Mandibular Molars PDF

Buccal aspect Permanent mandibular 1st molar 1- 5 cusps, two buccal,rwo lingual and There are two buccal evelopmental one distal grooves acting as a line of division...

Buccal aspect Permanent mandibular 1st molar 1- 5 cusps, two buccal,rwo lingual and There are two buccal evelopmental one distal grooves acting as a line of division between cusps The distobuccal 2-the buccal surface is inclined lingually, developmental groov, The mesio_buccal developmental groove, separation between the the the presence of 2 buccal separating between the mesiobuccal cusp and the distobuccal cusp developmental grooves distobuccal csp and the distal cusp The mesial contact The distal contct area area at the junction 3- the crown is wide mesiodistally than is a little lower thn between te middle buccolingually the mesial one and occlusal third The sevical line is curving apically 4-rectangular occlusal surface The buccal cusps are flat occlusally while The bifurcation the distal cusp is area is about 5- two well developed roots, one mesial rounded 3mm below the an one disral sevical line 6- the 1st molar is moer like a pentagon The mesiobuccal cusp is The distobuccal and wier than the istobuccal mesiobuccal and distal one and together make 7- the mesial cusps are larger than the cusps are clearly sen, 80% of the mesiodistal distal ones the distolingual and width of the crown while the distal cusp makes the mesiolingual TIPS 20% are a little seen  Lingual aspecti Mesial aspect There are 3 csps can be seen, the mesiolingual, distolingual and the The crown is rhomboidal lingual portion of the distal cusp with a lingual inclination of the buccal outline The lingual The buccal outline The servical The mesial cusp is developmental line is irregular is convex from the the widest mesiodistally and groove extend servical line to the and higher has the highest downward junction between lingually than cusp tip unlike the about 1/3 of the the servical and buccally distal cup which crown length, middle thirds has a lower cusp and it acts as a forming a ‘ buccal The lingual tip line of divistion servical ridge’ then outline is less between the the buccal outline convex , with the two lingual streightens up to cerst of curvature the buccal cusp tip at the center of The two cusps the middle third lingual cusps are pointed The mesial marginal making an ridge is 1mm below abtuse angle a The greater hight of the lngual cusp the cusp tip hides the buccal cusp their cusps tip The buccal cusp is flat Portion of the proximal surface are visible from the lingual view while the lingual one is sharp with the greater The lingual sevical line is nearly straight  Distal aspect The crown is shorter distally so most of the occlusal is The occlusal outline is rectangular visible and its larger mesiodistally than buccolingually about 1mm The istal marginal The distal cusp ridge is shorter is buccal to the and curved buccolingual The mesiodistal servically to form center , and measuerements an obtuse angle buccal the the is greater buccaly long axis of the tooth The buccolingual The distal root is The sevical line measurment is greater narrower than the on the mesial side is irregular mesial Five cups The mesiobuccal is the largest then the mesiolingual then the disto lingual then the distobuccal then the distal cusp  MANDIBULAR SECOND MOLAR Buccal aspect Principal Identifvina Features The crown is shorter cervico-occlusally and.I- It is smaller than the first molar in all narrower mesio-distally than that of the first Both mesiobuccal dimensions molar and distobuccal There is only one cusps are nearly.It has four well-developed cusps ; two developmental equal in their buccal and two lingual of nearly equal groove, the buccal mesio-distal developmental.measurements size-2 groove, which.separates between the mesiobuccal and The cervical There is no distal cusp but the disto- distobuccal cusps line in many buccal cusp is larger than that of the first The roots are instances molar-3 shorter than points sharply those of the to the root It has two roots; one mesial and one first molar bifurcation distal. They are broad bucco-lingually, but.They are usually closer together they are not as broad as those of the first and are parallel to each other- molar, nor are they as widely separated They are inclined distally forming an acute angle with the occlusal plane than is found on-.the first molar  Lingual aspect Mesial & distal aspect The buccal cervical ridge is less pronounced compared to the first -The crown and the molar The roots converge The mesial root has a mesiodistal lingually but to somewhat pointed apex slight degree, dimension therefore cervically is A. Little of the greater than mesial and distal that of the first surfaces may be seen molar from this aspect From this aspect this tooth is similar The contact areas are in form to the first molar, except for more noticeable frorn this the absence of a distal cusp aspect, and they are slightly more.cervically positioned contact area is centered on the distal than those of the first surface buccolingually and is centered molar between the cervical line and the marginal ridge  Occlusal aspect The occlusal surface is rectangular in shape The small Unlike the first molar, the occlusal surface distal cusp is is not smooth but is roughened by many not present supplemental grooves radiating from the developmental grooves and there is no distobuccal groove. Many teeth show The cusp considerable ridge of the prominence distobuccal cervically on cusp lies the buccal to the mesiobuccal cusp ridge of lobe only the mesiobuccal The buccal and lingual developmental grooves.cusp meet the central developmental groove a right angles at the central pit These grooves form a cross, dividing the occlusal surface into four parts that are nearly- equal  Mandibular Third molar -:Principal Identifing Features 1- This tooth varies considerably in different individuals and present many anomalies both 2- in form and position Generally, this tooth is more similar to the second molar regarding, the number of cusps 3-and occlusal form, than it does to the first molar dimension It has tendency for a rounded occlusal outline and a smaller buccolingual.distally The size of the tooth is variable, ranging from large teeth larger than the second molar with five or more cusps to dwarfed ( small) teeth