Arch dimensional changes following orthodontic treatment with extraction of four first premolars

BACKGROUND AND AIM: Tooth extraction as a part of orthodontic treatment plan to create space for leveling and aligning teeth or causing tooth movement leads to changes in arch width and length. The outcome of these changes is important for the clinicians and affects the treatment and retention plans. Despite some previous studies, data in this regard are still scarce and further investigation is required on this subject. The purpose of this study was to evaluate dental arch dimensional changes following four first premolars extraction orthodontic treatment. METHODS: In this study, 100 pairs of dental casts and respective patient records that fulfilled the inclusion criteria were randomly selected from the archives of the Department of Orthodontics, School of Dentistry in Shahid Beheshti University of Medical Sciences, Tehran, Iran. Length and width of dental arch were measured on the initial and final casts of patients using a digital caliper with 0.1 mm precision. The mean, standard deviation (SD) and standard error of variables were determined, and the data were analyzed using SPSS software. Paired t-test was applied to compare changes before and after treatment. RESULTS: The obtained results showed that the maxillary and mandibular inter-canine widths significantly increased as the result of fixed appliance therapy with the extraction of four first premolars. The arch width at the second premolar and molar at mesiobuccal cusp tip and distobuccal cusp tip regions in the maxilla and mandible showed a significant reduction (P < 0.001). In this study, arch length at different points was measured. In the maxilla, the incisor-canine distance in both quadrants experienced a significant increase (P < 0.001). Furthermore, the canine-molar distance and the incisor-molar distance in both quadrants and the total arch length showed a significant reduction (P < 0.001). In the mandible, the incisor-canine distance in the right quadrant significantly increased (P < 0.050), but the reduction in the incisor-canine distance in the left quadrant was not statistically significant. Moreover, the canine-molar and the incisormolar distance in both quadrants and the total arch length all decreased significantly (P < 0.001). CONCLUSION: Orthodontic treatment with extraction of four first premolars significantly increased the inter-canine width and incisor-canine distance in both jaws; but, the inter-premolar and inter-molar widths, canine-molar distance, incisor-molar distance, and total arch length significantly decreased. KEYWORDS: Dental Arch Length; Dental Arch Width; Extraction Orthodontic Treatmen

Dimensional changes of dental arch following non-extraction orthodontic treatment

Introduction: Since the emergence of normal occlusion concept, selecting an appropriate treatment plan with or without tooth extraction has been a controversial subject. Nowadays, both methods can be successfully used for treatment of patients. However, some clinicians still believe that non-extraction orthodontic treatments have fewer complications. The purpose of this study was to evaluate dental arch dimensional changes following non-extraction orthodontic treatment. Materials &Methods: A total of 200 pre- and post-treatment diagnostic dental casts belonging to 100 patients (non-ext treated by 0.18 roth system) who met the inclusion criteria for this study were collected from the archives of Shahid Beheshti Dental School. Sampling was nonrandomized. A digital caliper with the accuracy of 0.1 mm was used for the measurement of variables such as inter-canine width , inter-premolar width and inter-molar width. Results: Non-extraction orthodontic treatment increased all the variables, except for the mandibular inter-canine width and incisor-canine distance. Conclusion: Non-extraction orthodontic treatment causes a significant increase in almost all dental arch parameters. This increase manifests as teeth flaring

Evaluation of the Effects of Intravenous and Percutaneous Low Level Laser Therapy in the Management of Shoulder Myofascial Pain Syndrome

