Prevalence and Features of Maxillary Sinus Septa in Patients with Cleft Lip and Palate: Cone Beam Computed Tomography Imaging Technique.

OBJECTIVE: The development of the maxillary sinus is different in patients with cleft lip and palate (CLP) compared to non-CLP individuals. To investigate the prevalence and features of maxillary sinus septa (MSS) in patients with CLP in comparison with the non-CLP population. DESIGN: Retrospective study. INTERVENTION: Cone beam computed tomography (CBCT) evaluation. SETTING: CLP center in Shiraz faculty of dentistry, Iran. PATIENTS: A total 306 sinuses (88 cleft and 218 noncleft) on 153 images (CLP group: n = 66; control group: n = 87) were examined to determine the prevalence of septa and characterize them. MAIN OUTCOME MEASURES: Sinus septa were characterized according to height, orientation, angle, origin, and location. The chi-square test, Mann-Whitney U test, and Fisher's exact test were used for statistical analysis. RESULTS: The prevalence of septa was 28.9% and 32.1% in the CLP and control groups, respectively. No significant difference was found between the study groups in terms of prevalence, location, and orientation of MSS. The average height and angle of septa were significantly higher in the control group compared to the CLP group. Inferior origin was significantly more prevalent in the control group than in the CLP group (P = .004). CONCLUSION: There was no difference in the prevalence of MSS between patients with CLP and non-CLP individuals. However, certain features of the septa were different in patients with CLP.

Evaluation of torsional strength and torque presentation of coated rectangular stainless steel archwires, an in vitro study.

OBJECTIVES: An in vitro experimental study was performed to evaluate the torsional strength and torque released by esthetic coated archwires. MATERIALS AND METHODS: A total of 52 coated (study group) and 52 stainless steel (control group) rectangular archwires from two manufacturers (brand I: Gestenco International AB, Gothenburg, Sweden and brand II: Ortho Technology, Lutz, FL, USA) in two sizes (0.019â€¯× 0.025 and 0.017â€¯× 0.0250-inch) were evaluated. The straight parts on both ends of each preformed archwire were cut in 30 mm segments. A specially designed experimental device was attached to the universal testing machine (Model Z020, Zwick Roell, Ulm, Germany) to measure torsional strength and to calculate the clinically significant torque interval. The groups were compared based on their brand, presence of coating and size using three-way analysis of variance (ANOVA) test at a significance level of 5%. RESULTS: The results revealed that coating of the wires of brand 1 resulted in a significant reduction of torsional strength in both wire sizes (P-value = 0.0001). For the wires of brand 2, coating of the 0.017â€¯× 0.025-in wire resulted in a significant reduction in torsional strength. However, for the 0.019â€¯× 0.025 in wire size, the presence of coating significantly increased the torsional strength (P-value = 0.0001). Coating did not affect the measured clinical torque interval of the analyzed wires when a torque between 5 and 20 Nmm was applied (P-value = 0.062). CONCLUSIONS: Mechanical behavior of coated archwires depends mainly on the thickness of their inner core alloy. Reduction in the diameter of the inner alloy resulted in reduced torsional strength. Despite lower mean torsional strength, in the settings of this study, coated and conventional wires demonstrated comparable torque angles if loaded in the typical range of activation.

Epidemiological and Spatiotemporal Descriptive Analysis of Patients with Nonsyndromic Cleft Lip and/or Palate: A 12-Year Retrospective Study in Southern Iran.

