_a_, Ocular muscles; _b_, pterygoideus internus (cut); _c_,
stylo-glossus; _d_, digastricus (cut); _e_, genio-glossus; _f_,
genio-hyoideus; _g_, hyo-glossus; _h_, thyro-pharyngeus; _i_,
crico-pharyngeus; _k_, thyro-hyoideus; _l_, zygomatic process of
temporal (sawn off); _1_, parotid gland; _2_, submaxillary gland;
_3_, posterior part of sublingual gland; _3′_, anterior part of
same; _4_, submaxillary duct; _5_, ductus sublingualis major; _6_,
palatine glands; _7_, orbital or zygomatic gland; _8_, ducts of _7_;
_9_, lacrimal gland. (Ducts colored red.) (After Ellenberger, in
Leisering’s Atlas.)
]
The average periods of eruption are given below.
Tooth Eruption │ Change
│
I_{1} 4 to 5 weeks │4 to 5 months
I_{2} 4 to 5 weeks │ „
I_{3} 4 weeks │ „
C 3 to 4 weeks │4 to 5 months
P_{1} 4 to 5 months│5 to 6 months
P_{2} 4 to 5 weeks │ „
P_{3} 3 to 4 weeks │ „
P_{4} 3 to 4 weeks │ „
M_{1} 4 months │
upper 5 to 6 │
M_{2} months │
lower 4 ½ to │
5 months │
M_{3} 6 to 7 months│