Incidence of earlobe ptosis and pseudoptosis in patients seeking facial rejuvenation surgery and effects of aging

The authors have previously described a classification system for earlobe ptosis and have established a criterion for earlobe pseudoptosis. Earlobe heights were characterized based on anatomic landmarks, including the intertragal notch, the otobasion inferius (the most caudal anterior attachment of the earlobe to the cheek skin), and the subaurale (the most caudal extension of the earlobe free margin). The classification system was derived from earlobe height preferences as determined by a survey of North American Caucasians, and it identified the ideal free caudal lobule height range to measure 1 to 5 mm from otobasion inferius to subaurale (grade I ptosis). Also, earlobe pseudoptosis was defined by the attached cephalic lobule height measuring an intertragal notch to otobasion inferius distance greater than 15 mm. In this study, the preoperative earlobe height measurements of 44 patients seeking facial rejuvenation were evaluated. The average attached cephalic segment (intertragal notch to otobasion inferius distance) of patient earlobes measured 11.10 +/- 0.46 mm, and the average free caudal segment (otobasion inferius to subaurale distance) of patient earlobes measured 7.15 +/- 0.49 mm. Assessment of patient groups based on single-decade age differences demonstrated an increase in the free caudal segment (otobasion inferius to subaurale distance) with increasing age (p = 0.003). Assessment of patient groups based on single-decade age differences demonstrated no increase in the attached cephalic segment (intertragal notch to otobasion inferius distances) with increasing age (p = 0.281). When evaluating for the ideal otobasion inferius to subaurale distance, only 22.2 percent of earlobes demonstrated an ideal free caudal earlobe height (grade I ptosis). Moreover, pseudoptosis was detected in 12.3 percent of earlobes. Finally, a majority of earlobes demonstrated intrapatient variability, with only 16.2 percent of patients demonstrating identical attached cephalic segment (intertragal notch to otobasion inferius distances) and 37.8 percent demonstrating identical free caudal segment (otobasion inferius to subaurale distances) when compared with their contralateral ear. Plastic surgeons should be aware that a significant number of patients (77.8 percent of earlobes) may not possess an ideal free caudal segment and that 12.3 percent of earlobes may present with pseudoptosis. Therefore, earlobe height assessment should be an essential aspect of evaluation in patients desiring facial rejuvenation surgery. Evaluation of both ears should be performed independently due to intrapatient earlobe height variations. Finally, patients should be counseled with regard to the ideal earlobe parameters and aging patterns (stable attached cephalic segment versus increasing free caudal segment). With the natural progression of both facial rhytides and caudal segment earlobe ptosis (increasing free lobule segment) with increasing age, independent and accurate assessment of earlobe height is indicated so that the aging ear may be addressed concurrently with the aging face.     

The aesthetic earlobe: classification of lobule ptosis on the basis of a survey of North American Caucasians

North American Caucasian male subjects (n = 59) and female subjects (n = 72) were surveyed, to investigate earlobe height preferences that could serve as guidelines for aesthetic earlobe surgical procedures and reconstructions. Subjects were asked to rank their preferences for variously shaped earlobes in life-size-scaled sketched male and female profiles. Earlobe heights were varied on the basis of previously established anatomical landmarks, including the intertragal notch, the most caudal anterior attachment of the earlobe to the cheek skin (the otobasion inferius), and the most caudal extension of the earlobe-free margin (the subaurale). While the intertragal notch-to-otobasion inferius distance (range, 5 to 20 mm) and otobasion inferius-to-subaurale distance (range, 0 to 20 mm) varied, all other facial and ear anthropometric measurements were held constant. Each of the rank orders for the female and male facial profiles completed by the female and male subjects demonstrated statistical significance, as determined by one-way analysis of variance analysis of ranks (p < 0.001 for all four groups). No difference was noted between the two sexes' rank orders for either sex (p > 0.05). Therefore, analysis of the combined male and female preferences for each sex was completed with one-way analysis of variance analysis of ranks (p < 0.001 and p < 0.001) and a post hoc Dunn's test, to delineate significant preference differences between subgroups with respect to the intertragal notch-to-otobasion inferius and otobasion inferius-to-subaurale distances. Both female and male earlobe intertragal notch-to-otobasion inferius distances were preferred at either 5, 10, or 15 mm, more so than at 20 mm (p < 0.05 for all female and male comparisons). Furthermore, both female and male earlobe otobasion inferius-to-subaurale distances were preferred, in descending order, at 5 mm > 10 mm > 0 mm > 15 mm > 20 mm (p < 0.05 for all female and male comparisons). On the basis of the findings of this survey, the first classification of earlobe ptosis (based on otobasion inferius-to-subaurale distances), as well as a criterion for earlobe pseudoptosis (intertragal notch-to-otobasion inferius distance of greater than 15 mm), is presented. These findings suggest a role for independent assessment of the lobule length with respect to its anteriorly attached cephalad component (intertragal notch-to-otobasion inferius distance) and its free-margin caudal component (otobasion inferius-to-subaurale distance).     

