▁the ▁di ast ema , ▁but ▁only ▁ 7 . 0   mm ▁( 0 . 2 8 ▁in ) ▁below ▁the ▁third ▁che ek to oth . ▁The ▁origin ▁of ▁the ▁cor ono id ▁process , ▁a ▁projection ▁at ▁the ▁back ▁of ▁the ▁dent ary , ▁lies ▁far ▁to ▁the ▁front . ▁ ▁The ▁large ▁in cis or ▁is ▁incl ined ▁forward , ▁and ▁its ▁root — the ▁only ▁part ▁of ▁the ▁to oth ▁that ▁is ▁preserved — forms ▁an ▁angle ▁of ▁about ▁ 5 5 ° ▁with ▁the ▁horizontal . ▁At ▁the ▁tip ▁of ▁the ▁al ve ol us , ▁where ▁the ▁to oth ▁projects ▁out ▁of ▁the ▁b one , ▁it ▁is ▁ 3 . 0   mm ▁( 0 . 1 2 ▁in ) ▁high ▁and ▁ 2 . 1   mm ▁broad . ▁The ▁root ▁extends ▁through ▁the ▁dent ary ▁to ▁a ▁position ▁below ▁the ▁third ▁che ek to oth . ▁Only ▁the ▁roots ▁of ▁the ▁first ▁and ▁second ▁che ek te eth ▁are ▁preserved . ▁Both ▁are ▁about ▁ 1 . 5   mm ▁in ▁diameter , ▁but ▁the ▁first ▁to oth ▁may ▁have ▁been ▁slightly ▁smaller ▁than ▁the ▁second . ▁The ▁third ▁to oth , ▁the ▁largest ▁of ▁the ▁che ek te eth , ▁has ▁the ▁root ▁slightly ▁cur ved ▁back ward . ▁This ▁root ▁is ▁deeply ▁anch ored ▁in ▁the ▁dent ary , ▁extending ▁down ▁through ▁about ▁three - four th s ▁of ▁the ▁b one . ▁The ▁crown ▁is ▁preserved ▁in ▁the ▁form ▁of