Evidence map›Paper›PMID 28318312›Full record

ArticleThe Angle orthodontist2017

Evidence favoring a secular reduction in mandibular leeway space.

Tyler R Allen, Terry M Trojan, Edward F Harris

Abstract readComparative Study
In one paragraph

Article in The Angle orthodontist, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Tyler R Allen
Terry M Trojan
Edward F Harris

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveResearchers have documented secular trends in tooth size among recent generations. This study was a test for a change in mandibular leeway space. MATERIALS AND

methodsDental casts from participants in the Denver Growth Study (23 boys, 22 girls; born in the 1930s) were compared with casts from a contemporary series of orthodontic patients (23 boys, 22 girls; born in the 1990s). All were phenotypically normal, healthy American whites.

resultsAnalysis of variance (accounting for sex) showed that the cumulative mandibular primary canine plus first and second primary molar size (c + m1 + m2) was slightly larger in the recent cohort (23.53 mm earlier vs 23.83 mm recent cohort; mean difference: 0.30 mm; P = .009), principally due to larger second primary molars (m2) in the recent cohort. In turn, the sum of the permanent canine and two premolars (C + P1 + P2) was significantly larger in the recent cohort (21.08 mm earlier vs 21.80 mm recent cohort; mean difference: 0.72 mm; P = .002). Larger teeth in the contemporary series produced a mean leeway space per quadrant of 2.03 mm versus 2.45 mm in the earlier cohort-a clinically and statistically significant reduction (P = .030). Some tooth types (primary second molar and permanent canine) were significantly larger in boys than in girls, but the sex difference in leeway space was not statistically significant.

conclusionResults suggest that mandibular leeway space is decreasing in 21st century American whites and may present a challenge to orthodontists in managing tooth size-arch length discrepancies.

Indexed as

OdontometryDentition, MixedFemaleHumansMaleMandibleModels, DentalToothWhite PeopleArch sizeEnvironmentLeewaySecular trendTooth size

Identifiers

PMID28318312
PMCPMC8366692

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.