A comparison of CAD/CAM-based fixed retainers versus conventional fixed retainers in orthodontic patients: a systematic review and network meta-analysis

OBJECTIVE

Comparing computer-aided design and computer-aided manufacturing (CAD/CAM) fixed retainers and conventional fixed retainers for their effectiveness in orthodontic patients using systematic review and meta-analysis of literature.

SEARCH METHODS

A comprehensive search was conducted in MEDLINE, Web of Science, EMBASE, Scopus, Cochrane's CENTRAL, Google Scholar, Ovid, and LILACS up to May 2023, with no language or date restrictions.

SELECTION CRITERIA

Only randomized clinical trials (RCTs) that complied with PICO questions were included, and the Cochrane Risk of Bias 2.0 (RoB 2) tool was used to assess the risk of bias in the included studies.

DATA COLLECTION AND ANALYSIS

Using custom-piloted forms, relevant data were retrieved from the included studies. Then a random-effects inverse variance meta-analysis was used to pool the results. Primary outcomes were stability of treatment results measured through dental cast measurements and periodontal status, while secondary outcomes were failure rates and patient-reported outcomes.

RESULTS

Seven RCTs with 601 participants were included in the review. In the short term (≤6 months), the meta-analysis showed no significant differences in inter-canine distance or arch length between CAD/CAM and conventional fixed retainers in mandibular retainers. However, for Little's irregularity index, single-stranded stainless-steel retainers were notably worse than Ni-Ti CAD/CAM retainers at 3 and 6 months, while multi-stranded stainless-steel retainers only diverged from CAD/CAM at the 6-month milestone, despite the overall clinical inconsequence of these changes. CAD/CAM retainers were associated with a lower plaque index than traditional retainers but no significant difference in gingival index. Failure rates did not differ significantly between CAD/CAM and other types of retainers in mandibular retainers. Nonetheless, one study had a high amount of CAD/CAM retainer failures leading to the study being stopped.

CONCLUSIONS

In the short term, CAD/CAM fixed retainers show promise as an alternative to traditional retainers. They may enhance periodontal health, as indicated by lower plaque index scores than conventional retainers. However, extensive research is needed to determine the long-term durability and effectiveness of CAD/CAM retainers in orthodontic treatment, particularly regarding their failure rate. Until comprehensive evidence is available, the use of CAD/CAM retainers should be tailored for each case.

REGISTRATION

The protocol for this systematic review was registered at PROSPERO with the ID CRD42023412741.

Prioritized Commitment-Based Clinical Assessment: A New Method for Assessment of Orthodontic Treatment Outcomes

OBJECTIVE

Quality assessment is an essential part of orthodontic treatment. Most of the current indices are essentially based on occlusal assessment. However, an ideal occlusion is only one aspect of an ideal treatment. The aim of this article is to introduce a new prioritized commitment-based clinical assessment (PCCA) method and present its reliability and linear correlation test in comparison with the comprehensive clinical outcome assessment (CCA).

METHODS

One hundred treated cases were scored with the conventional assessment tool--the CCA--and the newly developed assessment tool--the PCCA--with 2 calibrated examiners at 2 different time intervals. These cases were randomly selected including equal numbers of the main malocclusions managed with fixed conventional edgewise appliances within the past 3 years and had complete pre-treatment and post-treatment routine records. The intraclass correlation coefficient (ICC) was used to assess the intra- examiner repeatability of the total scores of both methods. Pearson's correlation coefficients were computed to assess the linear relationships between the CCA and PCCA scores.

RESULTS

The intra-examiner reliability assessed for CCA and PCCA showed high repeatability for both examiners (ICC: 0.93 and 0.945, respectively). The inter-examiner reliability values for CCA and PCCA, assessed by ICC, were 0.84 and 0.96, respectively. The linear correlation between the 2 methods, assessed by comparing the mean score of each case by the 2 examiners was significant, at 0.01.

CONCLUSION

The PCCA method can be used for quality assessment in treated orthodontic patients. The preliminary test of the new method presented good inter- and intra-observer agreements and a significant linear correlation with the CCA method.

The correlation between external apical root resorption and electric pulp test responses: a prospective clinical trial

OBJECTIVE

The current study investigated the correlation between pulpal sensitivity to the electric pulp tester (EPT) and external apical root resorption (EARR) in four types of maxillary anterior teeth of fixed orthodontic treatment patients.

