Objective:This study aimed to assess the relationship between malocclusion severity and oral health-related quality of life (QoL) of 18 to 25-year-old Iranians who sought orthodontic treatment.Materials and Methods:A total of 126 patients between 18 and 25 years attending some private orthodontic clinics answered the oral health impact profile-14 (OHIP-14) and a demographic questionnaire. Two calibrated orthodontists recorded the Index of Orthodontic Treatment Need-Dental Health Component (IOTN-DHC) determining the severity of malocclusion (Kappa = 0.8). The IOTN-Aesthetic Component (IOTN-AC) was reported by patients for assessing the perception of their esthetic severity of malocclusion. Logistic regression analysis was used. Level of significance was set at α = 0.05.Results:The mean score of OHIP-14 was 20.87 ± 8.6. The frequency of patients with no/slight, borderline, and definite need for orthodontic treatment was determined as 13.4%, 23.8%, and 62.7%, respectively, by IOTN-DHC. There were significant correlations between borderline or definite need treatment and OHIP-14 overall score (P < 0.05). Patients with borderline and definite need for orthodontic treatment had 5 and 21 times lower QoL, respectively, than those with a slight need for orthodontic treatment. Based on IOTN-AC, 50.8% of the patients mentioned slight or no need based on IOTN-AC. No significant association was noted between IOTN-AC and OHIP-14 overall scores.Conclusions:The results showed negative impact of malocclusion severity on the QoL. This study highlighted the importance of individual assessment of orthodontic patients.

Objective:The aim of this study was to evaluate the effect of agents available in whitening toothpastes (Crest® and Sensodyne®) in vitro on the force decay of elastomeric chains used in orthodontics.Materials and Methods:A total of 300 specimens of elastomeric chains were divided into five groups (n = 60) and were evaluated. These groups included (1) the regular Crest® toothpaste and distilled water solution, (2) whitening Crest® toothpaste and distilled water solution, (3) regular Sensodyne® toothpaste and distilled water solution, (4) whitening Sensodyne® toothpaste and distilled water solution, and (5) distilled water as a control group. The samples' force was measured using Instron at intervals of 0, 1, 7, 14, 21, and 28 days. Data were analyzed by SPSS software.Results:At the initial time point, the difference in the force values of elastomeric chain between any of the groups was not significant (P > 0.05). On the 1st day, there was a significant difference (P < 0.05) between all groups except the groups of whitening Crest®, regular, and whitening Sensodyne® (P > 0.05). On days 7, 14, and 28, the rate of decline for all groups was statistically significant (P < 0.05).Conclusions:According to the results obtained in the present study, it seems that toothpastes without whitening agents have less effect on force decay of elastomeric chain over time.

Purpose This study reviewed the common conditions associated with displacement of inferior alveolar nerve canal. Materials and Methods General search engines and specialized databases including Google Scholar, Pub Med, Pub Med Central, Science Direct, and Scopus were used to find relevant studies by using keywords such as “mandibular canal”, “alveolar canal”, “inferior alveolar nerve canal”, “inferior dental canal”, “inferior mandibular canal” and “displacement”. Results About 120 articles were found, of which approximately 70 were broadly relevant to the topic. We ultimately included 37 articles that were closely related to the topic of interest. When the data were compiled, the following 8 lesions were found to have a relationship with displacement of mandibular canal: radicular/residual cysts, dentigerous cyst, odontogenic keratocyst, aneurysmal bone cyst, ameloblastoma, central giant cell granuloma, fibrous dysplasis, and cementossifying fibroma. Conclusion When clinicians encounter a lesion associated with displaced mandibular canal, they should first consider these entities in the differential diagnosis. This review would help dentists make more accurate diagnoses and develop better treatment plans according to patients' radiographs.

Purpose The aim of this study was to review the common conditions associated with mandibular canal widening. Materials and Methods General search engines and specialized databases including Google Scholar, PubMed, PubMed Central, Science Direct, and Scopus were used to find relevant studies by using the following keywords: “mandibular canal,” “alveolar canal,” “inferior alveolar nerve canal,” “inferior dental canal,” “inferior mandibular canal,” “widening,” “enlargement,” “distension,” “expansion,” and “dilation.” Results In total, 130 articles were found, of which 80 were broadly relevant to the topic. We ultimately included 38 articles that were closely related to the topic of interest. When the data were compiled, the following 7 lesions were found to have a relationship with mandibular canal widening: non-Hodgkin lymphoma, osteosarcoma, schwannoma, neurofibroma, vascular malformation/hemangioma, multiple endocrine neoplasia syndromes, and perineural spreading or invasion. Conclusion When clinicians encounter a lesion associated with mandibular canal widening, they should immediately consider these entities in the differential diagnosis. Doing so will help dentists make more accurate diagnoses and develop better treatment plans based on patients' radiographs.

