There is one more obstaele to making a diagnosis. This is the overlap ping of the bones, leading to the disappearance of the sutures, and distor tion of the fontanelles, particularly of the posterior one. In place of the depression formed by the sagittal suture, we now feel only an osseous ridge formed by the prominent border of one of the parietal bones. The angle of the occipital bone is also covered by the posterior border of the parietals, and the posterior fontanelle is replaced by a little depression not possessing the characters of the posterior fontanelle. We recommend, in these cases, to follow this ridge to its end. It terminates, necessarily, at the interior fontanelle, which, being larger, will always more clearly pre sent its distinctive characters, i.e., its rhombic shape with its four angles. In these cases, however, the four sutures ending at these angles will be replaced by prominences, formed by the projection of the parietal bones above the posterior border of the frontal, and by the ridge caused by the approximation of the lateral halves of the frontal.
2. Position O. L.P.
The details furnished above simplify the diagnosis of this position very much.
Palpation.—The hand again penetrates more deeply on the left than on the right. The resisting surface is, it is true, still on the left, but we find it far to the left and behind, and when we palpate in front it seems much narrower, and is, in reality, only the right lateral surface of the fcetus, the back being directed backward. To perceive this, which is not always easy, we must place the woman on her right side, the abdomen resting on the bed. We can thus, in many cases, feel the back.
Auscultat ion. —The maximum intensity of the heart-sounds is below the line dividing the uterus into two equal parts, and, according to De paul, on a line uniting the left sacroiliac synchondrosis to the umbilicus. According to Tarnier and Chantreuil it is on a line passing from the navel to the left antero-superior spine of the ilium.
Vaginal Touch.—The posterior fontanelle is behind and on the left, on a level with the left sacroiliac synchondrosis; the anterior fontanelle is on a level with the right ilio-pectineal eminence. That is, the sagittal suture occupies the right oblique diameter, the posterior or the anterior fontanelle being more or less accessible, according to the more or less marked flexion, and the more or less thorough engagement of the head.
3. Position O. L. T.
It is only by the touch that one clearly recognizes this position. The sagittal suture occupies the transverse diameter, and we feel the posterior fontanelle at the left extremity of the transverse diameter, i.e., at the middle of the left innominate line. The anterior fontanelle is at the other end of the transverse diameter, i.e., at the level of the middle of the right innominate line.
4. Position O.R.P.
This position is the most frequent after the position O.L.A.
a. Before Labor.—By palpation we ascertain the presentation to be a vertex. But here the hand which depresses the abdominal wall on the left side meets with the most opposition, and enters less profoundly be cause of the prominence of the forehead at the level of the left ilio-pecti neal eminence. We, therefore, seek the back on the right side, but, as it is turned backward, the resisting plane is narrower, and, in order to plainly feel the back, we must place the woman completely upon the left side, so as to be able to palpate the right postero-lateral region of the uterus.
Auscultation.—The point of maximum intensity of the heart-sounds is, according to Depaul, near the quadratus lumborum, on a line passing straight from the right sacroiliac synchondrosis to the umbilicus. Ac cording to Tarnier and Chantreuil, the maximum is on a line passing from the navel either to the right ilio-pectineal eminence or to the right antero-superior iliac spine. They say that, the left side of the fcetus being in relation with the antero-lateral wall of the uterus and of the abdomen, it is through this lateral surface and not through the back that the heart sounds reach the ear. Vaginal touch rarely allows a recognition of the position before labor.
b. During same signs on palpation and auscultation.
Vaginal posterior fontanelle is behind, on the right, on a level with the right sacro-iliac synchondrosis at the posterior extremity of the left oblique diameter. The anterior fontanelle is in front and on the left, on a level with the left ilio-pectineal eminence, i.e., at the ante rior end of the left oblique diameter. The sagittal suture occupies the left oblique diameter.
5. Position O. R. A.
On palpation, the liana enters farther on the right than on the left, the forehead being on the left. The resisting plane formed by the back occupies the whole right side of the abdominal wall.
maximum intensity of the heart-sounds is, accord ing to Depaul, on a line passing from the right ilio-pectineal eminence to the navel. According to Tarnier and Chantreuil, who base their view upon Ribemont's researches, this maximum is on the median line, or sometimes even a little to the left of that line.
Vaginal labor, the posterior fontanelle is in front and at the left, at the anterior extremity of the right oblique diameter, i.e., on a level with the right ilio-pectineal eminence. The anterior fonta nelle is on a level with the left sacroiliac synchondrosis, i.e., at the pos terior extremity of the right oblique diameter. The sagittal suture cor responds to the right oblique diameter.
6. Position O. R. T.
Vaginal touch, alone, establishes the diagnosis. The posterior fonta nelle occupies the right extremity of the transverse diameter, the ante rior fontanelle the left end of the same diameter. The sagittal suture is parallel to the transverse diameter.