METHODS

In this prospective cohort study, 232 anterior teeth of 58 patients (mean age 18.96 ± 6.13 years) treated with fixed orthodontic treatment were examined. The EPT readings were recorded at twelve time points immediately before archwire insertion. Root resorption of four maxillary incisors were measured by means of parallel periapical radiographs at three time intervals (six months interval from the start) through design-to-purpose software to optimize data collection. A multiple linear regression model and Pearson correlation coefficient were used to assess the association of EPT values and observed EARR (p< 0.05).

RESULTS

The highest level of EPT measurement was recorded at initial visit, and then there was a decreasing trend in EPT level during treatment for the next six and twelve months. There was another increasing trend after six months till the finishing time of the treatment. There was a significant correlation between changes in root length and time of recording the root length (p< 0.001). There was significant positive correlation between changes in EPT level and amount of observed root resorption (p< 0.001).

CONCLUSION

The relative decrease in electric pulp test level could be a diagnostic sign of root resorption during orthodontic treatment. Further studies with longer follow up are needed to confirm the current results.

The impact of platelet-rich fibrin (PRF) on delayed tooth replantation: A preliminary animal study

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) placed in delayed replantation of mature extracted teeth. Sixteen intentionally extracted teeth in two mature beagle dogs were selected. In one quadrant of each jaw, the extraction sockets were filled with PRF prior to replantation, and the other quadrant served as control without PRF. All extracted teeth underwent endodontic treatment and dried for 60 min. Thereafter, they were replanted with a flexible splint. After 8 weeks, the animals were euthanised, and the histological sections examined. Less inflammatory root resorption was noted in the PRF group compared to the control (P = 0.031). However, there was no significant difference between the two groups with regard to new bone formation, inflammatory status, connective tissue healing and replacement resorption (P > 0.05). Using PRF in the extracted socket before delayed replantation did not provide any significant benefit other than reduced inflammatory root resorption.

The effect of autologous leukocyte platelet rich fibrin on the rate of orthodontic tooth movement: A prospective randomized clinical trial

Objective:

The aim of this study was to evaluate the effect of LPRF, placed in extraction sockets, on orthodontic tooth movement (OTM).

Materials and Methods:

Thirty extraction sockets from eight patients (five males, three females, with a mean age of 17.37 years; range 12–25 years) requiring extraction of first premolars based on their orthodontic treatment plan participated in this split-mouth clinical trial. In one randomly selected quadrant of each jaw, the extraction socket was preserved as the experimental group by immediate placement of LPRF in the extraction socket. The other quadrant served as the control group for secondary healing. Immediately, the teeth adjacent to the defects were pulled together by a NiTi closed-coil spring with constant force. A piece of 0.016 × 0.022-inch stainless steel wire was used as the main arch wire. The amount of OTM was measured on the study casts at eight time points with 2-week intervals for 3 months. Analysis of random effect model was performed for the purpose of comparison between the experimental and control groups.

Results:

According to the random effect model, a statistically significant difference was found between the experimental and control group in rate of OTM (P = 0.006).

Conclusion:

According to the results, application of LPRF, as an interdisciplinary approach combining orthodontics and surgery, may accelerate OTM, particularly in extraction cases.

The Effect of Methylphenidate on Cervical Vertebral Maturation and Dental Age in Patients with Attention Deficit Hyperactivity Disorder

STATEMENT OF THE PROBLEM

It is postulated that attention deficit/hyperactivity disorder (ADHD) with or without medication has an inhibitory effect on the children's growth and development.

PURPOSE

This study aimed to assess the dental age and cervical vertebral maturation (CVM) stage in ADHD patients with or without medication.

MATERIALS AND METHOD

This cross-sectional study evaluated the pretreatment panoramic and lateral cephalograms of 129 patients (70 males, 59 females aged 8-14 years). Demirjian index and Baccetti's CVM index were used to determine the dental age and CVM stage, respectively. The subjects were evaluated in two groups of ADHD (case, n=59) and healthy individuals (control, n=70). The ADHD patients were divided into two groups of AWT (ADHD with Treatment, n=43) and AW (ADHD without treatment, n=16) based on the use of methylphenidate. Paired t-test was used to compare the mean dental age between the groups. Linear and ordered logistic regression models were used to detect differences between the groups. The association between dental and chronological age was assessed by using Pearson correlation coefficient (p< 0.05).

