Biomedical subjects

Z Smahel

Publications and source records attributed to Z Smahel.

At least 37 records · Page 2Linked to original sources

PubMed1997

Changes of craniofacial growth and development in males with complete unilateral cleft lip and palate between the age of 5 to 20 years.

The study is based on an anthropometric assessment of X-ray films obtained in two series of males with complete unilateral cleft lip and palate. The first series was examined at the age of 5, 10 and 15 years, the second series at 15 and 20 years. The films were assessed with Jarabak's analysis. The aim of our study was to compare the amount of growth and character of developmental changes in the prepubertal, pubertal and postpubertal period of life. The highest growth rate of skeletal structures was present in the prepubertal period, it was somewhat slighter in the pubertal period and it still continued in the postpubertal period. The high growth rate in the prepubertal period was probably related to the eruption of permanent teeth. In spite of a marked deterioration of sagittal jaw relations during the prepubertal period an improvement of an overjet was attained. However during the puberty and the postpubertal period a further improvement was not recorded. The results are in agreement with facial type of growth characterized by a slight pubertal spurt.

Adolescent↗

PubMed1997

Influence of primary septal cartilage reposition on development of the nose in UCLP.

The preceding study (Smahel, 1987) showed that after the abolishment of osteoplasty and introduction of primary reposition of nasal septum base in the 1970's the nasal deviation and asymmetry of nasal wing length in patients with unilateral cleft lip and palate had been reduced. The present study shows that this reduction continues after the introduction of total septum reposition. The deviation of septal base (columella) from the median plane and asymmetry in nostril position is reduced as well. The surgeon's experience however is the decisive factor determining the final shape of the nose.

Case-Control Studies↗

PubMed1997

Nomogram for assessment of restoration of a positive overjet in unilateral cleft lip and palate.

In 92 patients with unilateral cleft lip and palate investigated on a long-term basis correlation-regression analysis of the development of overjet according to the development of interalveolar relations assessed in a defined method from X-ray films at the ages of 5, 10, 15 years and in adult age was implemented. The limits comprising 95% of the assembled data were also defined. Based on this analysis a formerly elaborated nomogram for age 10-15 years was extended for the whole postnatal period. Nomogram makes it possible to estimate from a single X-ray cephalometric parameter the risk of failure of the restoration of a positive overjet according to the age of the patient. The system defines critical boundaries which must be achieved for safe restoration of a positive overjet and makes it possible to check the course of treatment. The simple work with the nomogram and readily obtainable baseline data (age and X-ray cephalometric parameter on the interalveolar relations) make its application in clinical practice possible. It can serve as part of the documentation of the patient's therapy.

Adolescent↗

PubMed1996

Position of upper permanent central incisors prior to eruption in unilateral cleft lip and palate.

The position and degree of eruption of permanent central incisors within the premaxilla were measured on x-ray films obtained in 102 patients with unilateral cleft lip and palate and in 52 normal individuals aged 5 years. The patients were subdivided according to sex and to the method of surgical repair (bone grafting or periosteal flap surgery). Individuals with rotated incisors were assessed separately. The results showed that maxillary depth was not significantly reduced prior to palate surgery while the alveolar process was markedly retroclined. An unerupted central upper incisor on the side of the cleft was situated more anteriorly than in controls. Because of the distortion of the alveolar process, it was retroclined and produced a deformation of the subspinal concavity. Both this deformation and the distortion of the alveolar process interfered with the measurements of maxillary depth and rendered it inadequate. The incisor on the normal side was situated more posteriorly than in controls and was less retroclined than the incisor on the affected side. The degree of eruption of incisors on both the normal and affected sides did not differ from controls. The type of surgical repair influenced only the retroclination of the alveolar process and of the incisors within this process. The retroclination was more marked after primary bone grafting than after periosteal flap surgery. The position and degree of eruption of rotated incisors did not differ from nonrotated incisors, and the presence of rotated incisors was not related to the degree of the shortening of maxillary depth. There were no significant differences between males and females.

Bone Transplantation↗

PubMed1996

Facial growth after primary periosteoplasty versus primary bone grafting in unilateral cleft lip and palate.

