Intercanine Width Research Articles

Maxillary Response Induced by Rapid Palatal Expansion vs. Clear Aligners: A Short-Term Retrospective Evaluation of the Dento-Alveolar Effects in Mixed Dentition

Background: to analyze the dento-alveolar effects induced by two treatment appliances (i.e., RME and Clear Aligners) in growing subjects presenting with early mixed dentition and mild maxillary deficiency. Methods: digital casts of 32 children treated with RME (RG: 17 subjects) or with Clear aligners (CAG: 15 subjects) were collected. Linear and angular values were measured in both groups on the upper arch for both pre- (T1) and post-treatment (T2) models. An unpaired t-test was used to test significant differences between groups (p < 0.05). Results: the comparison of T2-T1 changes for linear measurements between groups showed a greater increase in the inter-canine width (+1.5 mm ± 0.5 mm) and in the first inter-deciduous molar width (+1.4 ± 0.4 mm), also at the trans-palatal level in the CAG group. Conversely, in the posterior region of the upper arch, a greater increase in the first inter-molar distal width was found in the RG group (+1.2 ± 0.4 mm) when compared with the CAG group. A significant increase in the crown angulation in the CAG group was found for all the teeth except for the first molars. Conclusions: the rapid palatal expander widened the palate, tipping the first upper molars buccally to a greater extent, whereas the Clear aligners caused a greater increase in the canine width.

Assessment of clear aligner accuracy of 2 clear aligners systems

This study compared treatment efficacy for specific tooth movements between 2 clear aligner systems (Clarity [3M Oral Care Solutions, St Paul, Minn] and Invisalign [Align Technology, San Jose, Calif]). The study sample included 47 patients (7 males, 40 females; mean age, 36.57 ± 15.97 years) treated with Invisalign and 37 (4 males, 33 females; mean age, 34.30 ± 16.35 years) treated with Clarity aligners who completed their first set of aligners and had an initial refinement scan. Initial and predicted models were obtained from the initial simulated treatment plan. The first model of the refinement scan was labeled as achieved. SlicerCMF software (version 3.1; http://www.slicer.org) was used to superimpose the achieved and predicted digital models over the initial ones with regional superimposition on the relatively stable first molars. Nine hundred forty teeth in the Invisalign system were measured for horizontal, vertical, and angular movements and transverse width and compared with similar measurements of 740 teeth for the Clarity aligners. The deviation from the predicted was calculated and compared between both systems. The deviation achieved from the predicted was significant between the groups for the mandibular interpremolar and intercanine widths (P<0.05). Clarity aligners significantly undercorrected rotations compared with Invisalign for the mandibular first premolars, mandibular canines, maxillary canines, and maxillary central incisors. There was no statistically significant difference between the groups for the achieved vs predicted movements in the horizontal and vertical planes (P>0.05). The efficacy of clear aligner therapy systems (Clarity and Invisalign) in treating mild and moderate malocclusions was comparable. Deviation of the achieved movements from the predicted was greatest for rotational and vertical movements.

Assessment of the outcomes and stability after mandibular incisor extraction in orthodontic patients: A systematic review and meta-analysis.

This study assessed the stability of the outcomes after mandibular incisor extraction (MIE) using intercanine width and peer assessment rating (PAR) scores in orthodontic patients. PubMed, Cochrane Library, Science Direct, Google Scholar, Ovid, and SciELO were systematically searched without restrictions until August 2022. A risk of bias assessment was performed using Newcastle-Ottawa Scale (NOS). The Grading of Recommendations, Assessment, Development, and Evaluation tool was used to assess the quality of evidence. Random effects meta-analysis was performed using RevMan software. Seven retrospective studies met the inclusion criteria and were included. Meta-analysis identified a statistically significant reduction in intercanine width with MIE after the retention period. The mean difference in post-retention changes concerning intercanine width (MD=0.14, 95% CI: -2.17-1.89; P<0.00001) was significantly higher in premolar extraction (PE) compared to incisor extraction and significantly less in non-extraction compared to incisor extraction (MD=0.72, 95% CI: -0.59-2.03; P<0.00001). Improvements in PAR scores from the start of treatment to the retention period indicated a high outcome standard (>70%) with MIE treatment, with no significant difference in the reduction percentage compared to premolar and non-extraction groups. With the existing retrospective studies of limited evidence, treatment outcomes with MIE were found to show good improvements in PAR scores. Some reduction in the intercanine width was evident after the retention period, which was observed even with the other two treatment modalities that were compared. Hence, with careful evaluation, MIE could be considered a valid treatment option.