RESULTS

After age and sex adjustment, the skeletal maturity stage was found to be similar to the control group based on the presence of the disorder or use of medication (p= 0.711 and p= 0.436, respectively). Similarly, the patients' dental age was similar to the controls in AW and AWT groups (p= 0.180 and p= 0.421, respectively). The correlation between dental age and chronological age was 0.79 in AWT, 0.88 in AW, and 0.88 in control group (p< 0.001 for all the three).

CONCLUSION

After age and sex adjustment, the dental and skeletal age of ADHD patients with or without Methylphenidate treatment do no manifest a significant delay compared with the controls.

Correlation of Vitamin D status and orthodontic-induced external apical root resorption

Background

Adequate Vitamin D is essential for dental and skeletal health in children and adult. The purpose of this study was to assess the correlation of serum Vitamin D level with external-induced apical root resorption (EARR) following fixed orthodontic treatment.

Materials and Methods

In this cross-sectional study, the prevalence of Vitamin D deficiency (defined by25-hydroxyvitamin-D) was determined in 34 patients (23.5% male; age range 12-23 years; mean age 16.63 ± 2.84) treated with fixed orthodontic treatment. Root resorption of four maxillary incisors was measured using before and after periapical radiographs (136 measured teeth) by means of a design-to-purpose software to optimize data collection. Teeth with a maximum percentage of root resorption (%EARR) were indicated as representative root resorption for each patient. A multiple linear regression model and Pearson correlation coefficient were used to assess the association of Vitamin D status and observed EARR. P < 0.05 was considered statistically significant.

Results

The Pearson coefficient between these two variables was determined about 0.15 (P = 0.38). Regression analysis revealed that Vitamin D status of the patients demonstrated no significant statistical correlation with EARR, after adjustment of confounding variables using linear regression model (P > 0.05).

Conclusion

This study suggests that Vitamin D level is not among the clinical variables that are potential contributors for EARR. The prevalence of Vitamin D deficiency does not differ in patients with higher EARR. These data suggest the possibility that Vitamin D insufficiency may not contribute to the development of more apical root resorption although this remains to be confirmed by further longitudinal cohort studies.

Correlation between cervical vertebral maturation and chronological age in a group of Iranian females

BACKGROUND

Correlation between chronological age at different stages of cervical vertebral maturation (CVM) is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients.

MATERIALS AND METHODS

This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant.

RESULTS

The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62). The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra.

CONCLUSION

Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients.

The Effect of Orthodontic Forces on Tooth Response to Electric Pulp Test

Introduction:

The current study investigated the pulp response to electric pulp testing (EPT), before, upon initiation and one month after the start of orthodontic tooth movement.

Methods and Materials:

A total of 402 anterior teeth from 39 patients (mean age of 16.8±2.7 years) were examined in this non-controlled prospective study. The aligning forces were administered using initial NiTi archwires ligated on fixed appliances by using the MBT straight wire technique. The electrical stimulation was provided by the EPT. The EPT readings were recorded at three time points: before bonding (EPT₀), immediately upon initiation (EPT₁) and 1 month post-treatment (EPT₂). The data were statistically analyzed by the ANOVA and Bonferroni tests (P<0.05).

Results:

Prior to bonding of the orthodontic brackets, the mean EPT value for all the experimental teeth was 3.42 EPT units. Upon initiation, the mean value of EPT₁ for each tooth increased to 7.62 units. One month later, the mean EPT₂ values dropped to 6.27 units. At this time point, 64 teeth (16%) of the experimental teeth failed to respond. The differences among EPT values at different time points were significant. There was no association between the EPT values and the location or the type of teeth.

Conclusion:

The physiological changes in the pulp affect the nerve fibers in the early stages of the orthodontic force application. As a result, thresholds to electrical stimulation would increase and the EPT may not initiate a response. Therefore results obtained by electrical pulp testing should be interpreted accordingly.

Outcomes of revascularization treatment in immature dog's teeth

AIM

The purpose of the current study was to examine the success rate of a revascularization treatment protocol involving canal space disinfection using copious irrigation, a triantibiotic dressing, and induction of a blood clot matrix in immature dog's teeth.

