Skip to main content

Table 1 Characteristics and outcomes of included studies

From: Consequences of early extraction of compromised first permanent molar: a systematic review

Reference Site/Country Duration Study design Sample size Age at time of extraction Age at time of evaluation Method of assessment Findings P-value or OR and CI
Extraction group Non-extraction group Extraction group Non-extraction group
Effects on post extraction space
 Telli and Aytan, 1989 [7] Turkey 1988–1989 Case-control Split-mouth 40 (T) 28 (T) 9.5 years 10.5 Years Comparison of panoramic X-rays at extraction and a year later
Comparison of cephalometric radiograph angles and distances at extraction and a year later
(Angles: between long access of the SPM or second premolar and Frankfort horizontal plane in the maxilla and the occlusal plane in the mandible) (distances: between the distal surface of the upper SPM or second premolar and pterygomaxillary fissure in the maxilla and the distance between the lower SPM or second premolar and the ramus of the mandible)
Mean change in maxillary SPM angle and distance, 15.65° and 0.18 mm, respectivelyMean change in maxillary second premolar angle and distance, − 5.68° and − 2.58 mm, respectively
Mean change in mandibular SPM angle and distance, 4.62° and 3.83 mm, respectively
Mean change in mandibular second premolar angle and distance, − 4.63° and − 1.82 mm, respectively
Mean change in maxillary SPM angle and distance, − 2.40o and 0.10 mm, respectivelyMean change in maxillary second premolar angle and distance, 2.33° and 0.53 mm, respectively
Mean change in mandibular SPM angle and distance, 0.96° and 1.15 mm, respectively
Mean change in mandibular second premolar angle and distance, 5.08° and 0.54 mm, respectively
P < 0.05* for change in extraction group; P > 0.05 for change in non-extraction group
P < 0.05* for change in extraction group, P > 0.05 for change in non-extraction group
P < 0.05* for change in extraction group, P > 0.05 for change in non-extraction group
P < 0.05* for change in extraction group, P > 0.05 for change in non-extraction group
 Jälevik and Möller, 2007 [14] Specialist Clinic of Pedodontics, Sahlgrenska University Hospital, Mölndal, Department of Pedontontics, Faculty of Odontology, Göteborg University, Sweden NA Cross-sectional 27 subjects (16 girls and 11 boys) 66 (T) NA Median age 8.2 (range 5.6–12.7) years Median age 13.9 (range 12.1–19) years Eruption of permanent dentition, and space closure were documented by:
Panoramic X-ray
Dental casts
Bitewings
23/27 (85.2%) subjects had spontaneous closure 52/66 (78.8%) (T)
31/38 (81.6%) Spontaneous space closure, maxilla
21/28 (75%) Spontaneous space closure, mandible
NA Difference between mandible and maxilla P = 0.518
χ2 = 0.42
OR: 1.48
CI: (0.45, 4.83)
 Rãducanu et al., 2009 [16] Paediatric Dentistry Department, Dental Medicine Faculty of the UMF Carol Davila, Bucharest, Romania 2001–2007 Cross-sectional,hospital-based 17 subjects
22 (T)
Six maxillary and 16 mandibular
NA 9–15 years NA Intraoral examination using dental mirror and graduated probe to evaluate post-extraction space 10/22 (45.5%) with spontaneous space closure
2/6 (33.3%) with maxillary spontaneous space closure
8/16 (50%) with mandibular spontaneous space closure
NA Difference between mandible and maxilla P = 0.024*
χ2 = 5.1
OR = 0.50 CI (0.07, 3.55)
 Teo et al., 2013 [18] Paediatric DentistryDepartment in a London-based dental hospital, UK 2008–2013 Cross-sectional
Hospital based
63 subjects
236 (T)
127 SPM at Demirjian stage E *** (63 maxillary, 64 mandibular)
NA 7–13 (mean 8.9) years Mean age 13.7 years Panoramic X-ray to assess Demirjian’s developmental stages of SPM and to assess space closure between the contact point of the second premolar and the SPM using a ruler 101/127 (79.5%) spontaneous space closure
59/63 (94%) had spontaneous space closure in maxilla
42/64 (66%) had spontaneous space closure in mandible When SPM at stage E***)
NA Difference between mandible and maxilla
P = 0.0001*
χ2 = 15.32
OR = 7.73
CI (2.48, 24.07)
 Rahhal, 2014 [21] Arab-American University Clinic, Jenin, Palestine NA Prospective observational study 52 (T)
(maxillary FPM)
NA 10.5 years NA Panoramic X-ray to assess spontaneous space closure 44/52 (84.6%) maxillary spontaneous space closure NA NA
 Teo et al., 2015 [17] Dental Hospital, London, UK 2010 Cross-sectional,
hospital-based
66 subjects
94 (T) (mandibular FPM) (71 SPM at stage E** and 23 at stage F**)
NA Mean age 9.2 years 11–17 (mean 13.8) years At extraction time: Panoramic X-ray to assess Demirjian’s developmental stages of SPM
