Bilateral aplasia of the anterior cerebral artery in the presence of its vascular source: a case report.

PURPOSE: Our goal was to investigate the cases of bilateral aplasia of the anterior cerebral artery (ACA). METHODS: The macro- and microdissection of the target human brain arteries of 388 cadaveric cases was applied under the magnifying glass. Each case was photographed and diagrammatically represented in the workbook. The length and the outer diameter of the corresponding arteries on the photos were measured using a computer software program. RESULTS: There was only one case (1/388 or 0.25%) of bilateral ACA aplasia that belonged to a male adult cadaver. Except for the variations of the posterior communicating artery on one side and the basilar artery, the instance of cerebral pathology was not recorded in this case. We compared the recent case with available literature cases. CONCLUSION: Summarizing small number of literature cases, the recent case of bilateral ACA aplasia as the fifth case discovered so far, represents a true morphological rarity.

Anterior Esthetic Rehabilitation of an Alveolar Cleft Using Novel Minimally Invasive Prosthodontic Techniques: A Case Report.

Missing lateral incisors are the most frequent dental disorder associated with cleft alveolus. When orthodontic closure of the edentulous space is not possible, more aggressive prosthodontic treatments are required. Contemporary resin-bonded fixed dental prostheses (RBFDPs) represent a promising, time-efficient alternative treatment with fewer biological complications. This clinical report proposes a modified approach to the esthetic rehabilitation of a patient with a complete unilateral cleft lip and palate on the left side and an incomplete cleft lip and alveolar cleft on the right side. Digital diagnostics, treatment planning, and clinical procedures involved in the fabrication of facially bonded RBFDPs are presented. This modified technique enables the concurrent replacement of lateral incisors and correction of the malformed central incisors as well as increasing the retention of the restorations.

Bone remodeling during orthodontic tooth movement in rats with type 2 diabetes.

INTRODUCTION: Type 2 diabetes is known to affect bone metabolism. In this study, we aimed to determine the effects of type 2 diabetes on bone remodeling during orthodontic tooth movement. METHODS: The 48 rats were divided into 4 groups: Wistar control group (n = 8), Goto-Kakizaki (GK) control group (n = 8), Wistar appliance group (n = 16), and GK appliance group (n = 16). The distances between the teeth were measured weekly. On day 42, maxillary alveolar bone specimens were obtained for histologic evaluation and determination of the gene expression levels of the receptor activator of nuclear factor Ò¡B (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG). RESULTS: No significant difference was observed in the levels of tooth movement between the 2 appliance groups. After orthodontic force application, the alveolar bone volume and osteoblast surface in the GK rats were diminished compared with those in the Wistar rats. The increase in the osteoclast surface relative to the control groups was 2.4-fold greater in the GK rats than in the Wistar rats. Significant upregulations of the RANK and OPG gene expression levels in the Wistar appliance group were observed. The RANKL/OPG ratio was increased in the GK appliance group compared with the Wistar appliance group. CONCLUSIONS: Diminished bone formation and slightly increased bone resorption were observed during orthodontic tooth movement in the rats with type 2 diabetes.

PPIA, HRPT1, and PGK1 genes as the appropriate combination for RT-qPCR normalization in alveolar and femoral bone remodeling in olanzapine-treated rats.

Reliable gene expression analysis in bone remodeling studies requires an appropriate selection of internal controls, i.e. stable reference genes for the normalization of quantitative real-time PCR (RT-qPCR), the most common method used for quantifying gene expression measurements. Even the most widely used reference genes can have variable expression under different experimental conditions, or in different tissue types or treatment regimes, so selecting appropriate controls is a key step in ensuring reliable results. The aim of this research was to identify the most stable reference gene(s) for the study of olanzapine modulated bone remodeling in rats. RNA was isolated from the maxillary alveolar and femoral bones of olanzapine or placebo-treated Wistar rats and transcribed to cDNA. The expression of 12 candidate reference genes was assessed by RT-qPCR. Their expressions were analysed using GeNorm, NormFinder, BestKeeper and delta Ct algorithms, and by the comprehensive ranking method. PPIA, HRPT1 and PGK1 were the most stably expres sed reference genes and the combination of the three genes was optimal for normalization. This study is the first to identify the optimal reference genes for research in olanzapine-exposed rats, which serve as a pivotal benchmark for enhancing the accuracy and reliability of future RT-qPCR expression in bone studies.

