Iranian Journal of Orthodontics
Volume:19 Issue: 2, Dec 2024

This study evaluated correlations between Angle’s Class I and Class II malocclusions, lateral cephalometric parameters, and smile characteristics assessed through lateral and oblique smile views.

A sample of 20 patients (≥15 years, with no prior orthodontic treatment) were selected for this study. The selected individuals were grouped according to Angle’s classification of malocclusion. Pretreatment records were taken including lateral cephalogram and extra-oral smile photographs in lateral and oblique views. In the lateral cephalogram, skeletal, dental, and facial parameters and in lateral and oblique smile views, smile index, commissure angle, and incisal display angle were recorded. ANOVA and Pearson correlation test were used for data analysis. P-value<0.05 was considered as significant.

The results of this study showed no significant difference in cephalometric parameters except for UFH/LFH, which was higher in Angle’s Class II malocclusion. The smile index, commissure angle and incisal display angle differed significantly between the two malocclusions in both lateral and oblique smile views except for incisal display angle in the oblique view. 

The lateral and oblique smile index decreased from Class I to Class II. In contrast, the lateral and oblique smile commissure angle and lateral smile incisal display angle increased in Class II compared to Class I. No significant difference was found in skeletal and dental parameters between Angle’s Class I and Class II malocclusions except for UFH/LFH, which was higher for Angle’s Class II malocclusion.

Persistent foramen of Huschke (PFH), defined as open foramen tympanicum, is associated with some pathological disorders. The present investigation evaluated the incidence and dimensions of PFH in cleft lip and palate (CL/P) patients. 

We assessed the cone-beam computed tomography (CBCT) radiographs of 311 patients, 50 of whom were diagnosed with CL/P. Then, we used the images for the prevalence and dimensions of PFH. Fisher’s exact, Pearson’s chi-squared test and independent t-test were used for statistical analysis. P-value<0.05 was considered as significant.

In the case group, 18 individuals (36%) and in the control group, 61 individuals (23%) were diagnosed with PFH. No correlation was found between the side or laterality of CL/P and that of PFH. Also, no relationship was established between the severity of CL/P and the presence or magnitude of PFH. Despite the higher prevalence of PFH in the case group compared to the control group, the differences were not significant. In addition, axial diameters were significantly higher in the case group (2.15 mm in the case group and 1.82 mm in the control group; P=0.048). 

The prevalence of PFH in individuals with CL/P did not exceed that of the general population.

This study assessed the orthodontic treatment needs of Iranian and Arab university students using the Index of Orthodontic Treatment Need (IOTN). 

This cross-sectional study was conducted on 100 Arab and 100 Iranian patients presenting to Ajman University dental clinic in 2023. The subjects were selected by convenience sampling and were 19‒25 years of age. The dental health component (DHC) and esthetic component (AC) of the IOTN were used to assess their malocclusion and the need for orthodontic treatment. Data were analyzed using the chi-squared test at a significance level of 0.05. 

According to the DHC, 60% of Arab and 64% of Iranian patients had malocclusion with moderate to extreme need for treatment. Of the Iranian population, 12% were Grade I (no need), 24% were Grade 2 (little or mild need), 28% were Grade 3 (moderate need), 20% were Grade 4 (severe need), and 16% were Grade 5 (extreme need). These values were 17%, 23%, 32%, 20%, and 8%, respectively, for the Arab population. According to the AC, 59% of Iranians and 56% of Arabs required little or no treatment, while 27% of Iranians and 31% of Arabs had moderate need, and 14% of Iranians and 13% of Arabs had severe need for treatment. The difference between the two populations was insignificant in the DHC (P=0.431) or AC (P=0.681) grading. 

The two groups with different ethnic backgrounds exhibited no significant difference regarding orthodontic treatment needs.

This study aimed to evaluate the effect of incorporating Bioglass (BG) 45S5 into an orthodontic adhesive on the shear bond strength (SBS) of metal orthodontic brackets bonded to enamel and the adhesive remnant index (ARI) score.