Introduction: Myofascial pain syndrome (MPS) treatment is challenging with a high recurrence rate and still lacks a clear treatment frame. Therefore research on new, more efficient and long lasting effect treatment modalities is necessary. This study looked at the effects of intravenous laser therapy (IVL) and percutaneous low level laser (PLLL) in the management of shoulder MPS.Methods: In this randomized controlled trial, 30 patients fulfilling inclusion criteria were randomly equally allocated to 3 groups, control, IVL and PLLL. Control group received 12 sessions of placebo low level laser, IVL group received 12 sessions of IVL therapy, and PLLL group received 12 sessions of PLLL therapy. All patients were trained for better body posture, body mechanics, gentle massage of trigger points, stretching exercises of affected muscle (trapezius), and received 10 mg of oral nortriptyline regimen every night for 3 months. Outcomes included pain severity, functional disability, and quality of life. Patients were assessed using Numeric Rating Scale (NRS), Pain Disability Index (PDI), and Short Form Health Survey (SF-12). Data collected were analyzed using analysis of variance (ANOVA), Mann-Whitney and t tests.Results: The mean of PDI and maximum pain intensity during day and night significantly reduced in both PLLL and IVL groups compared to control group. Although pain severity and PDI reduction was more pronounced in IVL group compared to PLLL group, the differences were not statistically significant. Also, quality of life statistically significantly improved in both IVL and PLLL groups compared to control group was more, and although higher in IVL group, the difference was not statistically significant when compared to PLLL group. No side effects were observed in the intervention groups.Conclusion: Intravenous laser and PLLL therapy had a positive effect on pain severity and PDI reduction, and quality of life in this study. Also no adverse event was recorded. Thus, intravenous lasers and PLLL therapy seem to be effective complementary modalities in managing patients with shoulder MPS

Academic Impact Evaluation in National Health Research System: Toward Public Health Promotion

No Abstrac

Comparative effectiveness of Low Level Laser therapy and Transcutaneous Electric Nerve Stimulation on Temporomandibular Joint Disorders

Background: Temporomandibular joint disorders are the most common source of pain on the face. There are multiple etiologies, and several types of treatment have been reported. The use of non-invasive and reversible therapies in the treatment of such problems is recommended. The present study evaluated the effect of low level laser (LLL) therapy and transcutaneous electric nerve stimulation (TENS) on temporomandibular joint disorders. Methods: In this single-blind study, 40 patients with temporomandibular disorders were randomly divided into four groups: TENS (TENSTem dental), LLL (diode 810 nm CW), sham-TENS, and sham-LLL. All subjects were examined and data on pain and tenderness in the temporomandibular joint (TMJ) and masticatory muscles (using the visual analogue scale) and mouth-opening (distance between incisal edges before feeling pain; mm) were collected before baseline (T1), after each session (T2-T5) and one month after the end of the sessions (T6)), and analyzed using repeated measure ANOVA and Boneferronie statistical tests. A p-value &lt; 0.05 was considered significant. Results: The decrease in pain (p = 0.000), tenderness (p = 0.000) and increase in mouth-opening ability (p = 0.002) was greater in the TENS and LLL groups than in the placebo groups. At the one-month follow-up, significant decrease in pain and tenderness was recorded in the TENS and LLL groups (p = 0.000). There was no significant differences between TENS and LLL and the placebo groups for maximum mouth-opening at the end of the study (p = 0.692). Conclusion: Using TENS or LLL therapy can improve TMD symptoms at least for the short term. Although the effects of the placebo played a role in improving symptoms, their effects were less importan

The Intravenous Laser Blood Irradiation in Chronic Pain and Fibromyalgia

Intravenous laser blood irradiation was first introduced into therapy by the Soviet scientists EN.Meschalkin and VS.Sergiewski in 1981. Originally this method was developed for the treatment of cardiovascular diseases. Improvement of rheologic properties of the blood as well as improvement of microcirculation and reduction of the area of infarction has been proved. Further, reduction of dysrhythmia and sudden cardiac death was achieved. At first, only the Helium-Neon laser (632.8 nm) was used in this therapy. For that, a power of 1-3mW and a period of exposure of 20-60 minutes were applied. The treatments were carried out once or twice a day up to ten appointments in all1. In the years after, many, and for the most part Russian studies showed  that helium-neon laser had various effects on many organs and on the hematologic and immunologic system. The studies were published mainly in Russian which were little known in the West because of decades of political separation, and were regarded with disapproval. Besides clinical research and application for patients, the cell biological basis was developed by the Estonian cell biologist Tiina Karuat the same time. An abstract is to be found in her work “The Science of Low-Power Laser-Therapy

The study of association between reduced folate carrier 1 (RFC1) polymorphism and non-syndromic cleft lip/palate in Iranian population

