Table 3. Case-control studies included in this systematic review presented according to their quality score.
| Study | Country (Publication language) | Local setting | Initial sample (final sample) | Gender of the sample | Patients' mean age at dental examination (range in years) | Tooth erosion index (calibration/Kappa) | Type of eating disorder (diagnostic criteria) | Statistics (adjusted for confounders) | Outcomes (OR; 95% CI) or (p-value) | Quality score |
| Dynesen et al., 2008 [21] | Denmark (English) | Cases: Psychiatric clinic and University Controls: University | 40: 20 cases and 20 controls | Female | Cases: 23.8±4 (18–33) Controls: 23.1±2 (20–30) | Larsen et al. modified (K = 0.64) | BN‡‡ (DSM IV‡‡‡‡) | Multiple regression (age, salivary flow rate and acidic drinks) | TE†† score was significantly higher in BN‡‡ group compared with the control- group (p = 0.019) | 9(10) |
| Ohrn et al., 1999 [35] | Sweden (English) | Cases: Psychiatric clinic Controls: College of nursing | 152: 100 cases and 52 controls (133: 81 cases and 52 controls) | Male and female | Cases: 25 (17–47) Controls: 24 (19–41) | Eccles modified by Lussi et al. (NR†) | AN‡, BN‡‡, EDNOS (DSM III-R‡‡‡) | t-test, Mann-Whitney test and logistic regression (age, number of years suffering from eating disorders) | The eating disorders were associated with TE†† severity (<0.001) The period suffering from binge-eating was associated with TE†† (p<0.01) | 9(10) |
| Järvinen et al., 1991 [28] | Finland (English) | Cases and controls: Metropolitan Helsinki area | 206: 106 cases (with TE) and 100 controls (without TE) | Male and female | Cases: 33.1 (13–73) Controls: 36.3 (17–83) | Eccles and Jenkins (1974) (NR†) | --- | Logistic regression (age, gender) | Prevalence of ED: 7% of the patients from the case-group were suffering from AN‡. In the logistic model the practice of vomiting was associated with TE†† (OR = 31; 95%CI = 3–300) | 9(10) |
| Johansson et al., 2012 [4] | Sweden (English) | Cases: Eating Disorder Clinic Controls: Public Dental Health Clinic | 108: 54 cases and 54 controls | Male and female | Cases:21.5(10–50) Controls: NR† | Eccles (1979) modified (training and calibration was performed) | AN‡, BN‡‡, EDNOS (NR†) | Bivariate tests, conditional logistic regression (age) | Eating disorders associated with TE†† (OR:8.5; 95%CI: 2.1 – 34.4) Vomiting/binge eating behaviors associated with TE†† (OR = 5.5; 95%CI = 1.3–22.9) | 8(10) |
| Emodi-Perlman et al., 2008 [22] | Israel (English) | Cases: Weight and Eating Disorders Center Controls: School of Dental Medicine | 136: 86 cases and 50 controls (127: 79 cases and 48 controls) | Female | Cases: 23.46 ± 3.54 (18–35) Controls: 24.58 ±3.01 (18–36) | Johansson et al. (1993) (NR†) | AN‡, BN‡‡, EDNOS (NR†) | Chi-square, ANOVA and Tukey's test (no) | Vomiting and non-vomiting groups had higher degree of TE†† than controls (p<0.001) There was no difference between TE†† degree among vomiting and non-vomiting groups (p>0.05) | 8(10) |
