Extra-oral Appliances in Orthodontic Treatment

Influence of the maxillary third molars and the surrounding cortical plate during maxillary tooth movement with TADS- A CBCT Study

OBJECTIVE

To determine the influence of the presence/absence of third molars and intact/loss of cortical plate of the maxillary tuberosity on the amount of distal movement of the maxillary first permanent molar during distal movement of the maxillary dentition with mini-implants.

MATERIALS AND METHODS

Thirty six maxillary tuberosity sites were evaluated in eighteen young adult patients. The distal movement of the entire maxillary dentition was performed with mini-implants with 200 g of distalising force applied from the mini-implant placed in the maxillary posterior buccal region to attachments placed on the arch wire between the maxillary lateral incisor and canine bilaterally. The distal movement of the maxillary first permanent molars was measured on lateral cephalograms. The maxillary tuberosity sites with intact cortical plate due to congenitally missing third molars or atraumatic extraction of third molars (G1), partial loss of cortical plate due to surgical removal of third molars (G2), fully erupted third molars (G4), third molars located at (G3), and below the cementoenamel junction (G5) were evaluated with cone beam computed tomography. One way Anova and Fisher LSD test was done.

RESULTS

The order of greater to lesser amount of distal movement of the maxillary first permanent molar depending on the integrity of maxillary of tuberosity was partial loss of cortical plate, third molars at the cementoenamel junction, third molars below the cementoenamel junction, intact cortical plate and fully erupted third molars.

CONCLUSION

The integrity of the cortical plate and the relative position of the maxillary third molar to the second molar influence the amount of distal movement of the maxillary first permanent molar during distal movement of the maxillary teeth with TADS.

CLINICAL RELEVANCE

The amount of distal movement of the maxillary dentition appears to depend on the presence or absence of the third molars and the condition of the cortical plate in the region of the maxillary tuberosity and thereby greatly influence the outcome of treatment.

Compliance with Headgear Evaluated by Force- and Temperature-Sensitive Monitoring Device: A Case-Control Study

The aim was to objectively assess compliance in patients prescribed headgear and evaluate the impact of monitoring awareness, treatment duration, gender, and age on compliance levels. A total of 22 patients with Class II malocclusion wore the headgear integrated with the force and temperature sensitive Smartgear monitoring system (Smartgear, Swissorthodontics AG, Cham, Switzerland). Patients were instructed to wear the headgear for 13 h daily over a 3-month period. Randomly, 11 patients were informed that they monitored and 11 were not informed. Data were organized using Microsoft Excel and analyzed using R for statistical estimates, graphs, and hypothesis testing. Smartgear recorded an average daily compliance of 6.7 h. No statistically significant differences were found in cooperation between study group and control group over the 3 months of treatment, regardless of gender and age. However, there was slight greater cooperation in the first month than in the other months, and patients ≤10 years of age had almost 2 h more cooperation than their older counterparts. Moreover, the informed group exhibited an average of 1.1 more hours of cooperation per day than the uninformed group, which may carry clinical significance. This cooperation primarily occurred at night and was found to be statistically significant. Compliance among young patients typically remained lower than the prescribed level, regardless of their gender and psychological maturity. Although an awareness of monitoring does not seem to improve compliance, implementing such systems could still offer dentists a valuable means of obtaining objective information about their patients' adherence.

Effect of fence tray matching care on excess adhesive and bracket placement accuracy for orthodontic bonding: an in vitro study

OBJECTIVE

This study aimed to evaluate the effect of fence tray matching care (FTMC) in bracket bonding by measuring excess adhesive, as well as linear and angular deviations, and by comparing it with the half-wrapped tray (HWT).

MATERIALS AND METHODS

An intraoral scanner was used to acquire data on the maxillary dental arch of a patient with periodontitis.Furthermore, 20 maxillary dental arch models were 3D printed. Using 3Shape, PlastyCAD software, and 3D printing technology, 10 FTMC (method I) and HWT (method II) were obtained. By preoperative preparation, intraoperative coordination, and postoperative measurement, the brackets were transferred from the trays to the 3D-printed maxillary dental arch models. Additionally, the bracket's excess adhesive as well as linear and angular deviations were measured, and the differences between the two methods were analyzed.

RESULTS

Excess adhesive was observed in both methods, with FTMC showing less adhesive (P< 0.001), with a statistical difference. Furthermore, HWT's vertical, tip and torque, which was significantly greater than FTMC (P< 0.05), with no statistical difference among other respects. The study data of incisors, canines, and premolars, showed that the premolars had more adhesive residue and were more likely to have linear and angular deviations.

CONCLUSIONS

The FTMC had higher bracket bonding effect in comparison to HWT, and the adhesive residue, linear and angular deviations are smaller. The fence tray offers an intuitive view of the precise bonding of the bracket, and can remove excess adhesive to prevent white spot lesions via care, providing a different bonding method for clinical applications.

[The use of an individualized mini plate for the distalization of teeth]

The case of treatment of a 32-year-old patient with complaints about the aesthetics of a smile and the absence of teeth 17 and 46 is presented. During the examination, it was established: the retraction position of the teeth in the frontal part of the upper jaw, the closure of the molars according to the II class of the second subclass of Engl (distal bite), the vestibular position of the teeth 13, 23. To change the spatial position of the lower jaw, the fixation of the bracket system on the upper jaw was performed. and also an individualized mini-plate was installed in the area of the zygomatic alveolar ridge on the right and left, for distalization of the dentition of the upper jaw with the help of orthodontic traction applied from the teeth to the mini-plates. This clinical example demonstrates the possibility of using individualized mini-plates for distalization of the upper dentition, as an alternative and more stable method of treatment in such clinical cases.