Evaluation of Maxillary Transverse Arch Dimensions Following Leveling and Alignment with Different Archwire-Bracket Combinations During Fixed Appliance Treatment - A Retrospective Study

Background- Arch expansion is one of the non- extraction methods of gaining space. This study aims to assess and compare the arch expansion achieved during initial leveling and alignment with three different bracket-archwire combinations.&#x0D; Material and Methods- This was a retrospective study done in a university setup. From the available patient information archives, records of 30 subjects based on their advocated bracket system were identified and categorized into three groups. Their pre-treatment (T0) and post aligning (T2) 3D model maxillary scans were superimposed according to the reference points marked on the third palatal rugae using an OrthoAnalyzer software(3 shape version 19.0) to assess the changes in Intercanine width (ICW), Inter-premolar width (IPW) and Intermolar width (IMW) and arch length. For the recorded data, descriptive statistics, One-way ANOVA and Tukey HSD post hoc were analyzed using SPSS software. &#x0D; Results- Except for the Damon group that showed considerable increase in the intermolar and premolar dimensions, other groups had no statistically significant differences in terms of Intercanine width, Interpremolar width, and Intermolar width and Arch length.&#x0D; Conclusion- Changes in the transverse dimension were noticed among all the three groups with maximum in the Damon bracket and Damon archwire combination. Although the difference in expansion between groups showed no statistically significant difference, it was appreciated clinically in relieving dental crowding.

Effects of Nasoalveolar Molding on Maxillary Arch Dimensions and Malocclusion Characteristics of Deciduous Dentition Patients with Cleft Lip and Palate.

To evaluate the effects of nasoalveolar molding (NAM) therapy on maxillary arch dimensions and malocclusion characteristics in patients with unilateral (UCLP) and bilateral cleft lip and palate (BCLP). Patients in deciduous dentition were referred to the institutional department of orthodontics. The NAM group consisted of 21 patients with UCLP (mean age 4.7±0.7 years) and 12 patients with BCLP (mean age 4.8±0.7 years). Sixteen patients with UCLP (mean age 4.9±0.9 years) and 5 patients with BCLP (mean age 5.4±1.1 years) were included in the non-NAM group. The plaster models of all patients were digitized. Dental arch dimensions and malocclusion characteristics were analyzed via digital software. One-way ANOVA with Bonferroni correction was used for statistical analysis. Intercanine and intermolar widths showed statistically significant differences according to the cleft type (P<.01). There was no statistically significant effect of NAM therapy on maxillary arch parameters and malocclusion characteristics (P>.05). The prevalence of anterior crossbite was 12.1% in the NAM group, and 23.8% in the non-NAM group. NAM therapy did not affect the maxillary arch dimensions and malocclusion characteristics in patients with UCLP and BCLP. The cleft type was the main factor, leading to a significant difference in maxillary widths.

Retention using braided bonded wires: a 2-year follow-up of the dentition and oral hygiene with predictors of relapse

Abstract Objective To assess gingival health and predictors of relapse related to braided-wire bonded retainers after the active phase of comprehensive orthodontic treatment. Materials and methods Fifty-one subjects were recruited in a prospective study of whom 42 were available for analysis after 2 years of retention (pre-therapeutic ages 11–18 years; 66% female). A rectangular wire retainer (0.027 × 0.011″) was bonded to the mandibular incisors. Little’s index of incisor irregularity; intercanine width; the accumulation of biofilm, calculus and gingivitis; and the incidence of retainer detachment, were recorded. Subjects were examined before orthodontic therapy, upon therapy completion, and after 2 years of retention. Results The incidence of retainer detachment over the 2 years was 27%. The post-treatment incidence of irregularity was 17%, and intercanine width reduction was 24%. Calculus accumulation increased significantly during retention (p &lt; 0.001) but not the extent of gingivitis. A multiple logistic regression demonstrated that an increase of mandibular intercanine width by ≥3 mm correspondingly increased the odds of relapse 14.3 times (95% confidence interval [CI], 1.1–196.1; p = 0.046). Patients presenting with retainer failure were 10 times (95% CI 1.6–62.8; p = 0.014) more likely to experience relapse. Subjects who experienced relapse had retainer failure earlier than those without relapse (19 vs. 23 months; p = 0.003). The occurence of relapse was not related to a treatment change in incisor irregularity, the duration of treatment, the age of the patient, gender nor to a change of intercanine width during retention. Conclusion Post-treatment changes in the mandibular arch incorporating bonded retainers were not large, but were common. An increase in mandibular incisor irregularity during retention is mostly related to treatment-induced intercanine width expansion. The bonded retainer often detached and increased calculus accumulation.

