel mutation in the PAX9 gene

Tooth agenesis is one of the most common developmental anomalies in humans. To date, many mutations involving paired box 9 (PAX9), msh homeobox 1 (MSX1), and axin 2 (AXIN2) genes have been identified. The aim of the present study was to perform screening for mutations and/or polymorphisms using the capillary sequencing method in the critical regions of PAX9 and MSX1 genes in a group of 270 individuals with tooth agenesis and in 30 healthy subjects of Czech origin. This screening revealed a previously unknown heterozygous g.9527G>T mutation in the PAX9 gene in monozygotic twins with oligodontia and three additional affected family members. The same variant was not found in healthy relatives. This mutation is located in intron 2, in the region recognized as the splice site between exon 2 and intron 2. We hypothesize that the error in pre-mRNA splicing may lead to lower expression of PAX9 protein and could have contributed to the development of tooth agenesis in the affected subjects.

Polymorphisms in genes encoding purinoreceptor andosteoprotegerin and external apical root resorption in childrenafter orthodontic treatment

Orthodontically induced external apical root resoption (EARR) is a multifactorial inflammatory disease. Genes encoding proteins, which are involved in the modulation of inflammatory response and bone remodeling, are considered as the “candidate” for EARR. The aim of this study was to analyze possible associations of single nucleotide polymorphisms (SNPs) in the P2RX7 (encoding purinoreceptor) and TNFRSF11B (encoding osteoprotegerin) genes with EARR in Czech children after orthodontic treatment. A total, 99 orthodontically treated patients (69 healthy and 30 with EARR) were enrolled in this case-control study. Genotype determination of P2RX7 +489C/T (rs208294, Tyr155His) and +1068C/T (rs1718119, Thr348Ala), TNFRSF11B -163C/T (rs3102735) and TNFRSF11B +1181C/G (rs2073618, Lys3Asn) was based on polymerase chain reaction using 5 nuclease TaqMan® assays. While no significant differences were observed in allele or genotype frequencies of all four studied SNPs, specific combinations of variants in P2RX7 may be associated with lower/higher risk of EARR development (P<0.05). In addition, the length of treatment by orthodontic appliances positively correlated with the presence of EARR (P<0.05). Although the effect of P2RX7 SNPs themselves to the development EARR was not confirmed in the Czech population, haplotype analysis suggests, that variability in the P2RX7 gene, as well as the length of treatment, may be important factors contributing to the etiopathogenesis of post-orthodontic EARR.Results: 33.4% of the sample reported high stress. The study revealed significantly high stress in women with no or low income, chronic disease, sleep deprivation, no teeth brushing, irregular eating patterns, gestational diabetes, and no family support (P < 0.05). Self-reported oral health problems were significantly associated with high stress (P < 0.05). A multiple linear regression model shows no teeth brushing, chronic disease, sleep deprivation, gestational diabetes, and gingival redness predicted an increase in stress by (3.6, 2.4, 2.1, 1.4, and 1.4, respectively).TWAIN stands for “technology without an interesting name”. TWAIN is the interface standard for Windows and Mac that allows imaging hardware devices to communicate with imaging processing software. Prior to TWAIN, image acquisition devices all came with their own proprietary software, now nearly all imaging software is TWAIN compliant. If one wanted to work with a scanned image in a different application, one had to save the image to a disc first, then open the application of your choice and re-open the image there. Nearly all image processing software today is TWAIN compliant. If your software supports TWAIN, you will find an “Acquire” command in the menus or toolbar (though sometimes the command is hidden under an import in menu.