Lateral Crus Research Articles

The ‘C’ costal cartilage graft in reconstruction of the unilateral cleft lip nose

Summary The use of a ‘C’ shaped graft carved from costal cartilage is described to correct the tip projection, the buckled lateral crus and depressed nostril sill in the unilateral cleft lip nose.

Ponto-neocerebellar axonal branching as revealed by double fluorescent retrograde labeling technique

The organization ofponto-neocerebellar projections in the cat 4 has been recently re-examined with tracer techniquesT,11,17. Within the framework of the topographical organization, considerable overlap was found between sets of neurons which project to different subdivisions of the cerebellar hemisphere and neocerebellar vermis (lobulus Vlla, b4,11,17. In addition, projections from each half of pontine nuclear complex (PN) to lateral parts of crus I-II were found to be relatively more bilateral than hitherto described 17. In the present study, combinations of two fluorescent retrograde tracers1, 2 13,14,19,z0 were used to determine whether this bilaterality 17 could be accounted for by divergent axon collaterals given off by individual pontine neurons. In preliminary experiments the best results were obtained with 1 .5~ (w/v) bisbenzimide (Bb; Hoechst 33258) in distilled water, 10~ (w/v) Evans blue (EB; Merck 3169) in 1 700 poly-L-ornithine in distilled water or 5 ~ (w/v) 'Granular blue' (GB; compound 184/134)* in distilled water with survival times of 8-10 11 (Bb), 3 days (EB) or 9-10 days (GB). Therefore, in one group of 7 cats, 3 were injected with 10 ~ EB (0.8-1.6 /A) combined with 5 ~ GB (1.2-2.6 #1) and the other 3 cats with EB combined with 1.5 ~ Bb (0.6-1.2 #1). The tracers were injected into the lateral crus II, one on each side. In one experiment the cerebellum was transected at the midline 47 days before the EB and GB injections. In a second group of 3 cats, GB was injected into the vermal lobule VIIa,b and EB into one lateral crus II. At the various survival times, the animals were deeply anesthetized with Nembutal and perfused with 10~ formalin. The brain stem and cerebellum were impregnated with 30 ~ sucrose in 0. 2 M sodium cacodylate buffer, at 4 °C and then frozen serial sections, 25 #m frontal for the brain stem and 50 #m horizontal for the cerebellum, were cut. The sections were mounted on slides without coverslips,

Reliable methods of tip reduction.

Two reliable methods of reducing nasal tip projection include a direct method, which interrupts continuity of lower lateral cartilage by removal of the dome portion and leaves an intact vestibular skin cuff; continuity and cartilage volume are changed. The second method, indirect, preserves continuity of the inferior margin of the lower lateral cartilage, which is grossly weakened by resection of cartilage in cephalic areas of the lateral crus dome, and adjacent medial crus. Vestibular lining is preserved as a cuff. Volume loss and supportive strength of lower lateral cartilage allow the nasal tip to assume a less projected stance with resulting widening and outward flailing of nostrils, which can be corrected by vestibular wedging. Complete transfixion of the membranous septum and adequate lowering of the cartilaginous septal angle are adjuncts to success with either method.

Topology of the lateral nasal cartilages: the anatomical relationship of the lateral nasal to the greater alar cartilage, lateral crus.

AbstractThis investigation was undertaken to help fulfill the practical need of the rhinologic surgeon for a more accurate anatomical knowledge of the cartilages of the nasal tip.Four adult caucasian noses aged 62–88 years were embedded en bloc and serially sectioned. The nasal cartilages of one were reconstructed in wax. Anatomical relationships of the lateral nasal cartilage to the lateral crus of the greater alar cartilage were compared. The findings were compared with descriptions found in the literature.The lateral nasal cartilage curls to varying degrees laterally and upward on its inferior margin where it underrides the lateral crus of the greater alar cartilage. The curl is greater anteriorly and diminishes postero‐laterally to the point where the cartilage lies flat. The lateral crus of the greater alar cartilage also may curl medially and downwards on its superior margin where it overrides the lateral nasal cartilage. Sesamoid cartilages are present in all specimens.These findings, although known to many rhinologic surgeons, are not clearly established in the literature.

Studies on the support of the nasal tip

Anatomical studies on the nasal tip indicate four major areas of tip support: (1) the fibrous connection between upper and lower lateral cartilages; (2) the sesamoid complex extending the support of the lateral crus to the pyriform opening; (3) the ligamentous sling spanning between the paired domes of the lower lateral cartilages; and (4) the attachment of the feet of the medial crura to the posterior caudal septum. Routine rhinoplasty procedures compromise tip support predisposing to postoperative tip sagging (Pollybeak); however, tip rhinoplasty procedures can be modified to maintain tip support and projection by: high transfixion through the caudal cartilaginous septum confirming septal shortening to the anterior caudal septum, embricating the membranous septum over the anterior caudal septum, utilizing a cartilaginous strut, between and below the medial crura, or reestablishing the medial cruraposterior caudal septum anchorage.

