Canine substitution of congenitally missing maxillary lateral incisors in Class I and Class III malocclusions by using skeletal anchorage

Comparison between 2D cephalometric and 3D digital model superimpositions in patients with lateral incisor agenesis treated by canine substitution

INTRODUCTION

This study aimed to assess the reliability of measurements obtained after superimposing 3-dimensional (3D) digital models by comparing them with those obtained from lateral cephalometric radiographs in patients with lateral agenesis space closure by mesialization.

METHODS

Data were collected from premaxillary and postmaxillary dental casts and lateral cephalometric radiographs of 26 patients presenting lateral incisor agenesis and treated with rapid maxillary expanders and space closure by mesialization of the lateral sectors. Sagittal and vertical movements of the incisors and the maxillary molars were evaluated with lateral cephalometric radiographs and digitized 3D models superimposed on the palatal area. Paired sample t tests were used to determine if any significant difference existed between the 2 measuring techniques and between 2 different localizations of superimpositions.

RESULTS

Cephalograms and 3D digital model measurements were statistically similar in molars and incisor movements according to anteroposterior and vertical planes. Regarding incisor movements in the anteroposterior plane, measurements derived from second ruga 3D models were significantly greater than those derived from third ruga 3D digital models.

CONCLUSIONS

The 3D model superimposition method using the palate as a reference area is clinically reliable for assessing anteroposterior and vertical tooth movement as cephalometric superimposition in patients treated with rapid maxillary expanders and space closure by mesialization.

A cost analysis of orthodontic space closure and implant treatment in patients missing maxillary lateral incisors with a long-term perspective

OBJECTIVE

Few studies within orthodontics present both economic and clinical findings. Missing maxillary lateral incisors is a frequently occurring anomaly. The treatment alternatives most used are orthodontic space closure and prosthetic replacement of the missing tooth. Our aim is to compare the total societal costs of orthodontic space closure (SC) and implant therapy (IT) in patients missing maxillary lateral incisors.

METHODS

Records of 32 patients treated with SC (n = 18) or IT (n = 14) due to missing maxillary lateral incisors were retrieved from the archives. Direct costs and indirect costs in the short- and long-term were analysed using a cost analysis with a societal perspective up of to 12 years post-treatment.

RESULTS

Comparing cases treated with SC and IT, the difference in direct short-term costs for treatment is €735.54, whereas SC is the least costly. There is no difference between SC and IT in short-term parent loss of productivity, long-term loss of productivity, costs for transportation, or direct long-term costs. A difference was found between SC and IT-in favour of SC-when comparing patients' loss of productivity (P = 0.007), short-term societal costs (P < 0.001), long-term societal costs (P = 0.037), and total societal costs (P < 0.001).

LIMITATIONS

There is a limited number of patient records. Local factors such as subsidies, urban versus rural areas, taxes, etc. can influence monetary variables, so the transferability to other settings may be limited.

CONCLUSION

Patients treated with SC have a lower total societal cost compared to patients treated with IT. There was a difference in productivity loss for patients between SC and IT; however, concerning other indirect parameters and direct long-term costs, there was no difference between the two treatments.

Optimizing donor tooth selection for autotransplantation in the anterior maxilla via CBCT-based root width and crown-root angle measurements

BACKGROUND/AIM

The clinical management of growing patients with missing teeth in the anterior maxilla can be challenging due to limited treatment options and high esthetic demands. Tooth autotransplantation (AT) is a viable option for these cases. The selection of donor teeth has been reported to be driven by root development, existing malocclusion, and esthetics. The aim of this study was to add to the evidence base of tooth selection criteria for AT by examining candidate donor teeth root width and crown-root angles, two factors arguably important for surgical planning and esthetics.

MATERIAL AND METHODS

Cementoenamel junction (CEJ) tooth width and crown-root angle measurements were made using cone-beam computed tomography (CBCT) images of 30 children and adolescents of European descent (mean age = 13 years, range = 10-17 years; 63% male) from a private orthodontic practice. Measurements of maxillary central and lateral incisors (index teeth) were compared with measurements of maxillary second premolars, mandibular central incisors, and mandibular first and second premolars (candidate donor teeth). Analyses relied on descriptive statistics of mean within-subject differences between index and donor teeth and the proportion of individuals without clinically important differences (i.e., >1.5 mm width deficit and > 15 degrees crown-root angle difference).

RESULTS

Mandibular first premolars were the most compatible teeth for the replacement of maxillary central incisors based on both width (≥97% of individuals) and angle measurements (≥87% of individuals), followed closely by mandibular second premolars. Mandibular central incisors were the most compatible for the replacement of maxillary laterals, among all individuals based on width and ≥ 90% based on angle, whereas mandibular first premolars were somewhat less compatible.