Surgical design and algorithm for correction of earlobe ptosis and pseudoptosis deformity

A previously described classification system for earlobe ptosis and criterion for earlobe pseudoptosis deformity was based on height measurements of the two earlobe components: the free caudal segment and the attached cephalic segment. The "ideal" ear lobule free caudal segment was found to be between 1 and 5 mm (grade I ptosis), and the "ideal" attached cephalic segment was 15 mm or less. Earlobe pseudoptosis was defined by an attached cephalic segment measuring greater than 15 mm. Previous studies revealed an association between the elongated free caudal segment and increasing patient age and between the elongated attached cephalic segment and rhytidectomy. Sixteen fresh cadaver earlobes were used to design surgical patterns that would differentially reduce the free caudal segment, the attached cephalic segment, or both. A horizontal, medially based triangular excision pattern was designed. Triangular excisions limited to the attached cephalic segment resulted in 98 +/- 5 percent reduction of excision height from the attached cephalic segment but also resulted in an unexpected 32 +/- 2 percent augmentation of the excision height in the free caudal segment. Triangular excisions limited to the free caudal segment resulted in 88 +/- 4 percent reduction of the excision height from the free caudal segment and negligible reduction of 4 +/- 4 percent of excision height in the cephalic attached segment. An algorithm for correction of earlobe ptosis and pseudoptosis was subsequently derived and implemented in a clinical case. The authors propose that surgical treatment of patients with pseudoptosis be dependent on the ptosis grade. If the ptosis is grade I (1 to 5 mm), then excision of only the attached cephalic segment is recommended. If the ptosis is grade II or higher (more than 5 mm), then a combined attached cephalic and free caudal segment excision is recommended. In cases of isolated ptosis grade II or higher without pseudoptosis, then excision location of only the free caudal segment is recommended. The above simple algorithm and surgical designs will enable plastic surgeons to differentially correct earlobe ptosis and pseudoptosis.     

Morphometry of the adult human earlobe: a study of 547 subjects and clinical application

The purpose of this study was to define the factors that influence earlobe length and to establish a standard for adult earlobe length by sex and age. The study sample consisted of 547 adult subjects older than 20 years of age. A randomized, prospective design was used. Patients with malignancies, previous surgery or trauma to the earlobe, or congenital earlobe anomalies were excluded. The following variables were studied: sex; age; ethnic origin; skin complexion; height, weight, and body mass index; and piercing. Pearson's correlation, analysis of variance, t test, and multiple regression analysis were used for the statistical analysis. There were 383 women (70 percent) and 164 men (30 percent) aged 20 to 80 years. The average length of the left earlobe was 1.97 cm (SD, 0.42 cm), and that of the right earlobe, 2.01 cm (SD, 0.42 cm) (p < 0.0001). A post hoc test revealed a statistically significant difference among the three age groups (20 to 40 years, 40 to 60 years, and >60 years) in both men and women. Pendulous earlobes were significantly longer and less symmetrical than nonpendulous ones by t test. In men, nonpierced left earlobes were longer than pierced lobes; in women, there was no significant difference between pierced and nonpierced ears. Pearson's correlation tests for weight, height, and body mass index showed that only weight had a significant effect on earlobe length, and only in women. Analysis of variance for ethnic origin and skin color revealed a longer left earlobe in Ashkenazi and Sephardic Jews compared with Ethiopian, Asian, and American Jews and Arabs and a short earlobe in blacks compared with dark and fair-skinned people. On multiple regression analysis, sex and age were the only factors that contributed to earlobe length. A table of average earlobe length by age was formulated on the basis of the authors' findings. These data, together with the knowledge that earlobe length changes little in women over 40, that earlobes are not symmetrical, and that right and left nonpendulous earlobes are symmetrical in individual patients and shorter than pendulous earlobes, can assist the plastic surgeon in deciding on the proper time for loboplasty. The preferable technique is creating a nonpendulous earlobe to minimize the chances of further elongation with time.     

