Journal of Aligner Orthodontics, 02/2019

Adults may lose permanent teeth because of gingivitis, periodontal disease, caries or trauma. If edentulous areas are not restored, it can result in the rotation, tipping and drifting of neighbouring teeth and supra-eruption of opposing teeth. Some patients might feel only discomfort on occlusion, but others will have occlusal dysfunction. In the latter case, it is necessary to upright and move the dislocated tooth orthodontically, to restore the missing teeth and to treat the malocclusion. Currently, the most widely used orthodontic techniques are traditional fixed orthodontics and clear aligners. Due to the advantages of clear aligners in terms of superior aesthetics and comfort, these have gained in popularity as a treatment alternative among adult patients. The present case report demonstrates the use of clear aligner treatment for the correction of a 27-year-old female patient with an excessive overjet and missing mandibular premolar. Keywords: adult orthodontics, angelalign, case report, edentulism, mandibular arch narrowing, maxillary arch expansion, molar distalization

Patients with the characteristics of hyperdivergent facial patterns (dolichocephaly, shallow overbite and anterior open bites) are generally considered to be challenging to treat as many biomechanical approaches have extrusive side-effects that may lead to further bite opening and exasperate the clinical issues. However, with the increasing numbers of patients undergoing clear aligner therapy, there is a general clinical consensus that clear aligners are a good treatment option for this group of patients as vertical facial dimensions are not significantly affected with treatment. In the absence of literature on this topic, clinical cases are presented to demonstrate successful treatment of dolichocephalic patients with the ClearCorrect clear aligner system. These cases support the general notion that patients with increased facial dimensions can be treated with clear aligner therapy without adverse vertical changes. Keywords: aligner, facial dimension, hyperdivergent, open bite, orthodontic, vertical

The traditional bioprogressive philosophy has been reported to treat growing Class II malocclusion cases. The traditional technique involves the use of cervical headgear to extrude maxillary molars and to restrain maxillary growth while allowing forward arcial growth of the mandible. This case report utilises the same philosophy but using clear aligners. A 12-year-old girl presented with a skeletal Class II relationship due to mandibular retrognathism. The patient also presented full-step Class II, division 1 malocclusion with an increased overjet and deep overbite in addition to a spaced mandibular arch. Treatment included restraining maxillary forward growth while allowing maximum forward mandibular growth and correction of both skeletal and dental malocclusion/malrelationship using clear aligners. Detailed setup of the treatment plan using clear aligners utilising the bioprogressive philosophy is presented. Treatment was completed in 1 year. The treatment achieved improvement in skeletal and dental relationships. Critical evaluation of the case is also presented and the future management of similar cases of Class II malocclusion with a skeletal Class II relationship is discussed. Keywords: bioprogressive, Class II, clear aligner treatment, malocclusion, skeletal

Objectives: Assessment of sagittal jaw relationship is an important step in orthodontic diagnosis and treatment planning. The purpose of the present study was to assess the reliability and correlation of seven cephalometric parameters in assessment of sagittal jaw relationship for Sudanese orthodontic patients. Materials and methods: A total of 107 pretreatment cephalometric radiographs from the Orthodontic Department archive at the University of Khartoum that fulfilled the inclusion criteria were included in the present study. Each radiograph was manually traced; ANB angle, Wits appraisal, APP-BPP distance, Beta angle, W angle, Yen angle and anteroposterior dysplasia indicator (APDI) were identified. The sample was divided into Class I, II and III skeletal groups based on each measurement separately. Person's correlation analysis was performed to assess the reliability and correlation between the measurements among the various study groups (P value = 0.05 level of significance). Results: W angle was the most reliable method to assess Class I skeletal group, as it showed significant and correct correlations with all measurements except APP-BPP distance (P = 0.163). ANB angle and APP-BPP distance were the most reliable methods to assess Class II and III skeletal groups, respectively, as significant and correct correlations with all measurements were recorded. Conclusions: W angle, ANB angle and APP-BPP distance complement each other as clinically appropriate methods for assessment of sagittal jaw relationship in Sudanese orthodontic patients. Keywords: cephalometric radiograph, sagittal jaw relationship, skeletal malocclusion

With the progressing development of intraoral scanners, planning software and 3D printers, interest is increasing in an in-office workflow for aligner production. For the biomechanical planning of the treatment, accurate knowledge of the possibilities and limitations of the tooth movements with aligners is essential. One parameter to consider is the desired local force application of the aligner to the single tooth. This is essentially determined by the thickness of the material. The aim of this in-vitro study was to investigate the extent and localisation of changes in material thickness in the thermoforming process. The results showed up to 50% reduced layer thickness of the aligner foils, especially in the buccogingival regions. Thus the reduced force application should be taken adequately into account in the planning process. Keywords: aligner, material, polyethylene terephthalate (PET), polyurethane (PU), vacuum forming

Splints as therapeutic treatment instruments in temporomandibular disorder patients are widely accepted. The combination of splint therapy and aligner orthodontics not only provides comfortable and almost invisible treatment but also constitutes a powerful instrument for the orthodontic treatment of the temporomandibular disorder patient. To this end, precise knowledge of the temporomandibular joint, temporomandibular disorders and treatment using removable and fixed splints is indispensable. The two-phase treatment and the combination of fixed splint and aligner transform occlusal splint therapy into a permanently stable occlusion with physiological posterior vertical support. Keywords: aligner, temporomandibular disorder (TMD), temporomandibular joint (TMJ)