How We Design Clear Aligners Cases
The standing protocols behind every Digident Lab aligner plan: how a case is designed, the clinical factors we work with, how we place attachments and IPR, and what happens after the first scan.
4-5 Business Days
Treatment Design
4-5 Business Days
Manufacturing Instructions
2 Weeks
Standard Wear Per Aligner
22 Hours
Daily Wear, Minimum
Dental Professionals: We work with registered dental professionals only
Patient compliance is key. Tracking scans show whether the aligners are being worn and for how many hours a day. Where wear falls short, treatment will not track as planned and extra costs may apply.
Design Method
How a plan is built.
Every case starts as a digital set-up built on the classic Kesling set-up rules taught at university, combined with training from modern clear aligner courses. The teeth are moved step by step to the planned final position, then divided into aligner stages.
Treatment design: 4–5 business days from receipt of a complete case. Manufacturing instructions: a further 4–5 business days once the doctor has approved the design.
The doctor reviews the design and manufacturing only starts once the doctor gives the go-ahead.
Every case is designed individually. Staging, IPR and attachments come from the movements that case needs, not from a fixed template. Tracking scans are used to check that the teeth are moving as planned, and the design is redesigned from them where needed. This ongoing tracking is what gives our cases a high success rate.
Each plan says whether it is esthetic alignment or comprehensive correction, and what it does not change, such as posterior occlusion or molar relationship.
We identify the most difficult movement in the case first. Its staging, IPR and attachment support decide the strategy for the whole plan.
Treatment overview, scope, arch mechanics, Bolton analysis, predictability, progress scan schedule and clinical notes, written so the doctor can brief the patient before treatment starts.
Clinical Factors We Work With
What we assess on every case.
Overall and anterior ratios are calculated. A discrepancy is managed with staged IPR, or with staging and positioning when IPR is not indicated. The report states which and why.
Space comes from IPR and arch form, not uncontrolled expansion.
Rotation of round or near-round teeth, mainly lower incisors and canines, is the least predictable aligner movement. Large corrections are split across transition layers.
Torque is kept within what an aligner can express and staged conservatively. Where torque may under-express, the report says so.
Narrow or short crowns give an attachment less grip. We account for this in the attachment plan and the predictability rating.
Bite ramps (bite spots) on posterior teeth create clearance where it is needed. They are not retentive attachments.
The two arches often finish at different times. The report says when each completes and how the finished arch is held.
Rotated teeth relapse more readily, so retention advice is stronger where a case involved significant derotation.
Bone And Movement
What we assess on every case.
Aligner force loads the periodontal ligament (PDL). On the pressure side the PDL is compressed and osteoclasts resorb alveolar bone. On the tension side the PDL fibres are stretched and osteoblasts lay down new osteoid, which then mineralises.
Light force allows direct bone resorption and steady movement. Excess force compresses the PDL enough to cause a hyalinised zone, and movement stalls until the bone is undermined and the zone is cleared. Stage rates are kept conservative to avoid this.
Osteoid is laid down on the tension side from the first weeks of movement, but it mineralises slowly and is less dense at first. The two-week aligner interval is a staging step, not the time the bone needs to mature. This is why the end of active treatment is followed by retention.
PDL principal fibres reorganise over roughly 3 to 4 months or more. The supracrestal gingival fibres remodel far more slowly, which is why derotated teeth relapse most readily and need the strongest retention.
The aligner contacts the crown, away from the centre of resistance, so tipping is the movement it produces most readily. We rely on it for mesiodistal and labiolingual alignment.
Moving the crown and root together needs a force couple. We provide it through case-specific attachment geometry and a material stiff enough to express it. Predictability is lower than for tipping and is rated in the report.
Rotation about the long axis is staged in small steps. It is least predictable on round or near-round crowns (lower incisors, canines, premolars), where there is little crown form to push against.
Labiolingual root movement is staged conservatively and checked at the progress scan, because the aligner often under-expresses it.
Intrusion is generally well tolerated. Extrusion is the least predictable movement and is planned only with attachment support and a lower expectation of completion.
Staging
How movement is divided into aligners.
2 Weeks as standard.
Movement per stage is calibrated to the hardest movement in the case, then held consistently. Typical examples are 1° to 3° of rotation per stage, and 1° of torque with 2° of rotation per stage on a broad esthetic case.
Heavy derotation is staged in layers, for example 8 + 7 + 5 aligners, instead of one block.