A cephalometric evaluation of long-term changes resulting from two different surgical techniques for the correction of unilateral cleft lip and palate (UCLP) was undertaken on a sample of 19 males with primary bone grafting, and 42 males with primary periosteoplasty from the Science Academy of the Czech Republic, Prague. Lateral cephalometric radiographs collected at approximately 10 and 15 years of age were traced, digitized, and analyzed using the finite-element method. Facial growth and development between the two groups were compared. Significant differences between the two groups were found in the upper face, the posterior part of the maxilla, the anterior bony chin, and nasal bone areas. The periosteoplasty group demonstrated significantly greater vertical development between anterior cranial base and the maxilla. The bony chin was larger and a greater inferior displacement of the posterior palate were found in the periosteoplasty group. An increased proclination in the nasal bone was observed in the bone graft group. This investigation both confirms the findings of a previous study of these sample populations, and provides additional important details regarding the differences between the groups.

Adolescent↗

PubMed1996

Facial development in unilateral cleft lip and palate prior to the eruption of permanent incisors after primary bone grafting and periosteal flap surgery.

Roentgencephalometric studies were carried out at the age of five years in 27 boys with unilateral cleft lip and palate after primary bone grafting, as well as in 25 boys with the same type of cleft after primary periosteoplasty and in 27 normal boys who served as a group of controls. Both series with clefts differed from the group of controls by a reduced upper face height, maxillary dentoalveolar retroinclination, posterior position of the maxilla and by the shortening of mandibular body and ramus. There was a slight reduction of maxillary depth only in the series with bone grafts. The other skeletal deviations were secondary. The soft profile showed in both series with clefts a reduction of the upper lip height and of the nasal prominence. In patients with bone grafts was recorded in addition a reduced prominence of the upper lip. A comparison of both series with clefts disclosed that primary bone grafting reduced the vertical growth of the upper face and increased the dentoalveolar retroinclination of the maxilla resulting in a larger impairment of overjet and in a more marked retrocheilia. A better prominence of the nose in the series with periosteal flap surgery was produced by the primary reposition of the nasal septum, which was not performed during osteoplasty.

Bone Transplantation↗

PubMed1995

Craniofacial growth and development in unilateral cleft lip and palate: clinical implications (a review).

The main problem of facial development in cleft palate consists of deficient anterior growth of the upper jaw. Roentgencephalometric data showed that the sagittal jaw relations deteriorated gradually from palate surgery up to adulthood. In spite of this adverse trend of growth, orthodontic therapy succeeded in improving the occlusion of incisors during prepubertal period. However during the pubertal growth spurt occurred an impairment of occlusion which was caused by the depletion of compensatory dentoalveolar mechanisms of the jaws due to the previous orthodontic treatment. An effective compensation of the gradual impairment of sagittal jaw relations can be attained with fixed appliances. These observations showed that the main problems of facial growth in clefts developed only after palate surgery and in particular during puberty. For favourable sagittal jaw relations and the configuration of the facial profile is of paramount importance the restoration of a positive overjet which exerts marked effects on the position of the mandible. On the other hand the configuration of the facial profile and the results of orthodontic therapy are affected by the rotation of the lower jaw and the amount of posterior displacement of the TM joint, which represent inborn growth patterns of the skull. The most favourable developmental situation represents the posterior displacement of the TM joint associated with neutral type of rotation. Therefore, it is of importance to predict the development of these characteristics.

Adolescent↗

PubMed1994

Development of overjet and dentoskeletal relations in unilateral cleft lip and palate before and during puberty.

Roentgencephalometry was used for the assessment of the development of clinically important facial characteristics in complete unilateral cleft lip and palate during the prepubertal and pubertal period. Thirty-one patients aged 8 and 11 years and 30 patients aged 11 and 14 years were examined repeatedly. All of them were operated upon and orthodontically treated with the same methods. An unfavorable development of facial convexity, sagittal jaw relations, configuration of the soft profile, and of the prominence of the upper lip occurred during both periods. An improvement of overjet that was attained during the prepubertal period showed a renewed impairment during the period of puberty. The impairment was not caused by the higher facial growth rate, but was attributable to the exhaustion of the compensation and adaptation mechanisms of the dentoalveolar component of the upper jaw produced by the preceding orthodontic therapy. The development of sagittal jaw relations and of facial rotation was not related to the initial patterns of these characteristics, but the possibility of an improvement of the inclination of upper incisors and of overjet was influenced by their initial pattern. During the prepubertal period the development of overjet was not related to the development of sagittal jaw relations or of mandibular growth rotation, as was the case during puberty.

