Papers by Hamidreza Pakshir
European Journal of Orthodontics, Aug 11, 2021
Summary Background The highly prevalent white spot lesions around orthodontic brackets necessitat... more Summary Background The highly prevalent white spot lesions around orthodontic brackets necessitate introducing preventive materials without relying on patient compliance. Objective To evaluate the antidemineralizing effect of two concentrations of xylitol varnish. Trial design Triple-blind, four-arm, parallel-group, single-center, randomized controlled clinical trial. Methods A total of 120 orthodontic patients were randomly assigned to four groups (n = 30), using a computer-generated randomized block list. The treatment groups were: 10% xylitol, 20% xylitol, 5% fluoride, and placebo. Tooth demineralization was measured with DIAGNOdent at T1 (before treatment), followed by varnish application. At T2 (third month), the varnish was re-applied, and at the third (T2) and sixth (T3) months, and after treatment (T4), the demineralization was measured. The white spot lesion frequency was assessed visually after treatment. The participants, the clinician, and data assessors were all blinded to group assignments. Results A total of 115 patients underwent per-protocol analyses. At T2, the mean DIAGNOdent numbers in the fluoride and 10% xylitol groups were significantly lower than the placebo group (P = 0.00), with a mean difference of 0.63 (95% CI, 0.15–1.10) and 0.5 (95% CI, 0.04–0.95), respectively. At T3, the fluoride and 10% xylitol groups had significantly lower mineral loss than the placebo group (P=0.046) with a mean difference of 0.52 (95% CI, 0.14–0.89) in the fluoride and 0.45 (95% CI, 0.03–0.86) in the 10% xylitol groups, respectively. However, at T4, only the mean for the 10% xylitol group was significantly different (P=0.049) from the placebo group, with a mean difference of 1.18 (95% CI, 0.42–1.93). Visual assessment showed that after treatment, the prevalence of white spot lesions in the fluoride (P=0.03) and 10% xylitol (P=0.00) groups was less than the placebo group with the odds ratio of 0.67 (95% CI, 0.46–0.96) and 0.43 (95% CI, 0.28–0.64), respectively. Conclusion The 10% xylitol varnish short-term effects on caries control were significantly greater than 20% xylitol varnish and placebo but similar to fluoride varnish. However, the 10% xylitol long-term effect was almost better than fluoride varnish. Trial registration The protocol was registered at IRCT.ir under the code IRCT20180913041032N1.
Journal of Forensic Dental Sciences, May 30, 2023
Objective: HIV patients differ from other people in terms of dental age. Estimating the age of ch... more Objective: HIV patients differ from other people in terms of dental age. Estimating the age of children abandoned due to HIV is crucial for forensic records. The present study aimed to compare HIV-infected children with healthy controls in terms of dental age using the Willems method. Methods: The study sample consisted of orthopantomograms of 40 HIV patients aged 5-16 years and 50 children aged 6-16 years as the control group. The HIV group included children with vertical infections who had received antiretroviral therapy. The Willems method was used to compare two groups in terms of dental age. Results: Dental age estimation in both HIV and control groups was overestimated using the Willems method. Nevertheless, the overestimation rate was approximately one month in the control group and less than two months in the HIV group, making the method widely applicable for estimating dental age in both healthy children and HIV patients. The dental age of the HIV-infected children was lower than that of the control group. Conclusion: This study indicated a lower dental age in the HIV-infected children compared to the control group. The results demonstrated that dental age estimation using Willems method closely approximated the chronological age of HIV patients.
PubMed, 2012
Aim: To assess oral health-related quality of life (OHRQOL) and self-perceived esthetic impairmen... more Aim: To assess oral health-related quality of life (OHRQOL) and self-perceived esthetic impairment in patients seeking orthodontic treatment and to compare them with peers in the same age group who had never undergone orthodontic treatment. A correlation between OHRQOL and lower self-perceived esthetic impairment was also searched for. Methods: The sample comprised 209 individuals (12 to 20 years of age), of whom 110 were about to receive or had already started orthodontic treatment at Shiraz Dental School, Shiraz, Iran, (orthodontic group) and 99 participants who had never received orthodontic treatment (control group). OHRQOL was recorded with the validated Persian version of the short form of the Oral Health Impact Profile. The aesthetic component (AC) of the Index of Orthodontic Treatment Need (IOTN) instrument was used to record examiner and self-perceived esthetic impairment in both groups. Results: The Mann-Whitney test revealed that the orthodontic group had significantly worse OHRQOL than the control group (P = .005). The former group also had significantly higher self-perceived IOTN AC scores (P < .00). The weighted Kappa test was used to report the agreement between the examiner and self-perceived esthetic impairment. No significant intersex differences were found in either group. The Spearman correlation coefficient showed a significant correlation between higher IOTN AC scores and worse OHRQOL (P = .007) in the control group. No such correlation was found in the treatment group. Conclusion: Individuals who sought orthodontic treatment had higher self-perceived IOTN AC scores and worse OHRQOL than the control group.
