1. Mandibular First Molar
Group 7

2. Primary Tooth eruption facts:
Girls generally precede boys in tooth eruption
Every 6 months of life, approximately 4 teeth will erupt.
Lower teeth usually erupt before upper teeth
Teeth in both jaws usually erupt in pairs.One on the right and one on the left
By the time a child is 2 to 3 years of age, all primary teeth should have erupted

3. Characteristics of Deciduous Mandibular First Molars
The crowns are bulging buccally and lingually at the cervical rim
Thinner enamel and dentin
Cervical area is constricted
Will emerge in about 14 to 18 months. It will shed off in about 9 to 11 yrs.

4. Characteristics of Deciduous Mandibular First Molars
Smaller in size and whiter in color than the permanent teeth.
Longer and more slender roots in relation to crown size
Has a prominent mesio-buccal cervical bulge

5. Function
The mandibular molars are the largest and strongest teeth in the lower jaw.Its main role is for mastication.

6. Function It reserve space for their permanent counterparts.
It gives the face its normal appearance.
It aids in the development of clear speech.

7. Function It helps attain good nnutrition
It helps give a healthy start to the permanent teeth

8. Problem Associated with Eruption:
Ankylosis is caused by the fusion of the cementum of the root to the bone and accompanying loss of periodontal ligament attachment. One of the most commonly affected tooth is the primary mandibular first molar.

9. Ankylosis can lead to: Loss of arch length
Extrusion of teeth of the opposite arch
Interference with the eruption of succedaneous teeth

10. Treatment
- Placement of a stainless steel crown over the ankylosed tooth. - Extraction

11. Buccal Aspect Class traits and type traits
Mesial outline of the crown is almost straight.
Distal portion of the crown is shorter than the mesial portion.

12. Buccal Aspect Class traits and type traits
Two buccal cusp is distinct.No developmental groove.
Mesial cusp is larger than the distal cusp
Roots are long and slender

13. Lingual Aspect Class traits and type traits
Distolingual cusp is rounded
Mesiolingual cusp is long and sharp at tip
Mesial marginal ridge is well developed

14. Lingual Aspect Class traits and type traits
Part of the two buccal cusps may be seen from this angle
Crown length mesially and distally is more uniform than it is from the buccal aspect
Cervical line is straighter

15. Mesial Aspect Class traits and type traits
The most noticeable detail from the mesial aspect is the EXTREME CURVATURE bucally at the cervical third.

16. Mesial Aspect Class traits and type traits
Crown outline resembles the mesial aspect of of the primary 2nd molar and the mesial aspect of the permanent mandibular molars.

18. Mesial Aspect Class traits and type traits
Both the MB cusp and ML cusp are in view from this aspect , as is the well-developed mesial marginal ridge.

19. Mesial Aspect Class traits and type traits
Since the mesiobuccal crown length is greater than the mesiolingual crown length, the cervical line slants upward buccolingually.

20. Mesial Aspect Class traits and type traits
The buccal and lingual outlines of the root drop straight down from the crown and are approximately parallel for over half their length, tapering only slightly at the apical third.
The root end is flat and almost square.

21. Mesial Aspect Class traits and type traits
A developmental depression usually extends almost the full length of the root on the mesial side.

22. Distal Aspect Class traits and type traits
The cervical line does not drop buccally.
The length of the crown buccally and linguallyis more uniform.
The cervical line extends almost straight across buccolingually.

23. Occlusal Aspect Class traits and type traits
General outline is RHOMBOIDAL.
It accents the mesiobuccal line angle of the crown in comparison with the distobuccal line angle.

24. Occlusal Aspect Class traits and type traits
The mesiolingual cusp may be seen as the largest and the best developed of all the cusps, and it has a broad flattened surface lingually.

25. Occlusal Aspect Class traits and type traits
The buccal developmental groove of the occlusal surface divides the two buccal cusps evenly.

26. Occlusal Aspect Class traits and type traits
The central developmental groove separates the mesiobuccal cusp and the mesiolingual cusp.

27. Occlusal Aspect Class traits and type traits
The central groove ends in a mesial pit in the mesial triangular fossa, which is immediately distal to the mesial marginal ridge.

28. Occlusal Aspect Class traits and type traits
The lingual developmental groove separates the mesiolingual cusp and the distolingual cusp.