Eligibility criteria
systemic illness, dento-maxillofacial problems
SYSTEMIC ILLNESS, ROOT RESORPTION
A total of 82 children with an age range of 4-7years who were referred to the CBCT unit of the Oral Medicine, Periodontology, Oral Diagnosis & Oral Radiology Department, Faculty of Dentistry, Tanta University, requiring CBCT imaging for the diagnosis and management of dento-maxillofacial problems, were enrolled and evaluated using the study’s inclusion & exclusion criteria. Inclusion criteria were healthy cooperative children with asymptomatic non-vital mandibular primary second molars with sufficient coronal structure, intact 2/3rd root structure, and no mobility, or external pathological root resorption. Also, the included children should have no history of analgesic use 12 h before the pulpectomy treatment. Uncooperative children or children with systemic illness were excluded from this study. Also, non-restorable primary molars or those with severe mobility, or pathological root resorption were excluded. Accordingly, fourteen patients with non-restorable primary molars, also eight uncooperative patients were excluded. The end-study sample included 60 children who needed CBCT images with no additional radiation exposure for any of the participants. Fig. 
Flowchart explaining the child patient’s randomization and the variables assessed throughout the clinical study