SEP testing in deeply comatose and brain dead patients: the role of nasopharyngeal,scalp and earlobe derivations in recording the P14 potential

Median nerve somatosensory evoked potentials (SEPs) were tested in 50 patients (20 brain dead, 18 comatose and in 12 progessing from coma to brain death, i.e., 32 cases with brain death and 30 cases with coma were recorded).Derivations were taken from nasopharynx, earlobes, scalp, and neck using cephalic and non-cephalic references. Cortical and subcortical SEP components were evaluated, focussing on the P14 potential. There is evidence that rostral and caudal parts of the P14 generator (lemniscus medialis) are differently affected in brain death, resulting in an abolition of the rostral part, while occassionally leaving intact for some time the caudal part. Non-cephalic referenced scalp records pick up the whole P14 dipole, whereas nasopharyngeal and earlobe derivations pick up different parts of P14, depending on the reference used. Scalp-to-nasopharynx records derive the most rostral part of P14; this “rostral P14” was bilaterally lost in all brain dead patients, but preserved in all deeply comatose patients with diffuse brain-sttem injuries. Scalp-to-earlobe records in contrast, picked up a P14 dipole segment reaching more caudally, resulting in a P14 potential also in brain dead patients. It is concluded that midfrontal scalp-to-nasopharynx derivations give the moset valuable contribution to the electrophysiological assessment of brain death versus deep coma.     

Outcome analysis of reduction mammaplasty using the modified Robertson technique

The benefits of reduction mammaplasty have been well documented in previous literature. Anticipating and correcting for pseudoptosis (bottoming-out), however, can impair the cosmetic outcome as the inferior skin envelope stretches and lengthens over time. We present long-term results on patients using the modified Robertson technique for reduction mammaplasty, which appears to have significant benefit in helping to prevent bottoming-out. Surveys were sent to patients undergoing reduction mammaplasty surgery with this technique from 1987 to 1997. Patients were queried regarding preoperative and postoperative symptoms, satisfaction, and outcome related to their surgery and were also offered free follow-up examinations. The patients who returned for follow-up were then evaluated by the attending surgeons for evaluation of scarring, nipple position, ptosis, pseudoptosis, shape, and overall appearance. Reduced breasts were also compared with cosmetically optimal breasts to compare for measured levels of pseudoptosis using our defined visual inferior pole ratio measurements. Average reduction size was 910 g and follow-up was 4.7 years from the time of surgery. There was significant improvement demonstrated in all areas questioned, with the greatest relief shown in back and shoulder pain, shoulder grooving, and difficulty fitting clothing. There was also demonstrated to be significantly less use of medical modalities postoperatively and significant increases in activity levels. Satisfaction for size, shape, symmetry, and overall results was 85, 94, 98, and 94 percent, respectively. Evaluations for pseudoptosis by the attending surgeons were rated good or excellent in 95 percent of patients. Measurements of the visual inferior pole ratio for pseudoptosis also demonstrated no significant differences when compared with aesthetically optimal breasts. The modified Robertson reduction mammaplasty is a reliable technique that can be used for both small and large reductions, giving both reliable and consistent results. This technique significantly improves symptoms, as do other reduction techniques, but has the added advantage of helping to avoid pseudoptosis postoperatively.     

Treatment of keloids by surgical excision and immediate postoperative single-fraction radiotherapy

The authors report the outcomes of patients with keloid scars treated with a protocol of extralesional excision and immediate single-fraction adjuvant radiotherapy. The design of the study was a retrospective analysis with up to 5-year outcome data. The setting was a single treatment team, University Teaching Hospital in London, United Kingdom. Participants (n = 80) were treated for 80 keloid scars (59 percent female patients, 76 percent nonwhite), and 44 percent of keloids were located on earlobes. For all patients, prior treatment without radiotherapy had failed. The salvage treatment reported in this article is combined extralesional excision and immediate postoperative external-beam radiotherapy. A 10-Gy dose of superficial 60-kV or 100-kV photon irradiation was given within 24 hours of the operation. The main outcome measure was freedom from recurrence of keloid scars. Results were that all keloid scars were controlled at 4-week follow-up. Probability of relapse at 1 year was 9 percent; at 5 years, probability of relapse was 16 percent. The earlobe showed no greater chance of relapse than other sites on the body. The authors' report shows that extralesional excision of keloid followed by early, single-fraction, postoperative radiotherapy is both simple and effective in preventing recurrence at excision sites.     

