| Assessment Items | Factor 1 | Factor 2 | Factor 3 | Factor 4 | |
| Factor 1: Patient’s oral health status (α = 0.874) | |||||
| Bleeding during toothbrushing | 0.706 | 0.309 | 0.183 | 0.184 | |
| Abscess on gingiva | 0.697 | 0.315 | 0.238 | 0.175 | |
| Awareness of halitosis | 0.670 | 0.351 | 0.183 | 0.128 | |
| Dentures (partial or full) | 0.633 | 0.134 | 0.081 | 0.283 | |
| Biting firmly on molar or dentures | 0.603 | 0.237 | 0.239 | 0.188 | |
| Checking the patient’s inside of mouth | 0.555 | 0.263 | 0.073 | 0.255 | |
| Counting the patient’s total number of teeth (dentures, bridges and implants are excluded) | 0.446 | 0.136 | 0.104 | 0.135 | |
| Factor 2: Patient’s implementation of oral health behaviors (α = 0.890) | |||||
| Toothbrushing around the border between the teeth and marginal gingiva | 0.302 | 0.853 | 0.160 | 0.230 | |
| Toothbrushing one by one very carefully | 0.284 | 0.815 | 0.173 | 0.224 | |
| Supplementary tools (e.g., interdental brush, dental floss.) | 0.346 | 0.762 | 0.152 | 0.095 | |
| Checking the one’s inside of mouth (teeth, gums, buccal mucosa, and tongues) with a mirror by oneself | 0.385 | 0.583 | 0.221 | 0.178 | |
| Experience being given dentists’ instructions for brushing | 0.366 | 0.400 | 0.368 | 0.143 | |
| Dental visiting more than once a year | 0.169 | 0.333 | 0.270 | 0.243 | |
| Factor 3: Patient’s information transmission regarding dental visits (α = 0.862) | |||||
| Showing medicine information-sharing notebook to the dentist | 0.090 | 0.100 | 0.761 | 0.089 | |
| Showing diabetes information-sharing notebook to the dentist | 0.110 | 0.107 | 0.745 | 0.069 | |
| Showing self-monitoring blood glucose notebook to the dentist | 0.079 | 0.186 | 0.728 | 0.124 | |
| Telling dental treatment to the diabetes doctor | 0.241 | 0.154 | 0.685 | 0.190 | |
| Telling dental treatment to the diabetes nurse | 0.354 | 0.142 | 0.595 | 0.240 | |
| Factor 4: Patient’s perceptions and knowledge of oral health behaviors (α = 0.793) | |||||
| Perceptions of one’s oral health status | 0.362 | 0.245 | 0.212 | 0.717 | |
| Perceptions of oral care efficacy regardless of timing of care initiation | 0.300 | 0.271 | 0.239 | 0.578 | |
| Knowledge of a relationship between periodontal disease and systemic disease including diabetes | 0.334 | 0.158 | 0.195 | 0.545 | |
| Square sum of loading after rotation | Fixed value | 3.847 | 3.321 | 3.168 | 1.769 |
| Cumulative rate (%) | 18.321 | 34.133 | 49.217 | 57.640 | |
| Correlation factor between contents: significance probability (one sided test) Spearman | Factor 1 | 1.000 | |||
| Factor 2 | 0.692 | 1.000 | |||
| Factor 3 | 0.468 | 0.541 | 1.000 | ||
| Factor 4 | 0.626 | 0.589 | 0.488 | 1.000 | |