Adolescent↗

PubMed1994

Facial growth and development in unilateral cleft lip and palate during the period of puberty: comparison of the development after periosteoplasty and after primary bone grafting.

X-ray cephalometry was used in studies of facial growth and development carried out in 32 males with complete unilateral cleft lip and palate. They underwent primary periosteoplasty and were examined at the ages of 10 and 15 years. The results were compared with the development of the face in a longitudinal study of 20 males with the same type of cleft who were operated with a primary bone graft. The series with periosteoplasty showed a more marked proclination of the upper dentoalveolar component with the restoration of a positive overjet, as compared to a persistent anterior crossbite in the males with bone grafts. The lower jaw showed a larger protrusion, while individuals with bone grafts were characterized at the ages of 10 and 15 years by a larger posterior rotation of the mandible. The growth of the maxilla did not differ between series. In both series, there was a marked reduction in the growth of maxillary depth and of upper lip height, while the highest growth rate showed parameters of nasal prominence. An increasing mandibular protrusion and maxillary retrusion resulted in an impairment of sagittal jaw relations and in the flattening of the face, both of which occurred in almost all patients. The rotation of the lower jaw was not correlated with either the convexity of the face, sagittal jaw relations, or an overjet. The independence of developmental changes of selected characteristics at their initial state documented the impossibility of predicting the development of the face on the basis of a single x-ray examination at a given stage of development. Fixed appliances promoted a more marked proclination of upper incisors and the alveolar process than removable appliances, but they exerted no direct action on the other facial parameters studied.

Adolescent↗

PubMed1994

Treatment effects on facial development in patients with unilateral cleft lip and palate.

Retrospective studies into the effects of some aspects of treatment on facial development were based on x-ray films obtained in 58 men with unilateral cleft lip and palate operated on by palatal pushback. Because of mandibular retroposition, individuals subjected to systematic orthodontic treatment had better sagittal jaw relations and occlusion of incisors than insufficiently treated patients. The retroposition was attained with orthodontic proclination of upper incisors leading to a positive overjet and retraining the anterior development of the mandible. In patients with complete clefts operated on at about 6 years of age, sagittal jaw relations were more favorable than in those who had surgical repair at 4 years of age. The superior results in the group operated at a later age were due, in part, to the slighter retrusion of the maxilla. These differences were not apparent in incomplete clefts nor in patients with isolated cleft palate reported earlier. On the basis of these observations, a differentiated approach was proposed for determining the most convenient age for palatoplasty, according to individual types of clefts and their extent. The findings provided evidence of the essential role of orthodontic therapy for the configuration of the lower face in clefts.

Adult↗

PubMed1994

Effects of mandibular growth patterns on the development and configuration of the face in patients with unilateral cleft lip and palate.

Radiographic cephalometry has been used for the assessment of the effects of mandibular rotation and of posterior growth displacement of the temporomandibular joint on the development of the face and on overjet in 43 patients with complete unilateral cleft lip and palate between the ages of 10 and 15 years. Rotation acted mainly on vertical facial measurements and on the position of the lower jaw. The degree of posterior displacement of the temporomandibular joint exerted an influence on the position of the mandible, on the difference between the functional length of the upper and lower jaw, and on the occlusion of incisors. The direction of growth of the mandible as a whole represented the result of a combination of changes produced by the rotation of the jaw and by the degree of posterior displacement of the temporomandibular joint. The most favourable conditions for development were a combination of the neutral type of rotation with a more pronounced posterior displacement of the temporomandibular joint.

Adolescent↗

PubMed1994

The prediction of restoration of a positive overjet in unilateral cleft lip and palate.

