Resolving crowding in adult teeth

Resolving crowdingGary Dorman leads us through the treatment of severe maxillary and mandibular crowding using In-Line clear aligners.

People of all ages want a beautiful, natural smile as well as healthy teeth and gums. An increasing number of adult patients with anterior spacing or crowding are willing to undergo orthodontic treatment in order to achieve this.

However, they usually want the appliance to be as inconspicuous and comfortable to wear. In many cases, dental professionals successfully apply clear aligner therapy. In this case I treated the anterior crowding with In-Line aligners, produced in Germany by RKS Ortho GmbH (

Initial situation

Figure 1: Initial situation frontal view

The patient wanted to resolve her severe maxillary and mandibular crowding in order to improve both the appearance of her smile and also her dental hygiene. She expressed a desire to have the mal-alignment corrected with a therapy that is invisible as possible. The severity of the crowding was immediately apparent from a frontal view (Figure 1). However, you can clearly see the mal-alignment when viewed from the side or from occlusion (Figures 2 and 3).

UR1 was noticeably labial to UL1 and UR2. UL2 was rotated and labial to UL1 but palatal to UL3. LL1 was also noticeably labial to LL2 and LR1. I produced a study model and OPG for the diagnostics. Clinical examination showed that the patient’s teeth and gums were otherwise healthy with no problems relevant to orthodontic treatment.

  • Figure 2: Occlusal view of severe maxillary anterior crowding

Treatment decision and planning

I informed the patient about all the available treatment options. In addition to treatment with In-Line aligner therapy, we also discussed the possibility of fixed brackets. However, the patient even rejected braces made of tooth-coloured ceramics, on both aesthetic and comfort grounds. I showed the patient a sample of an In-Line aligner (Figure 4).

This solution met her need for comfort; the aligners affect the patient’s speech only initially and are visually barely noticeable. In-Line requested a quotation and treatment proposal with a 3D digital set-up/preview. The 3D preview includes seven images of the final situation, allowing patients to see how their teeth will appear post treatment from all angles. An overlaid image showing the movements made by each tooth is also provided (Figures 5 and 6).

  • Figure 4: An In-Line splint

The treatment proposal prescribed nine aligners for the upper arch and six aligners for the lower to be worn for between four and six weeks each. Due to the advanced technology of the In-Line system, each aligner can make a movement of up to 0.7mm also resulting in relatively short treatment times, usually between five and 10 months.

The treatment proposal indicated slight inter-proximal reduction between seven designated contact points in the upper arch and four in the lower arch. In-Line’s state of the art software is able to accurately calculate the amount of IPR required in advance of treatment.

Treatment progress

The patient was given new aligners successively at individual check-up appointments, at intervals of approximately four weeks. Inter-proximal enamel reduction was carried out incrementally over the first four to five splint fittings, until the enamel had been reduced by the specified amount.

The patient’s compliance was excellent. This made a significant contribution to the success of the treatment. She wore the aligners for the recommended time of at least 18 hours a day and the treatment goal was reached in around nine months (Figure 7). A comparison of the study models showing the anticipated final situation (sent by In-Line pre-treatment) and the post treatment study models shows that the treatment goal had been achieved almost perfectly (Figures 8 and 9).

  • Figure 7: Frontal view after treatment (teeth in protrusion)


Long-term retention is crucial following adult orthodontic treatment in order to avoid the risk of potential relapse. In-Line also includes a comprehensive long-term retention package for each case. In-Line has been an ideal addition to the cosmetic side of our practice. I have also found that I have been able to effectively treat cases of even quite severe crowding or gaps. In-Line provides all of the necessary training in a half-day seminar. With each case, In-Line provides me with a specific IPR prescription sheet to follow. It shows me exactly where and how much to strip teeth. This is easy with a dedicated IPR handpiece.

The lab is great to deal with is totally reliable. It provides consistent results for me with all my patients over the last 12 years. I would therefore have no hesitation in recommending In-Line to any dentist who wants want to do ethical dentistry based on aligning, whitening and bonding.

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This article first appeared in Orthodontic Practice magazine. You can read the latest issue here.

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