Gap finder
Search review questions
Each row is one question a systematic review asked: who, what, compared with what, and which outcome, with the effect it found and how certain that is. Every word you type has to appear somewhere in the question, and the closest matches are ranked first. Each row links to its question's own page, which gathers every review that asked it, however worded; see the questions asked by more than one review.
3,358 questions in 190 reviews · cluster CL0289
current versionsNo studies 599 · 17.8%Ungraded 1,759 · 52.4%Very low 612 · 18.2%Low 269 · 8%Moderate 107 · 3.2%High 12 · 0.4%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Intervention categories, outcome domains and clusters are a proposed key pending human validation. Clear all filters
| Question | Effect | Evidence | Status / GRADE |
|---|---|---|---|
ANB · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · End of treatment Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | MD 0.10 [-0.31, 0.51] | 1 study · 40 participants | Ungraded |
Burning sensation (VAS 0-100) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -7.00 [-28.8, 42.8] | 1 study · 30 participants | Very low |
Burning sensation (VAS 0-100) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · Less than 3 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -38.79 [-52.06, -25.53] | 2 studies · 85 participants | Very low |
Alignment rate · People receiving orthodontic treatment with fixed appliances (upper and/or lower full arch) Initial arch wires used in orthodontic treatment with fixed appliances (2024) · Cochrane | Alignment rate: not reported | 0 studies | No studies |
Perceived need for surgery in adulthood · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · 6-year follow-up Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | OR 3.34 [1.21, 9.24] | 1 study · 65 participants | Low |
Root resorption · People receiving orthodontic treatment with fixed appliances (upper and/or lower full arch) Initial arch wires used in orthodontic treatment with fixed appliances (2024) · Cochrane | Root resorption: not reported | 0 studies | No studies |
Discomfort · People with temporomandibular disorders (TMD) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | Listed in Summary of findings 4 as 'Not reported'; this outcome was not reported by any included study for this comparison. | 0 studies | No studies |
Pain at 7 days · Adults with symptomatic apical periodontitis (no signs of spreading infection or systemic involvement) · 7 days Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults (2024) · Cochrane | The median pain at 7 days in the control group was 0 (range 0 to 3); the median pain at 7 days in the intervention group was the same (median 0, range 0 to 1). P = 0.673 (Mann-Whitney U). | 1 study · 72 participants | Low |
Discomfort · People with temporomandibular disorders (TMD) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | Listed in Summary of findings 2 as 'Not reported'; this outcome was not reported by any included study for this comparison. | 0 studies | No studies |
Endodontic flare-up · Adults with a symptomatic necrotic tooth or localised acute apical abscess (no signs of spreading infection or… · 3 days Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults (2024) · Cochrane | RR 0.27 [0.01, 4.90] | 1 study · 19 participants | Ungraded |
Time to alignment · People receiving orthodontic treatment with fixed appliances (upper and/or lower full arch) Initial arch wires used in orthodontic treatment with fixed appliances (2024) · Cochrane | Time to alignment: not reported | 0 studies | No studies |
Difficulty in swallowing (participant-reported proxy) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | OR 0.17 [0.07, 0.44] | 1 study · 120 participants | Ungraded |
Maximal mouth opening (interincisal distance) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -8.00 [-14.47, -1.53] | 1 study · 40 participants | Low |
Maximal mouth opening (interincisal distance) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -4.88 [-12.87, 3.11] | 1 study · 12 participants | Very low |
Muscle pain at rest · People with temporomandibular disorders (TMD) · Short term (mean 2 months), Myofascial pain TMD Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | MD -11.63 [-29.37, 6.11] | 1 study · 37 participants | Very low |