X-ray cephalometric studies were carried out repeatedly in 92 individuals with unilateral cleft lip and palate at the age of 10 and 15 years with investigations of a possible restoration of a positive overjet in relation to the development of sagittal interalveolar relations. On the basis of this analysis was constructed a nomogram which according to the age of the patient allows to use a single easily determined X-ray cephalometric parameter for the estimation of the risk of a failure of the management aimed at the restoration of a positive overjet. The system includes critical boundaries which should be attained in the course of the treatment for the restoration of a positive overjet and it provides the possibility to check the effects of all therapeutic procedures. The simple application of the nomogram and the easy collection of data (the age and sagittal interalveolar relations) allow its use in the clinical practice as a component of the documentation on the management of the patient.

Adolescent↗

PubMed1993

Effects of premaxillary setback and of prolongation of the columella on the configuration of the facial profile in complete bilateral cleft lip and palate.

Roentgen-cephalometric studies were carried out in 26 adult males with complete bilateral cleft lip and palate. They were subdivided two times in two subgroups, with and without premaxillary setback, and with and without prolongation of the columella. The subgroups were compared mutually, as well as with a group of controls including 50 males matched in age. Premaxillary setback during childhood resulted in a more marked retrusion of the maxilla in adulthood. A simultaneous slighter oral slope of the premaxilla led to a normalization of the upper face height. Skeletal deviations acted on the configuration of the soft profile, in particular of the nasolabial transition: the slope of the columella towards the profile was reduced and so was the nasolabial angle. Thus the region appeared more markedly sunken. This surgical procedure should be used only in an exceptional situation in a small or posteriorly rotated mandible. Prolongation of the columella resulted in an excessive nasal depth. This was not caused by an adequate elevation of the tip of the nose which corrected a flattening of the tip, but rather by the sunken upper lip. An unfavourable effect exerted also a larger deepening of the nasolabial transition after a prolongation of the columella. However a slighter prolongation of the columella did not allow a sufficient elevation of the nasal tip. It is therefore necessary to seek a compromise.

Adult↗

PubMed1993

The effect of two-stage palatoplasty on facial development in unilateral cleft lip and palate.

Measurements on X-ray films were used for the assessment of facial development in 24 individuals with complete unilateral cleft lip and palate, ranging in age from 10 to 11 years and operated upon in two stages. The suture of the velum was performed simultaneously with cheiloplasty at the age of 7 months, the suture of the hard palate followed at the age of 6 years. They were compared with a series of 27 individuals with the same type of cleft who were subjected to one-stage closure of the palate at the age of 4 years. But for the more favourable occlusion of incisors after two-stage palatoplasty, which was due to the more intense orthodontic therapy, these two series showed no differences in facial growth and development. The delay of surgical repair of the hard palate by two years did not improve the growth and development of jaws. However, it is not possible to exclude favourable effects of a delay of the suture of hard palate into a substantially more mature age.

Cleft Lip↗

PubMed1993

Effects of soft tissue and osseous bridge on facial configuration in adults with unilateral cleft lip and palate.

Roentgencephalometric study was used for the assessment of 16 adult males with unilateral cleft lip and palate and an osseous bridge and of 10 males with a soft tissue bridge. They were compared with 32 individuals with a complete cleft and with a control group of 50 normal males. All patients were operated upon and subsequently treated with the same methods. In contrast to the soft bridge, an osseous bridge prevents the reduction of upper face height, and an increased width of the nasal cavity. Both an osseous and a soft tissue bridge exert a favorable effect on the shortening and retrusion of the maxilla and thus also on the maxillo-mandibular relations and on facial configuration. The thickness of the upper lip is related to the presence of a soft bridge, while deviations of the lower jaw and the posterior position of the maxilla are not related to the presence of either type of bridge. Alveolar retroinclination was insignificantly smaller in the presence of both types of bridges. These differences disclosed that clefts with soft bridges cannot be pooled with complete clefts (or with clefts with osseous bridges), when there is not definite evidence of the same proportion of both forms of clefts in the series used for comparison.

Adult↗

PubMed1992

Nasopharyngeal characteristics in children with cleft lip and palate.

