Dental Asia Jan/Feb 2019

Clinical Feature JANUARY / FEBRUARY 2019 DENTAL ASIA 37 I nvisalign first appeared at an orthodontic meeting in 1991 and a peer review was published later on in 2000. In the following years, aesthetic and socialisation demands have influenced more adult patients to seek orthodontic treatment. Different aesthetic orthodontic appliances have been advocated such as ceramic brackets and lingual appliances however, clear aligners seem to be most popular among them. 1 As Invisalign has been used for over 18 years, treating over six millions of people worldwide, most of the studies focus on one single aligner system. However, there are various systems with different features that can provide different treatment outcomes. 2 The aim of this report is to review and evaluate the literature available online that discuss the Nuvola aligner system, from a clinician’s point of view. General indications and advantages of clear aligners Orthodontic tooth movement using sequential thermoformed aligners was first proposed by Kesling and McNamara. This was later marketed by Align Technology in 1997. With the introduction of CAD/CAM software techniques, this concept became a feasible treatment modality. 10 Patients with dental crowding can be treated by performing interproximal enamel reduction (IPR). Teeth movement such as leveling, aligning, intrusion A report to review, evaluate and discuss the Nuvola aligner system from a clinician’s point of view. and even bodily distalisation of upper molars (<1.5 mm) were reported to be predictable. However, rotations, extrusion and torque movements were difficult to achieve. Aligners are unable to achieve programmed movement with 100% predictability. 3 Dental intrusions, deep-bite cases, minor tooth rotations, small antero-posterior discrepancies and crowding cases (<4mm) can easily be resolved with the use of vacuum formed appliances. Even more difficult dental movements such as root torque, uprighting molars can almost be entirely corrected if resin attachments are added on the tooth surface in the aligner design. Yet, computed tomography show that clear aligners can move crowns, but not roots of anterior teeth, to designated positions as only tiltingmovement of roots occurs. 5 Another reported advantage of aligner therapy is the improvement of sleep apnoea through the expansion the dental arches and teeth alignment as this relieves obstruction of air passageway. Elastics applied on interach aligners can also improve mandible position, which will further enlarge the air passage. 2 Digital set-ups, ClinChecks, 3D images and initial digital planning of treatments are important features of clear aligners. These are all used to predict treatment outcome and increase the patient’s compliance. Dentists and patients can now visualise the predicted toothmovement at any stage during the whole treatment process. The ClinCheck 2018 version considers the biological limitations of the hard tissue and provides assessments of root positions. A minor dental movement of 0.25 mm is recommended with each aligner. 4 A wide range of cases can be corrected effectively upon recognising the advantages and limitations of clear aligners. Refinements, adjustment and rebooting remain important techniques performed by dentists, including their ability to communicate effectivelywith their patients. Aligners are only an appliance, similar to traditional brackets, that require continuous monitoring and dentist skills. Fixed appliances could be added to correct tipping (>5°) during space closure of extraction cases. 1 Using oral buttons with elastics to improve and prevent tipping is also recommended. 4 At a 2016 Orthodontic Summit, Nelson stated: “The ClinCheck can be used for diagnosis and treatment planning such as evaluating the need for IPR, expansion, extraction, distalisation or proclination as well as verifying the modifications performed by technicians, tracks aligners, and evaluates anchorage with superimposition and staging. It is also a consultation device that can show patients treatment limitations and also help address the patient’s chief complaint at the beginning of the treatment.” There are numerous benefits to utilising clear aligners aside from those mentioned previously. Aswe all know, unlike traditional braces, aligners can be removed during A Literature Update on Nuvola Clear Aligners By Dr. Kevin Ng