Restoration of an alveolar bone defect caused by an ankylosed mandibular molar by root movement of the adjacent tooth with miniscrew implants

Early replacement of ankylosed first molar via mesial root movement facilitates bone formation and normal eruption of the third molar

Ankylosis of a molar during active growth leads to a significant vertical bone defect, extrusion of the opposing molar, and inclination of adjacent teeth. Treatment timing is an essential factor for the patient's quality of life. Early extraction of the ankylosed molar and protraction of the second molar is challenging because of the difficulty of tooth movement and the uncertainty of the normal eruption of the third molar. In view of the uncertainty of eruption of the mandibular third molar, it is essential to assess the potential for eruption according to the developmental stage of the third molar and to secure sufficient space for eruption. In this case report, a girl with an ankylosed right mandibular first molar and an advanced vertical bone defect was treated via early extraction of the ankylosed molar along with the intrusion of the maxillary molar and mesial root movement of the second molar before the initiation of third molar root formation. Restoration of the vertical bone defect was noted at the end of treatment. In addition, spontaneous eruption of the third molar was observed, which was in contrast to the mesioangular impaction of the contralateral third molar. This case emphasizes the importance of treatment timing to increase the chance of utilization of the third molar.

Long-term stability of miniscrew anchored maxillary molar distalization in Class II treatment

OBJECTIVE

To investigate treatment stability of miniscrew-anchored maxillary distalization in Class II malocclusion.

MATERIALS AND METHODS

This retrospective study included a distalization (n = 19) and a control (n = 19) group; a patient group with minor corrections served the control. Lateral cephalograms of 38 adult patients were taken before (T0), immediately after (T1), and 3-4 years after (T2) treatment. Horizontal and vertical movement and tipping of the maxillary first molars (U6) and central incisors (U1) were measured along with skeletal craniofacial parameters at three time points to compare the two groups regarding the achieved treatment effects and their stability.

RESULTS

Total arch distalization therapy led to 4.2 mm of distal movement of U6 without distal crown tipping (0.6° of axis change) and 3.3° of occlusal plane steepening. Over an average retention period of 42 months, maxillary total arch distalization provided high stability of treatment results, showing the same amount of mesial movement (0.7 mm) as the control group.

CONCLUSIONS

In Class II treatment, miniscrew-anchored maxillary total arch distalization can provide stable distal movement of the maxillary first molars and central incisors.

Posterior Available Space for Uprighting Horizontally Impacted Mandibular Second Molars Using Orthodontic Microimplant Anchorage

Treatment of horizontally and deeply impacted mandibular molars is challenging for both orthodontists and oral surgeons because of the limited access and anchorage control. We report on two patients who had horizontally and mesially impacted mandibular second molars (MM2s). Both patients were treated by a surgical orthodontic approach, and the crowns of the impacted teeth were brought into the arches by closed forced eruption. Mesially impacted MM2s were uprighted with orthodontic microimplants, inserted in the retromolar area, and then moved into their ideal position. The first patient was in an active growing stage, while the second patient was beyond the active growing stage. Therefore posterior available space (PAS) should be analyzed before treatment of impacted MM2s to prevent periodontal problems after uprighting of impacted teeth. If PAS is not enough for uprighting impacted MM2s, alternative treatment should be considered based on the stage of growth.

Mandibular molar uprighting using orthodontic miniscrew implants: a systematic review

The purpose of this systematic review was to identify studies and present the use of miniscrew implants (MIs) as an alternative treatment to mandibular molar uprighting. An electronic search and handsearching were conducted by two independent reviewers to identify relevant articles, published up to January 27, 2017. In order to methodologically assess the eligible studies, a pilot checklist consisting of 22 items was also implemented. After exclusion of all the irrelevant papers, only 17 studies were included, presenting 27 cases of mandibular molar uprighting in all planes using both direct and indirect force traction by MIs. Regarding the quality evaluation, the mean score of the included studies was 13.2, indicating a rather poor methodology implemented in the majority of the included cases. Due to many advantages, MIs provide a unique treatment alternative and constitute a reliable solution for treating tipped or impacted molars. Regarding the force application, a direct method is simpler, as it requires one MI and a single bracket or button, minimizing the patient's discomfort and also reducing chair time compared to more complex indirect anchorage. It also eliminates the possibility of unwanted movement of the anchorage unit, which can occur even with indirect anchorage as a result of technical errors. However, direct anchorage has limitations in cases of lingually tipped or rotated molars because a single force may be insufficient to upright the tooth.