Journal of Islamic Dental Association of Iran, Apr 15, 2014
Background and Aim: Orthodontic bracket bonding may encounter difficulties in fluorosed teeth. Th... more Background and Aim: Orthodontic bracket bonding may encounter difficulties in fluorosed teeth. The aims of this study were to compare the shear bond strength (SBS) of brackets bonded to fluorosed teeth with Core Max II and Transbond XT and to assess the enamel damage after debonding. Materials and Methods: In this in-vitro study, 60 fluorosed (TFI=4 and 5) and nonfluorosed teeth were divided into two subgroups. The standard edgewise metallic brackets were bonded to the teeth with Transbond XT in the first and third groups, and with Core Max II in the remaining groups. After bonding, the SBS of the brackets was tested with a universal testing machine. The obtained data were analyzed by two-way ANOVA, post-hoc (LSD), Kruskal-Wallis, Wilcoxon, and paired samples tests. Results: Fluorosis significantly reduced SBS (p=0.041). Core Max II significantly increased SBS (P=0.040). Teeth in group 4 (fluorosis and Transbond XT) had the lowest SBS (13.44±1.69 MPa); group 2 (fluorosis and Core Max II) showed the highest enamel damage. Conclusion: Core Max II is a good adhesive for orthodontic bracket bonding in fluorosed teeth but conservative debonding methods should be necessarily applied to decrease enamel damage.
PubMed, Mar 1, 2019
Statement of the problem: Palatal rugae have been considered equivalent to fingerprints, as they ... more Statement of the problem: Palatal rugae have been considered equivalent to fingerprints, as they are unique to each individual. It has been shown that palatal rugae are associated with specific racial groups and are known to aid sex identification. Due to the lack of any published data on palatal rugae morphology on Iranian children, the present study was performed. Purpose: The present study aimed to investigate differences in the morphology of individual palatal in a sample of Iranian children. Additionally, it is intended to develop discriminant function to identify sex, based on rugae morphology. Materials and method: A total of 120 pre-orthodontic casts were evaluated for different rugae patterns using the Thomas and Kotze classification. The casts were equally distributed between sexes with an age range of 6-12 years. Rugae length, shape, and associated morphology were recorded and the independent t-test and Chi-square test were used to compare the mean and relationship between the attributes. The discriminant function analysis was applied to the data in order to determine the applicability of palatal rugae patterns as an aid for sex identification. Results: While the total rugae count showed an insignificant difference between the males and females, the rugae count on the right side of the palates showed a significant difference (p= 0.046). The primary rugae were most common in both sexes, followed by the secondary and fragmentary rugae. The most prevalent rugae shape between both sexes was the wavy rugae followed by the curve and straight shapes in males and the straight and curve shapes in females. A significant difference was observed in the number of the curve rugae between the sexes. Discriminant function analysis allowed sex differentiation with an accuracy of 60.8%. Conclusion: Palatal rugae shapes are unique to each individual and could be used as a potential tool for sex identification. Further research on a larger sample is required to fully confirm the application of this method (e.g. in forensic medicine) as a complementary technique for sex identification.
مجله دندانپزشکی کودکان ایران, Jul 1, 2019
Evaluation of health care providers knowledge on importance of preventive orthodontic treatment
International Orthodontics, 2020
Journal of Dentistry, 2019
Statement of the Problem: In dental profession, exposure to risk factors of musculoskeletal disor... more Statement of the Problem: In dental profession, exposure to risk factors of musculoskeletal disorders raises the probability of musculoskeletal injuries in different parts of the body. Purpose: This study aimed to determine the prevalence of musculoskeletal disorders (MSDs), assess the risk of MSDs, and determine the risk factors of musculoskeletal injuries among dentists of Shiraz city. Materials and Method: In this cross-sectional study, 136 dentists of Shiraz city were randomly selected. The data were collected by Nordic musculoskeletal questionnaire (NMQ). Ergonomic assessment of exposure to MSDs risk factors was carried out by assessment of repetitive tasks (ART) technique. In order to assess dentists’ exposure to MSDS risk factors, the method of ART (ART) was adopted. This method has been designed to assess the risk of those tasks that required repetitive motion of upper limb, especially hands and arms. The collected data were analyzed through SPSS software (version. 22). The ...