Objectives: The current study is aimed at evaluating epidemiological characteristics and spatiotemporal distribution of cleft lip and/or palate (CL/P) in the south of Iran. Methods: Data were extracted from the 1840 medical records of patients who were referred to the Cleft Lip and Palate Center of Shiraz University of Medical Sciences, from January 1, 2011, to September 1, 2022. The collected variables included demographic data (gender, birth date and season, place, birth order, and weight), cleft types and the subtypes, parental information (health status, education level, marital status, and age during the pregnancy), and other basic parameters. The chi-square test at a significance level of 0.05 was used to analyze collected data. The geographic information system (GIS) analysis was also used for analyzing the spatial distribution of CL/P patients. Results: Based on our inclusion criteria, 1281 nonsyndromic patients were included in this study. The most common type was cleft lip and palate (CLP) with 48.32%, whereas cleft palate (CP) and cleft lip (CL) accounted for 40.75% and 10.93% of the patients, respectively. There was a progressive increase in the frequency of all types of clefts, and most of them were male (P ≤ 0.001). The urban population outnumbered the rural ones in all provinces. Parents were mostly healthy (>80%) with low educational status (47.5%). Most born CL/P patients were from consanguineous marriages (58.9%), especially between first-degree relatives. A majority of CL/P patients (73.1%) were born in the first two gestations with a birth weight of 2500-4000 g (77.4%). Most infants with CL/P (84.3%) were born from mothers who had at least one of the predisposing factors. Conclusion: In this study, the frequency of cleft types and subtypes was similar to the existing literature. However, high rate of consanguineous marriage, especially between first-degree relatives, was the most notable feature of this population.

Three-Dimensional Assessment of Eustachian Tube in Patients With Cleft Palate Versus Controls: A CBCT Study.

To compare the morphological characteristics of the Eustachian tube (ET) between patients with cleft palate and healthy controls with the use of cone-beam computed tomography (CBCT).Retrospective assessment of treated nonsyndromic patients with cleft palate and a control group.CBCT images of 51 patients with cleft palate who had previously undergone surgery to close the cleft palate and a control group of 51 patients were included in this study. Syndromic patients were excluded.The cleft group were divided into 3 groups according to the palatoplasty technique, which was done in the infancy period to close the cleft palate (Nadjmi modification of Furlow, Sommerlad, and V-Y pushback). Finally, ET length (ETL), ET angle, and auditory tube angle (ATA) were measured in all patients.The ETL, ETA, and ATA in the cleft and the normal control groups were 29.73 ± 3.14 and 32.18 ± 3.34 mm, 33.18 ± 2.57 and 35.40 ± 3.93, and 141.64 ± 4.13 and 138.87 ± 4.96, respectively. All 3 features were statistically significant among the groups (All Ps < .05). ETL and ETA were significantly higher in Nadjmi modification of Furlow and Sommerlad palatoplasty techniques compared to the V-Y pushback technique, while there was no significant difference in the ATA between the palatoplasty groups.Cleft palate can significantly affect the morphological characteristics of the ET. Type of the infancy palatoplasty can influence some of its dimensions.

Comparison of the mechanical properties and surface topography of as-received and as-retrieved Copper-Nickel-Titanium arch wires: An ex-vivo study.

AIM: The mechanical and surface characteristics of Copper NiTi wires following intraoral aging in an important topic. This ex-vivo study is designed to assess the three most important mechanical properties; torsional stiffness, 3-point bending and surface hardness of the as-received Copper NiTi orthodontic archwires and compare them to the retrieved ones. MATERIAL AND METHODS: In this study, 50 round CuNiTi (0.016 inch) and 50 rectangular (0.018×0.025 inch) CuNiTi orthodontic wires (American Orthodontics, Tanzo Copper Nickel Titanium, Sheboygan, WI) were tested. The groups were as follow: 25 as-received 0.016 inch round CuNiTi archwires (group 1), 25 as-retrieved 0.016 inch round CuNiTi archwires (group 2), 25 as-received 0.018×0.025 inch rectangular CuNiTi archwires (group 3), and 25 as-retrieved 0.018×0.025 inch rectangular CuNiTi archwires (group 4). The physical properties of all of the samples were examined using Vickers hardness, bending and torsional tests. The Kolmogorov-Smirnov test was applied to assess the normal distribution of data. An independent t-test was used to compare the variables between the groups. RESULTS: The results showed that the hardness does not significantly differ between the as-received and as-retrieved archwires in both 0.016 and 0.018×0.025 inch archwires (P< 0.05). The bending test of the round wires showed that the values of the activation forces in the as-received ones were significantly higher than those of the as-retrieved (P=0.00). The torsional and bending test results of rectangular wires showed that the amounts of forces exerted from the as-retrieved archwires were significantly higher than the new archwires (P=0.00). CONCLUSIONS: Round CuNiTi archwires could be retied in the succeeding visits. However, the bending activation that declines significantly should be took into consideration. On the other hand, since bending and torsion activation of CuNiTi rectangular archwires increased after intraoral use, these wires should be retied cautiously.

