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At least 649 records · Page 36Linked to original sources

PubMed1979

Influence of two-flap paltoplasty on facial growth in rabbits.

Three groups of rabbits were used in this study. Group I consisted of control rabbits who had had no surgery. Group II had surgically created but unrepaired clefts of the lip, alveolus, and palate. Group III had surgically created clefts of the lip, alveolus, and palate with the palatal clept having been repaired using a two-flap palatoplasty. At the end of the twentieth postoperative week, all animals were sacrificed. Results of the direct cephalometry of the skulls did not confirm the hypothesis that palatal repair inhibits overall facial growth. At the same time, certain asymmetries of the maxilla and mandible were found. These may have resulted from selective inhibition of certain growth processes.

Alveolar Process↗

PubMed1988

[Genioplasty, indications and therapeutic methods in dento-maxillary malformations].

Genioplasty constitutes an adjunctive surgical procedure used in adult plastic surgery of the facial profile. It is used after dental malocclusion has been corrected and facial morphological features have been reassessed (soft tissue changes consecutive to maxillary osteotomy should be previously analyzed by cephalometry). Genioplasty permits achieving a modification of the chin point in the three planes. The authors describe several types of genioplastic operations, depending on the aim.

Adult↗

PubMed1988

Denervated palmaris longus tendon as a skeletal muscle transplant in circumferential pharyngoplasty.

The incidence of velopharyngeal incompetence (VPI) following cleft palate surgery is fairly high in our country. We have attempted to analyse the aetiology and then selected 50 cases of VPI from our group of operated cleft palates. These patients were then evaluated using cephalometry, speech rating, pressure studies and nasendoscopy. We identified 13 patients in whom there was incompetence due to failure of movement of the walls responsible for proper closure of the velopharyngeal port. In these patients we performed circumferential sling pharyngoplasty using denervated palmaris longus; since this procedure narrowed the port circumferentially. We re-evaluated these patients and the results have been gratifying. Speech rating improved and E.M.G. tracings after 6 months showed evidence of reinnervation of the Palmaris Longus.

Cephalometry↗

PubMed1988

Genetic and environmental factors in the longitudinal growth of rats: II. Ventrodorsal craniofacial size.

By means of roentgenographic cephalometry and quantitative genetic analysis, the relative contribution of the genetic and environmental components to the ontogenic change of the ventrodorsal view of the craniofacial complex was shown to vary with age. The genetic component of variance significantly increased until the 80th day. Inversely, the maternal component of variance showed a large value during the early stage of postnatal growth and gradually decreased thereafter to a very small amount by the 80th day. In general, it appeared that the genetic effect became larger with the age of the rat and the maternal effects tended to diminish. The environmental component of variance did not change much over the course of the experiment. We thus concluded that the genetic effect contributed to the change of the ontogenic variation of the craniofacial complex through all experimental periods and the maternal effect contributed to the change at the early growth stage of the craniofacial complex.

Aging↗

PubMed1986

Masticatory muscle function and craniofacial morphology. An experimental study in the growing rat fed a soft diet.

The present series of investigations was performed in order to study the relationship between masticatory function and craniofacial morphology, and to elucidate the mechanism underlying possible functional changes in the craniofacial growth in rats fed a soft diet. The experimental model chosen was comprised of young rats with altered masticatory function, induced by changing the consistency of the diet. Possible influences on the craniofacial growth were studied longitudinally by x-ray cephalometry, and the bone graft reaction in the facial skeletal regions of rats was assessed in sutures and cortical bone by vital stain, micro-radiography and routine histology. The attrition and eruption rate of the rat incisors were measured "clinically", and the effect of an increased attrition was tested cephalometrically, to see whether it influences the craniofacial growth. In order to evaluate the forces developed by the masticatory muscles the active tetanic tension was measured after electrical stimulation. The muscle fibre composition and the fibre size of the masseter and digastric muscles were examined after enzyme histochemical analysis. The craniofacial morphology and the growth pattern of the rats fed a soft diet were found to be changed to a more orthocranial one, while a decreased bone apposition was found in the angle of the mandible and the upper viscerocranium, with an alteration in the cranial sutures. The morphological changes observed were independent of the attrition and eruption rate of the rat incisors but seem to be related to the low masticatory forces developed by the rats fed a soft diet. The alteration in the "biting" force level was possibly due to the masticatory muscles changes in the muscle fibre types and the smaller size of the fibres, caused by the decreased functional demand on the rats fed a soft diet. Thus, it seems that the alteration in the masticatory function caused structural changes in the masticatory muscles, as well as changes in their contractive capacity. These may be considered as the results of prolonged centrally decided functional alteration brought about by changing the consistency of the diet. The reduced functional forces and the changes in the masticatory muscle contraction caused a low functional strain on the bone and less tension on the periosteal membrane. This tension in the periosteal membrane has also been shown to regulate the displacement of bones in the craniofacial region. The change in the masticatory function may have induced changes in the interosseous movements, which can be underlying reason for the obliterative osteogenesis in the internasal suture.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1987

