Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:16 Issue: 2, Spring 2022

The study aimed to compare the airway morphology and hyoid bone position in children undergoing adenoidectomy or adenotonsillectomy with healthy individuals with no skeletal problems in similar age and development period.

The subjects in the study were divided into three groups. These groups were defined as those having undergone adenoidectomy (53 children), those having undergone adenotonsillectomy (48 children), and the systemically healthy control group (63 children). Seventeen pharyngeal airway, nine hyoid, and four area measurements were used in the cephalometric radiographs of the children in all the groups. One-way analysis of variance was used to evaluate the children in each group. In addition, Tukey tests were used for a bilateral comparison of significant parameters. The results were considered statistically significant at P<0.05.

The mean age of 164 patients in the study group was 12.76±2.85 years. The vertical airway length significantly decreased in the adenotonsillectomy group compared to other groups, while the epiglottic pharyngeal length significantly increased in the former than in the latter (P<0.05). The area measurements showed that although the oropharynx area significantly increased in the adenotonsillectomy group compared to other groups, the hypopharynx and total area measurements were significantly different compared with the control group (P<0.05). No statistically significant difference was found between the three groups in all measurements of the hyoid bone position (P>0.05).

 The study showed that adenotonsillectomy operations caused more increases in the oropharynx and hypopharynx parts of the pharyngeal airway. Adenoidectomy and adenotonsillectomy operations did not contribute significantly to the hyoid bone position.

Establishing an accurate occlusal vertical dimension (OVD) is a crucial clinical step during full-mouth rehabilitation. Various techniques have been suggested to evaluate OVD, but none of them is practically reliable, and each one has its shortcomings. The correlation between facial proportions and the lower third of the face is a reliable method but needs to be verified in many ethnic groups. Therefore, this study aimed to determine the correlation between OVD and various facial measurements in a Tunisian ethnic group.

 A cross-sectional study was conducted between November 2020 to January 2021. The participants were randomly selected from dental students, dental surgeons, and the patients referring to the University Dental Clinic for dental treatments. Seven facial measurements were clinically recorded using a digital caliper. The correlation between OVD and facial measurements was analyzed using Spearman’s coefficient and linear regression analysis.

A total of 201 dentate participants (134 females and 67 males) were included in the study. The mean OVD in male subjects was higher (67.60±4.49) compared to female subjects (60.72±3.84). The total facial height was positively correlated with OVD in both genders. OVD was statistically correlated with the height of the upper lip. This correlation was highly significant in males while it was weak in the female group.

 Facial proportions and linear equations are non-invasive, simple, and reliable methods to predict OVD, especially in males.

The present study evaluated and compared the surface roughness (SR) of five different types of orthodontic archwires made by two different manufacturers.

 In this in vitro study, 10 samples of five different archwires comprising of three types of shape memory wires, SmartArch (Ormco), Damon (Ormco), Heat-activated NiTi (HANT) (G&H Orthodontics), Stainless Steel wire (SS) (Ormco), and conventional NiTi (G&H Orthodontics) were examined by atomic force microscopy (AFM). The processing of 3D images was carried out using Gwyddion software, from which the root mean square (rms), the roughness average (Ra), and the maximum height (mh) of the scanned surface profile were documented. The data were analyzed with one-way ANOVA followed by post hoc Tukey tests for intergroup comparisons.

 The mean SR of SS wires was the least (Ra=8.70±0.17), followed by NiTi wires (10.29±2.00) with a significant difference between them (P<0.05). Among the three shape-memory wires, the HANT wires had the least SR (Ra=22.97±16.56) compared to SmartArch wires (Ra=25.55±3.78) and Damon wires (Ra=25.67±4.54), but the difference was not significant (P>0.05).

 The SS wires by Ormco had the least SR followed by G&H orthodontics NiTi wires. The three different shape-memory wires tested had no significant difference in SR values.

 Enamel microabrasion can eliminate enamel irregularities and discoloration. This study evaluated the staining susceptibility of enamel after microabrasion using different clinical protocols.

 A total of 210 extracted bovine incisors were used in this study. The teeth were randomly divided into five groups of 42 teeth each (n=42), including group 1: control (no treatment), group 2: microabrasion, group 3: microabrasion + fluoride polishing, group 4: macroabrasion (fine-grit diamond bur) + microabrasion, and group 5: macroabrasion (finegrit diamond bur) + microabrasion + fluoride polishing. The groups were then randomly divided into two subgroups for discoloration procedures: coffee and distilled water (n=21). A spectrophotometric evaluation was carried out at baseline and on the 1st, 7th, 14th, and 28th days of the staining period. Statistical analyses were performed using repeated-measures ANOVA and the post hoc Bonferroni test at a significance level of 0.05.