The effect of multiple enamel conditioning on enamel micro-hardness.

Background: White spot formation is one of the common side effects in orthodontic treatments and multiple enamel conditioning might happen even during on session of fixed orthodontic treatments. The aim of the present study was to evaluate the impact of multiple enamel conditioning with different methods on enamel micro-hardness (MH). Materials and Methods: In this In vitro experimental study, the buccal surfaces of 105 extracted premolars were evaluated in seven groups: One control and six experimental groups. The enamel conditioning was performed in three ways: Etching with phosphoric acid 37%, etching with phosphoric acid 37% followed by primer application and conditioning with self-etch primer. The conditioning process in each way was also performed twice consecutively. The specimens were submitted in pH cycling model with demineralization and re-mineralization solutions for 14 days. Afterward Vickers MH test was applied with 0.981N force on the teeth for 10 s indentation time. Data were analyzed using One-Way ANOVA and Tukey HSD (honestly significant difference) test for multiple comparisons. A value of P < 0.05 was considered statistically significant. Results: MH analysis showed statistically significant differences between the control group and the other conditioned groups (P < 0.05). The groups conditioned with acid-etch and primer, particularly twice, showed the lowest amount of MH in comparison to other groups. Self-etch primer had the least effect on MH of the enamel. Single time etching without using primer, made no considerable difference when compared to multiple etching. Conclusion: Etching process and covering the enamel with primer decrease enamel MH. Using self-etch primer is a more conservative method of enamel conditioning.

Salivary IGF-1 and Alkaline Phosphatase-Based Modeling for Skeletal Maturity Prediction in Orthodontic Patients.

RESULTS: A strong positive correlation was found between CA and cervical stages (r = 0.836, P < 0.001). Based on the regression model analysis, the model which combined IGF-1, ALP, and CA provided the best prediction at P < 0.001 with McFadden's pseudo R 2 value of 0.552 for cervical stage prediction and 0.646 for growth phase prediction. In particular, its predictive ability for the prepubertal, pubertal, and postpubertal growth phases was 95%, 80%, and 90%, respectively. CONCLUSIONS: A new model with the combination of salivary IGF-1 and ALP with CA can be used as a less invasive method to determine the cervical stage and also growth phase with high predictive ability in healthy subjects.

Use of nano-hydroxyapatite serum and different finishing/polishing techniques to reduce enamel staining of debonding after orthodontic treatment : A randomized clinical trial.

PURPOSE: The aim of this study was to assess the effect of nano-hydroxyapatite serum and different finishing, polishing techniques on color alterations of enamel caused by debonding procedures after comprehensive orthodontic treatment by use of a spectrophotometer. METHODS: This randomized clinical trial recruited 20 participants with previous non-extraction orthodontic treatment and acceptable hygiene to evaluate enamel staining after orthodontic debonding. The usage of a carbide bur alone, as the conventional method, and the combination use of carbide burs and Sof-Lex discs (3M™ ESPE, St. Paul, MN, USA) were compared to each other followed by 10 days application of nano-hydroxyapatite after debonding. Then the enamel staining was evaluated by a reflectance spectrophotometer in three periods: immediately, and 2 and 4 months after debonding. RESULTS: The comparison of the groups showed a significant interaction between Sof-Lex groups and the control side after the first interval of the study (p = 0.042). Application of nano-hydroxyapatite demonstrated no significant difference in color parameters between upper and lower arches of the participants at all intervals of this study (p > 0.05). The mean total color change (ΔE) in all groups and between all intervals had been clinically perceptible (ΔE > 3.3). CONCLUSIONS: The applied concentrations of nano-hydroxyapatite had no significant effect in reducing tooth color changes after debonding in orthodontic treatment. Sof-Lex discs can significantly reduce tooth color changes in a short time.