Dimensional Accuracy of 3D-Printed, Digital and Conventional Stone Dental Cast of Dentate Patients Using Arch and Teeth Measurements

Aim: This study aimed to compare the conventional, digital, and three-dimensional (3D)-printed casts in terms of their accuracy in quantifying arch and teeth measurements. Materials and Methods: The conventional casts were prepared using polyether dental impressions. Digital impressions of the typodont reference casts were accomplished using an intra-oral scanner. The digital casts were first converted to stereolithography (STL) files which were then edited, and printed using an SLA printer and photo-polymer resin material. The measurements of the first two groups were completed using a digital caliper, while an imaging software was used to measure digital casts. The occlusocervial (OC) height and mesiodistal (MD) width of canines, second premolars (PMs), and molars of each jaw were measured. Additionally, intercanine width (ICW) and intermolar width (IMW) were also measured. Results: Overall, the lowest OC measurement errors were observed for 3D-printed casts for the upper canine, lower canine, and lower molar (0.003±0.01 mm). Similarly, the lowest MD measurement errors were observed for 3D-printed casts for upper canine, upper PM, and lower PM (0.002±0.01 mm). The ICW and IMW measurement errors for the 3D-printed casts were significantly lower (p &lt; 0.01) for the upper ICW (0.011±0.01 mm) and lower IMW (0.017±0.01 mm) than the other two groups. Compared to the conventional and digital casts, the lower ICW (0.013±0.01 mm) and upper IMW (0.017±0.01 mm) measurement errors observed for the 3D-printed casts were also lower, but non-significantly (p &gt; 0.01). Conclusions: 3D-printed casts presented the lowest OC, MD, ICW, and IMW measurement errors, than the conventional and digital casts. The highest measurement errors were associated with the digital casts.

The Effects of Fixed Versus Removable Orthodontic Retainers on Stability and Periodontal Health: 4-Year Follow-Up of a Randomized Controlled Trial.

Long-term or even indefinite retention is routinely prescribed after orthodontic treatment as a preventive safeguard against post-treatment changes induced by tooth movement, physiological healing, and the aging process. Though both fixed and removable versions of retainers may be equally effective in terms of results, sufficient research to support this assumption is missing at the moment. Long-term effects of fixed and removable retention on the periodontium, and the compliance level when used for an extended period of time. For 4 years participants were given a supply of canine-to-canine retainers and vacuum-formed canine-to-canine retainers. The inter-canine, as well as inter-molar widths, the length, and the extraction space opening of the mandibular anterior portion, were measured. Gingival inflammation, calculus, and plaque were observed, as well as the attachment of clinical and the case of bleeding during probing. 42 members had returned in the follow-up period, with 21 from each of the two groups. Measurements of the modified gingival index and plaque scoring were performed on the 10 intra-oral photographs that were taken at 4-week intervals in this study to investigate the intra-examiner reliability. After controlling for confounding variables, there was a 1.64 mm (95% confidence interval [CI], 0.30, 2.98 mm) median between-groups difference among patients who utilized vacuum-formed retainers (VFRs). The treatment groups did not vary in inter-canine and intermolar widths (P = 0.52; 95% CI, -1.07, 1.05), arch length (P = 0.99; 95% CI, -1.15, 1.14), or opening of extraction spaces (P = 0.84). A long-term study demonstrates that fixed retention can preserve the alignment of the mandibular anterior over time for the first time. Gingival discomfort and higher plaque scores were reported in both types of retainers.