Suitable cases can be done as a single stage of 10 aligners with no transition layers.
IPR Protocol
Interproximal reduction.
The amount comes from the Bolton analysis and the space the planned movement needs. There is no default amount.
IPR is split into sessions. Each session is completed before the specific aligner that uses the space, so the gap is not lost before it is needed.
Every site is written as the two adjacent teeth (for example 32/33) with the amount and the aligner number it must be done before.
IPR sessions appear in the progress scan schedule, so none is left as a general instruction.
Where a case runs as one stage, any lower-arch IPR is done in a single session before aligner 1.
Attachment Style
Where and how attachments are used.
Attachments are bonded using an attachment template, fitted at aligner 1.
Attachment shape is chosen by what the case needs, not by habit. Oval is one option among others, and it is often used on canines and first premolars, which carry the most rotation and torque.
Attachments go only on the teeth whose movement needs them. Each attachment is listed by tooth number in the report with the movement it supports.
The set is designed to last the whole sequence. Where a change is needed, the report ties it to an aligner number. Seating is checked at each progress visit.
Where the treating doctor confirms it, anterior teeth can carry tip, rotation and torque with no attachments. This is stated as a design choice, not left open.
If an unattached tooth rotates further than planned, an attachment can be added at a refinement or mid-treatment redesign.
Material
What the aligners are made from.
We use a harder aligner material that carries the movement itself, so the attachment is not left to do the work. It holds rotation well, including on unattached teeth, which is what makes attachment-free anterior design possible on suitable cases.
Every case is produced on 3D printed upper and lower models.
Progress Scans And Redesign
Where and how attachments are used.
Scans are set at clinical events: an IPR session, an arch completing, the final assessment. They are not on a fixed weekly or monthly calendar.
After a progress scan we review tracking and redesign from the new scan where needed. The doctor inspects the redesigned set before the next set is couriered.
Contact the lab before the patient moves to the next aligner. Early correction is simpler.
On complex cases, close monitoring and refinement are part of the plan from the start, and the scope is confirmed at the final scan.
Revisions, Refinements And Replacements
Where and how attachments are used.
Changes to a design are sent as typed, clearly written instructions in reply to the design. Please send them together in one reply where possible. This avoids over-revising a plan that is already sound.
Each case is designed so that few revisions should be needed. Where a case does need more, we work through them with you.
Redesigns from tracking scans are included in the once-off design fee, as set out in our tracking protocol.
Refinements at the end of treatment carry no extra charge.
Lost or broken aligners are replaced at no charge. If loss or breakage becomes repeated and points to a lack of care by the patient, further replacements may be charged.
Patient compliance is key. Under-wear is visible at tracking scans. Where a patient has not worn the aligners as prescribed, extra costs may apply.
Wear And Retention
Guidance given with every report.
Scope And Limits
What we do and do not do.
We design and advise. The treating doctor decides on treatment.
We decide which cases are suitable for aligners. If we cannot take a case on, we still write a report so you know why.
We do not recommend tooth removal. A tooth removed in a digital set-up is a simulation to test whether a viable plan exists, and the decision stays with the doctor.
In accordance with the law, Digident Lab works only with dental professionals. We do not accept cases from patients or the public.
We stay within the scope of removable orthodontic appliances, as set by SADTC legislation. We do not produce fixed-appliance treatment plans.
Each report rates predictability by movement and names anticipated limitations.
Delivery
What the practice receives.
We courier anywhere in the country.
Every set is sent with clear numbering on the packet and on each aligner.
A printed report is sent with every set.
The next due date is logged by the lab, and a copy is included in the patient’s notes.
Submitting A Case
Send files any way your practice already works.
Register once, then upload your case.
Attach your scan files and lab slip.
Add us as a partner lab with this address.
In MyiTero, open Lab Locator and search for us.
Find or invite our lab with this address.
Send your files to this address.
Add us as your lab in Freqty Cloud.
The intraoral scan file and a panoramic radiograph (OPG) are needed to start. A midline (frontal) photo and a side profile photo are ideal.
Use the online lab slip or the paper slip. Both capture the case details.
Billing is per practice or directly with the patient, following the prescribing doctor’s protocol. Full payment or per-set billing is offered, depending on the case and the doctor.
Have a case for us?
Register your practice to upload a scan, or WhatsApp us to discuss your prescription.