Running loop in unusual molar extraction treatment

Evaluation of the effects of semipontic design on tooth movements during mesialization of mandibular second molar performed with clear aligner treatment by finite element analysis

INTRODUCTION

Loss of the mandibular first molar is common in orthodontic patients. One treatment option is the mesialization of the second and third molars. This study aimed to investigate the displacement and type of movement in the second molar during mandibular second molar mesialization with clear aligner treatment using finite element analysis in configurations with or without pontic, semipontic, and anatomic pontic for the edentulous space.

METHODS

Mesialization of the mandibular second molar with clear aligner treatment was simulated using the AlGOR Fempro program (ALGOR, Inc, Pa) with 3 different configurations.

RESULTS

In the transverse direction, the highest rotation occurred in the anatomic pontic model, whereas the lowest rotation was in the semipontic model. In the sagittal axis, although tooth movement was realized by tipping in all scenarios, the semipontic model showed the closest movement to translation because of a higher rate of crown-root movement. In the vertical axis, although extrusion occurred in all configurations, the semipontic model showed the least extrusion forces, whereas the anatomic pontic model showed the most.

CONCLUSIONS

Mesiobuccal rotation, mesial tipping, and extrusion were observed in all models. However, the semipontic design had the closest movement to translational. Further randomized, controlled clinical trials are needed to evaluate the effects of different pontic designs on tooth movements.

Sequelae of Unreplaced Tooth Loss in Orthodontic Patients: A Cross-Sectional Study in Najran, Kingdom of Saudi Arabia

Background

The early tooth loss has an adverse effect on the overall well-being of an individual. The aim of the current study was to highlight the orthodontic complications of long-term tooth loss in the city of Najran.

Materials and Methods

This was a cohort study of patients presenting for orthodontic rehabilitation. A total of 326 patients that presented for orthodontic rehabilitation were examined clinically and data such as age, gender, number of missing teeth, missing teeth, duration of missing teeth, tipping, and overerupted and rotated teeth were recorded. Patients that can be treated with orthodontic space closure were excluded from the study. Patients' data were analyzed using IBM SPSS Statistics and results were presented as simple frequencies and descriptive statistics.

Results

Out of 326 patients that presented for orthodontic rehabilitation, 259 patients had missing teeth with its sequelae that will demand prosthodontic rehabilitation with a prevalence rate of 79.4%. There are 97 (37.5%) males and 162 (62.5%) females with M:F ratio of 1:1.7. The age ranged from 15 to 52 years with mean ± standard deviation (28.5 ± 8.5). The age group 21-30 years constitutes the group with the highest number of missing teeth. A total number of 595 (60.2%) teeth were missing, 173 (17.5%) teeth were tipped, and 124 (12.5%) teeth were overerupted, whereas only 97 (9.8%) teeth were rotated (n = 989). Fixed orthodontic appliances (FOAs) were used for all cases with rotation and FOAs + Mini Screws were used for all cases with tipping, overeruption, and/or combinations. The dental loss was managed by prosthesis depending on patients' choice and financial capability ranging from removable/fixed prosthesis and dental implants.

Conclusion

Orthodontic consequences of early tooth loss include tipping and rotation of adjacent teeth and overeruption of opposing teeth. Early acknowledgment of tooth replacement after tooth loss is essential in preventing long-term orthodontic adverse effects.

Orthodontic treatment with passive eruption and mesialization of semi-impacted mandibular third molar in an adult with multiple dental losses

Objective:

This article describes the orthodontic treatment performed on an adult patient with multiple dental losses.

Case report:

A female patient, 20 years and 4 months old, presented with the following conditions: absence of teeth #26, #35, #36 and #46; semi-impacted tooth #48; inclined molars adjacent to an edentulous space; canines and premolars in a Class II relationship; a convex profile; biprotrusion; and forced lip sealing.

Results:

Space in the region of tooth #26 was closed, as well the space of tooth #46; tooth #48 erupted and followed mesial movement passively; space of the region of tooth #35 was maintained for the placement of a dental implant; uprighting of tooth #37 was obtained. Aesthetic and functional goals of the treatment were achieved. Results remained stable 10 years after the end of the treatment.

Conclusion:

The modified helical loop could be effectively used in orthodontic mechanics to close edentulous spaces. Passive semi-impacted mandibular third molar eruption and mesialization can occur in adults when proper space is provided.