Tomographic evaluation of changes induced by herbst treatment - buccolingual inclination of mandibular canines and the intercanine distance

The aim of this study was to perform a three-dimensional evaluation of Herbst appliance effects on the mandibular canines.The subjects consisted of 23 Class II:1 patients (12 men, 11 women), mean age of 15.76± 1.75 years, consecutively treated with a Flip-Lock Herbst®appliance (TP Orthodontics, Inc., La Porte, IN, USA). The lower anchorage unit for the Herbst appliance consisted of two anchor bands connected by a lingual arch with 3mm distance from the incisor’s lingual surface. Treatment changes in mandibular canine inclination and mandibular intercanine width at the cusp and apex levels were evaluated by means of cone-beam computed tomography images (i-CAT® Classic unit, Imaging Sciences International, Hatfield, PA, USA) obtained before and after treatment with the Herbst appliance. There were no statistical differences between genders. Herbst appliance treatment did not result in any statistically significant changes for mandibular canine inclination and mandibular intercanine width. There were associations between mandibular canine inclination and mandibular intercanine width at the cusp (/r/ = 0.43 to 0.66) and apex levels (/r/ = 0.34 to 0.60). The three-dimensionalcone-beam computed tomography analysis of the mandibular canine segment revealed that the Herbst appliance with a mandibular anchorage unit distant from the incisor’s lingual surface does not change mandibular canine inclination and mandibular intercanine width significantly during treatment. However, large interindividual differences may result in undesired amount of mandibular canine anchorage loss in individual patients.

Evaluation of intercanine arch width, intermolar arch width and the canine fossa width in the determination of gender of an individual between 18 and 35 years – An in vitro analytical retrospective study

Objective s: The aim of this study is to verify and assess the usefulness of intercanine arch width, intermolar arch width, and canine fossa width in maxilla and intercanine and intermolar width in mandible for gender determination in the adult population. In medicolegal cases, estimation of gender using the skeletal remains of victims is imperative. The identity of an individual can be verified by examination of teeth and surrounding tissues from skeletal remains. Measurements from teeth and skull can help a Forensic Odontologist to identify deceased victims by age, gender, or race. The association of skeletal remains with gender gains utmost importance in cases of mass fatality such as earthquakes, tsunami, accidents, cyclones, and floods. If an individual is not in a condition to be identified, then they can be identified from the dentition or remains of dentition during any natural or manmade calamities. The benefit of determining gender in mass calamities is that accurately determined gender confines the number of missing individuals to one-half of the population in the majority cases. Many studies pertaining to maxillary arch widths have been performed yet the literature regarding mandibular arch widths remains scarce. Furthermore, in the literature, very few studies have been carried out to correlate canine fossa width and gender of an individual. Material and Methods: The study was carried out on a sample size of 120 study models, between 18 to and 35 years in department of orthodontics and dentofacial orthopedics and the samples had equal male and female distribution. A digital vernier caliper measured the intercanine arch width, intermolar arch width and canine fossa width and the parameters were measured by a single observer and statistical analysis was performed. Results: Intercanine arch width in maxillary arch was 36.38 ± 3.08 mm and 33.44 ± 2.72 mm for males and females correspondingly with P &lt; 0.001 which is statistically highly significant. Intermolar arch width in maxillary arch was 47.81 ± 3.02 mm and 45.2 ± 2.64 mm for males and females correspondingly with P &lt; 0.001 which is statistically highly significant. Canine fossa width in maxillary arch was 43.42 ± 2.58 mm and 40.36 ± 2.32 mm for males and females correspondingly with P &lt; 0.001 which is statistically highly significant. Intercanine arch width in mandibular arch was 27.43 ± 2.96 mm and 26.2 ± 1.97 mm for males and females correspondingly with P &lt; 0.05 which is statistically significant. Intermolar arch width in mandibular arch was 41.88 ± 3.47 mm and 39.89 ± 2.48 mm for males and females correspondingly with P &lt; 0.001 which is statistically highly significant. After employing the receiver operating curve, to figure out specificity and sensitivity of the parameters, high specificity of 97%, with the best sensitivity of 78% was recorded for the maxillary canine fossa width. Conclusion: The results show that in cases of mass calamities, maxillary canine fossa width will prove to be useful tool in gender determination accurately after analyzing the dental remains of young missing adults with multiple missing teeth. This will further aid the forensic odontologist to determine identity of the missing individual.