In this in vitro study, 55 extracted sound premolars were randomly divided into five groups (n=11 each). Metal brackets were bonded using Ambar FGM orthodontic adhesive without BG (control group) and with BG 45S5 added at concentrations of 5%, 10%, 15%, and 20% by weight in groups 2 to 5, respectively. The SBS was measured using a universal testing machine, and the ARI score was determined under a stereomicroscope at ×10 magnification. Data were analyzed using one-way ANOVA at a significance level of α=0.05.

The highest mean SBS was observed in the 20% BG Group (48.28±24.5 MPa), followed by the control group (35.81±11.11 MPa), 15% BG Group (19.64±5.42 MPa), 10% BG Group (16.3±9.33 MPa), and 5% BG Group (14.21±4.23 MPa). The SBS in the 20% BG Group was significantly higher than in the control (P=0.013), 5% BG (P=0.000), and 10% BG (P=0.002) groups. No significant differences were found in ARI scores among the groups (P=0.810).

Adding BG 45S5 to the orthodontic adhesive at concentrations of 5%, 10%, and 15% did not significantly affect the SBS, but a 20% concentration increased the SBS. Incorporating BG at these levels does not adversely impact the SBS or ARI scores.

This study assessed the perspectives of laypeople, prosthodontists, orthodontists, and general dentists regarding the efficacy of different photographs in revealing the orthodontic treatment results. 

In this cross-sectional study, one Class I and one Class III orthodontic patient were selected by consensus of several orthodontists, and their preoperative and postoperative photographs were shown to 125 raters in 4 groups of laypeople, prosthodontists, orthodontists, and general dentists. The raters were asked to rate the clarity of the impact of treatment shown on each photograph using a 100-mm visual analog scale. Kruskal-Wallis, Chi-square, Wilcoxon, and Friedman tests were used for statistical analysis. P-value < 0.05 was considered as significant. 

In the Class I malocclusion patient, the frontal smiling view acquired the highest score among extraoral photographs, followed by the profile view and frontal view at rest (P<0.001). Of intraoral photographs, the frontal view of occlusion acquired the highest score, followed by the maxillary occlusal view, mandibular occlusal view, and left and right views of occlusion (P<0.001). In the Class III patient (orthognathic surgery), the profile view acquired the highest score among extraoral photographs, followed by the frontal smiling view and frontal view at rest (P<0.001). Of intraoral photographs, the frontal view of occlusion acquired the highest score, followed by the left and right occlusal views, maxillary occlusal view, and mandibular occlusal view (P<0.001). 

For patients with intraoral and intra-arch changes, the extraoral frontal smiling photograph and the intraoral frontal occlusal photograph, best revealed the results. In patients with additional facial and extraoral changes, the extraoral profile view and intraoral frontal occlusal view, best revealed the treatment results.

This study aimed to evaluate the alterations in lip area before and after fixed orthodontic treatment in adult patients with Class II Division I malocclusion who underwent premolar extractions. Assessments were conducted using frontal photographs and measurements from lateral cephalograms focusing on dentoalveolar and soft tissue parameters.

Twenty-three adult patients with Class II skeletal malocclusion were selected from the archive and pre and post-treatment lateral cephalograms in addition to frontal photographs were assessed. The same investigator manually traced both the cephalograms and photographs to minimize observer variability. Measurements were computed both manually and digitally for comparison purposes. Data were analyzed using paired t-test and p-value<0.05 was considered as significant.

The study found a significant increase in the thickness from the cervical portion of the upper incisors to the upper lip after treatment (mean pre-treatment: 13.70±1.92 mm; post-treatment: 14.37±2.18 mm; P=0.006). Conversely, the thickness from the lower incisors to the lower lip decreased significantly post-treatment (mean pre-treatment: 16.00±2.07 mm; post-treatment: 14.00±2.80 mm; P<0.001). Additionally, this study showed there were a significant decrease in vermilion height near to lip corners(p<0.05).

Significant soft tissue changes were observed in adults with Class II skeletal malocclusion following orthodontic treatment involving premolar extractions. Notable changes included increased thickness from the cervical portion of the upper incisors to the upper lip, decreased thickness from the lower incisors to the lower lip, and significant decrease in vermilion height near to lip corners.