Long term dental transversal stability of Class II division 1 treated with cervical headgear

Introduction:

In several conditions, outcome stability is a great challenge for Orthodontics. Previous studies have reported that relapse commonly occurs along the years after orthodontic treatment finishing.

Objective:

The aim of the present study was to evaluate in the long-term transversal dental arch changes of Class II division 1 patients treated with cervical headgear and fixed appliance.

Methods:

Plaster study casts of 20 patients treated with cervical headgear without dental extractions were 3D-scanned and evaluated in three distinct times: initial (T₁), immediate post-treatment (T₂) and long-term retention (T₃ - minimum 20 years). Transversal teeth distance of maxillary and mandibular canines, premolars and first molars were measured.

Results:

A statistically significant increase during treatment was observed for all maxillary teeth transversal distances (p< 0.05). In turn, a significant reduction was observed in the long term (p< 0.05). For the mandibular teeth, canine transversal distance presented statistically significant constriction in the retention period (p< 0.05). Mandibular first molars distance was significantly expanded by treatment (p< 0.05) and remained stable in the long term. The changes observed for the other teeth or other times were considered not statistically relevant.

Conclusions:

For the accessed sample, transversal changes occurred during treatment and retention phases in Class II division 1 patients treated with cervical headgear and fixed appliance. Relapse was considered statistically relevant, even with the institution of a retention protocol.

Evaluation of anteroposterior and vertical stability 25 years after Angle class II division 1 treatment with cervical headgear

PURPOSE

The goal was to investigate long-term (minimum 20 years) skeletal and dental changes in Angle class II division 1 patients treated with full-fixed orthodontic appliances and cervical pull headgear.

METHODS

A longitudinal retrospective study was performed with 20 orthodontic patients, who were treated exclusively by one experienced clinician and whose treatment had been completed a minimum of 20 years ago. Former patients who had been treated from the mid-1970s to the early 1990s were actively sought. After the recall, 20 patients agreed to participate in the study. Lateral cephalometric radiographs at pretreatment (T1), posttreatment (T2), and long-term follow-up (T3) were digitized and measurements were performed. Angular variables used were SNA, SNB, ANB, OcclPl-FH, PalPl-FH, GoMe-FH, 1‑NA, and Y axis. Linear measures were A‑NPerp, Pg-NPerp, 1‑NAmm, Wits, and LAFH.

RESULTS

From T1 to T2, a significant reduction (p < 0.01) in ANB angle from 4.70 to 2.48° and in Wits value from 3.42 to 0.98 mm were observed. It was also noticed a significant increase (p < 0.01) in LAFH from 62.02 to 67.39 mm, probably due to normal facial growth. From T2 to T3, these variables remained stable. No significant changes were observed for any other measure in any of the periods studied.

CONCLUSIONS

In the assessed sample, Angle class II division 1 patients treated with cervical pull headgear presented cephalometric outcome stability of treatment, even after a long-term follow-up of a mean of 25 years postretention.

Effects of the cervical headgear in growing Angle Class II malocclusion patients: a prospective study

Objective:

Evaluate dental and skeletal changes resulting from the exclusive use of the cervical headgear for 15 ± 4 months in the treatment of patients with Class II division 1 malocclusion.

Methods:

Differences between the beginning (T₁) and immediately after the end of the therapy (T₂) with the cervical headgear in growing patients (Experimental Group, EG, n = 23) were examined and compared, during compatible periods, with those presented by a group of untreated individuals (Control Group, CG, n =22) with similar malocclusions and chronological age. The cephalometric variables evaluated were: ANB, GoGn.SN, AO-BO, S'-ANS, S'-A, S'-B, S'-Pog and S'-U6 (maxillary first molar). The Shapiro-Wilk and Levene tests were used to evaluate the results.

Results:

Significant differences were found relative to the ANB, S'-U6, AO-BO, S'-ANS, S'-A, S'-B and S'-Pog variables between T₁ and T₂ when comparing both groups. No statistically significant variation was found regarding the GoGn.SN angle.

Conclusions:

The use of cervical headgear promoted distal movement of the maxillary first molars and restricted the anterior displacement of the maxilla, without significantly affecting the GoGn.SN angle.

Attitudes of orthodontists and laypersons towards tooth extractions and additional anchorage devices

Background

This study investigated the attitudes of orthodontists and laypersons towards the choice of extracting second premolars, rather than first premolars, based on tooth condition and the use of additional anchorage devices.

Methods

Questionnaires were sent to two groups: 324 orthodontists who were members of the Thai Association of Orthodontists, and 100 randomly selected Thai laypersons aged above 20 years and who were unrelated to the field of dentistry. Descriptive and chi-square statistics were used to analyze the data.

Results

Questionnaires were returned by 142 orthodontists (43.8%) and completed by 100 laypersons. The larger the size of the caries lesion in the maxillary second premolar was found, the more orthodontists and laypersons both chose to extract a carious maxillary second premolar instead of a healthy maxillary first premolar. For orthodontists, the use of mini-implant anchorage was significantly related to their extraction decision. Orthodontists who were familiar with mini-implants usage would choose to extract the second premolar at a lower size of extent of caries. Besides, when larger sizes of caries lesions in maxillary second premolars were considered, laypersons tended to have greater acceptance of the use of additional anchorage devices in order to keep the healthy maxillary first premolar.

Conclusions

In this study, tooth condition and the use of anchorage devices are currently the main considerations by both orthodontists and laypersons when selecting the teeth to be extracted for orthodontic treatment.