Auricular displacement with rhytidectomy.

The auricle is more mobile than generally recognized and is subject to displacement during rhytidectomy. When the auricle is displaced by a rhytidectomy, movement generally occurs in an anteroinferior direction with forward rotation of the inferior pole. This displacement/rotation is often obscured by concurrent elevation of the temporal hairline and insetting errors of the lobule that may appear to be the sole deformities. Using computer assistance, auricular position was compared in before and after photographs of published rhytidectomy results. Auricular displacement of varying degree was found in 62 percent of the analyzed results. Correlation of the presence, direction, and severity of the displacement with the described surgical technique implicates distraction on the periauricular superficial musculoaponeurotic system/platysma and skin at the time of closure as the causative agent. This retrospective photogrammetric study confirms that the auricle can be displaced if direct or indirect tension is placed on it during rhytidectomy.     

Repeat reduction mammaplasty

Repeat reduction mammaplasty is an uncommonly performed procedure. Currently, no clear operative guidelines of management exist. Sixteen patients (28 breasts) with a mean age of 29 years (range, 13 to 52 years) underwent repeat breast reduction over an 11-year period. Before the first reduction, the mean notch to nipple distance was 29.6 cm (range, 24 to 38 cm) and mean nipple to inframammary crease distance was 15.5 cm (range, 12 to 18 cm). The mean mass of tissue excised was 615 g per breast. A number of different pedicles were used (six inferior, five superior, four superomedial, one unknown). All patients subsequently developed pseudoptosis. The nipple to inframammary crease distance was a mean of 11.4 cm (having initially been set at 7 cm) before the second procedure. At the second operation, two patients (three breasts) had their initial pedicles transected and the nipple-areola complex moved, and both patients developed vascular compromise of the nipple-areola complex (two breasts). Where the same pedicle was used in the second operation (five patients, 10 breasts), one patient developed unilateral nipple-areola complex necrosis. In eight patients, because of the development of pseudoptosis, the nipple was in a satisfactory position, and therefore only an inferior wedge of tissue required excision. This was performed without nipple-areola complex compromise, irrespective of the initial pedicle. The mean mass of tissue excised in the second operation was 325 g per breast (range, 120 to 620 g). Fourteen patients were available for follow-up after a mean of 5.1 years (range, 3 months to 11.7 years) following the repeat reduction mammaplasty. In the repeat breast reduction, where nipple-areola complex transposition is planned, the initial pedicle should be reused to maintain nipple-areola complex perfusion. Where the initial pedicle is not known, a free nipple graft may be the safest option. In patients with pseudoptosis, in whom the nipple does not require transposition, an inferior wedge of tissue can be safely excised, irrespective of the initial pedicle.     

A surgical approach for earlobe keloid: keloid fillet flap

Earlobe keloid can form after cosmetic ear piercing, trauma, or burns, and it poses several difficulties in treatment and distinctive cosmetic implications. Treatment methods for earlobe keloids include both surgical and nonsurgical methods. After excision of the earlobe keloid, healing by secondary intention, primary suture, skin graft, or local flap has revealed some disadvantages. The authors approached this problem with a new excision and covering method. The surgery was performed under local anesthesia. Skin over the keloid was dissected from the keloid mass as a flap, which they termed a "keloid fillet flap," and the keloid mass was completely removed. Subcutaneous sutures were not used, and the keloid fillet flaps were closed with 6-0 nylon sutures after trimming. Other intraoperative or postoperative preventive procedures, such as steroid injection, pressure device, or irradiation, were not applied primarily. In the period from May of 1999 to October of 2000, nine earlobe keloids in eight patients were treated with this protocol. One patient had bilateral keloids. Of the eight patients, there were six women and two men, ranging in age from 21 to 61 years (mean age, 28.5 years). The causes of keloids were ear piercing in six cases and trauma in three cases. The largest lesion was 3 cm in its greatest dimension, and the smallest was 1.5 cm (mean, 2.3 cm). All flaps survived completely. There were four cases of recurrence. Seven cases, including two recurrences, showed good results. The authors believe the recurrence of earlobe keloid was closely related to the method for coverage of the defect after its surgical excision, and the "5 As and one B" (Asepsis, Atraumatic technique, Absence of raw surface, Avoidance of tension, Accurate approximation of wound margin, and complete Bleeding control) are important factors in reducing the recurrence rate of earlobe keloids in surgical excision. The authors' protocol is very effective in closing the defect after surgical excision of earlobe keloids and offers many advantages over other surgical approaches. The recurrence rate of earlobe keloid may be lower than in their results if other intraoperative and postoperative treatment procedures are combined with their protocol.     