Introduction: Cleft lip/palate is one of the most common congenital defects and is supposed to have multifactorial etiology, including a complex interaction between genetics and environment. Reduced folate carrier 1 (RFC1) gene takes part in folate transportation within the cells. In this study, the association of A80G polymorphism in the RFC1 gene with the non-syndromic cleft lip/palate (nsCL/P) was investigated in Iranian infants for the first time. Methods: In this case-control survey, 122 Iranian infants with nsCL/P and 164 healthy infants were investigated for RFC1 polymorphism by PCR and RFLP methods. The results were statistically compared with control group, odds ratios with 95% CI were estimated by univariate and multivariate logistic regression model and a P &lt;0.05 was considered statistically significant. Results: The RFC1 G allele was significantly higher (P=0.001; OR=7, 95% CI: 4.7-10.2) in the cases (60.3%) compared with the controls (17.9%). Not only the RFC1 AG genotype was significantly higher (P&lt;0.001; OR=44, 95% CI: 14.6-133) in cases (67.8%) than the controls (27.4%), but also GG genotype (P&lt;0.001; OR=85, 95% CI: 20.5-352) was much higher in cases (26.4%) than the controls (4.3%). Conclusion: Our study indicated that the RFC1 (A80G) polymorphism was associated with the nsCL/P in Iranian population. Moreover, 80GG homozygosity was significant in the cases. The presence of G allele can be considered as a risk factor for the nsCL/P. Infants with the GG and AG genotypes were more prone to cleft lip/palate as compared to the AA ones. This finding emphasizes the role of RFC1 gene and the intracellular levels of folate

Related risk factors of cleft lip and palate in a group of infants born in Tehran (2012-2015)

Background: Cleft lip and palate is one of the most common congenital anomalies. The etiology of non syndromic orofacial clefts is multifactorial. Objective: The aim of this study was to evaluate the related risk factors of cleft lip and palate in a group of infants born in Tehran during the years between 2012-2015. Methods: In this case-control study the files of 105 newborns with oral clefts, and 218 normal newborns as control group with their mothers were evaluated in Mofid Hospital in Tehran. Data were analyzed by Chi-square test. Findings: Among 105 cases, 40 cases (38%) were females and 65 cases (62%) were males. The frequency of cleft lip and palate, cleft palate and cleft lip were 58%, 27.6% and 14.2% respectively. A significant relationship was found between parents with familial marriage (P=0.001). The highest number of clefts belonged to 25-35 year-old mothers (51.4%), 41% of mothers reported smoking during pregnancy thus maternal smoking would be an effective predisposing factor to have a child with oral clefts (P=0.001). Conclusion: The results of this study indicate that history of familial matrimony, mother’s age above 35 years and maternal smoking during pregnancy can enhance the risk of orofacial clefts 18, 17 and 14 times respectively. These findings emphasize the importance of preconception counseling of mothers-to-be on amendable lifestyle factors in order to reduce the birth prevalence of cleft lip/ palate in future generations

Comparison of Bolton’s Ratios before and after Treatment in an Iranian Population

Background and aims. The correct relationship of the total mesiodistal width of the mandibular teeth to that of the maxillary teeth (Bolton’s ratios) is among the main factors considered in obtaining an optimal occlusion. The present study was conducted to determining the Bolton’s ratios before and after treatment in skeletal class I patients. Materials and methods. In this descriptive analytical study, 200 study casts of 100 patients (including 73 females and 27 males) were selected from 1,700 patient files with fixed, non-extraction orthodontic treatment protocol. The greatest mesiodistal width of teeth was measured using a digital caliper. The total Bolton index (TBI) and anterior Bolton index (ABI) were calculated for subjects and the obtained results were compared with the values reported by Bolton using one-sample ttest. The alterations in these indexes before and after treatment were compared with paired t-test. Results. Post-treatment ABI and TBI in patients were 77.35% ± 4.12% and 91.2% ± 1.66%, respectively. No significant difference was detected in ABI and TBI of patients after treatment when compared with the results of Bolton’s study (P > 0.05). However, a significant correlation was observed in values of ABI (P < 0.001) and TBI (P < 0.01) before and after treatment. Conclusion. These findings suggest that patients with mild hypodontia have narrower teeth than normal subjects especially in posterior segments, which may have clinical implications during the orthodontic treatment process