Asymmetric extractions in a patient with a hopeless maxillary central incisor, followed by treatment with mini-implant anchorage

Treatment of an adult patient with severe dental crowding by applying asymmetric extraction, fixed appliance, and micro-implant anchorage: a case report

BACKGROUND

Severe dental crowding and protrusion often necessitate symmetric extraction for correction. However, asymmetric extraction may serve as a viable, albeit challenging, treatment option when the prognosis of individual tooth is poor. In this report, we present a case where asymmetric extraction was employed to address severe dental crowding and deviated midlines, resulting in satisfactory outcomes following retention.

CASE PRESENTATION

We report a case of a 31-year-old woman with severe dental crowding and deviated dental midlines. A fixed appliance, micro-implant anchorage, and asymmetric extraction, including a mandibular canine with severe buccal malposition, were applied to the patient. The treatment outcomes demonstrated successful achievement of the treatment objectives, with well-aligned teeth exhibiting solid interdigitation and the dental midlines aligned with the facial midline. At the 21-month follow-up, midline stability, favorable occlusal interdigitation, and improved smile line were observed.

CONCLUSIONS

Asymmetric extraction may be considered a viable approach for patients with individual tooth of poor prognosis. Treatment stability can be achieved through well-interdigitated occlusion and the use of various retention methods.

Asymmetric Extraction Treatment in a Middle-Aged Patient with Dental Crowding and Protrusion using Clear Aligners

Frequently, orthodontic treatment involves symmetrically extracting premolars to correct severe crowding or protrusion. Nevertheless, in some cases, a more reasonable alternative may be to remove teeth with poor prognoses to improve protrusion and relieve crowding. A middle-aged woman sought treatment for dental protrusion and crowding. Her mandibular right first molar had been treated with root canal therapy due to pulpitis, but she still felt uncomfortable. In addition, her maxillary left second premolar had become carious. Extractions of the maxillary right first premolar and left second premolar, as well as mandibular right first molar and left first premolar were chosen to resolve the occlusion problems. The patient opted for clear aligners on the demands of esthetics as well as comfort. Following orthodontic treatment, the patient attained properly aligned teeth, a pleasing smile, and a facial profile that exhibited greater harmony. This case report demonstrates that, under proper planning, clear aligners are capable of handling challenging cases, including those involving middle-aged individuals and molar extractions.

Treatment of facial asymmetry and severe midline deviation with orthodontic mini-implants

This case report describes the treatment of a 29-year-old woman with facial asymmetry and 2 hopeless teeth. Her lower dental midline was shifted to the left side, and the mandibular left second molar would need to be extracted because of severe caries. The maxillary right second premolar was root rest, and the upper dental midline was shifted to the right side. Because of the patient's asymmetry and Class III skeletal pattern, a severe Class III relationship in the right canine region and lingual crossbite in the left side was observed. She did not want jaw surgery. The mandibular right first premolar, 2 hopeless teeth, and maxillary left second premolar were extracted, and orthodontic mini-implants were used to correct the dental midline, crossbite, and crowding. The mandibular left third molar was moved to the second molar extraction space by using orthodontic mini-implant anchorage. Adequate functional and esthetic results were obtained. Correction of the crossbite on the left side could improve facial asymmetry by changing the drape of the overlying lips.

Three-Dimensional Finite Element Analysis on En-Masse Retraction of the Maxillary Anterior Teeth With Quantitative Combined Loading Control

This study aims to elucidate the biomechanical effects of combined loading of maxillary anterior and posterior implants using the sliding method on en-masse retraction of the anterior teeth and to quantify the loading ratio (LR) of anterior and posterior implants to achieve controlled retraction of the maxillary anterior teeth. A three-dimensional finite element model of the maxilla-upper dentition appliance was constructed. Implants were placed on the distal (A) and mesial (B) sides of the lateral incisors as well as on the mesial (C) side of the first molar and different amounts of force were loaded between the implants using 2- or 5-mm traction hooks. The labiolingual movement of the anterior teeth was recorded and the relationship between the LR of the implants and the movement of the central incisors was evaluated. With 2-mm traction hooks, the central incisors exhibited a translation tendency during retraction at lower A/C and B/C LR and labial or lingual crown inclination at higher values. With 5-mm traction hooks, the central incisors, lateral incisors, and canine teeth exhibited a labial crown inclination. The results of this study suggest that 2-mm traction hooks can cause labial crown inclination, translation tendency during retraction, or lingual crown inclination of the central incisors due to alterations in the LR of the anterior and posterior implants. The central incisors only exhibited labial crown inclination during combined loading of the anterior and posterior implants when 5-mm traction hooks were used.