The adjunctive effect of autologous platelet concentrates on orthodontic tooth movement: A systematic review and meta-analysis of current randomized controlled trials.

OBJECTIVE: To evaluate the effectiveness of autologous platelet concentrates (APCs) as adjuncts on accelerating orthodontic tooth movement (OTM) of the human subjects undergoing orthodontic treatment and to critically appraise the available literature. METHODS AND MATERIALS: Five electronic databases (PubMed, Scopus, Web of Science, Embase, and Cochrane Central Register of Controlled Trials) were searched from 2000 up to May 2021 to retrieve eligible randomized controlled trials (RCTs) investigating patients who underwent orthodontic treatment that involved OTM of maxillary and mandibular incisors and canines. All the enrolled cases were treated with APCs and had no local or systemic interfering factors. The quality of the included studies was assessed using the modified JADAD scale. The effect sizes were assessed using mean difference (MD). The heterogeneity analysis was conducted using (I2) statistic at α=0.10. RESULTS: Finally, seven RCTs were included in the qualitative, and two RCTs were included in the quantitative analysis. The meta-analysis was performed regarding the effect of injectable platelet-rich fibrin (I-PRF) on the rate of canine tooth movement in millimeters at different intervals of the 1st, 2nd, and 3rd months. In the 1st month, I-PRF (WMD:0.12mm, CI95% -5.01 to 5.24, I2=90%) did not significantly affect OTM. In the 2nd month, I-PRF (WMD:0.66mm, CI95% 0.60 to 0.73, I2=10%) significantly increased the OTM. However, in the 3rd month, I-PRF did not significantly increase the OTM (WMD:0.54mm, CI95% -1.38 to 2.47, I2=67%). CONCLUSIONS: According to the low certainty of evidence about this topic, providing a definite conclusion is not possible. However, applying I-PRF seems to be efficient in accelerating the OTM of the canines. Further high-quality studies with larger sample sizes will be indispensable to validate this conclusion.

Influence of a bleaching agent on surface and mechanical properties of orthodontic thermoplastic retainer materials : An in vitro study.

OBJECTIVE: To investigate the effect of a tooth whitening agent on surface roughness, surface hardness, and force delivery properties of polyethylene terephthalate glycol (PETG) thermoplastic retainer materials of two different thicknesses. METHODS: PETG sheets (1 mm and 1.5 mm) were thermoformed over a 30â€¯× 60â€¯× 10 mm3 rectangular stone model. Surface hardness, surface roughness, and results of a three-point bending test were evaluated before and after treatment (5 h daily for 14 days) with a 15% carbamide peroxide home bleaching agent. Data were analyzed using an independent sample t­test. RESULTS: Exposure of PETG specimens to the bleaching agent for 14 days significantly reduced surface hardness and increased surface roughness of samples of both thicknesses. The magnitude of force at different deflection points decreased significantly in the 1.5 mm thickness specimens treated with the bleaching agent, but no significant change was observed in the specimens with 1 mm thickness. CONCLUSION: Use of a home bleaching agent could have adverse effects on surface roughness and hardness of PETG materials leading to reduced survival time of thermoplastic orthodontic retainers.

Farsi version of the CLEFT-Q: translation, cultural adaptation process and reliability.