Range of mandibular motion · People with temporomandibular disorders (TMD) · Short term (3 months), Disc displacement with reduction (DDwR) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | MD -0.33 [-3.31, 2.65] | 1 study · 40 participants | Ungraded |
Root resorption · People receiving orthodontic treatment with fixed appliances (upper and/or lower full arch) Initial arch wires used in orthodontic treatment with fixed appliances (2024) · Cochrane | Root resorption: not reported | 0 studies | No studies |
Muscle pain at rest · People with temporomandibular disorders (TMD) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | Listed in Summary of findings 2 as 'Not reported'; this outcome was not reported by any included study for this comparison. | 0 studies | No studies |
Maximal mouth opening (interincisal distance) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · More than 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -0.60 [-3.76, 2.56] | 1 study · 28 participants | Very low |
Burning sensation (VAS 0-100) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · Less than 3 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -9.10 [-16.23, -1.97] | 1 study · 30 participants | Very low |
Maximal mouth opening (interincisal distance) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -1.00 [-7.18, 5.18] | 1 study · 30 participants | Very low |
Swelling at 7 days · Adults with a symptomatic necrotic tooth or localised acute apical abscess (no signs of spreading infection or… · 7 days Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults (2024) · Cochrane | MD 0.02 [-0.28, 0.32] | 1 study · 41 participants | Very low |
Pulp necrosis incidence · Vital teeth · Kontakiotis et al. 2015 mandibular posterior Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations:… (2023) | Proportion 7.1 | 1 study | Ungraded |
Patient satisfaction · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | Not measured | 0 studies | No studies |
Clinical and radiographic success · Patients with carious pulp exposure in permanent teeth undergoing pulpotomy · 1 to 2 years, Success after full or partial pulpotomy, Full or partial pulpotomy Comparative efficacy of materials used in patients undergoing pulpotomy or direct pulp capping in carious… (2023) | OR 2.36 [0.47, 11.75] | 6 studies · 341 participants | Low |
Disease-free survival · Adults with oral cavity or oropharyngeal cancer · oral cavity Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Disease-free survival: not reported (Iyer 2015). | 0 studies | No studies |
Patient satisfaction: aesthetics (VAS 0-10 cm, lower arch) · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | MD 1.49 [0.76, 2.22] | 1 study · 32 participants | Very low |
Locoregional recurrence · Adults with oral cavity or oropharyngeal cancer Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Locoregional recurrence: not reported. | 0 studies | No studies |
Clinical and radiographic success (composite) · Patients with carious pulp exposure in immature permanent teeth undergoing pulpotomy · ≥6 months follow-up, Dental/endodontic clinical settings across multiple countries (university, hospital, specialist and general dental practice); permanent teeth with carious pulp exposure Comparative efficacy of materials used in patients undergoing pulpotomy or direct pulp capping in carious… (2023) | PRF vs MTA was investigated in 2 RCTs (Alawwad 2020; Keswani 2014) for the primary outcome; the two trials provided contradictory evidence and differed in risk of bias, so were not pooled. Weak evidence. | 2 studies | Ungraded |
CAD/CAM nitinol fixed (bonded) retainer vs Conventional/analogue multistrand fixed (bonded) retainer Patient satisfaction: discomfort/pain (lower arch) · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | No studies measured or reported this outcome | 0 studies | No studies |
Stability: Little's Irregularity Index (lower arch) · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | MD 0.92 [0.23, 1.61] | 1 study · 56 participants | Very low |
Stability: Little's Irregularity Index (lower arch) · People who had received fixed appliance orthodontic treatment · 2 years, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | MD -0.30 [-0.73, 0.13] | 1 study · 47 participants | Ungraded |
Total mortality · Adults with oral cavity or oropharyngeal cancer · 3 years Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | HR 0.24 [0.10, 0.59] | 1 study · 35 participants | Very low |
Pulp necrosis incidence · Vital teeth · Cheung et al. 2005 mandibular anterior Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations:… (2023) | Proportion 0 | 1 study | Ungraded |