Prediction of optimal bending angles of a running loop to achieve bodily protraction of a molar using the finite element method

Objective

The purpose of this study was to predict the optimal bending angles of a running loop for bodily protraction of the mandibular first molars and to clarify the mechanics of molar tipping and rotation.

Methods

A three-dimensional finite element model was developed for predicting tooth movement, and a mechanical model based on the beam theory was constructed for clarifying force systems.

Results

When a running loop without bends was used, the molar tipped mesially by 9.6° and rotated counterclockwise by 5.4°. These angles were almost similar to those predicted by the beam theory. When the amount of tip-back and toe-in angles were 11.5° and 9.9°, respectively, bodily movement of the molar was achieved. When the bend angles were increased to 14.2° and 18.7°, the molar tipped distally by 4.9° and rotated clockwise by 1.5°.

Conclusions

Bodily movement of a mandibular first molar was achieved during protraction by controlling the tip-back and toe-in angles with the use of a running loop. The beam theory was effective for understanding the mechanics of molar tipping and rotation, as well as for predicting the optimal bending angles.

A finite element analysis of the optimal bending angles in a running loop for mesial translation of a mandibular molar using indirect skeletal anchorage

OBJECTIVES

To estimate the optimal bending angles in the running loop for mesial translation of a mandibular second molar using indirect skeletal anchorage and to clarify the mechanics of tipping and rotating the molar.

METHODS

A three-dimensional finite element model was developed for predicting tooth movement, and a mechanical model based on the beam theory was constructed for clarifying the force systems.

RESULTS

When using a running loop without bends, the molar tipped mesially 14.4° and lingually 0.6°, rotated counterclockwise 4.1°, and the incisors retracted 0.02 mm and intruded 0.05 mm. These angles were about the same as those estimated by the beam theory. When the amount of tip back and toe-in angles was 11.0°, mesial translation of the molar was achieved, and incisors retracted 0.10 mm and intruded 0.30 mm.

CONCLUSIONS

Mesial translation of a mandibular second molar without any significant movement of anterior teeth was achieved during protraction by controlling the tip back and toe-in angles and enhancing anterior anchorage with the combined use of a running loop and indirect skeletal anchorage.

Molar Uprighting: A Considerable and Safe Decision to Avoid Prosthetic Treatment

Background:

Tipped lower molar over edentulous space is very common in orthodontics practice when adults seek treatment. The segmented arch technique features a predictable force system that provides a controlled release of force that can produce light and continuous tooth movement.

Case Description:

A female adult patient, who lost a permanent lower first molar, needed correction of the position of her permanent first molar place. Instead of making space for rehabilitation, it was closed after second molar uprighting and a balanced interdigitation was created without prosthetics. The patient was successfully treated with segmented arch technique using root correction spring activated with geometry VI to promote uprighting of a tipped molar and Niti spring coil to promote space closure.

Practical Implications:

Segmented arch technique is known to provide predictable light and continuous forces, which is very much indicated in adult treatment. There are several things to consider when orthodontically treating adult patients. Their periodontal conditions might not be ideal, less bone apposition may occur, and side effects of orthodontic tooth movement are expected. Thus, a predictable and controlled orthodontic treatment is needed.

Treatment of Class II malocclusion with bialveolar protrusion by means of unusual extractions and anchorage mini-implant

INTRODUCTION: Patients with dental Class II bialveolar protrusion are generally treated by extracting the four first premolars or two first and two second premolars, and retracting the anterior teeth. This case report describes the treatment of an adult patient with bialveolar protrusion, a Class II canine and molar relationship, and lip protrusion. METHODS: In this patient, the maxillary right second molar (1.7) had to be extracted due to extensive caries. To create sufficient space to retract the anterior teeth, the maxillary right posterior teeth were distalized with a maxillary posterior mini-implant (1.2~1.3 mm in diameter, 10 mm long), which was placed into the maxillary tuberosity area and allowed an en masse retraction of the maxillary anterior teeth. RESULTS: Overall, mini-implant can provide anchorage to produce a good facial profile even without additional premolar extraction in cases of dental Class II bialveolar protrusion with the hopeless second molar. CONCLUSION: The total treatment period was 42 months and the results were acceptable for 34 months after debonding.