www.eda-egypt.org • Codex : 00/21.01 • DOI : 10.21608/edj.2020.46954.1297 Print ISSN 0070-9484 • Online ISSN 2090-2360 Orthodontics, Pediatric and Preventive Dentistry EGYPTIAN DENTAL JOURNAL Vol. 67, 41: 54, January, 2021 * Researcher at Orthodontic Department, Faculty of Dentistry, Cairo University. ** Professor, Pediatric Dentistry and Public Health Department, Faculty of Dentistry, Cairo University. *** Associate Professor, Pediatric Dentistry and Dental Public Health Department, Cairo University, and Modern University of Technology and Informations. THE ERUPTION SEQUENCE OF PRIMARY AND PERMANENT TEETH IN A GROUP OF CHILDREN (A CROSS-SECTIONAL STUDY) Moataz Elkhatib * , Norhan El- Dokky ** and Rania Nasr *** ABSTRACT Aim: Determine eruption dates & sequence and to correlate between chronological and developmental age of eruption of primary and permanent teeth. Methods: Study sample consisted of 1526 apparently healthy children of both genders, 1020 children were selected from schools, and 506 children were selected from children attending Maternal and Child Welfare Centers. Results: Eruption sequence in primary teeth in both genders was: lower primary central incisor (LA), Upper primary central incisor (UA), upper primary lateral incisor (UB), lower primary lateral incisor (LB), upper primary frst molar (UD), lower primary frst molar (LD), Upper primary canine (UC), lower primary canine (LC), lower primary second molar (LE), and upper primary second molar (UE). Sequence of eruption of permanent teeth in boys was: lower permanent frst molar (L6), lower permanent central incisor (L1), lower permanent lateral incisor (L2), upper permanent central incisor (U1), upper permanent lateral incisor (U2), upper permanent frst molar (U6), lower permanent frst premolar (L4), upper permanent frst premolar (U4), upper permanent second premolar (U5), lower permanent canine (L3), lower permanent second premolar (L5), lower permanent second molar (L7), upper permanent second molar (U7) and upper permanent canine (U3). In girls: L1, L2, U1, U2, U6, L6, L3, L4, L5, U4, U5, L7, U7, and U3. In boys, deviation from the standard range exceeding 50% except for LA, UE, and LE. In girls, deviation was exceeding 50% in UC, UE, LA, LB, LC, LD, and LE. There were statistically signifcant difference between means age of eruption of permanent teeth in boys and girls for U1, U2, U5, U6, and L6. Conclusion: Sequence and dates of eruption of teeth differ among populations. Orthodontists and pediatric dentists can rely on specifc standards of Eruption dates & sequence for diagnosis, treatment planning, and preventive programs. KEYWORDS: Eruption sequence, Chronology of tooth eruption, Permanent teeth and Deciduous teeth.