BACKGROUND: The purpose of this study was the translation and cultural adaptation of the CLEFT-Q to Farsi and evaluating the reliability of it. METHODS: The English version of the CLEFT-Q was translated to Farsi following the guidelines set forth by the International Society for Pharmacoeconomics and Outcomes Research (ISPOR). To calculate the reliability, 50 participants filled out the Farsi version of the questionnaire twice at 2-week intervals. RESULTS: The difficulties during the translation and cultural adaptation process were as follows: 7.56% of items from the independent forward translations, 62.18% of items from the comparison between two forward translations, and 21% of items from the comparison between post-back translation and the original version. The internal consistency and stability of the Farsi version of the CLEFT-Q were 0.979 and 0.997, which both were categorized as excellent. CONCLUSION: The Farsi version of the CLEFT-Q is a valid and reliable tool currently available for Farsi-speaking families around the world.

In Vitro evaluation of immediate cytotoxicity of resterilised orthodontic bands on HGF-1 cell line.

OBJECTIVES: The aim of this study was to evaluate the immediate cytotoxic effects of orthodontic molar bands, on HGF-1 cell line, after multiple times of sterilization following size selection procedure. MATERIAL AND METHODS: 48 stainless steel orthodontic molar bands were divided into 4 groups according to times of sterilization (1, 2, 4 and 8 times). A liquid extract containing the ions released from each band was prepared and the HGF-1 cell line was exposed to the extracts. 2 control groups (positive and negative) were designated. An MTT assay was performed, and the absorbance was read at 492nm in a microplate reader (Antos 2020, Austria). RESULTS: There was no significant difference in pure optical density (OD) among the 4 groups (P=0.749) however a statistically significant difference was seen between the positive control group and other 4 groups (P<0.001). CONCLUSION: The stainless-steel orthodontic bands used in this study were inert as manufactured and even multiple times of sterilization did not decrease the biocompatibility of these bands for clinical use. The present study shows that clinicians can sterilize the tried-in molar bands for at least 8 times without any risk of cytotoxicity for patients.

Effect of high concentration nano-hydroxyapatite serum on shear bond strength of metal brackets following three different enamel surface preparation methods: An in vitro study.

OBJECTIVE: White spot lesion (WSL) is one of the most important complications of fixed orthodontic treatment. Many methods have been studied to prevent this problem. This study is aimed to investigate the effect of high concentration nano-hydroxyapatite (nHAP) on shear bond strength (SBS) of metal brackets and Adhesive Remnant Index (ARI) score in different preparation methods. MATERIAL AND METHODS: Sixty human premolars, which were extracted for orthodontic reasons were included in this in vitro study. The teeth were randomly divided into 4 groups of 15 each: one control group and three nHAP groups. After applying nHAP for 2 to 3 minutes daily for 10 days, the groups 2 to 4 underwent sandblasting using 50µm aluminium oxide and 30 seconds etching, 60 and 30 seconds etching, respectively, and the brackets were then bonded to the teeth. After debonding, SBS and ARI scores were recorded. Data were analysed using the ANOVA test and posthoc test for pairwise comparisons. RESULTS: No significant difference was observed in SBS between the control group and the nHAP groups. The sandblasted teeth showed significantly higher SBS than the 30 seconds etching after nHAP application (P=0.02). The teeth etched for 60 seconds showed a significantly higher ARI score than the 30 seconds etched teeth with (P=0.003) or without (P<0.001) nHAP application. CONCLUSIONS: The use of nHAP before bracket bonding can be considered as a caries preventive method since it did not compromise the SBS. Sixty seconds etching is recommended for less likely damage to the enamel after debonding.