 The greatest color change was observed in group 2 specimens, which were immersed in coffee solutions. The color change values for groups 3, 4, and 5 specimens, which were immersed in distilled water, were higher than those in group 1 specimens (P<0.05). The fluoride polishing + enamel microabrasion treatment groups (groups 3 and 5) exhibited greater resistance to color changes than the matched non-fluoride-polished groups (groups 2 and 4) (P<0.05).

The teeth that underwent enamel microabrasion treatment and were polished with fluoride gel became more resistant to color changes. Our findings confirm that enamel microabrasion treatment is a conservative method for localized discoloration.

Although there are various intraoral and extraoral appliances for anchorage management in orthodontics, most fail to preserve the anchorage efficiently. Thus, there is a need for an appliance that can preserve anchorage in the sagittal, vertical, and transverse directions with good patience compliance and cost-effectiveness. This study compared the efficacy of butterfly arch and transpalatal arch (TPA) as an anchorage reinforcing unit during orthodontic space closure using a linear finite element model.

A 3D model of the maxilla and associated structures was developed from CT images of an individual’s skull at a slice thickness of 1 mm. The magnitude of movements of anchor teeth in vertical, horizontal, and transverse directions was calculated in first premolar extraction cases during anterior retraction using a linear finite element model analysis and compared in two situations―butterfly arch and TPA attached to maxillary first molar for anchorage.

The anterior teeth had similar movements in the case of TPA and butterfly arch. There was more mesial and lingual movement in the first molars with TPA than in the butterfly arch, which had buccal but no mesial movement. The anterior teeth showed extrusion and the second premolars showed intrusion with TPA. Also, the von Mises stress and maximum principal stress were maximum with TPA at the cervical region of anterior and posterior teeth compared to the butterfly arch, where both stresses were uniformly distributed all over the teeth.

Conclusion:

A butterfly arch with its unique design, configuration, and biomechanical properties can be used as a device that can maintain the posterior anchorage efficiently

 Hypodontia, or the absence of one or more teeth during tooth formation, is a highly prevalent dental anomaly. Nevertheless, the main causes are still unknown. Mutations in PAX9, MSX1, WNT10A, and AXIN2 genes are most commonly associated with non-syndromic tooth agenesis in the literature. This study investigated these candidate genes in an Iranian family with non-syndromic hypodontia and oligodontia.

Peripheral blood samples of the proband and her family members were collected, and DNA extractions using the salting-out method were carried out. In addition, polymerase chain reaction (PCR) and Sanger sequencing for candidate genes were performed.

 A missense variant (rs4904210) was identified in the PAX9 gene, with one heterozygous missense variant (rs2240308) and one stop-gained variant (rs121908568) in the AXIN2 gene.

 By surveying similar studies and analyzing the variant in bioinformatics websites, we concluded that the heterozygous stop-gained variant rs121908568 in exon 8 of the AXIN2 gene could be responsible for tooth agenesis in the Iranian population.

 This experimental study sought to assess the biocompatibility of Resil, an experimental epoxy resin-based sealer, in comparison with AH26 and AH-Plus sealers in rats.

 Twelve male Wistar rats weighing 400 to 500 grams were evaluated in this experimental study. Four polyethylene tubes containing Resil, AH-Plus, AH26 sealers, and an empty tube were implanted subcutaneously in rats. The degree of inflammation, type of inflammatory cells present, foreign body reaction, quality of connective tissue, and presence of fibrotic capsule were evaluated histopathologically at 7 and 30 days after implanting the tubes to assess the biocompatibility of sealers. Data were analyzed using the Chi-square test.

 At 7 days, the degree of inflammation in Resil group was almost similar to AH26 group, and 66.7% of rats showed moderate inflammation. AH-Plus group showed less inflammation than Resil and AH26 (50% of rats showed low degree of inflammation), At 30 days, the inflammatory status of all groups was the same, and 83.3% of rats showed very low degree of inflammation. The inflammatory response during the experiment decreased from day 7 to day 30 in all groups. The neutrophil count (P=0.00), fibrotic capsule (P=0.01) and the amount of granulation tissue (P=0.05) significantly decreased from day 7 to day 30 in Resil group.

 Resil sealer showed appropriate biocompatibility at 7 and 30 days after subcutaneous implantation in rats, comparable to AH26 and AH-Plus. Clinical studies are required to confirm these results.

 This study evaluated the combined effects of silver nanoparticles (AgNPs) and chitosan on the dentin bond strength of resin-based root canal sealers using the push-out test and scanning electron microscopy (SEM).

