Administration, Oral ; Analysis of Variance ; Anti-Bacterial Agents ; therapeutic use ; Cohort Studies ; Databases, Factual ; Disease Progression ; Emergency Service, Hospital ; statistics & numerical data ; Female ; Follow-Up Studies ; Hospitalization ; statistics & numerical data ; Hospitals, Pediatric ; Humans ; Incidence ; Infusions, Intravenous ; Logistic Models ; Male ; Multivariate Analysis ; Orbital Cellulitis ; diagnosis ; drug therapy ; epidemiology ; microbiology ; Predictive Value of Tests ; Retrospective Studies ; Risk Assessment ; Severity of Illness Index ; Singapore ; Treatment Outcome