A text-book of dental histology and embryology, including laboratory directions . The distribution of bone in the aiveolar process. ing the course of the inferior dental artery and nerve isfound what Cryer has called the cribriform tube. Thisextends from the point where the arteries and vein enterthe substance of the bone on the lingual surface of theramus, posterior to the alveolar process and below theoblique line, and extends through the cancellous portion of RELATION OF THE TEETH TO THE BONE 379 the body of the bone, emerging at the mental is really a rather definite arrangemen
A text-book of dental histology and embryology, including laboratory directions . The distribution of bone in the aiveolar process. ing the course of the inferior dental artery and nerve isfound what Cryer has called the cribriform tube. Thisextends from the point where the arteries and vein enterthe substance of the bone on the lingual surface of theramus, posterior to the alveolar process and below theoblique line, and extends through the cancellous portion of RELATION OF THE TEETH TO THE BONE 379 the body of the bone, emerging at the mental is really a rather definite arrangement of the plates ofcancellous bone around the vessels and the nerves. Alveolar Process.—If the adult alveolar process as seen inthe skull is examined, it is apparent that the bone is arrangedso as to give the greatest support with the least possible bulk,and where there is an increase in bulk it is to meet somespecial force (Fig. 287). The incisors and cuspids are usedchiefly to bite off pieces of food, and when the food cannot be Fia. 288. Skull of orang-outang. bitten it is torn and wrenched away. This puts a heavystrain in all directions on the roots of the teeth, which mustbe supported by the bone. For this reason the roots of theincisors are usually well covered with bone through theirentire length. The cuspid root is long and the upper portionof it so well supported in the bone at the side of the noseand toward the orbit that the most convex portion of it issometimes uncovered. In animals that use the incisorslargely for tearing, wrenching, and fighting, the bone is 380 THE TEETH AND DEVELOPMENT OF THE FACE greatly thickened over the incisor roots, as is shown in theskull of the orang (Fig. 288). In the upper molars the spreading of the three roots givesabundant support against the direct forces of grinding motions bring lateral pressure against theinclined planes of the cusps, which is met by a thickeningof the process in its occlusal third (Fig. 287), for
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectteeth, bookyear1912