Suprahyoid biomechanics and head posture. An electromyographic, videofluorographic and dynamographic study of hyo-mandibular function in man.

Suprahyoid and masseter muscle function was studied in 49 adult males with normal dentofacial morphology and normal soft tissue profiles, with special reference to head posture. The different parameters were investigated by EMG during chewing, by EMG synchronized to an opening force dynamograph during static and dynamic conditions, and by EMG synchronized to videofluorography during the open-close-clench cycle. Cephalometry was applied to evaluate the videofluorographic images of the hyo-mandibular complex. The EMG amplitude for the entire group did not vary significantly between different test occasions with an interval of 5-24 hours. The individual variation was large, however. Repeated EMG registrations within such time intervals should therefore be reliable for groups of individuals. Hook electrodes gave about 10% higher maximal EMG compared to surface electrodes. Registrations with the two types of electrodes could therefore not be directly compared. An increased interelectrode distance resulted in larger EMG amplitudes. The interelectrode distance should therefore be standardized. Head posture influenced the EMG amplitude and should therefore also be standardized. The electrical activity in suprahyoid muscle contraction preceded the mechanical activity. During opening, a time- lag of approximately 200 msec was found between the peak EMG activity of the anterior belly of the digastric muscle and the maximal opening force. A direct correlation existed between the IEMG activity of the digastric muscle and force during static (r = 0.89) and dynamic (r = 0.72) conditions. The maximal recorded force of the opening muscles of the mandible was found to be 70 N. No absolute reciprocity existed between opening and closing EMG activity. During chewing, suprahyoid maximal IEMG activity was less than one-third of that from the masseter. Maximal IEMG activity was reduced for the masseter during forward flexion, and for the suprahyoid muscle group during backward extension. Head posture is an important factor in EMG registrations of opening and closing muscle function during chewing. During upright head posture, the hyoid bone exhibited on average an elliptical movement pattern and reached its most elevated position at the start of opening and its most depressed position at the start of closing. A small movement before opening an upward and forward direction and before closing in a further downward and backward direction was found. Suprahyoid EMG activity was registered before start of opening, during opening and during the first half of the open phase.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1987

Anthropometric guidelines in cranio-orbital surgery.

Surface measurements and proportions of the cranio-orbital region provide valuable information to the surgeon both before and after surgery. They supplement the data obtained from x-ray cephalometry. Preoperatively, the proportion indices help to identify the most deformed areas and reveal which measurements contribute to the disproportion. When surgery is being planned, the defective measurements help the surgeon to calculate the changes necessary. After surgery, the quality of proportionality achieved permits assessment of the degree of improvement.

Adolescent↗

PubMed1985

The application of roentgencephalometry to the study of craniofacial anomalies.

Objective quantitative methods for standardized reproducible descriptions of the findings of an examination are prerequisite for the optimal care of patients with congenital or acquired craniofacial anomalies. The present report gives a brief review of the development of roentgencephalometry with special emphasis on the infant roentgencephalometric techniques pioneered by Dr. Samuel Pruzansky. In addition, some of the significant findings that have emerged from the application of these techniques to patients with craniofacial anomalies are presented, again, with emphasis on the contributions made by Dr. Pruzansky and co-workers. Finally, perspectives for future clinical and research work within the field are outlined. These perspectives include improvement of cephalometric units for studies of patients with craniofacial anomalies; inclusion of additional cephalometric projections, especially in patients with craniofacial asymmetry; increased utilization of infant cephalometry; utilization of metallic implants in selected cases; greater utilization of computerized cephalometrics and multivariate statistics; and combined use of longitudinal cephalometric studies and various longitudinal physiological examinations, eg, electromyography, kinesiography, and air flow studies, in the individual patient.