Reducing orthodontic treatment duration is a significant concern for both patients and clinicians, as prolonged treatments can lead to complications like dental caries, root resorption, and decreased patient compliance. This study aims to compare the effectiveness of two minimally invasive techniques—Piezocision and platelet-rich plasma (PRP) injection in accelerating orthodontic tooth movement during space closure in patients with bimaxillary protrusion.

Sixteen patients diagnosed with Angle's Class I bimaxillary protrusion requiring extraction of first premolars were randomly assigned to two groups. Group A (n = 8) underwent Piezocision-assisted orthodontic treatment, while Group B (n = 8) received submucosal PRP injections. In both groups, one side of the maxillary arch served as the experimental side, and the contralateral side served as the control. Measurements of space closure were taken at the initiation of retraction (T0) and after 90 days (T1). Paired t-test, independent t-test, ANOVA and post hoc Tukey test were used for statistical analysis. P-value<0.05 was considered as significant.

There were significant differences in mean difference of space closure between Piezocision experimental group and Piezocision controls(p=0.003);also, there were significant differences between PRP experimental group and PRP controls (p=0.000). In addition, this study did not show any significant differences in the mean difference of space closure between  Piezocision experimental and PRP experimental groups(p=0.252).

Piezocision and submucosal injection of PRP could increase the rate of space closure. There is no difference between Piezocision and PRP in rate of space closure.

This study aimed to assess and compare the initial stress and displacement in vertically displaced canines using finite element analysis. Both conventional and self-ligating bracket systems were evaluated at displacement heights of 2, 4, and 6 mm.

Six finite element models of maxillary dentitions with canines vertically displaced by 2, 4, and 6 mm were developed using specialized software. Continuous arch wire techniques were applied in both the conventional system with 0.022" × 0.028" slot MBT brackets (3M Unitek™) and the self-ligating system with 0.022" × 0.028" slot passive self-ligating brackets (Damon Q), both utilizing a 0.014-inch CuNiTi arch wire. The study calculated canine displacement, reactionary effects on adjacent teeth (lateral incisors and first premolars), and compressive and tensile stresses along the X, Y, and Z axes at 12 specific points.

The self-ligating bracket system demonstrated greater extrusion of the canine compared to the conventional bracket system, with the most significant movement observed in the 2-mm model, followed by the 4-mm and 6-mm models. Reactionary effects on adjacent teeth included intrusion and tipping away from the canine, most pronounced in the 2-mm model. Compressive and tensile stresses were higher in the conventional bracket system and decreased with increased displacement.

For vertically displaced canines, using a continuous arch wire with a self-ligating bracket system is more advantageous than a conventional bracket system, as it results in greater canine movement and less stress on adjacent teeth. However, its effectiveness diminishes with increased displacement height due to resistance caused by higher contact angles and decreased wire expression.

The present study aimed to establish the mesiodistal crown dimension and intra-maxillary tooth width ratios of permanent teeth in a Tanzanian population.

A cross-sectional study was conducted at Muhimbili University Dental Clinic involving 204 orthodontic study models with normal intra-arch occlusion. The mesiodistal width of all the permanent teeth, excluding the second and third molars, was measured using a digital Vernier caliper. Data were analyzed using SPSS 25.0. Tooth width means comparison between sexes and sides was performed using an independent t-test with the significance level set at P<0.05. Intra-arch tooth width ratios, correlation of variance, and mesiodistal tooth width means were calculated and presented in descriptive statistic tables.

The widest tooth was the first lower molar (11.55 mm), followed by the upper first molar (10.53 mm) and upper central incisor (9.22 mm). The smallest teeth were the central incisors in the lower jaw (5.67 mm) and the second premolar in the upper jaw (7.12 mm). Males had statistically wider teeth than females in all teeth except the second premolars and upper lateral incisor (P<0.05). The proportions of the upper laterals to upper central incisors were 80.5% and 81.3% in males and females, respectively. Furthermore, the ratio of the upper first premolar to that of the upper canine was 96.3% in females and 93.6% in males. 