Patient perception of pain and discomfort (VAS 0 to 100 mm) · Adolescents and adults with malocclusion undergoing fixed orthodontic appliance treatment · First visit Non‐surgical adjunctive interventions for accelerating tooth movement in patients undergoing orthodontic… (2023) · Cochrane | MD -0.80 [-2.20, 0.62] | 1 study · 39 participants | Very low |
Total mortality · Adults with oral cavity cancer Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Total mortality: 2 trials reported HR but could not be pooled (different surgical procedures); neither indicated a difference (BHNCSG 1998 HR 1.14, 0.70 to 1.86; Bier 1994 HR 0.87, 0.41 to 1.83); 252 participants (2… | 2 studies · 252 participants | Very low |
Periapical pathosis incidence · Vital teeth · Bone level < 35% Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations:… (2023) | Proportion 1.4 | 1 study | Ungraded |
Change in angulation of teeth adjacent to the space (molar and canine tipping/rotation) · Adolescents and adults with malocclusion undergoing orthodontic treatment with fixed or removable appliances Non‐surgical adjunctive interventions for accelerating tooth movement in patients undergoing orthodontic… (2023) · Cochrane | Siriphan 2019 (lateral cephalometric radiographs): rate of molar movement and tipping, and canine rotation and tipping were not significantly different between groups (P>0.05). | 1 study | Ungraded |
Pulp necrosis incidence · Vital teeth · Eugenol-based Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations:… (2023) | Proportion 3.34 [1.66, 5.58] | 7043 participants | Ungraded |
Recurrence · Adults with oral cavity or oropharyngeal cancer Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Recurrence: Garrel 2020 reported that the number of patients with recurrences in both arms was almost identical; unable to use the data (variable follow-up); 279 participants (1 RCT). | 1 study · 279 participants | Very low |
Stability: Little's Irregularity Index · People who had received fixed appliance orthodontic treatment · 12 months, upper and lower arches Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | no estimate extracted | 3 studies | Ungraded |
Patient perception of pain and discomfort (VAS 0 to 100 mm), immediately after ligation of initial archwire · Adolescents and adults with malocclusion undergoing orthodontic treatment with fixed or removable appliances · Immediately after ligation of initial archwire (also 4-8h, 1, 3, 7 days) Non‐surgical adjunctive interventions for accelerating tooth movement in patients undergoing orthodontic… (2023) · Cochrane | MD 2.56 [-2.35, 7.47] | 3 studies · 153 participants | Low |
Pulp necrosis incidence · Vital teeth · Cheung et al. 2005 mandibular posterior Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations:… (2023) | Proportion 6.1 | 1 study | Ungraded |
Disease-free survival · Adults with oral cavity or oropharyngeal cancer Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Disease-free survival: not reported. | 0 studies | No studies |
CAD/CAM nitinol fixed (bonded) retainer vs Conventional/analogue multistrand fixed (bonded) retainer Survival of retainers (failure, lower arch) · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | RR 1.29 [0.67, 2.49] | 1 study · 41 participants | Very low |
Survival of retainers (failure, lower arch) · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | RR 3.42 [1.38, 8.47] | 1 study · 77 participants | Very low |
Locoregional recurrence · Adults with oral cavity or oropharyngeal cancer · 3 years Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | HR 1.04 [0.91, 1.19] | 1 study · 279 participants | Low |
Survival of retainers (failure, lower arch) · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | RR 1.01 [0.84, 1.21] | 7 studies · 1337 participants | Low |
Recurrence · Adults with oral cavity or oropharyngeal cancer with nodal disease (stage N2 or N3) Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Recurrence: outcome not reported in a usable way (Mehanna 2017: nodal recurrence 3 vs 1; distant metastases 21 vs 23). | 1 study | Ungraded |
Survival of retainers (failure, lower arch) · People who had received fixed appliance orthodontic treatment · 12 months, lower arch Retention procedures for stabilising tooth position after treatment with orthodontic braces (2023) · Cochrane | RR 0.44 [0.20, 0.98] | 1 study · 57 participants | Very low |