Analysis of maxillary arch expansion in growing patients treated with early Class III protocol versus RME.

To evaluate and compare the maxillary arch expansion obtained in growing patients treated with Class III early treatment protocol (the modified SEC III protocol), or rapid maxillary expansion (RME). This retrospective observational study included patients in the mixed dentition with maxillary constriction and/ or dental crowding. The first group consisted of 30 patients (11 males and 19 females, mean age 9.4 ±1.7 years) with dentoskeletal Class III malocclusion treated with the modified SEC III protocol. The second group of 30 patients (14 males and 16 females, mean age 9.3 ±1.5 years) with Class I or II malocclusion was treated with a Hyrax-type expander applied to bands on the first upper molars. For each subject, initial (T0) and post expansion (T1) digital dental casts were collected. The intermolar and intercanine widths, the arch lengths at both cusp and gingival levels, the anteroposterior length and the palatal depth were measured at T0 and T1. At T1 there were statistically significant differences for 3-3 occlusal (OC) (P < 0.009), arch-length OC (P <0.030), anteroposterior arch-length (AP) (P <0.003), Depth (P <0.030) and Ap (P <0.000). No statistically significant T0-T1 changes were found between the modified SEC III and Hyrax groups except for Depth (P <0.011) with a mean difference of 2.3 mm between the two groups. Both bonded and banded expanders, used in the modified SEC III protocol and RME treatment respectively, produced similar changes in the upper arch. The different initial dentoskeletal malocclusions of the two sample groups were not relevant to the post-expansion arch changes.

A retrospective study of the accuracy of Invisalign Progress Assessment with clear aligners

The objective of this study was to detective the accuracy of model superimposition and automatic analysis for upper and lower dentition width in Invisalign Progress Assessment during the process of clear aligners. 19 cases were included in this study. Pre-treatment dental cast (T0) and post-treatment dental cast after staged treatment (T1) were available for three-dimensional model superimposition. Subsequently, movements of maxillary teeth in the horizontal plane (cross-section) after staged treatment and width of upper and lower dentition were measured by three-dimensional model superimposition in the real world and Invisalign Progress Assessment separately. Consequently, the data collected from these two methods were compared. In Invisalign Progress Assessment, movements of maxillary teeth in the horizontal plane after staged treatment was 2.31 (1.59,3.22) [median (upper quartile, lower quartile)] millimeter (mm), while in three-dimensional model superimposition, the result was 1.79 (1.21,3.03) mm. The difference between the two groups is significant (P < 0.05). Intercanine width upper, intermolar width upper, intercanine width lower, and intermolar width lower were 36.55 ± 2.76 mm, 56.98 ± 2.62 mm, 28.16 ± 1.85 mm, 53.21 ± 2.72 mm separately in Invisalign Progress Assessment and were 36.48 ± 2.78 mm, 56.89 ± 2.58 mm, 28.05 ± 1.85 mm, 53.16 ± 2.64 mm separately in three-dimensional model analysis, which was no significant difference among these groups (P > 0.05). The data from Invisalign Progress Assessment was not in parallel with what was achieved from model superimposition with palate as a reference completely. The accuracy of model superimposition in Invisalign Progress Assessment needs further investigation, whereas the accuracy of model analysis in Invisalign Progress Assessment was accurate. Thereby, results from Invisalign Progress Assessment should be interpreted with caution by the orthodontist in the clinic.

Dental changes induced by a modified Herbst appliance followed by fixed appliances: A digital dental model analysis.

Herbst therapy is an effective treatment for Class II malocclusions. However, the maintenance of the effects after fixed appliances treatment remains questionable. This retrospective study aimed to assess, using digital dental models, the sagittal and transverse dental arch changes in young patients during two Class II Division 1 treatment phases, first with modified Herbst appliance (HA) and then with fixed appliances. The treated group (TG) comprised 32 patients (17 boys, 15 girls; mean age, 12.85 ± 1.16 years) treated with HA and fixed appliances. The control group comprised 28 patients (13 boys, 15 girls; mean age, 12.21 ± 1.35 years) with untreated Class II malocclusions. Digital models were obtained immediately before and after HA therapy and after fixed appliances. Data were statistically analyzed. Compared with the control group, the TG showed an increase in maxillary and mandibular arch perimeters and in intercanine and intermolar arch widths, a decrease in overjet and overbite, and an improvement in canine and molar relationships. In the time after HA therapy until the end of fixed appliances treatment, the TG showed a decrease in maxillary and mandibular arch perimeters, overjet, upper and lower intermolar widths; an increase in molar Class II relationship; and no changes in canine relationship, overbite, and upper and lower intercanine widths. In this sample of patients treated with HA, on average, there was an improvement in the Class II relationship, which seemed to remain after fixed appliances. The transverse dental changes achieved in HA phase relapsed after treatment with fixed appliances.