| Rytömaa et al., 1998 [20] | Finland (English) | Cases: University Hospital Controls: Universities Dental Services and Colleges | 140: 35 cases and 105 controls | Female | Cases: 25.3 ± 6.8 Controls: 25.7 ±7.0 | Eccles and Jenkins & Järvinen et al. (K = 0.74–0.94) | BN‡‡ (DSM III-R‡‡‡) | Chi-square and t-test (no) | BN‡‡ were associated with TE†† (p<0.01) Prevalence of TE††: 11% among controls; 63% among BN group | 8(10) |
| Robb et al., 1995 [19] | England (English) | Cases: Psychiatric institutions Controls: dental attenders | 244: 122 cases and 122 controls | NR† | NR† | TWI developed by Smith and Knight (NR†) | AN‡ (purging and restrictive type) and BN‡‡ (NR†) | Student's t-test (no) | AN‡ (both types) and BN‡‡ were associated with TE†† (p<0.005) | 7(10) |
| Milosevic & Slade, 1989 [32] | England (English) | Cases and controls: Medical School and School of Dentistry | 108: 58 cases and 50 controls | Male and female | Cases:(16–43) Controls: (15–39) | TWI developed by Smith and Knight (NR†) | AN‡, BN‡‡ without SIV†††, BN‡‡ with SIV††† (DSM III-R‡‡‡) | Chi-square, ANOVA (no) | Prevalence of TE††: 6% among controls 33% among AN‡ patients 28% among BN‡‡ without SIV††† patients42% among BN‡‡with SIV††† The EDs were associated with TE†† (p<0.001) | 7(10) |
| Jones & Cleaton-Jones, 1989 [31] | South Africa (English) | Cases and controls: Private dental office | 33: 11 cases and 22 controls | Female | Cases:29.8±8.4 Controls: 28.9 ± 9 | Own criteria (NR†) | BN‡‡(NR†) | Chi-square (no) | Prevalence of TE††: 7% among controls 69% among BN‡‡ patients BN‡‡ was associated with TE††(p<0.001) | 7(10) |
| Howat et al., 1990 [18] | USA (English) | Cases: University Eating Disorder Clinic Controls: University (other departments) | 20: 10 cases and 10 controls (18: 8 cases and 10 controls) | Female | Cases:24.6 Controls: 22.2 | NR† | BN‡‡ (DSM III-R‡‡‡) | T-test, Fisher's exact test, ANOVA and Pearson Correlation (no) | No difference between the presence of TE†† between the groups (p>0.05) | 6(10) |
| Sivolella et al., 2000 [33] | Italy (Italian) | Cases: Eating Disorder Hospital Controls: NR† | 26: 14 cases and 12 controls | Female | Cases: 23.28 ± 4.9 Controls: 22.58 ± 1.8 | NR† | AN‡, BN‡‡ (DSM IV‡‡‡‡) | Fisher's exact test (no) | AN‡ and BN‡‡ were associated with TE†† (p = 0.009) Prevalence of TE††: 41.6% among controls 92.8% among BN‡‡ group | 5(10) |
| Greenwood et al., 1988 [30] | Ireland (English) | Cases: University Hospital patients Controls: University Hospital staff | 48: 24 cases and 24 controls | Female | AN‡ group: (15–24) BN‡‡ group: (19–35) Controls: NR† | NR† | AN‡, BN‡‡ (NR†) | NR† | Prevalence of TE††: 9% among AN‡ patients 30% among BN‡‡ patients All patients who SIV††† had TE†† | 5(10) |
| Touyz et al., 1993 [34] | Australia (English) | NR† | 45: 30 cases and 15 controls | Female | AN‡ group: 20.1 ± 8.3 BN‡‡ group: 19.1 ± 3.8 Controls: 22.1 ±3.3 | NR† | AN‡, BN‡‡ (DSM III-R‡‡‡) | Chi-square and t-test (no) | AN‡ and BN‡‡ were associated with TE†† (p-value was not reported) | 3(10) |
AN‡ = anorexia nervosa; BN‡‡ = bulimia nervosa; DSM III- R‡‡‡ = Diagnostic and Statistical Manual of Mental Disorders, 3rd Edition, Revised; DSM IV‡‡‡‡ = Diagnostic and Statistical Manual of Mental Disorders, 4th Edition; NR† = not reported; TE†† = tooth erosion; SIV††† = self-induced vomiting.