A morphometric study of the external ear: age- and sex-related differences

The human ear is a defining feature of the face. Its subtle structures convey signs of age and sex that are unmistakable yet not easily defined. With analysis of normative cross-sectional data, this study explored anatomic and aesthetic differences in the ear between men and women, as well as changes in ear morphology with age. A total of 123 volunteers were randomly selected for this study. The cohort consisted of 89 women ages 19 to 65 years (median age, 42 years) and 34 men ages 18 to 61 years (median age, 35 years). The average total ear height across the entire cohort for both left and right ears was 6.30 cm, average lobular height was 1.88 cm, and average lobular width was 1.96 cm. As expected based on head size, significant sex-related differences were noted in the distance from the lateral palpebral commissure to both the helical root and insertion of the lobule. Measured distances in both vectors were approximately 4.6 percent longer in men than in women. Similarly, the height of the pinna was significantly larger in men than in women by approximately 6.5 percent. The average height and width of the lobule, however, were nearly identical in men and women. Analysis of age-related data showed a significant difference in the total ear height between the subpopulations; however, this difference was not significant after the lobular height was subtracted from total ear height, suggesting that the lobule was the only ear structure that changed significantly with age. In addition, lobular width decreased significantly with age. This study establishes normative data for ear morphology and clearly demonstrates the changes in earlobe morphology that occur with advancing age.     

Long-range afferents in the rat spinal cord. 1. Numbers, distances and conduction velocities.

The caudal extent of the penetration of primary afferent axons from the T12 and L1 dorsal roots and sural nerve has been investigated in adult decerebrate spinal rats. Microelectrode stimulation at the root entry zone (REZ) and at further caudal points in the spinal cord was used to generate antidromic action potentials in single fibres recorded in dorsal roots or peripheral nerves. A total of 209 units were recorded in T12 and L1 dorsal roots and 27% of these could be antidromically activated 10 mm caudal to the REZ. Fifteen percent of the units could be stimulated at the L4-5 border, 15 mm caudal to the T12 segment whereas 4.5% of the axons could be stimulated 25 mm caudally in the S4 segment, 11 segments caudal to the entry segment. Similar recordings made from units in the sural nerve showed that of all the sural axons that penetrated to the L6 segment 50%, 18% and 2% of these reached the S1, S2 and S4 segments respectively. The conduction velocities of these units were clearly in the A-beta range when recorded in the nerve but decreased on entering the spinal cord and were reduced by 83% at their caudal end point. The results show that substantial numbers of primary afferents have long-ranging caudal branches in areas beyond the regions of known postsynaptic effects. The functions of these caudal projections are unclear but they may represent a potential substrate for the development of functional connections under conditions of disease or denervation.     

Osteological development of the lophiid anglerfish,lophius gastrophysus

The osteological development of the head skeleton and dorsal, pectoral, and anal fin supports, are described from cleared and stained specimens ofLophius gastrophysus larvae, ranging from 4.6 to 21.8 mm NL; the results are compared with those of juvenile (79.8 mm SL) and adult (398 mm SL) specimens. Tiny conical teeth are present on the premaxillary, dentary, palatine and vomer since early stage. The first three dorsal fin spines are initially positioned on the midline of body posterior to the supraoccipital, but they migrate forward with growth and become cephalic in juveniles. The forward movement of the dorsal spines is produced by the forward extension of the cartilaginous basal inside the subepidermal space. During the planktonic larval stage the pectoral fins are on the sides of body as in ordinary fishes, but they move ventrad and become leg-like in bottom living juveniles and adults. Ossification of the caudal complex ofL. gastrophysus larvae proceeds very slowly and only the 21.8 mm NL larva has an almost completely ossified caudal complex. Eight principal caudal rays are loosely attached on the posterior edge of the hypurals and no procurrent rays are present. Larvae have well developed parhypurapophysis at the mid-portion of the urostyle which transforms into keel-like structure in juveniles and adults.     