Evaluation of flexural strength and antibacterial effect of orthodontic acrylic resins containing Galla chinensis extract

ABSTRACT Objective: To evaluate different concentrations of Galla chinensis extract (GCE) added to poly(methyl methacrylate) (PMMA), which is widely used for fabrication of removable orthodontic appliances, regarding the effectiveness of this herbal extract on antimicrobial effect and flexural strength of PMMA. Methods: Acrylic resin samples containing 0.4%, 0.8% and 1.6% GCE were prepared. Flexural strength was investigated via three-point flexural strength test for the 15 acrylic resin blocks of each concentration. Disk diffusion test was used to evaluate antibacterial effects of incorporating the same concentrations of GCE into acrylic resin. All these three groups were compared with the control group, with no added GCE, regarding flexural strength and antibacterial properties. Results: Comparison of flexural strength between the three study groups and the control group showed significant differences between the groups (P=0.018). However, there was no significant difference between the groups containing GCE. There were significant differences in antimicrobial activity between the four groups (P=0.026). Conclusion: Within the limitations of this study, it is suggested that incorporation of GCE into PMMA would be beneficial for antimicrobial activity and flexural strength of PMMA, but further studies on other physical properties and antimicrobial effects on other bacterial strain would be beneficial prior to clinical investigations.

RESUMO Objetivo: Avaliar se diferentes concentrações de extrato de Galla chinensis (EGC) adicionado ao polimetilmetacrilato (PMMA), que é amplamente utilizado para a fabricação de aparelhos ortodônticos removíveis, interferem no efeito antimicrobiano desse extrato e na resistência à flexão do PMMA. Métodos: Foram preparadas amostras de resina acrílica com concentrações de 0,4%, 0,8% e 1,6% de EGC. Para a avaliação da resistência à flexão, utilizou-se o teste de flexão em três pontos para as 15 amostras de resina em cada concentração. O teste de disco-difusão foi utilizado para avaliar os efeitos antibacterianos da incorporação das mesmas concentrações de EGC na resina acrílica. Esses três grupos foram comparados ao grupo controle, sem adição do EGC, em relação à resistência à flexão e quanto às propriedades antimicrobianas. Resultados: As comparações dos três grupos com o grupo controle mostraram diferenças significativas (p=0,018) para a resistência à flexão. Entretanto, não houve diferença significativa entre os grupos contendo EGC. Foram encontradas diferenças significativas na atividade antimicrobiana entre os quatro grupos (p=0,026). Conclusão: Dentro das limitações desse estudo, parece que a incorporação de EGC no PMMA seria benéfica para a atividade antimicrobiana e a resistência à flexão do PMMA. Porém, estudos adicionais sobre outras propriedades físicas e sobre os efeitos antimicrobianos contra diferentes cepas de bactérias seriam interessantes antes de se fazer pesquisas clínicas.

Prevalence of Malocclusion and Occlusal Traits in Children with Autism Spectrum Disorders.

BACKGROUND: The purpose of this cross-sectional study was to evaluate the prevalence of malocclusion in children with autism spectrum disorders (ASDs) and to determine the most common occlusal traits. MATERIALS AND METHODS: The present cross-sectional study was conducted among 7-15 years old children with ASDs and randomly selected healthy children with the same demographic characteristics. Molar relationship, lip incompetence, overbite, overjet, midline deviation, crossbite, and crowding/spacing were recorded. A descriptive analysis was performed for all variables. A comparison of the presence or absence of malocclusion traits between children with and without ASDs was assessed using the chi-square test. Univariate and multivariate logistic regressions were used to calculate odds ratio (OR) and 95% confidence intervals (95% CI) to assay various parameters between autism and non-autism group. RESULTS: A total of 96 patients were assessed, 47 patients in the ASD group, and 49 in the control (non-ASD) group. The results showed no significant difference between the ASD and control groups in terms of the overall prevalence of malocclusion (P>0.05). However, the prevalence of increased overjet and Class II molar relationship was significantly higher in the ASD group compared to the control group (P=0.03). Patients in the control group showed a higher prevalence of midline deviation (P=0.001). CONCLUSION: Despite a higher prevalence of overjet and Class II molar relationship in children with ASDs, the prevalence of malocclusion was not higher in this group of patients.

Effect of mini-screw-facilitated micro-osteoperforation on the rate of orthodontic tooth movement: a single-center, split-mouth, randomized, controlled trial.