Comparison of Efficiency of Bonded retainers and Vacuum formed retainers- A Randomized Clinical trial

Background: Major goal of orthodontic treatment is long term stability of the corrected teeth after orthodontic treatment. After orthodontic treatment there is always chance of relapse. To prevent relapse several appliances are available as a retention device such as bonded fixed retainers, vacuum formed retainers, removable Hawley retainer, Begg’s retainer. Now a days vacuum formed retainer has become more acceptable due to low cost, esthetic and easy fabrication. Objective: The purpose of this study was to analyze the clinical success of bonded retainers with vacuumformed retainers, as far as keeping up the consequences of orthodontic treatment in the lower arch as long as a year after debond. Methods: This was a randomized clinical trial (RCT) carried out at the department of Orthodontics, Bangabandhu Sheikh Mujib Medical University, Dhaka. In the study a total of 40 subjects who had fulfilled the selection criteria were randomly allocated to one of two groups, receiving either a vacuum-formed retainer or a bonded retainer for the mandibular arch. Qualification criteria was patients approaching debond after treatment with preadjusted edgewise fixed orthodontic appliance whose pretreatment records and study models were accessible to confirm pretreatment labial segment crowding or spacing and who had clinically acceptable alignment after treatment. The principle purpose was to research the clinical adequacy of the 2 kinds of retainers regarding changes in incisor irregularity at one year of preservation of treatment outcome. The following measurements were documented at each time point (6 and 12 months) with a digital caliper: Little’s irregularity index, intercanine width, intermolar width, arch length, extraction space opening. Result: The two groups were very much coordinated as for age, sex, clinical qualities, and treatment plans. Four patients did not attend in the follow up period and the study finished up in 36 patients. There was a statistically significant difference between the groups for changes in Little’s irregularity index and arch length. Vacuum-formed retainer group showed greater changes than the bonded retainer group (P value 0.035 and 0.022). There were also no statistically significant changes at any time for intercanine width and intermolar width. Conclusion: Some relapse is likely after fixed orthodontic treatment regardless of retainer choice, and this is negligible in many patients after debond. Bonded retainers have a superior capacity to hold the mandibular incisor arrangement after orthodontic treatment than vacuum-formed retainers. Trial registration: not done. Bangladesh Medical Res Counc Bull 2022; 48: 105-111

Long-term stability of mandibular incisor alignment in patients treated nonextraction with or without interproximal enamel reduction

This study aimed to compare long-term mandibular incisor stability in nongrowing patients with moderate crowding treated nonextraction with and without interproximal enamel reduction (IPR). Forty-two nongrowing patients with Class I dental and skeletal malocclusion with moderate crowding were divided into 2 groups with an equal number of patients depending on whether IPR was used (IPR group) or not (non-IPR group) during treatment. All patients were treated by the same practitioner and used thermoplastic retainers full-time for 12 ± 1 months at the end of the active treatment. Changes in Peer Assessment Rating scores, Little's irregularity index (LII), intercanine width (ICW), and mandibular incisor inclination (IMPA and L1-NB°) were evaluated using pretreatment, posttreatment, and 8 ± 1 years postretention dental models and lateral cephalograms. At the end of the treatment, Peer Assessment Rating scores and LII decreased, and ICW, IMPA, and L1-NB° increased significantly (P<0.001) in both groups. At the end of the postretention period, in both groups, LII increased, and ICW decreased significantly (P<0.001) compared with posttreatment values, whereas IMPA and L1-NB remained stable. When treatment changes were compared, increases in ICW, IMPA, and L1-NB were significantly (P<0.001) higher in the non-IPR group. When postretention changes were compared, the only significant difference between 2 groups was observed in ICW. The decrease in ICW was significantly higher in the non-IPR group. Long-term stability of mandibular incisor alignment in Class I nongrowing patients with moderate crowding treated nonextraction with and without IPR was similar.