STOMATOLOGY EDU JOURNAL, 2017
Introduction: The present study aimed to evaluate the cephalometric changes in Class II Division ... more Introduction: The present study aimed to evaluate the cephalometric changes in Class II Division I mandibular deficient patients treated with the Fränkel 2 and Farmand appliances as a new functional appliance. Methodology: Fifty-five subjects treated for Class II Division I malocclusion and mandibular deficiency were selected for the study. Twenty-seven of the subjects (17 girls, 10 boys) with the mean age of 11.1 (SD 1.4) years were treated with the Farmand appliance and twenty-eight of them (15 girls, 13 boys) with the mean age of 11 (SD 1.5) years were treated with the FR-2 appliance. T-test, paired t-test, Wilcoxon and Mann-Whitney test were used to evaluate the data. Results: A skeletal Class I relationship and a marked reduction in overjet were achieved in both treatment groups. ANB decreased significantly by 3.2 (SD 1.7) degrees in the Farmand appliance group and it decreased significantly by 3.5 (SD 1.6) degrees in the Fränkel group. Conclusion: Both Farmand and Fränkel appliances were successful in the correction of mandibular deficiency in Class II Division 1 patients.
DOAJ (DOAJ: Directory of Open Access Journals), Apr 1, 2013
Background and Aim: During fixed orthodontic treatments the absolute number and percentage of sal... more Background and Aim: During fixed orthodontic treatments the absolute number and percentage of salivary Streptococcus mutans increase. This will cause increase of enamel demineralization and dental caries. The purpose of present study is to evaluate the effect of fluoride-releasing elastomeric chains in the streptococcus mutans levels in saliva and bacterial plaque. Materials and Methods: In this randomized clinical trial sixty patients, who were under fixed-orthodontic appliance treatments were selected and randomly divided into two groups of 30 each. Conventional elastomeric chains were used in group 1. As for the second group fluoride-releasing elastomeric chains were utilized. Four samples of saliva collected on days 0, 7, 14 and 28, and two plaque samples were collected on the beginning and finishing days in both groups. The fluoride-releasing and conventional elastomeric chains were removed on day 28. All samples were then used for microbial culture to count the Streptococcus mutans colonies. The results were analyzed statistically with the repeated measures Analysis of Variance (ANOVA) and Student t-tests. Results: The result of Streptococcus mutans (CFU) in saliva at each time point in the study showed no statistically significant difference between the two groups (p80.301). Comparison of the effect of elastomeric chains on the Streptococcus mutans colonization in dental plaque and elastomeric chains surface, also did not show any statistically significant difference between the two groups (p=0.317and 0.803 respectively). Conclusion: There was no clinical evidence that fluoride-releasing elastomeric chains were effective in reducing the formation and colonization of Streptococcus mutans in saliva and dental plaque.
Journal of Dentistry, Shiraz University of Medical Sciences, Sep 1, 2011
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2008
International Orthodontics, Mar 1, 2019
Introduction > The aim of this study was to determine the effect of bleaching and desensitizing o... more Introduction > The aim of this study was to determine the effect of bleaching and desensitizing on shear bond strength (SBS) of metal brackets to enamel. Methods > One hundred extracted human premolar were randomly assigned to 5 groups of 20. In the first group (control), no bleaching or desensitizing agent was used. Groups 2 to 5 were bleached with 37.5% hydrogen peroxide and desensitized with 6.0% potassium nitrate. Surface treatment comprised of etching for 15 seconds in groups 1, 2 and 3, Er:yag laser irradiation and etching in group 4 and sandblasting and etching in group 5. Premolar brackets were bonded with Transbond XT and cured for 20 seconds and the SBS was tested using a universal testing machine. Adhesive remnant index (ARI) score was used to record the mode of bond failure. Results > No significant difference was found between the mean SBS (MPa) in groups 1(15.22), 4 (14.02), and 5(12.62). SBS in group 4 was significantly higher than group 2 (8.15) (P < 0.001). Also, SBS in groups 2 (P < 0.001) and 3(11.74) (P = 0.012) were significantly lower than group 1. An increased frequency of ARI score of 2 and 3 was observed in groups 1, 4 and 5. Conclusions > Bleaching plus desensitizing significantly decreased the SBS of orthodontic brackets. Delaying the bonding procedure for at least 2 weeks or alternative surface treatment methods such as combined laser and acid etching or combined sand blasting and acid etching can improve the SBS.
