2Primary Tooth eruption facts: Girls generally precede boys in tooth eruptionEvery 6 months of life, approximately 4 teeth will erupt.Lower teeth usually erupt before upper teethTeeth in both jaws usually erupt in pairs.One on the right and one on the leftBy the time a child is 2 to 3 years of age, all primary teeth should have erupted
3Characteristics of Deciduous Mandibular First Molars The crowns are bulging buccally and lingually at the cervical rimThinner enamel and dentinCervical area is constrictedWill emerge in about 14 to 18 months. It will shed off in about 9 to 11 yrs.
4Characteristics 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 sizeHas a prominent mesio-buccal cervical bulge
5FunctionThe mandibular molars are the largest and strongest teeth in the lower jaw.Its main role is for mastication.
6Function It reserve space for their permanent counterparts. It gives the face its normal appearance.It aids in the development of clear speech.
7Function It helps attain good nnutrition It helps give a healthy start to the permanent teeth
8Problem 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.
9Ankylosis can lead to: Loss of arch length Extrusion of teeth of the opposite archInterference with the eruption of succedaneous teeth
10Treatment- Placement of a stainless steel crown over the ankylosed tooth. - Extraction
11Buccal 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.
12Buccal Aspect Class traits and type traits Two buccal cusp is distinct.No developmental groove.Mesial cusp is larger than the distal cuspRoots are long and slender
13Lingual Aspect Class traits and type traits Distolingual cusp is roundedMesiolingual cusp is long and sharp at tipMesial marginal ridge is well developed
14Lingual Aspect Class traits and type traits Part of the two buccal cusps may be seen from this angleCrown length mesially and distally is more uniform than it is from the buccal aspectCervical line is straighter
15Mesial Aspect Class traits and type traits The most noticeable detail from the mesial aspect is the EXTREME CURVATURE bucally at the cervical third.
16Mesial 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.
18Mesial 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.
19Mesial Aspect Class traits and type traits Since the mesiobuccal crown length is greater than the mesiolingual crown length, the cervical line slants upward buccolingually.
20Mesial 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.
21Mesial Aspect Class traits and type traits A developmental depression usually extends almost the full length of the root on the mesial side.
22Distal 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.
23Occlusal 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.
24Occlusal 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.
25Occlusal Aspect Class traits and type traits The buccal developmental groove of the occlusal surface divides the two buccal cusps evenly.
26Occlusal Aspect Class traits and type traits The central developmental groove separates the mesiobuccal cusp and the mesiolingual cusp.
27Occlusal 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.
28Occlusal Aspect Class traits and type traits The lingual developmental groove separates the mesiolingual cusp and the distolingual cusp.