Comparison of alignment efficacy and arch dimensions changes with superelastic-, heat-activated-, and seven stranded coaxial nickel-titanium archwires during fixed orthodontic treatment – A double-blind randomized clinical trial

Objectives: The objectives of this study were to compare the alignment efficacy, changes in arch dimensions, and pain experience with three different nickel-titanium (NiTi) archwires. Material and Methods: Forty-five subjects were subjected to indirect bonding in the mandibular arch, and allocated to three groups using block randomization; Group 1 (0.014” Superelastic NiTi), Group 2 (0.014” 27° Copper NiTi), and Group 3 (0.016” seven stranded coaxial NiTi archwire). The mandibular study models were retrieved periodically at 4-week intervals for 12 weeks, which were blinded to measure the change in Little’s irregularity index (LII) and dental arch dimensions. Pain and discomfort were recorded with visual analog scale at five different time intervals, namely, immediately after bonding (0) and at 1-, 4-, 8-, and 12-h for initial 7 days. Repeated analysis of variance, Wilcoxon Signed-Rank test, post hoc Bonferroni test, and Friedman’s test was applied for the comparison and was used for data analysis. Results: A significant reduction of LII score and increase inarch length, intercanine, interpremolar, and intermolar width (P ≤ 0.001) were observed after 12 weeks among all groups. However, intergroup comparison showed significant mean changes only for intercanine width (Group 1 versus 3) and interpremolar width (Groups 1 and 3; Groups 2 and 3). All other variables were found to be insignificant at all-time intervals when compared among each group. The increase in pain score was maximum with Group 1and least with Group 3. Conclusion: All archwires were found to be effective in reducing the LII score. Nevertheless, Group 3 archwire could achieve reduction of LII to zero in 14% of subjects than Groups 1 and 2.

Effect of the quality of orthodontic finishing on the stability of anterior tooth alignment.

To evaluate whether the quality of orthodontic finishing influences long-term stability of anterior tooth alignment. This retrospective study evaluated 38 patients. Data were obtained at the beginning of treatment (T0), at the end (T1), and at least 5 years after T1 (T2). At this point, the individuals were no longer wearing retainers. Anterior tooth alignment was measured using Little's index (LI). Effect on alignment stability was tested with multiple linear regression using LI-T0, LI-T1, intercanine width difference T1-T0, overbite (T1), overjet (T1), age, gender, time without retention, and presence of third molars as predictor variables. Well-aligned (LI < 1.5 mm) and misaligned (LI > 1.5 mm) cases were compared at T2. At T2, the alignment stability in the upper arch was inversely associated with the alignment quality (R2 = 0.378, P < .001) and directly associated with overbite (R2 = 0.113, P = .008) at T1. Posttreatment changes caused cases finished with poor alignment to become similar to those finished with excellent alignment (P = .917). In the mandible, posttreatment changes were directly associated only with overjet (R2 = 0.152, P = .015) and well-finished cases displayed better alignment than poorly finished cases (P = .011). Other variables showed no significant association. In arches without retention, better quality of orthodontic finishing does not guarantee the stability of anterior alignment. In the maxilla, long-term changes were more significant the greater the overbite and the better the quality of alignment at end of treatment. In the mandible, changes were not dependent on the quality of finishing but were associated with greater overbite at T2.

Assessment of Dental Crowding Occurring in Mixed Dentition in Maxillary and Mandibular Arches Based on Tooth Size-Arch Length Relationships and Certain Cephalometric Parameters.