Eastern Mediterranean Health Journal, Dec 1, 2010
To provide quantitative data about the prevalence of malocclusions in the Shiraz orthodontic popu... more To provide quantitative data about the prevalence of malocclusions in the Shiraz orthodontic population, we studied the records of 700 patients (391 girls and 309 boys) aged 6-14 years attending the undergraduate Department of Orthodontics at Shiraz University of Medical Sciences. The prevalence of Angle class I, II and III malocclusion of first molars was 52.0%, 32.6% and 12.3% respectively. Skeletal class I, II and III malocclusion was found in 18.0%, 70.0% and 12.0% respectively. There were no significant differences between the sexes in the prevalence of different types of skeletal malocclusion. Children with class III were significantly younger (mean age 8.9 years) than those with class I (9.6 years) or class II (9.7 years) malocclusions. Orthodontics students need more education and training in the management of class II malocclusion to improve the overall quality of care for patients.
Progress in orthodontics, Apr 11, 2016
Background: The aim of this prospective in vitro study was to evaluate the effect of nanohydroxya... more Background: The aim of this prospective in vitro study was to evaluate the effect of nanohydroxyapatite (nanoHAP) serum on the enamel surface roughness and tooth color stability after orthodontic debonding procedure. Methods: The crowns of 30 premolars were embedded in acrylic blocks with a 4 mm × 5-mm-sized window on the middle third of buccal surfaces. Primary roughness values were evaluated by an atomic force microscope (AFM). After bracket debonding, and polishing procedures, the second roughness parameters were recorded. Specimens were then randomly assigned to two equal groups. NanoHAP serum and HAP toothpaste were applied for 10 days in the first and second groups, respectively. Then, after the third AFM, initial color parameters were measured. Following 1-week immersion in the coffee solution, second color assessment was performed. The fourth AFM was registered after 2 months of aging process. Results: All roughness parameters were elevated following debonding procedure. There was no statistically significant reduction in roughness parameters after 10 days of nanoHAP serum or HAP toothpaste application. Both groups showed significant color change after immersion in the coffee solution. Conclusions: NanoHAP serum with the protocols used in this study could not restore enamel surfaces to their original condition.
Egyptian journal of forensic sciences, Mar 2, 2023
Background Because of the individuality of the palatal rugae, they are applicable for human ident... more Background Because of the individuality of the palatal rugae, they are applicable for human identification purposes the same as the fingerprints. Therefore, it is important to assess the effect of different factors on rugae characteristics. We assessed the characteristic changes of the palatal rugae following extraction and expansion during orthodontic treatments. Before and after orthodontic treatment dental casts of 30 patients were scanned by 3Shape Trios 3D intraoral scanner, and superimposed in Geomagic X 2018 software. Displacement of 13 reference points was analyzed in three dimensions. The length of the palatal rugae was also measured. SPSS version 22.0 was applied for data analysis, using independent t test, sample t test, and chi-square test. Results The alterations in the mean palatal rugae length were significant in the first right and third right ridges after extraction, and right and left second ridges after expansion treatment (P < 0.05). Changes in coordinates in the X, Y, and Z axes were significant at 8 points on the rugae after extraction, and 5 points after expansion treatment (P < 0.05). The changes in the sum of means of displacements were significant at all 13 points after extraction and expansion treatments (P < 0.05). Conclusions The palatal rugae do not remain stable during expansion and extraction orthodontic treatments. Some changes occurred in length, and the most medial and most lateral points on each ridge were displaced. The length of the incisive papilla did not change during treatment; thus, it can serve as a stable landmark. If we consider palatal rugae as an individual landmark, we can refer the patients after orthodontic treatment for scanning of their palatal rugae to document their post treatment pattern; but it should be noted that treatment relapse may change it again.
International Journal of Oral and Maxillofacial Surgery, Aug 1, 2016
The mandibular angle represents an important part of facial aesthetics. Mandibular osteotomy can ... more The mandibular angle represents an important part of facial aesthetics. Mandibular osteotomy can affect the gonial angle. The aim of this study was to compare the effects of sagittal split osteotomy (SSO) and intraoral vertical ramus osteotomy (IVRO) on the gonial angle. This retrospective cohort study assessed subjects with mandibular prognathism who underwent SSO (group 1) or IVRO (group 2). Lateral cephalograms obtained before and 1 year after the osteotomies were analyzed. In this study, age, sex, the change in occlusal plane (OP) and mandibular plane (MP) angles, and the amount of mandibular setback were considered as variable factors, while the type of surgery (SSO or IVRO) was considered the predictive factor. Fifty-six subjects were studied: 26 in group 1 and 30 in group 2. The changes in MP angle and OP angle were not significantly different between the groups (P > 0.05). The change in gonial angle was 6.07 AE 4.468 in group 1 and 7.33 AE 5.738 in group 2; assessment of the data did not demonstrate a significant difference between the two groups studied (P = 0.53). Mandibular osteotomy (SSO or IVRO) may change the gonial angle, but a significant difference between SSO and IVRO was not detected.