At recall: clinical examination with periodontal probe placed occlusally between each tooth distal to the canine to assess space closure
54/94 (57.4%) mandibular spontaneous space closure$
Stage E**: 41/71 (58%) mandibular spontaneous space closure$
Stage F**: 13/23 (56.5%) mandibular spontaneous space closure$
NA NA
Effect on third molar development and eruption
 Ay et al., 2006 [13] Department of Oral and Maxillofacial Surgery, Cumhuriyet University, Sivas, Turkey 1997–2004 Cross-sectional,
hospital-based
107 subjects
(unilateral extraction of mandibular FPM) 107 (T)
107 subjects 107 (T) < 16 years 18–40 (mean 25.69) years (Comparison of extraction and non-extraction sides in the same patient)
Panoramic X-ray to assess state of impaction and impaction depth of third molars using Pell and Gregory classification and to assess third molar angulation
77/107 (72%) third molars in Class I ramus relationship#
82/107 (76.6%) Class A impaction depths^78/107 (81.3%) in vertical positions
20/107 (18.7%) third molars in Class I ramus relationship#
50/107 (46.7%) Class A impaction depths^37/107 (34.6%) in vertical positions
Difference between extraction and non-extraction group
P < .001*
P < .001*
P < .001*
 Yavuz et al., 2006 [19] Department of Orthodontics, Dental Faculty, Atatürk University, Erzurum, Turkey NA Cross-sectional (comparison of extraction and non-extraction sides in the same patient), hospital-based 165 (T) 165 subjects 165 (T)165 subjects < 12 years 13–18 (mean 15.35) years Panoramic X-ray to assess development and eruption of third molars by measuring the vertical distances between the mesiobuccal cusp tips of the third molar and occlusal plane
Dental casts to assess eruption of third molar when part of the crown is piercing the gingival tissues
28/165 (17%) third molar erupted 11/165 (6.6%) third molar erupted P < 0.05*OR: 2.86*,***CI: 1.37, 5.96
Caries and/or filling of adjacent teeth
 Oliver et al., 1988 [15] Schools of South Glamorgan, UK 1981–1984 Cross-sectional, disproportionate stratified sampling, schools-based Occlusal384 (S)
Proximal
415 (S)
Occlusal4910 (S)
Proximal
5038 (S)
11–12 years (in 1980) 15–16 years (in 1984) Intraoral examination to record caries using a two numeric code system: a tooth description code, and a surface description code
Bitewings to supplement the clinical diagnosis of proximal caries
Occlusal
131/384 (34.1%) carious Proximal
33/415 (7.9%) carious
Occlusal
1153/4910 (23.5%) carious
Proximal
771/5038 (15.3%) carious
P < 0.001*
OR: 1.64*,***
CI: 1.35, 2.1*,***
OR: 0.48
CI: 0.33, 0.69
Effects on incisors
 Normando and Cavacami, 2010 [20] Private clinics NA Case-control (matched for gender and age) 34 (P) (bilateral extraction of mandibular FPM) 34 (P) ≥11 years* Non-extraction: 16–26.2 years
Extraction 16–36 years
Analysis of lateral cephalometric X-rays from routine orthodontic
records
1.NB (mean 23.2o) lingual tipping 1.NB (mean 28.4o) lingual tipping P = 0.004*
Effects on skeletal development
 Normando and Cavacami, 2010 [20] Private sector NA Case-control (matched for gender and age) 34 subjects (bilateral extraction of mandibular FPM) 34 subjects ≥11 years* Non extraction: 16–26.2 years
Extraction 16–36 years
Analysis of lateral cephalometric X-rays from routine orthodontic
records
Mean GnSN 65.2o
Counter-clockwise rotation of occlusal plane (mean 5.6o)
Lower anterior face height (mean 68.6 mm)
Mean GnSN 67.2o
Counter-clockwise rotation of the occlusal plane (mean 12.6o)
Lower anterior face height (mean 70.8 mm)
P = 0.05*
P = 0.0001*
P = 0.048*
  1. Notes: (−), decrease in value; *statistically significant (P ≤ 0.05); **according to Demirjian: stage E of dental development indicates early bifurcation development, stage F indicates late bifurcation development; ***this value was calculated by the authors according to the numbers mentioned in the study; #according to Pell and Gregory classification of state of impaction in relation to the ramus, class I described as the crown is near the anterior border of the ramus; ^according to the Pell and Gregory classification of depth of impaction, class A described as the occlusal surface of the impacted tooth being level or nearly level with the second molar; $described by the author as having contact-point displacements less than 1 mm
  2. Abbreviations: S surfaces of teeth, T teeth, FPM first permanent molar, SPM second permanent molar, OR odds ratio, CI confidence interval, 1.NB. lower incisor to nasion-B-point angle, GnSN gnathion to sella-nasion angle, NA value not applicable
\