The aim of the study is to find indicators of crowding in primary and mixed dentition that may lead to occurrence of dental crowding in future dentition using dental measurements. A sample of 300 children was selected and divided into two groups based on their age primary dentition and mixed dentition. Dental arch impressions were made and casts were poured. The study was then divided into two phases for assessment of degree of crowding by Little's irregularity index (LII) and by measurement of tooth size-arch length discrepancies. Appropriate statistical analysis was used to assess the correlation of measurements in crowded and noncrowded groups. It was found that Little's index is less dependable as an indicator of anterior crowding. In the primary dentition, there is significant difference in inter-canine width between lower noncrowded and crowded dentition. In the mixed dentition, there is significant difference in Intermolar width between upper noncrowded and crowded dentition and in sum of incisors between noncrowded and crowded dentition in both the arches. Little's index is not a reliable indicator of crowding in both primary and mixed dentition. Inter-canine width of lower arch can be considered as an indicator of crowding in primary dentition. The intermolar width of upper arch, sum of incisors in upper and lower arch and the intercanine width of upper and lower arch can be considered indicators of crowding in the mixed dentition. Kandakkeel FN, Nagar P, Saseendran A, et al. Assessment of Dental Crowding occurring in Mixed Dentition in Maxillary and Mandibular Arches based on Tooth Size-Arch Length Relationships and Certain Cephalometric Parameters. Int J Clin Pediatr Dent 2023;16(2):357-362.

Maxillary and Mandibular Interarch Width Among Different Malocclusions

Objective: To determine the association of maxillary and mandibular interarch width among different malocclusions. Material and Methods: This cross-sectional study was done at the Department of Orthodontics of the Dr. Ishrat Ul Ibad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, during a period of one year from January 2017 to December 2017. Individuals with a Class I canine and molar relationship with minor crowding, normal growth and development, and mal-aligned upper and lower dental arches. Class II molar and canine relationship on at least one side, Class II division 1 or 2 groups, bilateral Class III molar relationship in centric occlusion, Class III permanent canine relationship with excessive negative overjet, good facial symmetry, and participants had to have all their permanent teeth present except for their third molars were included. Readings were obtained by measuring the interarch width using a vernier gauge caliper. The calibration of the vernier caliper was checked daily using the standard technique. The intercanine arch width was measured from the cusp tip of one canine to the contralateral canine. Intermolar width was assessed as the distance between the central fossae of the left and right first molars. The readings were taken by a single examiner, and the measurement was repeated three times with an interval of two minutes between each measurement to reduce the possibility of errors. To assess the reliability of the measurements, the intra-examiner reliability was determined using the intraclass correlation coefficient (ICC). The collected data was analyzed using statistical software, SPSS version 26. Results: The study examined the maxillary and mandibular interarch widths of participants with different types of malocclusions. Class I had the highest maxillary intercanine width, and Class III had the highest maxillary intermolar width. Class III had the highest mandibular intercanine and intermolar width. Class II Division 2 had the lowest intercanine and intermolar width in both arches. Significant differences were observed in the mean intermolar width in the mandibular arch between Class II Division 2 and Class III malocclusions and in the maxillary intercanine width between Class I and Class II Division 2 malocclusions. No significant difference was found in other width measurements among the different types of malocclusions. Conclusion: It has been concluded that patients with Class III malocclusion had narrower upper width measurements compared to the normal occlusion sample. Keywords: Maxillary, mandibular, interarch width, malocclusion

Dimensional changes in the palate associated with Invisalign First System: a pilot study.

To compare palatal dimensions and molar inclinations after Invisalign First System (IFS) to those in patients treated with slow maxillary expansion (SME) and normal controls. Twenty-three mixed dentition patients treated with IFS were gender- and dental age-matched to another two groups: Haas-type SME and control group. The intercanine width (ICW), intermolar width (IMW), palatal surface area (SA), volume (V), and first molar buccolingual inclinations (MI) were measured before (T1) and after (T2) treatment. Analysis of variance was used to compare the differences among the three groups. The ICW increased significantly by 3.10 mm after IFS, 4.77 mm with SME, and 0.54 mm in controls; the difference among the groups was statistically significant (P < .001). The IMW increased by 1.95 mm in IFS, 4.76 mm in SME, and 0.54 mm in controls, with significant intra- and intergroup differences. Palatal SA and volume increased by 43.50 mm2 and 294.85 mm3 in the IFS group, which differed significantly from SME, but was similar to controls. The right and left MI increased 0.24° and 0.08° buccally, respectively, in the IFS group, which was comparable to controls, while significantly increased buccal MI was observed in the SME group. IFS expands the upper arch with increased ICW and IMW compared to controls, but the expansion amount is smaller than SME. Unlike SME, IFS has no effects on palatal dimensions and molar inclinations.