MATERIALS AND METHODS

Thirty-six immature mongrel dog's teeth were divided into two experimental and two control groups. The experimental groups included a necrotic-infected group (n = 20) and a vital group (n = 10). In the group with the necrotic-infected teeth, periapical lesions were induced, and disinfection of the canals was carried out using copious irrigation and a triple antibiotic medication (metronidazole, ciprofloxacin, and tetracycline). Subsequently, the periapical tissues were irritated to initiate bleeding, producing a blood clot. A double seal of the coronal access was then placed. In the vital group, the pulp was aseptically removed before the canal was irrigated and periapical tissues irritated to induce bleeding. The same protocol as that used for the necrotic-infected group was used to seal the coronal access. In the positive control group (n = 3), after pulp removal, sterile sponges soaked in plaque suspension were placed in the pulp chambers of the teeth, after which the chambers were sealed. In the negative control group (n = 3), one untouched 1st premolar tooth in each dog was assigned and left to develop naturally. Radiographic and histological findings were evaluated at 3 and 6 months. Data analysis was performed using Fisher's exact test.

RESULTS

The necrotic-infected group radiographically demonstrated apical healing and apical closure in 70% of the cases and thickening of the walls in 40% after 6 months. The vital group showed apical closure in 77% and thickened walls in 44% of the cases after 3 months. Histological findings confirmed the radiographic findings. No significant difference was observed between the two groups (P > 0.05).

CONCLUSIONS

If necrotic-infected canals are effectively disinfected and treated according to the protocol, the ensuing revascularization response is similar to that of vital immature teeth.

Rapid, conservative, multidisciplinary miniscrew-assisted approach for treatment of mandibular fractures following plane crash

Mandibular fractures are among the most common facial injuries. This case report demonstrates the efficacy of simultaneous usage of miniscrews and direct bonding techniques without open reduction in an extensive traumatized patient. A 25-year-old girl with multiple injuries in the head and facial region 1 month after a plane crash accident was referred to manage the mandibular fractures. Due to the presence of multiple injuries, a conservative treatment of symphysiseal fracture was performed. In order to keep the fractured fragments of the mandible close together, the anterior teeth of the lower arch were tied by means of the orthodontic wire. Ten miniscrews were used to improve the anchorage units and also, settling the occlusion by means of light intermaxillary elastics. Following the active treatment, clinical and radiographic analysis showed satisfactory healing without any periodontal involvement of the teeth in the fracture line.

The 808 nm Laser-Assisted Surgery as an Adjunct to Orthodontic Treatment of Delayed Tooth Eruption

INTRODUCTION

Failure of teeth to erupt from gingival tissues at usual developmental time is called delayed tooth eruption (DTE). Delayed tooth eruption lead to prolonged fixed orthodontic treatment and its eventual complications. The purpose of the present study was to evaluate the effect of laser-assisted (808 nm) surgical uncovering, on the tooth emergence and orthodontic treatment of DTE.

METHODS

A total of 16 orthodontic patients were included in this study and were equally assigned to an experimental and a control group. Subjects for experiment consisted of eight patients (6 girls and 2 boys) with a mean age of 14±0.9 years. All patients exhibited delayed second premolar eruption. The laser wavelength was 810 nm and it was set in a continuous wave mode at a power output of 1.6 watt with a 0.3-mm diameter fiber tip. When the target tissue was sufficiently anesthetized, the tip was directed at an angle of 10 to 20 degrees to the tissue (light contact mode); and was applied continuously for approximately 12 Seconds until an acceptable tooth exposure area was visible. The facial axis of the clinical crown (FACC) line represents the most prominent portion of the facial central lobe for premolars. All orthodontic brackets are aligned along this reference and are located on FA (Facial Axis) point. The standard for adequate tooth eruption was the accessibility of facial axis of the clinical crown (FACC) for bonding the brackets. Data gathered from the patients were statistically surveyed and compared by means of Tukey's Test and Analysis of Variance (ANOVA).

RESULTS

All patients showed good gingival status, no significant bleeding during or immediately after the surgery, and acceptable level of healing after laser surgery. The biologic width of the teeth was preserved and no violation of this important periodontal parameter was observed. The average time for accessing the FA point in experimental group was 11±1.1 weeks and the mentioned period was increased to 25±1.8 weeks in control group. The data analysis showed that in patients with DTE, laser intervention significantly accelerated tooth eruption (P < 0.05).

CONCLUSION

Laser-assisted surgical removal of the fibrous tissue over erupting premolars (DTE) with appropriate irradiation parameters appears to be a promising adjunct to orthodontic treatment for bringing the premolar to the aligned and leveled dental arch.