Mandibular First Permanent Premolar PDF

The mandibular first permanent premolar is the fourth root from the Distal aspect: midline. The tooth number in the The outline features are the same as the middle side. However, some FDI system is 34 and 44,in...

The mandibular first permanent premolar is the fourth root from the Distal aspect: midline. The tooth number in the The outline features are the same as the middle side. However, some FDI system is 34 and 44,in differences the universal system 21 and 28 and are seen. The distal marginal ridge is at a higher level than the mesial in the Zsygmondy Palmar system it is 4 with appropriate marginal ridge. quadrilateral brackets. Moreover, it is not slanted but more horizontal. As a result, less occlusal The tooth develops in 4 developmental lobes, with the buccal lobe surface area is seen forming the buccal cusp, the mesial lobe forming the mesial marginal distally. In contrast to the medial side, there is no developmental groove ridge, the distal lobe forming the distal marginal ridge, and the lingual on the distal side. lobe forming the lingual cusp. The lingual lobe is very poorly developed, making the lingual tuberosity very small. As a result, the Occlusal aspect: lingual cusp is unable to connect to the opposing arch and renders it On the occlusal side, the crown's external shape is diamond-shaped due to non-functional. the sharp lingual convergence. Both cusps can be seen, a large buccal cusp, First evidence of calcification: 1 3/4 yrs - 2 yrs approximately in the Enamel completed: 5-6 yrs middle, and a small lingual cusp near the lingual outline. Coming to the Eruption: 10 -12 yrs hills. Both cusps have Root ompleted: 12 -13 yrs two cusp ridges, one medial cusp ridge and one distal cusp cusp. 2 triangular ridges, the longer BUCCAL aspect: buccal triangular ridge and the smaller triangular lingual ridge. Each runs The detailed shape of the crown from the buccal side is trapezoidal, from the cusp toward with its longer side towards the cusp and its shorter side towards the the center. 2 marginal ridges, a medial marginal ridge on the intermediate root. Only the buccal cusp is visible while the smaller lingual cusp is striatum and a distal hidden behind it. The tip of the buccal cusp is slightly mesial to the marginal ridge on the distal striatum. The occlusal surface contains two axis of the middle line of the tooth. Both cusp slopes are seen, with the fossa, called the distal distal cusp slope being longer than the middle cuspal slope. Coming to fossa and the mesial fossa. It is not called a triangular hole, as is the case the contact areas. The mesial contact zone, through which the tooth in other teeth, connects to the canine, and the distal contact zone, through which the because its shapes are irregular. The middle fossa is more linear in shape, tooth connects to the second premolar in the middle third. The crown while the distal outline, mesial outline, and distal outline are all slightly concave. The fossa is more circular. 3 grooves appear on the occlusal side. The mesial cervical line is convex with its convexity towards the root. The crown developmental surface is smooth with a prominent buccal ridge extending from the tip groove in the medial fossa, which extends and joins the mesial lingual of the cusp to the cervical line. The lower mandibular premolar has a groove on the lingual single root that is smooth and conical. surface. and the distal developmental groove in the distal fossa. A few accessory grooves can Ligual aspect: also be seen. Some clinical considerations. Since the tooth has a rhombic All the features of the crown's detailed shape from the buccal side can shape, any be seen from the lingual side as well. In addition, both cusps, the restorative procedure performed on the crown must be done carefully, buccal cusp and the lingual cusp are visible. From the lingual side, the taking into account the tip of the lingual cusp is in line with the buccal cusp. The lingual cusp lingual inclination of the crown. Although the normal shape of the is much narrower than the buccal cusp causing marked lingual permanent lower premolar convergence, making the mesial and distal surfaces visible. has one root with one root canal, numerous variations are seen in the pulp Furthermore, the lingual cusp is much smaller than the buccal cusp, canals, and for this making most occlusal landmarks visible. Protrusions such as the reason, for the endodontist, the treatment of the tooth's root canal mesial marginal ridge, the distal marginal ridge, and the tri-buccal becomes difficult, and is ridge appear. The fossa, medial fossa, and distal fossa on either side of sometimes called a “puzzle.” Teeth. the partially triangular ridge can also be seen. On the lingual surface, a groove is seen extending vertically between the mesial marginal ridge and the lingual process, called the mesial lingual developmental groove. Mesial aspect: The outer shape of the crown is rhombic, and is the same in all posterior mandibular teeth. Both humps are viewed from this side. The well-developed buccal cusp and the small lingual cusp. The height of the lingual cusp is about 2/3 the height of the buccal cusp. The tip of the buccal cusp almost reaches the midline of the tooth, while the tip of the lingual cusp is in line with the lingual border of the root. Both, the buccal outline and the lingual outline are convex with the buccal outline being more convex. The buccal triangular ridge, which extends from the apex of the buccal cusp to the center, and the lingual triangular ridge, which extends from the apex of the lingual cusp to the centre, meet at a point above the mesiolingual groove. The middle marginal ridge is seen, which is not horizontal but oblique and roughly parallel to the buccal triangular ridge, and ends at the middle lingual developmental groove which is seen extending vertically downward