232 
ON DISEASES OF THE DENTAL APPARATUS 
affected, how can evulsive instruments be applied to the one or 
the other ? The continual approaching of the two jaws by the 
powerful contraction of the masticatory muscles makes these last 
molars so crowded together towards each other, in spite of the dila- 
tation of the mouth by the speculum, that it is frequently impossi- 
ble to slide the instrument along between them. Moreover, let us 
add, that the tongue, however well fixed it may be without the 
mouth, has still the power to displace the instrument by the play 
and energy of its undulatory movements at its base. Still, again 
it should be borne in mind, that the hinder molars, as we stated in 
the beginning of this Memoir, ordinarily have less of their bodies 
above the gum than the others, and, therefore, offer less hold ; 
and, finally, that the obstacles which oppose the application of 
extirpating apparatus to these teeth are nearly insurmountable. 
In other cases, the tooth excavated by the caries is destroyed 
almost to a level with the gums, and the part above the gum is then 
so small that it does not offer any point d’appui to the claws of the 
instruments. 
Lastly, in some cases the exostosis of the root of the tooth is so 
great, that it is as if wedged in the interior of the alveolar cavity, 
and resists the most violent efforts at its extraction. 
Still, however, what is to be done 1 The caries persisting may 
lead to grave local complications, and, consecutively, the most 
dangerous general disorders. 
In such a case we would advise having recourse to trepanation 
of the diseased sinuses, and, by the aid of an opening made upon 
the parietes of these cavities, punch by its root into the mouth the 
tooth which could not be wrenched out by a direct effort. 
In his memoir on the evulsion of the teeth, published in 1831, 
Monsieur Delafond admits that this operation, before recommended 
by D’Arboval in the first edition of his Dictionnaire de Midtcine 
Vtttrinaire, “ was only practicable upon the three most anterior 
molars, seeing that, in order to trepan the sinuses above the three 
last molars, it would be necessary to incise the zygomato-maxillctris 
muscle, and the nervous plexus which clothes it.” We, however, 
are not of the same opinion. We think that, applied to the three 
first molars, the operation of which we are speaking is most or- 
dinarily entirely useless, and that it may even be rendered emi- 
nently dangerous by the contiguity of the facial portion of the fifth 
pair of nerves, which makes its exit upon the face just above the 
roots of these teeth ; whilst the trepanation made in order to reach 
the three pos.eriormost molars not being below the insertion of 
the masseter, but, on the contrary, well above it, can be practised 
without including or interesting this muscle, and without lesion 
of any important organs or parts. 
