[Measurements of the sella turcica in idiopathic hypophyseal nanism]

The size of the sella turcica was measured in 66 cases of so-called idiopathic hypopituitary dwarfism, and compared to Silverman's standards. In 55 % of patients the sella was abnormally small for age, and in 45 % abnormally small for height. No significant differences were found from male to female patients nor from isolated somatotropic deficiencies to multiple tropic hormones deficiencies.

The vasculature of the diaphragma sellae. A postmortem injection study

The postmortem injection study demonstrated that the main blood supply to each quadrant of the competent diaphragma sellae appears to come from the following vessels: posterior quadrant, inferior hypophyseal arteries; right and left marginal quadrant, tributaries of the intracavernous portion of the carotid artery; anterior marginal quadrant, anterior capsular arteries. When the diaphragm is incomplete or absent the inferior hypophyseal arteries are the main source of blood supply. Microscopic analysis of the vascular bed in the diaphragma sellae reveals that there are fine arterial filaments mostly in the superior layer, while venules are situated in the inferior part of the diaphragm.

The dichotomous pattern of craniofacial expansion during aging

The craniofacial skeleton expands during adult life and previous investigations have demonstrated non-uniformity in continuing growth. This report confirms the fact that sella turcica, frontal sinus and the skull tables remodel at a rate per unit time which is twice the amount of the anterios and posterior skull diameter. The dual enlargement pattern occurs in both male and females and has been observed longitudinally from the third through the eighth decades of life. Though associations in the continuing growth process of separate anatomical parts throughout the human skeleton remain obscure, the degree to which components vary within the craniofacial system is now clearly evident.

The saddle angle: constancy or change?

Serial cephalometric radiographs of 165 children have been used to analyze age-associated changes in the saddle angle (Ba-S-N). There are mean decreases in this angle of about 5 degrees from birth to 2 years in those with either a Class I or a Class II occlusion; later changes are slight. The mean values tend to be slightly smaller in Class I boys than in those with Class II. Generally, the means are slightly larger in boys than girls but in adults this sex difference is in the reverse direction while remaining slight. It is reasonable to conclude that change is dominant in the first two years. Even after pubescence the angle is not constant but the changes are much smaller. The variability of the angle is greater for Class II than Class I individuals and its variability is greater in girls than boys after 12 years. Almost all the median increments are negative; that is, the flexure of the cranial base decreases with age particularly if the increments begin at the first available radigraph. This tendency is more marked in Class II then Class I occlusion. The increments are markedly variable in each occlusion group with large changes occurring in some individuals. Correlations between the saddle angles at different ages are high; this shows a marked constancy of the relative levels for individuals. The correlations between increments are small; presumably this reflects the small sizes of these increments relative to error terms. In the present group the saddle angle is positively correlated with Ba-N length, but the correlation between the saddle angle and either cranial vault length of stature are near zero. These findings show that there is marked constancy within individuals after the age of 2 years although, as noted earlier, there is marked variability in the size of the angle at particular ages and the serial data for some unusual individuals show large changes that are generally decreases.

Structure and postnatal organization of heretofore uninvestigated and infrequent ossifications of the sella turcica region

A heretofore unreported spine, which protrudes into the pituitary fossa, has been described and recorded. Complete and incomplete 'sella bridges', their angle formations with the planes of the head, dimensions and sutures have been detailed and their origin postulated. The development and formation of the carotico-clinoid foramina have been exhibited and interpreted. Development stages of the ophthalmic canals have been elicited. An ossified trigeminus bridge has been measured and its origin elucidated. The supracochlear cartilages have been traced from their appearance in the new-born to their supposed fate (os suprapetrosum).

Transnasal transsphenoidal approach to the sella

The transnasal transsphenoidal approach to the sella turcica has been refined and perfected through advances in medicine and technology. Originally performed for excision of pituitary adenomas, its present primary use is pituitary ablation is hormonally dependent diseases. Our study of 55 patients who have undergone this procedure during the years 1970-1975 demonstrates that this microscopic technique gives excellent exposure and visualization of intrasellar contents. Our method gives excellent exposure and visualization of intrasellar contents. Our method with several instrument modifications is discussed. It is technically an easy procedure with a minimum of morbidigy and mortality.

Intercavernous connections of the cavernous sinuses. The superior and inferior circular sinuses

Morphological features of the intercavernous connections of the cavernous sinuses are described and illustrated by photographs of vinylite casts. Surgeons should be aware of the course, potential size, and arrangement of the channels in the dura of the hypophyseal fossa. This is particularly important in exposure of pituitary gland by the transpheniodal route.

Evaluation of sellar and parasellar masses by computed tomography

Computed tomography is the method of choice for initial evaluation of patients with potential suprasellar masses. In our experience, CT has proved completely reliable for detecting or ruling out the presence of a suprasellar mass, the direction and degree of parasellar extension, and the presence of any calcific or cystic component of the lesion. When multiple cut CT has been negative, further diagnostic studies have proved unrewarding. When CT has been positive, additional studies have been required in some cases to rule out aneurysm prior to craniotomy.