OBJECTIVE: The present study aimed to evaluate the effect of MOP over a 3-month period and to determine the influence of the number of perforations on the rate of canine retraction. In addition, the amount of pain and discomfort caused by the MOP method was evaluated. TRIAL DESIGN: A single-center, split-mouth, triple-blind, randomized, controlled trial was conducted. METHODS: The clinical trial was conducted from December 2018 to July 2019 in the Orthodontic Clinic, Shiraz Dental School. Twenty-eight patients (range from16.3 to 35.2 years) who need fixed orthodontic treatment were recruited and randomly assigned to MOP1 and MOP2 groups. In each patient one side of the mouth worked as a control side which received no MOPs. Four months after first premolars extraction, patients in MOP1 group received 3 MOPs on the buccal surface of alveolar bone in the experimental side to accelerate canine retraction whereas patients in MOP2 group received 3 buccal MOPs and 3 palatal MOPs in the experimental side. The amount of canine retraction was measured every 28 days at three intervals on both sides of the mouth. Pain perception was also measured on the day of MOP procedure and subsequently at 24 h. Randomization was performed using online software RANDOM.ORG; the recruited patients were divided into two parallel groups with a 1:1 allocation ratio then the side of MOPs intervention in each subject was randomly determined with coin tossing. Triple blinding design was employed. RESULTS: The result of the intra-examiner reliability using ICC was 0.97 (P <  0.001), indicating excellent repeatability and reliability of the measurements. The baseline characteristics between the groups were similar (P > 0.05). There was a significant difference in the rate of canine retraction between the MOP groups and the contralateral control sides, as well as between the MOP1 and MOP2 groups (P <  0.05). CONCLUSION: The MOP procedure was effective in accelerating orthodontic tooth movement, although the amount of acceleration was not clinically significant in the case of canine retraction. An increase in the number of MOPs resulted in a significant acceleration of the canine retraction. TRIAL REGISTRATION: The trial was registered 30 November 2018 at the Iranian Registry of Clinical Trials (IRCT20181121041713N1).

Evaluation of flexural strength and antibacterial effect of orthodontic acrylic resins containing Galla chinensis extract.

OBJECTIVE: To evaluate different concentrations of Galla chinensis extract (GCE) added to poly(methyl methacrylate) (PMMA), which is widely used for fabrication of removable orthodontic appliances, regarding the effectiveness of this herbal extract on antimicrobial effect and flexural strength of PMMA. METHODS: Acrylic resin samples containing 0.4%, 0.8% and 1.6% GCE were prepared. Flexural strength was investigated via three-point flexural strength test for the 15 acrylic resin blocks of each concentration. Disk diffusion test was used to evaluate antibacterial effects of incorporating the same concentrations of GCE into acrylic resin. All these three groups were compared with the control group, with no added GCE, regarding flexural strength and antibacterial properties. RESULTS: Comparison of flexural strength between the three study groups and the control group showed significant differences between the groups (P=0.018). However, there was no significant difference between the groups containing GCE. There were significant differences in antimicrobial activity between the four groups (P=0.026). CONCLUSION: Within the limitations of this study, it is suggested that incorporation of GCE into PMMA would be beneficial for antimicrobial activity and flexural strength of PMMA, but further studies on other physical properties and antimicrobial effects on other bacterial strain would be beneficial prior to clinical investigations.

Difficulty of palatal impacted canine treatment in different sagittal and vertical skeletal malocclusions: A retrospective 3D evaluation.