Journal of Dentistry, Jun 1, 1988
Journal of Craniofacial Surgery, Oct 1, 2015
Previously described strategies for the treatment of craniofacial intraosseous venous malformatio... more Previously described strategies for the treatment of craniofacial intraosseous venous malformations include partial resection with superficial osteotomies, or en bloc resection with immediate reconstruction. 1,3,7 In consideration of these treatment options, the surgeon must weigh the increased rates of recurrence associated with partial resection against the potential postoperative morbidity that can occur with an en bloc resection; to this point, however, the mainstay of surgical treatment has involved complete primary resection, followed by immediate reconstruction with autologous bone grafts. 1,7 The complex three-dimensional structure of the zygoma, however, creates a challenging dilemma, and complicates the efforts of the reconstructive surgeon to achieve the desired functional and/or aesthetic results. The versatile technology associated with VSP, although, provides a solution to a number of inherent surgical issues associated with complex cases such as these, and is beginning to find an expanded role in the reconstruction of all areas of the craniofacial skeleton. To date, a variety of materials, including autografts, allografts, xenografts, and alloplasts have been described for use in the reconstruction of various craniofacial defects in association with this technology. 4,5,8,9 PEEK, which was used in this case, is an alloplastic material that possesses appropriate strength, stiffness, and durability, as well as an excellent biocompatibility profile. 8 There have been 2 similar cases reported in the literature wherein the reconstructive surgeons made use of preoperative CT-based modeling and implant design for reconstruction of the zygoma. In 2009, Arribas-Garcia et al 10 described a case of zygomatic reconstruction using a predesigned alloplastic prosthesis-a methyl methacrylate implant designed using a CT-based model of the contralateral zygoma. And in 2012, Scolozzi 4 reported on the use of computer-designed PEEK PSI based on mirroring computational planning for maxillofacial reconstruction. The protocol described in this case designed with the assistance of Medical Modeling and KLS Martin Group, however, uses a digital three-dimensional model formatted from high-resolution CT images to virtually define the area of bony resection, and thereby generate custom osteotomy guides, as well as the PEEK PSI used for reconstruction. This strategy allows for immediate reconstruction in a single-stage procedure with accurate, predefined marginal excision, generates a more precise alloplastic prosthesis compared with previously documented techniques, and it does so with an overall relative decrease in operative time. CONCLUSION This advance in virtual preoperative surgical planning provides the opportunity for innumerable new applications in craniomaxillofacial reconstructive procedures. Precise marginal resection of lesions and reconstruction of the resulting defect can be implemented via use of a virtual defect in conjunction with patient-specific osteotomy guides and alloplastic implants. We believe the successful implementation of this protocol will lead to greater subsequent use of this innovative technology to treat patients with functional and cosmetic defects of the craniofacial skeleton.
European Journal of Orthodontics, Jun 8, 2006
This retrospective investigation was designed to compare tooth size discrepancies among subjects ... more This retrospective investigation was designed to compare tooth size discrepancies among subjects with different skeletal malocclusions in an orthodontic population. The study employed the pretreatment models of 200 patients (100 males, 100 females, aged from 14 to 20 years) selected from the records of the Orthodontic Department, Shiraz Dental School. The subjects were from four malocclusion groups, Class I, Class II division 1, Class II division 2, and Class III, with the corresponding skeletal characteristics. Each group comprised 50 healthy individuals (25 males, 25 females). The mesio-distal dimensions of teeth were measured using digital electronic callipers (accurate to 0.01 mm) and the Bolton indices were determined. The data were statistically analysed using analysis of variance and Duncan's multiple range test, with the level of signifi cance set at P < 0.05. The results revealed that the mean anterior ratio (79.01) for the whole sample was statistically signifi cantly different from Bolton's (77.2) but no signifi cant difference was found for the overall ratio. The posterior and overall ratios of the Class III malocclusion group were statistically greater than the other malocclusion groups (P < 0.05). The mean anterior ratio of the Class III group was greater than that of the Class II group. However, there was no difference when compared with the Class I malocclusion group. For the two types of Class II malocclusion, no signifi cant ratio differences were observed.
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Papers by Hamidreza Pakshir