CONCLUSIONS

The study offers evidence of within-person, CBCT-based root width dimension and crown-root angle compatibilities. This information can be considered in addition to existing tooth selection criteria for AT including Angle's classification, midline deviation, crowding severity, root development, and esthetics.

Agenesis of maxillary lateral incisors: diagnosis and treatment options

Introduction:

There are different possibilities of orthodontic planning for cases with congenital absence of maxillary lateral incisors. This subject divides the opinion of orthodontists and oral rehabilitation clinicians, due to the advantages and disadvantages of each treatment option, which may involve opening spaces for future implants and/or prosthetic restorations, or closing the spaces by positioning the maxillary canines in the place of lateral incisors. The correct diagnosis and careful evaluation of each patient allow to determine the best therapeutic approach. This paper discusses the main topics to be considered when planning these cases.

Objectives:

To evaluate the main aspects related to orthodontic treatment planning in cases of congenital absence of maxillary lateral incisors, to aid the decision-making, with clinical and scientific basis.

Mutation Detection and Functional Analysis of MSX1, PAX9, AXIN2, and BMP in Nonsyndromic Congenital Missing Teeth Based on Intelligent Image Detection

Due to the complexity of clinical manifestations and the lack of standardized diagnostic criteria, it is still difficult to distinguish the etiological types of congenital edentulousness corresponding to genetic defects. This paper studies the application of deep learning image processing and digital image processing in medical images in detail and analyzes the functions of congenital edentulous hotspot genes. The cases in the control group and the study group were collected, and the gene mutations of direct sequence MSX1, PAX9, AXIN2, and BMP were analyzed, and new pathogens were found. The experimental results suggest that PAX9 and MSX1 genes may have a synergistic effect in nonsyndromic congenital edentulous patients. In severely missing teeth, the role of PAX9 may be greater than that of MSX1. The experimental results will help us lay the foundation for further understanding of the disease in the future.

Laypeople and dental professionals' perception of the aesthetic outcome of two treatments for missing lateral incisors

Objective

To investigate laypeople and dental professionals' opinions of the aesthetic outcome from implant therapy (IT) and orthodontic space closure (SC) for missing maxillary lateral incisors.

Material and methods

Evaluation was performed by three groups: laypeople 20–30 years of age (n = 26), laypeople 50–70 years of age (n = 26) and orthodontists (n = 25). The assessors viewed photographs of 44 different cases treated with IT or SC, and made an evaluation of the aesthetics.

Results

The gingival color adjacent to the replaced tooth was rated as having better aesthetics in the SC cases (p = 0.000). The orthodontists preferred the aesthetics of the dentition in the SC cases (p = 0.042). The young laypeople, compared to the older laypeople and orthodontists, were more dissatisfied with the color of the tooth replacing the missing lateral incisor in SC cases (p = 0.043).

Conclusion

The color of the gingiva adjacent to the implant‐supported crowns had a lower aesthetic rating than the SC group. Laypeople rated both treatments as equally good. The orthodontists had a slight preference for the aesthetics in the SC cases.

When to Substitute a Missing Upper Lateral With a Canine: A Simplified Approach

Introduction:

The upper lateral incisor is the most commonly missing tooth in the anterior segment. It leads to esthetic and functional imbalance for the patients. The ideal solution is the one that is most conservative and which fulfills the functional and esthetic needs of the concerned individual. Canine substitution is evolving to be the treatment of choice in most of the cases, because of its various advantages. These are special cases that need more time and effort from the clinicians due to space discrepancy in the upper and lower arches, along with the presentation of individual malocclusion.

Aims and Objectives:

Malocclusion occurring due to missing laterals is more complex, needing more time and effort from the clinicians because of space discrepancy, esthetic compromise, and individual presentation of the malocclusion. An attempt has been made in this article to review, evaluate, and tabulate the important factors for the convenience of clinicians.

Method:

All articles related to canine substitution were searched in the electronic database PubMed, and the important factors influencing the decision were reviewed. After careful evaluation, the checklist was evolved.

Result:

The malocclusions in which canine substitution is the treatment of choice are indicated in the tabular form for the convenience of clinicians. Specific treatment-planning considerations and biomechanics that can lead to an efficient and long-lasting result are also discussed.

Conclusion:

The need of the hour is an evidence-based approach, along with a well-designed prospective randomized control trial to understand the importance of each factor influencing these cases. Until that time, giving the available information in a simplified way can be a quality approach to these cases.