Beyond the face: An interdisciplinary evaluation of satisfaction with appearance in young people with orofacial clefts.

Orofacial clefts are the most common congenital anomaly of the face, and they significantly affect appearance. The combined effects of demographics, psychology, neurophysiology, and cleft characteristics to explain satisfaction with appearance in young people with a cleft have not yet been comprehensively studied in an interdisciplinary manner. We found that interpersonal difficulties, age, and conscientiousness were significant explanatory factors for satisfaction with appearance (tinterpersonal difficulties = -3.022, p = 0.006; tage = -3.563, p = 0.016; tconscientiousness = 4.161, p = 0.003); the model explained 50% of variance in satisfaction with appearance (R2 Adjusted = 0.504, Fvs. constant = 4.05, p = 0.00117). Furthermore, frontal alpha asymmetry was complexly intertwined with other variables, affecting the overall accuracy of the model, but explaining only 10.5% of variance in satisfaction with appearance when used as a factor alone. The results show that an interdisciplinary approach can substantially expand our understanding of the factors influencing self-perception in young people with orofacial clefts.

Marital status and survival in cancer patients: A systematic review and meta-analysis.

BACKGROUND: In recent years, authors have repeatedly reported on the significance of social support in cancer survival. Although overall the studies appear to be convincing, little is known about which types of social support promote better survival rates, and which subgroups of cancer patients are more susceptible to the benefits of it. The aim of this study was to identify, organize, and examine studies reporting on the significance of social support in cancer survival. METHODS: The PubMed, CINAHL and EBSCO databases were searched using the keywords social support/marital status, cancer, and survival/mortality. Where possible we used a meta-analytical approach, specifically a random effect model, in order to combine the results of the hazard ratios in studies from which this information could be obtained. When interpreting clinical relevance, we used the number needed to treat (NNT). RESULTS: Better survival was observed in married patients when compared to unmarried (single, never-married, divorced/separated, and widowed) in overall and cancer-specific survival. Gender group differences showed that the association was statistically significant only in cancer-specific survival when comparing divorced/separated male and female cancer patients (p < 0.001), thus confirming results from the previous meta-analysis. CONCLUSIONS: Being unmarried is associated with significantly worse overall and cancer-specific survival. The most vulnerable group found in our study were divorced/separated men. The results of this review can motivate physicians, oncologists, and other healthcare professionals to be aware of the importance of patients' social support, especially in the identified sub-group.

Maxillary arch dimensions, occlusion assessment and space conditions in patients with cleft palate in the period of deciduous dentition-A retrospective study.

PURPOSE: The aim of this study was to evaluate the maxillary arch dimensions, dentoalveolar relationships and spacing conditions in patients with cleft palate in comparison with the control group. METHODS: The subjects consisted of 31 children with cleft palate only (CP) aged 5.5 ± 0.51 (20 with a cleft of hard and soft palate (SHPC group) and 11 with a cleft of soft palate only (SPC group)). In the control group 30 subjects had a normal occlusion at age 5. Maxillary arch dimensions, dentoalveolar relationship according to the Huddard Bodenham index (HBI) and space conditions were compared with the control group. RESULTS: In all variables of maxillary arch dimensions except for total arch height the control group exhibited greater values. Most of the significant differences were on account of differences between the control and the SHPC group, with only three comparisons yielding significant results when comparing the two groups of children with clefts (SHPC vs SPC, IV-IV central: pDunnett T3= 0.0002, 95%CIDifference=-9.9-(-3.18); V-V distopalatal cusps: pDunnett T3= 0.0002, 95%CIDifference=-9.97-(-3.17); Total arch length: pDunnett T3= 0.0014, 95%CIDifference=1.74-7.85). The three groups differed significantly in anterior HBI only (HKruskal-Wallis=15.56, p = 0.0067). The spacing conditions in both jaws were also shown to be significantly dependent on the group of subjects studied (Upper jaw: χ2omnibus= 16.79, p = 0.0018; lower jaw: χ2omnibus= 13.75, p = 0.0102). CONCLUSIONS: The growth of the upper dental arch at the age of five is impeded in participants with CP in comparison to a control group. It is important to assess the effect of cleft subtypes on growth and development to get a better understanding.

Hypoplastic arteries of the cerebral arterial ring in the blind spot of computed tomography angiography.