Cephalometric assessment of the nasopharynx and its adjacent structures was carried out in two experimental groups of 5-year-old male patients with unilateral cleft lip and palate. The first group included individuals who had not had surgery, and the second was comprised of individuals who were at least 1 year postpalatoplasty with primary pharyngeal flap. They were compared with a control group of boys of comparable average age who did not have clefts. Both groups of patients with clefts showed a reduction of the nasopharyngeal bony framework related to the posterior position and decreased posterior height of the maxilla without hypertrophy of the adenoids. The smaller nasopharyngeal airway was consistent with the reduction of the size of the bony nasopharynx. There was shortening of the anterior cranial base located in the region of the middle cranial fossa. The height of the body of the sphenoid bone was reduced, but the angle of the cranial base was within normal limits.

Adenoids↗

PubMed1992

Growth and development of the face in complete unilateral cleft lip and palate during prepubertal and pubertal periods.

Roentgencephalometry was used for the assessment of the growth and development of the face during prepubertal and pubertal periods in children with complete unilateral cleft lip and palate treated with the same methods. The first series included 16 boys and 15 girls, the second series consisted of 15 boys and 15 girls examined repeatedly at the beginning and at the end of the follow-up period. There were no definite differences in the growth rate of the face between the two periods of age. Therefore, the deterioration of overjet during puberty could be due to the depletion of the compensation and adaptation mechanisms after the previous orthodontic treatment rather than to the enhanced growth rate. As compared to other facial dimensions a lower growth rate showed during both periods the length of the anterior base, the depth of the maxilla and in particular the height of the upper lip. Developmental changes of variables of shape and position proceeded similarly during both periods of age. An exception represented the rotation of the mandible and the inclination of upper incisors. During the prepubertal period the lower jaw showed a very slight posterior rotation, while during puberty an anterior growth rotation was present. A rapid improvement of the proclination of upper incisors was attained only during the prepubertal period. It was accompanied by an improvement of overjet. However, during the period of puberty there was a renewed deterioration of overjet. A marked retrusion of the maxilla developed already in the prepubertal period. During both periods occurred an identical impairment of sagittal jaw relations and of the upper lip prominence, accompanied by a flattening of the facial profile and reduction of the nasolabial angle. The prominence of the nose increased, the angle of the cranial base remained unchanged. Intersexual differences were not demonstrated in any studied characteristics.

Adolescent↗

PubMed1992

Configuration of facial profile in adults with cleft lip with or without cleft palate.

X-ray cephalometric studies were carried out in 114 adult males with cleft lip and with or without cleft palate. According to the type and extent of the cleft they were subdivided into 4 groups and were compared with a control group of 50 normal males matched in age. Investigated were the parameters of the skeletal and soft facial profile. The results showed that cleft lip alone is associated with deviations of local character concerning only soft tissues within the oronasal region. The ascertained deviations included a flattening of the nose, reduction of the height, concavity and prominence of the upper lip, increased height of the upper lip vermilion and a more horizontal slope of the columella leading to a reduction of the nasolabial angle. Cleft lip and palate was associated with deviations of global character related predominantly to the extent of retrusion of the upper and lower jaw. The skeletal profile was altered and its deviations were reflected by changes of the soft profile. Of the deviations of soft tissues per se were most important the flattening of the nose and reduction of the height and thickness of the upper lip, which underlined the presence of retrocheilia. Maxillary retrusion was more marked in complete than in incomplete unilateral clefts, while mandibular retrusion and maxillary dentoalveolar retroinclination were more marked in bilateral than in unilateral clefts. Occlusion was always impaired. In unilateral involvement, especially in complete clefts the more horizontal slope of the columella resulted in a marked reduction of the nasolabial angle. Incomplete clefts, similarly as cleft lip alone were not associated with a reduction of thickness of the upper lip and showed an increase of the vermilion height. Because of the persisting protrusion of the premaxilla bilateral clefts were accompanied by only a slight flattening of the skeletal profile and by an excessive nasal depth after the prolongation of the columella. The nasolabial angle was unchanged. The concavity of the upper lip was reduced in complete unilateral and bilateral clefts. Certain characteristics of the oronasal region disclosed a similarity between incomplete cleft lip and palate (in unilateral involvement) and cleft lip alone, however global deviations (due to skeletal changes) were identical with those recorded in complete clefts.

Adult↗