 This in vitro study was conducted on 72 extracted mandibular premolar teeth. All the teeth were decoronated perpendicular to the long axis to leave a 13-mm root length. The root canals were prepared, and the samples were randomly divided into seven experimental groups and one control group based on final irrigation solutions. All the final irrigation procedures were performed for one minute. The root canals were dried using paper points and filled with a resin-based sealer and gutta-percha points using a lateral condensation technique. Sections measuring 2 mm in thickness were taken from the apical, middle, and coronal thirds of each root using a cutting machine. The push-out test was performed using a universal testing machine.

  The solution of AgNPs combined with 0.4% chitosan showed higher bond strength in the coronal region than a combination with 0.2% chitosan. Samples treated with 0.4% chitosan solution exhibited a higher bond strength than the 0.2% chitosan group. There were no significant differences between chlorhexidine (CHX) solution alone and in combination with 0.2% or 0.4% chitosan solution.

 The combination of chitosan and AgNPs was as effective as CHX in improving the bond strength of resin-based sealers.

Aesthetic restorations of severely decayed anterior primary teeth are challenging due to the small size of the teeth and the large pulp chambers. Therefore, this study evaluated and compared the tensile and shear bond strengths of conventional versus modified methods (slot technique) of Cl IV restorations in primary incisors.

A total of 120 extracted intact maxillary primary central and lateral incisors were divided into two groups. In group A, conventional Cl IV cavities were prepared. In group B, after conventional cavity preparation, four and three incisal slots were prepared on the incisal edges of the central and lateral incisors, respectively. All the teeth were restored using composite resin, and then the tensile and shear bond strengths were evaluated.

A statistically significant increase in the tensile bond strength of restorations was recorded in the modified technique compared to the conventional method (P=0.001). Although an increase in the shear bond strengths was found in the modified method, the value did not reach a statistically significant level (P=0.158). The most frequent fracture type was adhesive in the conventional group and cohesive in the modified group, considering the tensile and shear bond strength tests. In both groups, the highest average tensile bond strength was recorded in teeth with the cohesive fracture in dentin, and the lowest average was seen in the adhesive type.

  Incisal slots could increase the tensile bond strengths of Cl IV composite resin restorations in primary teeth.

 Lichen planus is considered a potentially malignant condition with an unknown etiology. This study aimed to determine the carcinoembryonic antigen (CEA) and IgG serum levels in different oral lichenoid lesions before and after treatment with local corticosteroids.

 Two groups of 23 individuals, including oral ulcerative lichenoid lesions patients and healthy ones, were evaluated. Toluidine blue staining and biopsy examinations were carried out while visual analog scale (VAS) was used to evaluate symptoms. By applying corticosteroids, CEA and IgG serum levels were determined before and three weeks after intervention and at the end of the study (9 weeks) with ELISA and turbidimetry methods, respectively.

Before the intervention, there was no significant difference in CEA serum levels between the control and case groups (P=0.19). Moreover, the CEA serum levels indicated no significant difference before and after treatment in the case group (P=0.30). While IgG serum level was significantly higher before the intervention (P=0.01), it decreased significantly in the case group after treatment (P=0.02). In addition, pain intensity reduced significantly in the case group (P=0.05). According to statistics, 8.2% out of 21.7% of patients with positive staining results exhibited dysplasia signs.

 However, neither CEA nor IgG serum levels were different in patients diagnosed with or without dysplasia and positive or negative staining results (P>0.05). IgG serum levels and pain severity effectively decreased in the oral ulcerative lichenoid lesions patients treated with local corticosteroids. Therefore, this treatment can be considered an effective and low-complication treatment modality for lichenoid lesions.

After periodontal surgery, in most cases, the surgical area is covered with a surgical pack. It has been suggested that these packs might minimize complications. This study aimed to compare the effects of Diplen LX membrane and Coe-Pak on pain, wound healing, and patient preference after a periodontal flap surgery in patients with moderate to severe chronic periodontitis.

  In this randomized clinical trial, 26 patients were evaluated. Pain scores were assessed using visual analog scale (VAS) on the 3rd and 7th days postoperatively and compared between the two dressings. On the 7th and 14th days after both flap surgeries, surgical site healing was evaluated using the wound healing index (WHI).

 The mean age of the patients was 31. It was observed that the severity of pain in the studied patients on the 3rd and 7th days postoperatively was significantly lower in the intervention group than in the control group. It was also observed that the value of WHI in the studied patients on the 7th and 14th days postoperatively was significantly higher in the intervention group than in the control group.

 The pain was less severe in both groups using periodontal dressing and also lower in the Diplen LX membrane group. In addition, based on WHI, wound healing score in patients was also higher and more favorable in the Diplex LX membrane group. Due to the above factors, the majority of patients preferred the use of the Diplen LX membrane.