Orientation-sella-nasion or Frankfort horizontal

The controversy regarding the most appropriate line for cephalometric orientation has been resolved and can be summarized in the following five areas of consideration: 1. Clinical significance. The ability of the clinician to visualize the Frankfort horizontal plane affords him the opportunity for effective clinical communication, which is lacking with sella-nasion. In addition, he is able to demonstrate the orientation of the face, chin, and palate to Frankfort horizontal plane, which is also lacking in the sella-nasion system. 2. Anatomical significance. The direct relationship of the Frankfort horizontal plane with the basic sense organs of sight and hearing displays a relationship to the face. Sella, in contrast, relates to the brain and not the face. 3. Measurement accuracy. Studies performed to test the accuracy of selection of the planes under consideration showed no significant differences when true porion and not the ear rod was used and when experienced technicians performed the tracings. 4. Application in description. If the reference line is to be considered reliable for description, the correlation between the measurements of the maxilla and the mandible to the reference line should be minimal. In a study performed, SNA and SNB displayed a significantly higher correlation than N-Po to FH and N-A to FH. 5. Application in growth forecasting. A study was performed in order to evaluate the application of these lines of orientation to growth forecasting. In every instance the reference frame which utilized the Frankfort horizontal plane was appreciably better than that which utilized sella-nasion.

Volume of sella turcica in normal subjects and in patients with primary hypothyroidism and hyperthyroidism

In an attempt to assess a possible relationship between pituitary size and TSH secretion, the volume of sella turcica was measured in 570 subjects, 26 primary hypothyroid patients, and 34 thyrotoxic patients. The volume of sella turcica, measured by a 3-dimensional approach, increased progressively with age until 20 years of age and was rather constant thereafter in normal subjects. In thyrotoxic patients, the volume of sella turcica was normal in spite of decreased plasma TSH concentration. In contrast, 81% of primary hypothyroid patients had an abnormal enlargement of the sella turcica. The magnitude of an increase of sella turcica inversely related with a decrease in serum T4 and T3 concentrations. On the other hand, the magnitude of an increase of sella turcica correlated well with an increase of circulating TSH. We suggest that an increase of sella turcica indirectly reflects an increase in pituitary size and TSH-secreting capacity, possibly due to hypertrophy and hyperplasia of TSH cells in primary hypothyroid patients.

Variation of the sella-nasion plane and its effect on SNA and SNB

The sella-nasion plane is one of the basic planes used in the cephalometric evaluation of candidates for orthognathic surgery. The relationship between SN and the Frankfort horizontal plane was studied. It was shown that as the angle between FH and SN increases, the SNA and SNB angles decrease in the normal individual. Compensation can be made for this variation by using the values presented.

Microsurgical anatomy of the sellar region

Fifty adult sellae and surrounding structures were examined under magnification with special attention given to anatomical variants important to the transfrontal and transsphenoidal surgical approaches. The discovered variants considered disadvantageous to the transsphenoidal approach were as follows: 1) large anterior intercavernous sinuses extending anterior to the gland just posterior to the anterior sellar wall in 10%; 2) a thin diaphragm in 62%, or a diaphragm with a large opening in 56%; 3) carotid arteries exposed in the sphenoid sinus with no bone over them in 4%; 4) carotid arteries that approach within 4 mm of midline within the sella in 10%; 5) optic canals with bone defects exposing the optic nerves in the sphenoid sinus in 4%; 6) a thick sellar floor in 18%; 7) sphenoid sinuses with no major septum in 28% or a sinus with the major septum well off midline in 47%; and 8) a presellar type of sphenoid sinus with no obvious bulge of the sellar floor into the sphenoid sinus in 20%. Variants considered disadvantageous to the transfrontal approach were found as follows: 1) a prefixed chiasm in 10% and a normal chiasm with 2 mm or less between the chiasm and tuberculum sellae in 14%; 2) an acute angle between the optic nerves as they entered the chiasm in 25%; 3) a prominent tuberculum sella protruding above a line connecting the optic nerves as they entered the optic canals in 44%; and 4) carotid arteries approaching within 4 mm of midline within or above the sella turcica in 12%.

Echoencephalographic A-scan study of the aqueduct and brain stem

The author utilizes autopsy models and normal clinical subjects with and without pneumoencephalography to demonstrate the value of echoencephalography in delineating the position of the aqueduct of Sylvius. Echoes from the dorsum sellae, the anterior wall of the sella turcica, and the aqueduct proved consistently identifiable, while echoencephalographic examination of 25 normal subjects revealed in all instances well-defined aqueduct echoes. Thus the aqueduct echo method may be a diagnostic aid in determination of the anterior-posterior position of the brain stem.

Normal position of the aqueduct of Sylvius. Part 2: evaluation of two preaqueductal proportional methods

Two new proportional methods for determination of the normal or abnormal position of the cerebral aqueduct are described. The position of the iter is expressed by the quotients (see article) and (see article), when d-aq represents the distance between the upper posterior surface of the dorsum sellae and the dorsal center of the air-filled aqueduct. Ts equals aq is the distance from the tuberculum sellae to the same point, and TW is Twining's line. The normal value of the dorsum to aqueduct ratio was 0.32 plus or minus 0.02 standard deviation (SD) and of the tuberculum to aqueduct ratio 0.44 plus or minus 0.03 SD. Both proportional methods are independent of skull dimensions. These are compared to another proportional method described in Part 1 of this report.

Normal position of the aqueduct of Sylvius. Part 1: significance of aqueduct to dorsum sellae measurements

The author describes a method for estimating the position of the aqueduct of Sylvius based on the ratio of the measured distance from surface to aqueduct (A) to that from the surface to dorsum sellae (B). The normal ratio A:B is 0.72 with a range from 0.68 to 0.75. Values below 0.68 indicate a dorsally displaced aqueduct.

The pharyngeal hypophysis in some laboratory animals

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