BACKGROUND: Some variations of the cerebral arterial circle (CAC) are associated with an increased risk for the development of various pathological conditions. This paper aimed to determine the prevalence of hypoplastic arteries of CAC and to emphasize the limited possibility of their visualization by computed tomography angiography (CTA). MATERIALS AND METHODS: The research was performed on 400 adult cadavers by macro- and microdissection of the cerebral arteries. Each case was photographed and the diameter of the arteries was measured digitally, by analyzing photographs of the bases of the brain in the ImageJ program. RESULTS: The largest prevalence of artery diameter <1mm (<0.6mm) in CAC had the posterior communicating artery (PCoA). PCoA on the left side was hypoplastic in 44.9% (11.4%) of cases, while the same artery on the right side was hypoplastic in 44.3% (6.6%) of cases. The posterior cerebral artery was hypoplastic on the left side in 3% (0.6%) and on the right side in 4.2% (0.6%) of cases. The anterior cerebral artery had a hypoplastic caliber only on the right side in 2.4% (0.6%) of the cases, while the internal carotid arteries did not have a diameter <1mm in any case. The anterior communicating artery showed the greatest variability in morphology. Studies on CTA describe the occurrence of aplasia in a statistically significantly higher percentage, and the occurrence of hypoplastic arteries in a statistically significantly lower percentage compared to studies on cadavers. CONCLUSIONS: Due to significant differences between cadaveric and radiological studies, it is necessary to analyze their results regarding arterial hypoplasia and aplasia separately. A diameter of less than 1 mm has been suggested as a criterion for arterial hypoplasia.

Olanzapine decreased osteocyte maturation and Wnt/ß-catenin signaling during loading of the alveolar bone in rats.

Several studies indicate the influence of olanzapine on bone metabolism; however, the results are contradictory. We evaluated the effects of olanzapine on the Wnt/ß-catenin signaling pathway, physiological alveolar bone turnover, and alveolar bone modeling due to an applied orthodontic force. Adult male rats (n=48) were treated with either olanzapine or a vehicle for 21 days; then 8 rats from each group were sacrificed and the rest were divided into 4 groups: control, appliance-only, olanzapine-only, and olanzapine-appliance. The rats in the appliance groups were mounted with a superelastic closed coil spring that maintained constant orthodontic force between molars and incisors. We studied the effects of olanzapine on physiological alveolar bone turnover on day 21 of the experiment, and on alveolar bone modeling due to orthodontic force on day 56. We determined tooth movement, alveolar bone volume, activity of bone-specific cells, serum alkaline phosphatase (ALP) activity, and gene expression levels of Wnt/ß-catenin signaling target genes. During forced bone modeling, olanzapine increased osteoblast volume (P<0.0001) and ALP activity (P=0.0011) and decreased osteoclast volume (P<0.0001) and gene expression of the Wnt/ß-catenin signaling target genes Fosl1, Axin2, and Dkk1(P=0.001, P=0.0076, and P=0.036, respectively), and the osteocyte markers Sost and Dmp1 (P=0.0432 and P=0.0021, respectively). Similar results were obtained during physiological alveolar bone turnover on day 21, when olanzapine downregulated the gene expression of osteocyte markers and Wnt/ß-catenin signaling target genes. We concluded that olanzapine attenuated osteocyte maturation during forced bone modeling and physiological alveolar bone turnover, potentially through downregulation of the Wnt/ß-catenin signaling pathway.

Palate dimensions in six-year-old children with unilateral cleft lip and palate: a six-center study on dental casts.

OBJECTIVE: To compare palatal dimensions in 6-year-old children with unilateral cleft lip and palate (UCLP) treated by different protocols with those of noncleft children. DESIGN: Retrospective intercenter outcome study. Patients : Upper dental casts from 129 children with repaired UCLP and 30 controls were analyzed by the trigonometric method. SETTING: Six European cleft centers. Main outcome measures : Sagittal, transverse, and vertical dimensions of the palate were observed. STATISTICS: Palate variables were analyzed with descriptive methods and nonparametric tests. Regarding several various characteristics measured on a relatively small number of subjects, hierarchical, k-means clustering, and principal component analyses were used. RESULTS: Mean values of the observed dimensions for five cleft groups differed significantly from the control (p < .05). The group with one-stage closure of the cleft differed significantly from all other cleft groups in most variables (p < .05). Principal component analysis of all 159 cases identified three clusters with specific morphologic characteristics of the palate. A similar number of treated children were classified into each cluster, while all children without clefts were classified in the same cluster. The percentage of treated children from a particular group that fit this cluster ranged from 0% to 70% and increased with age at palatal closure and number of primary surgical procedures. CONCLUSION: At 6 years of age, children with stepwise repair and hard palate closure after the age of two more frequently result in palatal dimensions of noncleft control than children with earlier palatal closure and one-stage cleft repair.