Factors related to the time of fixation of the conceptus in mares

The temporal relationships among day of conceptus fixation (cessation of mobility), conceptus diameter, uterine tone, uterine contractility, and myometrial and endometrial thickness of the middle and caudal segments of the uterine horns were assessed in 13 pony mares with fixation in the caudal segment of a uterine horn. The mean day of fixation (14.9 +/- 0.3) was established by 2-h mobility trials. Uterine tone increased (P < 0.0001) gradually over Days 11 to 21, whereas uterine contractility decreased (P < 0.0001) between Days 14 and 18. The diameter of the spherical embryonic vesicle increased (P < 0.0001) between Days 11 and 17. The day of fixation and vesicle diameter on Day 14 were negatively correlated (r = -0.9, P < 0.007); the larger the vesicle, the earlier fixation occurred. Each of 4 uterine-horn diameters (endometrium and endometrium plus myometrium of middle and caudal segments) decreased (P < 0.0001) correspondingly over Days 11 to 21. On the day of fixation conceptus diameter (21.5 +/- 1.0 mm) was similar to endometrial diameter (21.1 +/- 0.4 mm) at the caudal segment. The endometrial diameter represents the distance between the inner opposite walls of the myometrium. The percentage of change between the day before and day of fixation was greater for the conceptus (18.1% increase) than for the endometrial diameter at the caudal segment (1.0% decrease). The results suggest that fixation occurred when the mobile and growing conceptus attained, on the average, a diameter equivalent to the distance between opposite inner myometrial walls at the caudal segment. The uterus became turgid by this time and presumably did not expand adequately to accommodate continued mobility of the expanding conceptus.     

Generation of segment polarity in the paraxial mesoderm of the zebrafish through a T-box-dependent inductive event

The first morphological sign of vertebrate postcranial body segmentation is the sequential production from posterior paraxial mesoderm of blocks of cells termed somites. Each of these embryonic structures is polarized along the anterior/posterior axis, a subdivision first distinguished by marker gene expression restricted to rostral or caudal territories of forming somites. To better understand the generation of segment polarity in vertebrates, we have studied the zebrafish mutant fused somites (fss), because its paraxial mesoderm lacks segment polarity. Previously examined markers of caudal half-segment identity are widely expressed, whereas markers of rostral identity are either missing or dramatically down-regulated, suggesting that the paraxial mesoderm of the fss mutant embryo is profoundly caudalized. These findings gave rise to a model for the formation of segment polarity in the zebrafish in which caudal is the default identity for paraxial mesoderm, upon which is patterned rostral identity in an fss-dependent manner. In contrast to this scheme, the caudal marker gene ephrinA1 was recently shown to be down-regulated in fss embryos. We now show that notch5, another caudal identity marker and a component of the Delta/Notch signaling system, is not expressed in the paraxial mesoderm of early segmentation stage fss embryos. We use cell transplantation to create genetic mosaics between fss and wild-type embryos in order to assay the requirement for fss function in notch5 expression. In contrast to the expression of rostral markers, which have a cell-autonomous requirement for fss, expression of notch5 is induced in fss cells at short range by nearby wild-type cells, indicating a cell-non-autonomous requirement for fss function in this process. These new data suggest that segment polarity is created in a three-step process in which cells that have assumed a rostral identity must subsequently communicate with their partially caudalized neighbors in order to induce the fully caudalized state.     

Lower auricular malformations: their representation, correction, and embryologic correlation

Seventy-seven lower auricular malformations in 74 patients treated during the last 6 years were analyzed. Sixty cases (77.9 percent) were of malformations involving the earlobe; 54 cases involved the earlobe alone, and 6 cases were of complex deformities involving the earlobe and adjacent helix and/or tragus. Cleft earlobe was the most common lower auricular malformation (49 cases, 63.6 percent); four subtypes and their corrective methods are described. Cases of complex earlobe malformations, corrected by fabricated costal cartilage and expanded skin flap, are presented. A question mark ear (5 cases, 6.5 percent), a malformation with an ectopic anthelical fold (5 cases, 6.5 percent), and a malformation with a lower conchal stria (5 cases, 6.5 percent) are considered to be major lower auricular malformations. An attempt has been made to correlate the presented malformations with the embryologic-fetal development of the auricle. It is suggested that "clefting" ear malformations such as the cleft earlobe, the question mark ear, and the ectopic anthelical fold deformity may provide clues to understanding the embryologic-fetal development of the human auricle. It appears that hillocks 1 and 6 produce the earlobe and that hillock 4 or 5 produces the anthelix or helix.     