Introduction. Numerous devices have been introduced for correction of Class III malocclusion and maxillary deficiency. Aim. To assess the dentoskeletal effects of miniplates combined with Class III traction in treating Cl III malocclusion and maxillary deficiency in growing patients. Methods. This case describes the treatment of a maxillary-deficient 11-year-old boy by using miniplates. The patient's parents rejected the use of extraoral appliances and major surgical correction; therefore the treatment was done by using Class III elastics connected from two mandibular miniplates to an upper removable appliance. Two miniplates were inserted in the anterior part of the mandible in the canine areas under local anaesthesia. The treatment lasted for 10 months after which favourable correction of the malocclusion was observed. Results. The SNA and ANB angles increased by 5.1° and 4.4°, respectively. Lower 1 to mandibular plane decreased by 3.4°. Conclusions. This case demonstrates that miniplates can be a suitable method to extraoral appliances and major surgery in maxillary deficiency cases.

Background: Growth hormone plays a significant role in determining craniofacial morphology. Mutations of its receptor gene might be associated with mandibular prognathism (MP). Purpose: The aim of the current study was to evaluate growth hormone receptor (GHR) gene polymorphisms in relation to facial dimensions. Material and Method: The study enrolled 65 participants with class III profile in MP group and 60 orthognathic control participants. Genomic DNA was extracted from a blood sample from the patients and the P561T and C422F polymorphisms of GHR gene were screened by PCR-RFLP method followed by Sanger sequencing of randomly selected samples to validate the genotyping results. Chi square was used to compare distribution of polymorphism in MP and control groups (p<0.05). Results: Heterozygous P561T mutation was found in 10.77% and 8.33% of MP and control groups, respectively (p=0.644) while none of the subjects had the C422F mutation. Sanger sequencing confirmed the genotyping results from the PCR-RFLP method. P561T polymorphism was significantly associated with ramus and lower facial height in MP patients and with ramus height in orthognathic patients (p<0.05). Conclusion: The results indicate that the P561T polymorphism of the GHR gene is associated with the vertical dimension of the mandible in an Iranian population.

Introduction: It is recently suggested that titanium dioxide (TiO2) nanoparticles can be added to bracket luting agents in order to reduce bacterial activity and protect the enamel. However, it is not known if this addition can affect the shear bond strength (SBS) below clinically acceptable levels. Therefore, this study examined this matter within a comprehensive setup. Methods: This in vitro experimental study was conducted on 120 extracted human premolars randomly divided into four groups (n=30): in groups 1 and 2, Transbond XT light-cured composite with or without TiO2 was applied on bracket base; in groups 3 and 4, Resilience light-cured composite with or without TiO2 was used. Brackets were bonded to teeth. Specimens in each group (n=30) were divided into three subgroups of 10 each; then incubated at 37°C for one day, one month, or three months. The SBS and adhesive remnant index (ARI) were calculated and compared statistically within groups. Results: The SBS was not significantly different at one day, one month or three months (p>0.05) but composites without TiO2 had a significantly higher mean SBS than composites containing TiO2 (p<0.001). The SBS of Transbond XT was significantly higher than that of Resilience (p<0.001). No significant differences were noted in ARI scores based on the type of composite or addition of TiO2 (p>0.05). Conclusions: Addition of TiO2 nanoparticles to Transbond XT decreased its SBS to the level of SBS of Resilience without TiO2; thus, TiO2 nanoparticles may be added to Transbond XT composite for use in the clinical setting.

Introduction: Force decay elastomeric chains are significant, and it is a clinical problem. Aim:The aim of this study was to evaluate the effects of bleaching agent in the mouthwash on the force decay of orthodontic chains. Materials and methods:In this experimental study, 160 gray closed elastomeric chains were randomly divided into three groups (one control and two test groups). Clinical significance: Use of whitening mouthwash by orthodontic patients could decrease the force of elastomeric chains, so it could be recommended to use them for a short time.