Evaluation of fluoride varnish treatment of postorthodontic white spot lesions by visual inspection and laser fluorescence-A randomized controlled study.

OBJECTIVES: White spot lesions (WSLs), as a side effect of orthodontic therapy, can be treated with fluoride varnish, with the difference in efficiency reported. MATERIAL AND METHODS: Patients with buccal WSLs were consecutively included in a randomized controlled double-blind study. At first inspection and at three follow-ups over 6 months, 0.1% fluoride varnish and placebo (water) were applied in the test group (N = 21) and control group (N = 21), respectively. The maximum laser fluorescence value (LFV) of WSLs was recorded using DIAGNOdent. Between the groups, differences in the mean numbers of WSLs and the mean LFV of WSLs per patient at different time points were analyzed with mixed-design analysis of variance. Orthodontic therapy duration (OTD) was included in the model as a covariate. RESULTS: A decrease in the mean WSLs number and LFV was observed; however, there were no significant differences between study groups at any time point. OTD was in interaction only with LFV. Analysis showed a different pattern of mean LFV changes for patients with OTD of >48 months compared to patients with OTD of ≤24. CONCLUSION: The changes in numbers of WSLs and LFV over the study period indicated regression of WSLs, but an additional effect of FV was not confirmed.

Specifies of the fetal median callosal artery.

BACKGROUND: A variable artery in the anterior cerebral circulation, named median callosal artery (MdCA) belongs to one of the three groups of anteromedial central branches of the anterior communicating artery (ACoA). The lack of information on MdCA in human fetuses inspired the authors to explore and present its morphological features. METHODS: The arteries of the brain base were analyzed and measured on 193 specimens of human fetuses, whose values are preserved from the time of preparation of PhD thesis. RESULTS: The median callosal artery was observed in 45% (87/193) of fetuses from 12.5 to 25 weeks of gestation. The MdCA originating from the single ACoA was found in 4.66% cases. MdCAs originating from the so-called anterior communicating rete (16.58%), as well from the partially duplicated (5.69%) and total duplicated ACoA (10.88%) were also found. A statistically significant difference of the artery OD between male and female fetuses was not found. There was a non-significant positive correlation between fetal age presented in gestational weeks and the artery OD (r = 0.214). The OD of the MdCA did not correlate with the diameters of the anterior cerebral artery (ACA). An unusual convergent union of initial ACA medial vessels and partial duplication at MdCA beginning and its trunk fenestrations were shown, along with bilateral distribution of MdCA branches. CONCLUSIONS: The wide range of variability of the median callosal artery in human fetuses, presented in this paper, contributes to anatomical knowledge on the anterior part of cerebral circulation.

Effect of cetirizine, a histamine (H(1)) receptor antagonist, on bone modeling during orthodontic tooth movement in rats.

INTRODUCTION: Histamine (H(1)) receptor antagonists are widely used drugs for treatment of allergic conditions. Although histamine was shown to be involved in bone remodeling, the aim of this study was to determine the effects of cetirizine, an H(1) receptor antagonist, on bone modeling processes during orthodontic tooth movement. METHODS: We used 3 groups of Wistar rats: control group (n = 16), appliance-only group (n = 16) and cetirizine group (n = 16). Each animal of the last 2 groups was fitted with a superelastic closed-coil spring appliance and treated daily with saline solution or cetirizine. Tooth movement was measured weekly from day 0 to day 42. Gene expression levels for bone turnover markers cathepsin K and osteocalcin were determined by means of real-time polymerase chain reaction. Histologic samples were analyzed by using histomorphometry. RESULTS: Cetirizine decreased the amount of tooth movement from day 28 onward (P <0.01), and it also decreased osteoclast volume density (P <0.001). An increase in alveolar bone volume density was observed in the cetirizine group (P <0.01) compared with the appliance-only group. No statistically significant differences were observed in osteoclast activity, osteoblast volume density, and osteoblast activity between the cetirizine and the appliance-only groups. CONCLUSIONS: Cetirizine influences bone modeling, mainly by inhibiting bone resorption. Therefore, H(1) receptor antagonists could interfere with orthodontic treatment.