Orthodontic Microimplants Assisted Intrusion of Supra-erupted Maxillary Molar Enabling Osseointegrated Implant Supported Mandibular Prosthesis: Case Reports

Loss of mandibular molars, when not replaced in time, are usually associated with overeruption of maxillary molars. To provide prosthetic replacement for missing lower posteriors, over erupted maxillary teeth have been intruded in past with great difficulty in adults with conventional orthodontics, along with associated problems of root resorption. Currently orthodontic microimplants provide stable intraoral anchorage, allow predictable maxillary molar intrusion enabling reestablishment of functional posterior occlusion with mandibular implant supported prosthesis, thereby reducing need for prosthetic crown reduction in maxillary arch. The added advantage of microimplant is it enables use of sectional appliance in area of concern instead of full arch bracketed appliance which an adult may not accept. The case reports demonstrates, overerupted maxillary molars were intruded using orthodontic microimplants to enable prosthetic rehabilitation of mandibular dentition by osseointegrated implant supported prosthesis. The second case report also demonstrates use of CBCT scan in planning and execution.

Orthodontic treatment of severe anterior open bite and alveolar bone defect complicated by an ankylosed maxillary central incisor: a case report

Incisor trauma is common in children, and can cause severe complications during adolescent growth and development. This report describes the treatment of a 16-year-old patient with severe anterior open bite due to ankylosis of the maxillary left incisor after dental trauma as an 8-year-old. No examination or active treatment was undertaken until he was 16 years old. Clinical examination revealed that the maxillary left incisor was severely intruded accompanied by a vertical alveolar bone defect. Orthodontic treatment combined with surgical luxation took 3 years and 7 months. During treatment, the intruded incisor was moved to the occlusal level and the alveolar bone defect was restored, achieving normal occlusion. After two years of retention, the maxillary left incisor was retained in a stable normal position with a slightly reduced overbite. This case demonstrates that surgical luxation with orthodontic traction can be an effective approach, especially when the ankylosed tooth has a single root. Long-term monitoring of orthodontic stability and the maintenance of periodontal health are crucial in the post-treatment period.

Timely relocation of subapically impacted maxillary canines and replacement of an ankylosed mandibular molar are the keys to eruption disturbances in a prepubertal patient

Eruption disturbances such as impaction and ankylosis complicate orthodontic treatment because soft-tissue and hard-tissue considerations must be taken into account. Treatment is further complicated when such eruption disturbances occur in a growing patient. Extraction of impacted or ankylosed teeth can be an option that carries the weight of additional prostheses and bony defects, whereas exposure or luxation followed by orthodontic traction can preserve the patient's teeth and bony structure with improved esthetics. Therefore, an accurate diagnosis is needed in establishing an efficient and effective force system to achieve the desired tooth movements with few unwanted sequelae. This case report describes the process of differential diagnosis with the aid of 3-dimensional imaging in constructing a force-driven system, using the centers of resistance as reference points, to successfully bring a pair of impacted maxillary canines into alignment and protract a mandibular molar to achieve an acceptable occlusion in an adolescent girl.

Algorithm for the differential diagnosis of posterior open bites: two illustrative cases

PURPOSE

Posterior open bites can result from several causes: trauma, degenerative changes, tongue thrust habits, single-tooth ankylosis, multiple-tooth ankylosis, and/or condylar hyperplasia. Occasionally, posterior open bites are secondary to a combination of condylar hyperplasia and dental ankylosis, which can be difficult to diagnose and treat because of the large array of causative problems.

MATERIALS AND METHODS

This article presents 2 unusual cases of posterior open bite secondary to multiple etiologies in adolescent male patients. A useful method of algorithmic diagnosis, treatment, and protocol is presented that was used for these cases.

RESULTS

The 2 cases were successfully diagnosed and treated using the formulated algorithm for posterior open bites.

CONCLUSIONS

The algorithms presented facilitate the differential diagnosis of posterior open bites with ambiguous etiology.