OBJECTIVE: To evaluate the difficulty of impacted canine treatment in different kinds of sagittal and vertical malocclusion using the KPG index, a novel 3D classification system for canine impaction. MATERIALS AND METHODS: In this cross-sectional study, 74 cone-beam computed tomography (CBCT) images of subjects with palatally impacted canines were collected from one dental radiographic clinic. Impacted canines were assessed and KPG index of difficulty of treatment was calculated for each tooth. Lateral cephalograms corresponding with each CBCT were also traced and analysed. To assess the relationship between the level of treatment difficulty and type of malocclusion, the Chi2 test was used. The Kruskal-Wallis H test was used to assess the difficulty score between the three classes of malocclusion. RESULTS: There was no correlation between different sagittal skeletal measurements and treatment difficulty of impacted teeth (P>0.05). A positive correlation was shown between KPG index and linear measurements of A to Pn and facial angle (FH-N Pog) (P<0.05). Difficulty of treatment did not differ among various patterns of vertical growth. CONCLUSION: Treatment of impacted canines is more difficult in patients with maxillary prognathism and it is recommended that these patients be more meticulously evaluated prior to treatment.

Photogrammetric Evaluation of Soft Tissue Profile and Frontal Photographs in Repaired Bilateral Cleft Lip and Palate.

OBJECTIVE: To evaluate the soft tissue profile and frontal photographs of 8- to 12-year-old patients with repaired complete bilateral cleft lip and palate (BCLP). METHODS: The profile and frontal photographs obtained from 31 nonsyndromic BCLP children (aged 8-12 years: 14 boys and 17 girls) were analyzed and compared with an age- and sex-matched normal population (18 boys and 32 girls). In each patient, 12 soft tissue angular and proportional parameters on the frontal photograph and 12 angular parameters for the profile photographs were developed and measured. Student t test was used to compare the mean value of the parameters between both sexes. RESULTS: In the frontal view, there was a significant difference between the 2 study groups in the facial symmetry angle (P < .001), lower facial height proportion (P < .001), upper lip proportion (P < .001), and interalar width/distance between the inner canthus of the eyes (P < .001). In the profile view, there was a significant difference between the control group and the patients with cleft lip and palate in terms of nasofrontal angle (P < .001), nasal angle (P < .001), angle of the inferior facial third (P = .032), head position angle (P < .001), facial convexity angle (P < .001), total facial convexity angle (P < .001), and vertical nasal angle (P < .001). CONCLUSION: In comparison with the normal population, the face of patients with repaired BCLP showed several soft tissue deformities, especially in the nasofrontal region, even after a surgical repair.

Dentoskeletal effects of class II malocclusion treatment with the modified Twin Block appliance.

BACKGROUND: The purpose of this study was to prospectively assess the dentoskeletal effect of a modified Twin Block appliance for treatment of class II malocclusions. MATERIAL AND METHODS: Lateral cephalograms of 25 Class II malocclusion patients were compared to evaluate skeletal, dentoalveolar and soft tissue changes pre- and post-treatment with a modified Twin Block appliance. A total of 33 angular and linear variables were used for analysis. The differences were calculated at the start and end of treatment. The paired T test was performed to compare the cephalometric measurements before and after treatment. RESULTS: Compared the pre- and post- treatment measurements, there was a significant increase in SNB (P<0.001), CO-Gn (P<0.001), ANS-Me (P=0.001), Mandibular base (P<0.001), Lower 1 to NB (°) (P=0.004), Lower 1 to NB (mm) (P<0.001), and Z-angle (P=0.001) following functional therapy with modified Twin Block appliance. On the other hand, a significant decrease was observed in ANB (P<0.001), NA-Pog (P<0.001), overjet (P<0.001), and overbite (P=0.007), Upper 1 to palatal plane (P=0.007), UL-E-line (P<0.001), LL-E-line (P=0.001), and H-angle (P=0.002) after treatment with modified Twin Block appliance. CONCLUSIONS: The modified Twin-Block improves facial esthetics in Class II malocclusion by a combination of changes in skeletal as well as dentoalveolar structures. The increase of mandibular unit length was observed to be due to a true mandibular growth not just a repositioning of the mandible. The modified appliance, however, did not show any superior effects in terms of less dental compensation compared to the conventional Twin-Block appliance. Key words:Dentoskeletal effect, Modified Twin Block, Class II malocclusion.