Electrical responses in crus II evoked by stimulating various parts of the cat cerebellar cortex

Little is known about the functional connections of crus II with other parts of the cerebellar cortex. To study this, we decerebrated cats under ether and exposed much of the cerebellar surface. Simultaneous monopolar and bipolar recordings were taken from the surface of crus II on one side while electrically stimulating various vermal and hemispheral regions of the cerebellar surface. Both singleshock and group-pulse stimuli were used. The largest and most consistent potentials were evoked with ipsilateral stimulation of the anterior two-thirds of crus I or the hemispheral part of lobulus simplex. Responses of somewhat lesser amplitude resulted from stimulation of the posterior one-third of ipsilateral crus I, ipsilateral paramedian lobule, the anterior two-thirds of ipsilateral lateral lobule V, medial lobule V, lobule VI, lobule VII, the posterior three-fourths of the medial part of contralateral crus I, contralateral hemispheral lobulus simplex, and the posterior folia of contralateral crus II. Even smaller potentials were evoked by stimulating the posterior folia of lobule IV, the posterior part of ipsilateral lateral lobule V, the anterior two-thirds of contralateral lobule V, lobule VIII, contralateral paramedian lobule, and contralateral lateral crus I. The smallest and least consistent responses appeared with stimulation of the posterior part of contralateral lateral lobule V and the anterior portion of contralateral crus I. We conclude, under these experimental conditions, that crus II has extensive functional connections with other cerebellar cortical regions.

Studies on the support of the nasal tip.

Anatomical studies on the nasal tip indicate four major areas of tip support: (1) the fibrous connection between upper and lower lateral cartilages; (2) the sesamoid complex extending the support of the lateral crus to the pyriform opening; (3) the ligamentous sling spanning between the paired domes of the lower lateral cartilages; and (4) the attachment of the feet of the medial crura to the posterior caudal septum. Routine rhinoplasty procedures compromise tip support predisposing to postoperative tip sagging (Pollybeak); however, tip rhinoplasty procedures can be modified to maintain tip support and projection by: high transfixion through the caudal cartilaginous septum confirming septal shortening to the anterior caudal septum, embricating the membranous septum over the anterior caudal septum, utilizing a cartilaginous strut, between and below the medial crura, or reestablishing the medial cruraposterior caudal septum anchorage.

Electrical responses in the paramedian lobule evoked by stimulating various parts of the cat cerebellar cortex

Except for certain relationships with the anterior lobe, little is known about the functional connections of the paramedian lobule with other parts of the cerebellar cortex. To study this, we decerebrated cats under ether and exposed much of the cerebellar surface. Simultaneous monopolar and bipolar recordings were taken from the surface of the left paramedian lobule while stimulating electrically various vermal and hemispheral regions of the cerebellar surface. Both single-shock and group-pulse stimuli were used. The largest and most consistent potentials were evoked with stimulation ipsilaterally of the medial part of crus I, the hemispheral portion of lobulus simplex, or the posteromedial region of crus II. Responses of lesser amplitude occurred with stimulation of the ipsilateral lateral portion of culmen, lobule VI, the inferior part of sublobule VIIA, sublobule VIIB, lobule VIII, or lateral region of ipsilateral crus II. Even smaller potentials were evoked with stimulation of the medial or contralateral lateral parts of culmen, the hemispheral portion of contralateral lobulus simplex, the posteromedial regions of contralateral crus I or crus II, the contralateral paramedian lobule, or the major part of sublobule VIIA. The smallest and least consistent responses occurred with stimulation of ipsilateral lateral crus I or the anterior two-thirds of contralateral medial crus I. No evoked potentials resulted from stimulation of the anterior part of the dorsal paraflocculus of either side or the contralateral lateral portions of crus I or crus II. Differences were noted in the responsiveness of various regions to single-shock stimulation as compared to group-pulse stimulation.

PREVENTION AND CORRECTION OF CICATRICIAL INTRANASAL ADHESIONS IN RHINOPLASTIC SURGERY

THE NASAL VESTIBULE PRACTICALLY all rhinoplastic maneuvers are performed through the intranasal route by incisions made in the nasal vestibule. The latter forms a dilatation inside the aperture of the nostril. It is bound laterally by the ala and the lateral crus of the alar cartilage and medially by the columella and the membranous septum. The vestibule extends from the nares to the intercartilaginous fold, which separates the alar and lateral cartilages. In a frontal section each vestibule has the approximate shape of a right-angle triangle, with the lateral wall of the nostril forming the hypotenuse. The concavity of the lateral crus and its junction with the medial crus form the high vault of the vestibule. This vault makes the diameter of the vestibule larger than the diameter of the nostril. The lining of the vestibule consists of a thin layer of the skin intimately adherent to the underlying cartilage.

New technique for corrective surgery of nasal tip.

IN RHINOPLASTY correction of nasal tip has challenged surgical skill and esthetic sense of surgeons. It is, in effect, axiomatic that the tip makes nose. It can also be said that most of imperfections in a rhinoplasty are readily discernible in reconstructed tip. One may ask: What are surgical and esthetic errors and mistakes in failures to approximate perfect nasal tip ? The pinched-in surgical tip is not only esthetically inadequate but also, as a rule, functionally imperfect. The sacrifice of cartilage or vestibular skin or mucosa, with healing followed by contracture-induced synechiae between lateral crus and septum or columella and, in some cases, between lateral nasal wall, septum, and mesial crura, often gives a bizarre effect. The production of alar clefts, alar collapse, vestibular stenosis or artesia, dimples and dents in alae, web-like cicatrices in vestibule, and scar