Odontometrics data for the Tanzanian population was determined. The derived measurements were relatively higher compared to those reported in most other populations.

This research aimed to assess the understanding, attitudes, and clinical practices of orthodontists and orthodontic residents in managing impacted maxillary canine teeth.

This cross-sectional study surveyed orthodontists and residents from nine provinces in Iran. A custom-designed questionnaire evaluated their knowledge, attitudes, and practices regarding the treatment of impacted upper canines. Data analysis involved multiple backward linear regression and Pearson's correlation tests. P-value<0.05 was considered as significant.

A total of 96 participants(72 orthodontists and 24 residents) completed the questionnaire. The average knowledge score was 6.41 ± 1.94, and the mean attitude score was 15.9 ± 2.7. A significant positive correlation existed between knowledge and attitude scores (P = 0.001). Participants who saw more patients weekly had higher knowledge scores (P = 0.002), while those with more clinical experience had lower knowledge scores (P = 0.002). Attendance in additional periodontology or oral surgery courses significantly influenced attitudes (P = 0.001). Faculty members preferred apically positioned flaps for labially impacted canines, whereas other participants favored closed exposure techniques (P = 0.025). Clinicians with a higher patient load (P = 0.02) and more experience (P = 0.00) were more inclined to extract the lateral incisor and replace it with the impacted canine.

Iranian orthodontists and residents demonstrated above-average knowledge and positive attitudes toward managing impacted maxillary canines.

Patients undergoing fixed orthodontic treatments face a higher risk of white spot lesions (WSLs) due to difficulties in effective plaque control. Several preventive measures provide remineralization and antibacterial benefits that reduce WSLs. These measures, while protective, may adversely affect the shear bond strength (SBS) of orthodontic brackets, potentially leading to bracket debonding and impacting overall treatment effectiveness. This study comparatively evaluated the effects of pretreatments with fluoride varnish, chlorhexidine fluoride mouthwash (CHXF), and fluoridated casein phosphopeptide-amorphous calcium phosphate (CPP-ACPF) on the shear bond strength (SBS) of orthodontic brackets bonded with GC Ortho Connect composite resin.

Sixty extracted premolar teeth were randomly divided into four groups. The first group was the control without pretreatment, and the second to fourth groups were pretreated with 5% fluoride varnish for 4 minutes, with a CHXF for 7 days, and with CPP-ACPF for 3 minutes, respectively.  Specimens were subsequently tested for the SBS in a universal testing machine. Each tooth was visually examined and magnified (×10) using a Nikon SMZ800 to evaluate the adhesive remnant index (ARI).One-way ANOVA, followed by post hoc Tukey tests used for statistical analysis. The significance level was set at P<0.05.

Evaluation of SBS showed no significant differences between the control, chlorhexidine fluoride mouthwash, and CPP-ACPF groups (P>0.05). However, the SBS of the fluoride varnish group was significantly lower than in other groups (P<0.05). Adhesive remnant index (ARI) scores did not show significant differences between the four groups (P=0.057).

The results showed that the SBS of the brackets in the CPP-ACPF paste, CHXF, and fluoride varnish groups were higher than the appropriate range for orthodontic purposes.

Cleft lip and palate (CLP) are among children’s most common congenital craniofacial abnormalities. CLP results from the failure of the fusion of facial processes during embryogenesis. The etiology of CLP is complex and thought to involve genetic influences along with variable interactions from environmental factors. The treatment process involves a multidisciplinary approach while focusing on achieving functional and aesthetic well-being for the patient. 

Case Report:

 In this paper, we report using a multidisciplinary approach to treat a complex case of bilateral CLP in a 7-year-old female patient. The treatment significantly changed the patient’s facial profile, in addition to improving her occlusion, aesthetics, and function. 

The treatment of CLP should follow a multidisciplinary approach while considering several factors, such as age, developmental stage, and psychosocial factors. This approach has been shown to improve patients’ well-being and quality of life.