scholarly journals The Histological Structures and the Developmental Process of Lower Molar Teeth in Guinea Pigs

1976 ◽  
Vol 30 (3) ◽  
pp. 201-223
Author(s):  
Akiomi Kudoh
Keyword(s):  
Guinea Pigs ◽  
Developmental Process ◽  
Molar Teeth ◽  
Lower Molar

Uprighting Lower Molar Teeth

1976 ◽  
Vol 3 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Lesley M. Reynolds
Keyword(s):  
Individual Case ◽  
Molar Teeth ◽  
The Individual ◽  
Lower Molar

Several methods of uprighting lower molar teeth are discussed. The method of choice depends on features of the individual case and partly on the type of impaction to be corrected.

Tooth onoteny in Didelphis virginiana (Marsupialia : Didelphidae)

1978 ◽  
Vol 26 (1) ◽  
pp. 61 ◽  
Author(s):  
BKB Berkovitz
Keyword(s):  
Didelphis Virginiana ◽  
Ontogenetic Development ◽  
Crown Rump Length ◽  
Dental Lamina ◽  
Permanent Molar ◽  
Molar Teeth ◽  
Lower Molar

The ontogenetic development of the teeth was studied in a series of seven specimens of Didelphis virginiana whose crown-rump length varied from 11 to 49 mm. Though all developing teeth showed undifferentiated lingual downgrowths of dental lamina, there was no evidence of any non-functional teeth. No more than five upper incisors were present at any one time. The metacone was the first cusp to calcify in the upper deciduous and fist permanent molar teeth. The protoconid was the first cusp to calcify in the lower molar teeth. The results were compared with findings from a recent study of tooth ontogeny in Antechinus flavipes.

scholarly journals Morphometric analysis of the masseter muscle post unilateral lower molar exodonty: experimental study

2016 ◽  
Vol 33 (02) ◽  
pp. 090-095
Author(s):  
M. Benigno ◽  
E. Amstalden ◽  
E. Liberti ◽  
N. Leal ◽  
K. Rodrigues ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Masseter Muscle ◽  
Wistar Rats ◽  
Morphological Changes ◽  
Optical Microscope ◽  
Morphometric Study ◽  
Surgical Extraction ◽  
Molar Teeth ◽  
Masseter Muscles ◽  
Lower Molar

Abstract Introduction: To check the morphological changes of the masseter muscle after surgical extraction of inferior molar teeth. Methods: 24 Wistar rats had samples of their masseter muscles analysed in the Optical Microscope (OM). The rats were randomly divided into three groups as follows: GI-15, GII-30, GII-60 days after surgical extraction of inferior molar teeth. Each group had 5 experimental and 3 normal control rats for OM observation. The OM allowed the morphometric study of the masseter muscle. The morphometric study was based on the measurement of the fiber's area by AXION-VISION software. ANOVA test was applied for data analysis. Results: No alteration was detected in all morphometric analysis of the masseter muscle. Conclusion: The masseter muscle adapts to the occlusal modiication caused by the extraction of the molar teeth during the analysed periods.

Aegialodon dawsoni , a new trituberculosectorial tooth from the Lower Wealden

1965 ◽  
Vol 162 (989) ◽  
pp. 535-554 ◽  
Keyword(s):  
Middle Jurassic ◽  
Upper Jurassic ◽  
Upper Triassic ◽  
Main Line ◽  
Molar Teeth ◽  
The Trinity ◽  
Morphological Expression ◽  
Morphological Series ◽  
Lower Molar

This paper describes a new mammalian tooth from the Lower Wealden bone-bed at Cliff End, near Hastings. The tooth is a lower molar. It has a trituberculate structure with a well-developed talonid. The nature of the wear on this talonid shows that a true protocone (a definite pointed cusp as against an enlarged lingual cingulum) must have been present in the upper molars. Aegialodon is the first mammal in which the existence of a definitive protocone can be inferred. A good morphological series can be traced back from Aegialodon through Peramus (Upper Jurassic), Amphitherium (Middle Jurassic) to the Upper Triassic Welsh pantotheres. This series illustrates the increasing importance of the crushing as against the shearing function of the molar teeth as their evolution progresses. The morphological expression of this development is the enlargement of the talonid and associated enlargement of the lingual cingulum of the upper molars. Finally, in the last member of the series ( Aegialodon ) the lingual cingulum becomes a true protocone. From this main line of therian evolution first the symmetrodonts and then the dryolestid pantotheres branched off by emphasizing the shearing function of the teeth and reducing their crushing function. This would have been an adaptation to an exclusively insectivorous diet. From Aegialodon can be derived the teeth of the Trinity Sands ‘ Theria ’ and Endotherium by a further increase in the size of talonid and protocone. A continuation of the same process would give rise to the teeth of marsupials and placentals.

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