The pigmentary system of planaria

The pigmentary system of the planaria, Dugesia gonocephala s.l. (Platyhelminthes, Turbellaria, Tricladida), consists of granules contained in chromatophore cells distributed in the parenchyma tissue. The administration of MSH release-inhibiting Factor (M.I.F.) leads to an easily observable general decolouration of the animal due to the migration of the pigment granules towards the deeper-lying cell nucleus. In planarians bisected transversely through the pharyngeal region, the decolouration occurs only in the cephalic segment, and the caudal segment remains dark. When, however, the decapitated caudal segment regenerates a head region, a decolouration response occurs when exposed to M.I.F. The significance of these results is discussed, and an hypothesis on the hormonal regulation of the pigmentary system is proposed.     

Observation of the embryonic development in Pseudoplatystoma coruscans (Siluriformes: Pimelodidae) under light and scanning electron microscopy

Pseudoplatystoma coruscans is a very popular species for tropical fish culture as it has boneless meat of delicate taste and firm texture. Few studies on fish reproductive biology refer to the morphological features of eggs. The goal, therefore, of this present work was to perform a structural and ultrastructural analysis of fertilization and embryonic development in P. coruscans. The incubation period, from fertilization to hatching, lasts 13 h at 28/29 degrees C and 18 h at 27 degrees C. The oocytes had a mean diameter of 0.95 mm and hatched larvae were 2.55 mm in diameter. Analysing their development, we observed round, yellow oocytes that bore a double chorion membrane and a single micropyle. At 10 s after fertilization, several spermatozoa were detected attached to the oocyte surface. After 1 min of development, a fertilization cone that obstructed the micropyle could be observed. Segmentation started between 20 and 30 min after fertilization, when the egg cell was then formed. The first cleavage occurred between 30 and 45 min after fertilization, prior to reaching the morula stage (75 and 90 min after fertilization). The epiboly movement started at 120 and 180 min after fertilization and ended at 360 and 480 min after fertilization. Differentiation between cephalic and caudal region was detected after 420 and 600 min after fertilization and larvae hatched between 780 and 1080 min after fertilization. Seven main embryonic development stages were identified: egg cell, cleavage, morula, blastula, gastrula, segmentation with differentiation between cephalic and caudal regions, and hatching.     

The pigmentary system of planaria

Summary The pigmentary system of the planaria, Dugesia gonocephala s.l. (Platyhelminthes, Turbellaria, Tricladida), consists of granules contained in chromatophore cells distributed in the parenchyma tissue. The administration of MSH release-Inhibiting Factor (M.I.F.) leads to an easily observable general decolouration of the animal due to the migration of the pigment granules towards the deeper-lying cell nucleus.In planarians bisected transversely through the pharyngeal region, the decolouration occurs only in the cephalic segment, and the caudal segment remains dark. When, however, the decapitated caudal segment regenerates a head region, a decolouration response occurs when exposed to M.I.F.The significance of these results is discussed, and an hypothesis on the hormonal regulation of the pigmentary system is proposed.     

Development of the vertebral column and caudal complex in a flyingfish,Parexocoetus mento mento (Teleostei: Exocoetidae)

The developmental pattern of the vertebral column and caudal complex in juvenile (16.9 mm SL) to adult (112.2 mm SL)Parexocoetus mento mento is described Juvenile external caudal morphology was similar to the adult condition, although juveniles exhibited various internal ontogenetic changes. Osteological develoment was almost completed at 60–69 mm SL. Complete ossification of the vertebral column and caudal complex appeared to be the optimal condition giving strength for flight. Loss of perforations in the centra, neural and haemal arches may be consistent with the rigid and straightened body position during take-off. Some ontogenetic changes in the caudal complex were related to functional aspects. Ankylosis of the NPU2 spur to the uroneural notch, fusion of hypurals 3+4 and 5 and the elongated hypural 1+2 (lower hypural) were linked to the acquisition of stability and strength in the caudal complex.