Table 3.
Literature conclusions and quality of evidence were determined based on GRADE. GRADE: Grading of Recommendations Assessment, Development, and Evaluation; CQ: clinical question; OPT: orthopantomography; PA: periapical radiography; CBCT: cone beam computed tomography; EARR: external apical root resorption; NiTi: nickel titanium; CuNiTi: copper nickel titanium; SS: stainless steel
| Clinical question item | Evidence | Quality of evidence | Reference |
|---|---|---|---|
| CQ #1—Diagnosis | |||
| OPT versus PA | Given the lack of data, it is not possible to draw a conclusion about the potential added diagnostic value of a periapical radiograph compared to an orthopantomogram. The estimated degree of EARR appeared to be larger when measured on an orthopantomogram than when measured on a periapical radiograph. | Low | (18) |
| CBCT versus OPT | See Guideline for Radiology in orthodontics | (17) | |
| CBCT versus PA | See Guideline for Radiology in orthodontics | (17) | |
| CQ #2—Risk factors | |||
| Patient-related factors | |||
| Gender | There are indications that gender is not an independent predictor of EARR severity. | Moderate | (8, 20–22) |
| Age | There are indications that age is not an independent predictor of EARR severity. | Moderate | (8, 20–22) |
| Trauma | There are indications that trauma preceding an orthodontic treatment is not an independent predictor of EARR severity, although the included studies reported contradictory results. | Low | (8, 20, 21) |
| Endodontically treated teeth | It is not clear whether endodontically treated teeth comprise a risk factor for EARR severity. There are some indications that endodontically treated teeth might be a preventive factor. | Very low | (21) |
| Root and tooth morphology | There are indications that root width is not an independent predictor of EARR severity, but the included studies reported contradictory results. There are indications that abnormal root shape is not an independent predictor of EARR severity, but the included studies reported contradictory results. |
Low | (8, 21) |
| Pre-treatment tooth/root length | It is not clear whether pre-treatment tooth or root length is associated with EARR severity. The studies reported contradictory results. | Very low | (8, 21, 22) |
| Agenesis | There are indications that agenesis is not an independent predictor of EARR severity. | Low | (8) |
| Earlier orthodontic treatment | There are indications that earlier orthodontic treatment is not an independent predictor of EARR severity. There are indications that an earlier orthodontic treatment is a preventive factor for the degree of EARR during the next orthodontic treatment. | Low | (8, 21) |
| Lip/tongue dysfunction/habits | It is not clear whether patients with lip and/or tongue dysfunctions are at increased risk of developing more severe EARRs. The studies reported contradictory results. | Very low | (20, 21) |
| Impacted canines | It is not clear whether the correction of impacted canines is associated with EARR severity. The studies reported contradictory results. | Very low | (20, 21) |
| Overjet | It is not clear whether an increased overjet has an influence on EARR severity. The included studies reported no association between overjet and EARR severity. | Very low | (20, 21) |
| Overbite | There are indications that an increased overbite has no influence on EARR severity. The included studies reported no association between overbite and EARR severity. | Low | (20, 21) |
| Angle classification | It is not clear whether the Angle classification is associated with EARR severity. The included study reported no association between the Angle classification and EARR severity; however, we have low confidence in this finding. | Very low | (21) |
| Treatment-related factors | |||
| Duration of active treatment | There are indications that the duration of active treatment is not an independent predictor of EARR severity. | Low | (8, 20–22) |
| Duration of rectangular wire use | It is not clear whether the degree of EARR is related to the amount of treatment time with rectangular wires. These studies reported contradictory results. | Low | (8, 20, 21) |
| Horizontal apical displacement | It is not clear whether horizontal apical root displacements are associated with EARR severity. The included study reported a positive correlation; however, we have low confidence in this finding. | Very low | (21) |
| Vertical apical displacement | It is not clear whether vertical apical root displacements are associated with EARR severity. The included study reported no association between vertical apical displacement and EARR severity. | Very low | (21) |
| Overjet reduction | It is not clear whether reducing a large overjet during the fixed appliance phase has an influence on EARR severity. The included study reported no association between overjet reduction and EARR severity. | Very low | (20) |
| Extraction versus non-extraction | There are indications that the extraction of premolars is an independent predictor of EARR severity. | Low | (8) |
| Elastics, Class II | It is not clear whether wearing Class II elastics have an influence EARR severity. The included studies reported contradictory results. | Very low | (20, 21) |
| Elastics, anterior vertical | There are weak indications that wearing anterior vertical elastics is no independent predictor of EARR severity, except for the maxillary cuspids. | Low | (8, 21) |
| Wire sequence or type | The wire sequence or wire type do not have an influence on EARR severity (0.016 NiTi, 0.018 × 0.025 NiTi, 0.019 × 0.025 SS; or 0.016 NiTi, 0.016 SS, 0.020 SS, 0.019 × 0.025 SS; or 0.016 × 0.022 CuNiTi, 0.019 × 0.025 CuNiTi, 0.019 × 0.025 SS). | Low | (19) |
| Distance to palatal cortical bone | It is not clear whether the distance of the apex to the palatal cortical bone is associated with EARR severity. The study reported no association between the distance to the palatal cortical bone and EARR severity. | Very low | (21) |
| CQ #3—Treatment strategy | |||
| Treatment strategy/management | There is insufficient evidence on orthodontic management when EARR occurs during orthodontic treatment. | — | — |
| CQ #4—After-treatment care requirements | |||
| Progress of EARR after orthodontic treatment | There are indications that the EARR process will stop after active orthodontic treatment is stopped. | n/a | (23) |
| Long-term effects (mobility, vitality) | There is insufficient evidence on the long-term effects of EARR. | — | — |
| Prognosis of teeth with (severe) EARR | There is insufficient evidence on the prognosis of EARR. | — | — |
| Pain/discomfort and costs after orthodontic treatment for the patient | There is insufficient evidence on pain/discomfort and on the costs to the patient after orthodontic treatment. | — | — |
The last column lists the studies that investigated the clinical question item and contributed to the final conclusion. The wording of the evidence reflects the quality level of the evidence.