(2) root of max i i lary central incisors 1) single, strong and straight, crown-to-root ratio is 2) The cervical cross sect ion is round tri ang le 3)root apex is straight or cur ved distally
（2） root of maxillary central incisors 1）single，strong and straight， crown-to-root ratio is 1：1.1-1.2 2）The cervical cross section is round triangle. 3）root apex is straight or curved distally
>Incisors 2. maxi l lary lateral incisors 22 compared to the max i l lary centra nc i sors: -resemble in form but sma ler -appear nar row and l ong -more prominent labia aspect and deeper ungual fossa -more blunt distal incisal angle
2. maxillary lateral incisors 2 2 compared to the maxillary central incisors: -resemble in form but smaller; -appear narrow and long. -more prominent labial aspect and deeper lingual fossa. -more blunt distal incisal angle. ➢Incisors
(1)crown of maxi l lary lateral incisors labia -nar row and prom i nent r ounded inc i sal ang les r ounded inc i sa ridge mesial incis angle: acute distal: blunt incisal ed inclined distally
（1） crown of maxillary lateral incisors 1）labial -narrow and prominent -rounded incisal angles -rounded incisal ridge mesial incisal angle: acute distal: blunt incisal edge: inclined distally
crown of maxillary lateral inc isors 2)I inga l narrow and deep I lingual fossa obvious margina l r i dge deep deve l opment l groove within the fossa jo ins the cingu l um
2）lingual -narrow and deep lingual fossa -obvious marginal ridge -deep developmental groove within the fossa joins the cingulum crown of maxillary lateral incisors
crown of maxillary lateral incisors 3) proximal prom i nent labial edge contact area: more gingival than centra l Incisor s incisal ridge: lab ial to long axis
3）proximal -prominent labial edge -contact area:more gingival than central incisors -incisal ridge:labial to long axis crown of maxillary lateral incisors