Crowding Diagnosis Treatment

This guide organises possible treatment options for a crowding diagnosis. The document is a treatment planning tool to assist you assist how to best treat patients. Treatments are graded by complexity, ranked by the orthodontic technique required, as a guide to the efficacy of treatment and enable providers to select cases that best matches their ability to apply advanced techniques. In this regard, it is particularly useful for dentists who are just beginning to provide clear aligner treatment.

Disclaimer

As doctors are solely responsible for the treatment they’re providing their patients, they should understand their limits and not hesitate to consult a specialist for further guidance when required. Note when applying this guide only general, high-level information on how each isolated condition might be treated is provided. The relationships between different conditions that exist in the majority of patients are not addressed. In this regard, always consider each patient’s individual dental and periodontal condition, restorative needs, facial proportions, and age when considering treatment options.

Proligner experience treatment grading:

Novice (0-15 cases)

Experienced (16-50 cases)

Advanced (>50 cases)

Crowding

Crowding is a common aspect of malocclusion, which can manifest itself in varying amounts from mild to moderate to severe. In general, mild crowding can be resolved with some proclination, rounding out of the arches, or even mild IPR. Moderate crowding can be corrected by arch expansion, proclination, IPR and/or extractions. Severe crowding usually requires a combination of expansion, proclination, IPR, extractions, and/or distalisation. Depending on the arch width and whether crossbites are present or not, the amount of expansion possible will determine the amount of proclination and/or IPR needed to resolve the remaining balance. Extractions can also be used to change anterior-posterior (A-P) relationships, minimise advancing incisors, or changing facial strain. In general, a combination of approaches are used to resolve crowding, each amount depending on the facial profile of the patient, dental positions of the teeth, arch forms, size of teeth, and buccal class relationship of the case.

Mild

Expansion / Proclination / IPR Novice (0-15 cases)

Expansion and proclination can be utilised to resolve mild crowding, or proclination and IPR with Proligner. IPR may also be used if space is limited. The amount of expansion and proclination will vary case by case depending on the patient’s arch form (narrow vs. omega vs. square), periodontal condition, and enamel thickness present.

Moderate

Expansion / Proclination / IPR Novice (0-15 cases)

The amount and location of expansion, proclination, and/or IPR is determined on a case-by-case basis. Consider the periodontal condition of the patient and initial dental position and arch forms. If unsure, a pre-orthodontic evaluation by a periodontist may be beneficial. If there is adequate periodontal support, consider expansion and/or proclination in relation to the arch form and treatment goals. If there is minimal periodontal support, consider less expansion and proclination and more IPR or extractions. When considering IPR, evaluate any tooth size discrepancy and/or how IPR may affect the overjet as well as resolving the crowding.

Lower incisor extraction Experienced (16-50 cases)

When considering extracting a lower incisor, keep in mind any tooth size discrepancy, as well as the patient’s overbite and overjet relationship. Patients who are generally suitable for single lower incisor extractions are Class I or mild Class II, have moderately crowded lower incisors, mild or no crowding in the upper arch, acceptable soft-tissue profile and minimal to moderate overbite and overjet. A tooth size discrepancy such as missing lateral incisors or peg laterals, can resolve the inevitable tooth-size discrepancy without any IPR. Regardless of the criteria, a full diagnostic setup should be made with these cases to be sure the occlusal results will be acceptable before extracting any teeth. It is important to note the amount of interproximal space that is required to close once the tooth is extracted, and note at the crown and root position of the teeth adjacent to the tooth deciding to extract. The greater the space to close and/or the farther positioned the roots are away from the extraction site, the greater the potential for tipping into the extraction site. This may create black triangles with insufficient interproximal tissue. Therefore, closing of the extraction site needs to be monitored for root parallelism. Consider specifying rectangular attachments to help control tipping. Sectional appliance or auxiliaries may be needed at the end of treatment if tipping is noticed. This is important to disclose to the patient before treatment begins.

Distalisation Experienced (16-50 cases)

Upper distalisation can be used to reduce crowding and/or change the AP relationship of the buccal segments. Note that when distalisation is used to reduce crowding this will affect the relationship of the buccal segments and may or may not reduce the overjet. Lower distalisation is not a common treatment option. Adding distalisation to treatment can significantly increase Proligner treatment time.

Severe

Expansion/Proclination/IPR Novice (0-15 cases)

The amount and location of expansion, proclination, and/or IPR is determined on a case-by-case basis. Consider the periodontal condition of the patient and initial dental position and arch forms. If unsure, a pre-orthodontic evaluation by a periodontist may be beneficial. If there is adequate periodontal support, consider expansion and/or proclination in relation to the arch form and treatment goals. If there is minimal periodontal support, consider less expansion and proclination and more IPR or extractions. When considering IPR, evaluate any tooth size discrepancy and/or how IPR may affect the overjet as well as resolving the crowding.

Lower incisor extraction Experienced (16-50 cases)

When considering extracting a lower incisor, keep in mind any tooth size discrepancy, as well as the patient’s overbite and overjet relationship. Patients who are generally suitable for single lower incisor extractions are Class I or mild Class II, have moderately crowded lower incisors, mild or no crowding in the upper arch, acceptable soft-tissue profile and minimal to moderate overbite and overjet. A tooth size discrepancy such as missing lateral incisors or peg laterals, can resolve the inevitable tooth-size discrepancy without any IPR. Regardless of the criteria, a full diagnostic setup should be made with these cases to be sure the occlusal results will be acceptable before extracting any teeth. It is important to note the amount of interproximal space that is required to close once the tooth is extracted, and note at the crown and root position of the teeth adjacent to the tooth deciding to extract. The greater the space to close and/or the farther positioned the roots are away from the extraction site, the greater the potential for tipping into the extraction site. This may create black triangles with insufficient interproximal tissue. Therefore, closing of the extraction site needs to be monitored for root parallelism. Consider specifying rectangular attachments to help control tipping. Sectional appliance or auxiliaries may be needed at the end of treatment if tipping is noticed. This is important to disclose to the patient before treatment begins.

Distalisation Experienced (16-50 cases)

Upper distalisation can be used to reduce crowding and/or change the AP relationship of the buccal segments. Note that when distalisation is used to reduce crowding this will affect the relationship of the buccal segments and may or may not reduce the overjet. Lower distalisation is not a common treatment option. Adding distalisation to treatment can significantly increase Proligner treatment time.

Bicuspid extraction with a combination treatment Advanced (>50 cases)

When considering bicuspid extractions, auxiliaries or fixed appliances may be needed at the end of treatment to achieve root parallelism and close the remaining extraction site. If deciding to begin an extraction case using Proligner, keep in mind the initial root position of the canines and bicuspids. The greater the space to close and/or the farther positioned the roots are away from the extraction site, the greater the potential for tipping into the extraction site. Therefore, closing of the extraction site needs to be monitored for root parallelism. Consider specifying rectangular attachments to help control tipping. Sectional appliance or auxiliaries may be needed at the end of treatment if tipping is noticed. Class II or Class III extraction cases may require elastics to optimise anchorage control.