The endothelin system mediates bone modeling in the late stage of orthodontic tooth movement in rats.

The endothelin system is involved in orthodontic tooth movement (OTM). The aim of the study was to examine the role of ET-1, ET(A) and ET(B) in bone modeling during OTM in rats. Male Wistar rats (n=62) were divided into three groups: control animals (n=10; control group) without appliance, and two groups of experimental animals, which were applied a super-elastic closed-coil spring between the first left maxillary molar and the incisors and were treated daily with either TBC3214 (n=10; TBC3214 group) or with saline (n=42; appliance only group). TBC3214 is a highly selective antagonist on ET(A) receptors. The distance between teeth was measured on days 0 and 42. On days 0, 14, 28 and 42 animals of the appliance only group (n=8) were sacrificed and tissue samples were taken. Total RNA and protein contents were isolated. Gene expression levels of ET-1, ET(A) and ET(B) were assessed by means of relative RT-PCR. Protein levels of ET(A) and ET(B) were examined by immunoblotting. Ten animals of each group were sacrificed on day 42 and tissue samples were prepared for histological analysis. Alveolar bone volume, osteoblast and osteoclast volume were determined histomorphometrically. Gene expression levels of ET-1, ET(A) and ET(B) varied throughout the experiment and were significantly up-regulated on day 42 (p<0.001). The immunoreactivity of ET(A) and ET(B) significantly decreased on day 14 (p<0.001) and increased on day 28 (p<0.001). Alveolar bone volume was significantly higher in the TBC3214 group compared to the appliance only group (p<0.001). Osteoclast volume was significantly lower in the TBC3214 group compared to the appliance only group (p<0.05). Gene and protein expression levels of ET-1, ET(A) and ET(B) varied significantly during OTM, suggesting their different roles in the various stages of OTM. TBC3214 significantly increased alveolar bone volume and significantly decreased osteoclast volume, indicating that it decreased bone resorption in stage three of OTM. These data suggest that ET-1 increases osteoclastic bone resorption via ET(A) in the late stage of OTM.

Arterial abnormalities and associated variations of the vertebrobasilar system on the brain base: apropos of a rare case / Anomalías arteriales y variaciones asociadas del sistema vertebrobasilar en la base del cerebro: un caso raro

SUMMARY: The presented case characterizes an association of primitive and definitive arteries with variations on the cadaveric brain base of a very old man. This case is found by the retrospective review of the data archive obtained during many years of cooperation of the author and co-authors. Fenestration of the (ectatic) basilar artery, partial and total duplication of some cerebellar arteries was associated with other variations of the vertebrobasilar and carotid systems. Although this is a case autopsied because of the myocardial infarction, the peculiarity of the case lies in the absence of the aneurysm based on the fenestration or dissection of one of the cerebral arteries.

RESUMEN: El caso presentado caracteriza una asociación de arterias primitivas y definitivas con variaciones sobre la base cerebral cadavérica de un anciano. Este caso se encuentra mediante la revisión retrospectiva de datos obtenidos durante muchos años de un trabajo de cooperación del autor y coautores. La fenestración de la arteria basilar (ectásica), la duplicación parcial y total de algunas arterias cerebelosas se asoció con otras variaciones de los sistemas vertebrobasilar y carotídeo. Si bien se trata de un caso de autopsia a causa de un infarto del miocardio, la peculiaridad del caso radica en la ausencia del aneurisma en base a la fenestración o disección de una de las arterias cerebrales.

Effects of endothelin antagonist tezosentan on orthodontic tooth movement in rats.

INTRODUCTION: Endothelin is a cytokine peptide present in the periodontal ligament in physiological conditions. Its concentration in the periodontal ligament doubles after 3 hours of axial loading of a tooth. The role of endothelin in orthodontic tooth movement has not yet been explained. We tried to determine the effect of tezosentan, a specific dual endothelin receptor antagonist, on orthodontic tooth movement in rats. METHODS: Twenty-one rats were divided into 3 groups (n = 7). In the tezosentan group, closed-coil springs were placed, and the animals were treated daily with tezosentan; in the coil-spring group, closed-coil springs were placed, and the animals were treated with an inert physiological solution. The appliance was placed between the maxillary left first molar and the incisor. The third group was the control group. On days 0, 7, 14, and 25, the distances between the maxillary molars and incisors were measured at the experimental and contralateral sides. RESULTS: Changes in measured distances at the experimental sides were significantly different between the tezosentan and the coil-spring groups on day 25 (P < .001), with the tezosentan group showing greater changes in the measured distances. There were no differences between the tezosentan and the coil-spring groups at the contralateral side. In the control group, the measured distance increased at both sides (P < .001). CONCLUSIONS: Tezosentan, an endothelin dual antagonist, enhanced tooth movements in rats.

The influence of the respiration disturbances on the growth and development of the orofacial complex.

The disturbances of orofacial functions lead to abnormal growth and development of the orofacial complex. The aim of the study was to determine the prevalence of incompetent lip seal and respiration disturbance, and to improve the understanding of correlation between incompetent lip seal and morphological malocclusions. In the sample of 84 children (45 girls and 39 boys, aged 8.96 +/- 0.66 years) a very high prevalence of the incompetent lip seal was found (35.72%). The study cast analysis was performed. The prevalence of the morphological malocclusion was significantly higher in the incompetent lip seal group (p < 0.001). There were also differences in types of malocclusions. The most frequent malocclusion found in incompetent lip seal was Class II / 1 malocclusion (53.3%). In the competent lip seal group this malocclusion was determined in only 15.57% (p < 0.001). Narrower upper dental arches, higher palate (p < 0.05) and larger overjet (p < 0.001) were found in incompetent lip seal group.

The influence of incompetent lip seal on the growth and development of craniofacial complex.

Abnormal orofacial functions in the period of growth and development can cause morphological anomalies of the craniofacial complex. The aim of this study was to determine the correlation between open mouth posture and morphology of craniofacial complex. The shape, size and relationships of skeletal parts of craniofacial complex were determined by analysis of lateral cephalograms in the sample of 84 children--45 girls and 39 boys (aged 8.96 +/- 0.66 years). The sample was divided into two groups--lip competence and lip incompetence group. Differences in cephalometric values between observed groups were found. The values of inclination of lower central incisors (angle ILi/NB), interbasal angle (NL/NSL), angle between occlusal and mandibular plane and anterior lower facial height were significantly higher in the group with open mouth posture. It can be concluded that lip incompetence plays an important role in growth and development of craniofacial complex.

Sagittal maxillary growth in children with unilateral cleft of the lip, alveolus and palate at the age of 10 years: an intercentre comparison.

OBJECTIVE: Aim of this intercentre study was to compare sagittal facial growth in children with unilateral cleft lip and palate treated with different surgical protocols. A first evaluation had been carried out at the age of 6 years, now the patients have been re-evaluated at the age of 10 years. MATERIAL AND METHOD: 22 patients had been analyzed in centre 1, 32 patients in centre 2. All patients had presurgical orthopaedics. Centre 1 had lip repair at the age of 3 months and one-stage palatal closure with 1 year. Centre 2 had lip repair with 6 months, soft palate repair at 12 and hard palate repair at the age of 30 months. Sagittal growth was evaluated on lateral cephalograms. As control, data of 35 non-cleft children were used. Statistical analysis was carried out with student's t-test, multiple comparisons with Bonferroni. RESULTS: There was considerably normal sagittal facial growth in centre 1, with tendency of forward growth of the mandible. In centre 2 there was a slight decrease in sagittal maxillary and mandibular growth with unchanged intergnathic relation. There was no statistically significant difference in sagittal growth between the centres. A re-evaluation has to be carried out after the final growth spurt.

Evaluation of NiTi Superelastic Retraction Coil Springs for orthodontic tooth movement in rats.

The purpose of this investigation was to assess mechanical properties of Superelastic Retraction Coil Springs for orthodontic use. To reach a goal, a test frame, comprising measuring force transducers was developed. To perform metallographic analyses of the nickel-titanium wire the samples of Superelastic Retraction Coil Springs were observed by scanning electron microscope. For in vivo testing, twenty male Wistar rats, 11-12 weeks of age, were used (Group I with Superelastic Retraction Coil Springs, Group II controls). To simulate human distraction as close as possible, all the applied Superelastic Retraction Coil Springs were modified. The Superelastic Retraction Coil Springs creating a constant force of 25 cN were then attached between the upper left first molars and upper left incisors. Results showed that the reproducible force of 25 cN was shown over a range of 1-11 mm extension. Results also showed that the distance between aforementioned teeth, measured on days 0, 7, 14, 21, 24, 32, 37 and 40, decreased in Group I. Contrary, in Group II the distance between the teeth increased during the study (p<0.001).