Cephalometry↗

PubMed1985

Routine ultrasound screening for the prediction of gestational age.

In a technician-oriented routine ultrasound program, the value of screening an entire obstetric population for predicting gestational age based on a single measurement was evaluated over selective scans performed on the basis of uncertain menstrual history. Consecutive pregnancies of 4527 women were scanned, and the results were analyzed. Gestational ages were determined by both menstrual history and ultrasonic crown-rump length or biparietal diameter (BPD) measurements. The estimated date of confinement based on ultrasound measurements was compared with menstrual history in its ability to predict the actual onset of spontaneous labor. Of patients with optimal menstrual history, 84.7% delivered within +/- two weeks of the date predicted. Only 69.7% delivered within +/- two weeks of the estimate date of confinement based on suspect menstrual history. Crown-rump length measurements were as predictive (84.6%) as optimal menstrual history. Biparietal diameter measurements done between 12 and 18 weeks' gestation were significantly more accurate in gestational predictions (89.4%) than those based on menstrual history (P less than .001). It is concluded that ultrasound cephalometry before 18 weeks is the single best dating parameter.

Cephalometry↗

PubMed1985

Age changes of skull dimensions.

At cranial level, external apposition during ageing has been postulated by some authors. In longitudinal studies, a gradual increase of cranial diameters has been shown by cephalometry (Kendrick et al. 1967) or by lateral radiography (Israel 1968, 1970). However, these results are contested at methodological level by other longitudinal studies (Tallgren 1974). It is the aim of this study to analyse, in a cross-sectional sample, the effects of senescence on several cephalic dimensions. A series of skulls of known age and sex has been selected for this purpose.

Adult↗

PubMed1984

Genetic variation and craniofacial growth in inbred rats.

There has been no experimental study clarifying the contribution of genetic variation to craniofacial growth on a longitudinal basis, although its importance is generally accepted. Utilizing diallel crosses of five strains of inbred rats, the present study concerns an estimation of the contribution genetic variation makes to the longitudinal change of craniofacial size. The overall sizes of craniofacial complex components of F1-offspring rats were investigated postnatally by means of roentgenographic cephalometry, and quantitative genetic analysis was performed by the method of Wearden [1964]. It was revealed that the relative contributions of the genetic and environmental components to total variance in craniofacial size varied with age and that the genetic component of variance significantly increased until the 80th day. On the other hand, the maternal component of variance showed the maximum value during the early periods of postnatal growth (ie, the 10th to 25th day), gradually declining thereafter to a very small amount by the 80th day. The environmental component of variance increased slightly and gradually with age through the experimental period. In conclusion it appeared that genetic variation became more significant during longitudinal growth of the craniofacial complex as the maternal effects diminished.

Age Factors↗

PubMedDate not supplied

[Determination of gestational age using crown-rump length and the biparietal diameter in the 1st half of pregnancy--comparison of 2 methods].

In the first half of pregnancy ultrasound investigations was made on women with known gestational age by regular menstruation or conception. In 221 cases of single pregnancies fetal crownrump length was measured. Biparietal cephalometry was performed in 198 single fetuses. All examinations were done with a Kranzbühler Linearscanner using an ADR 3.5 MHZ transducer. Growth curves and the velocity of growth from biparietal diameter and from crown-rump length were determined and compared. The accuracy of the estimation of gestational age was observed to be +/- 10 days (2 SD) with both methods. A difference in accuracy could not be found. Even if the first half of pregnancy was separated in an early and a late part there wasn't any improvement of accuracy.

Cephalometry↗

PubMed1983

Mandibular adaptations following total maxillary osteotomy in adolescent monkeys.

The purpose of this study was to investigate the growth and remodeling changes of the mandible following superior anterior surgical repositioning (Le Fort I) of the maxilla in adolescent Macaca fascicularis monkeys. Eight adolescent monkeys served as controls, and seven monkeys underwent surgical procedures. All monkeys received tantalum implants on both sides of certain facial bones for stereometric and conventional cephalometry. The animals were followed up to 24 months postoperatively. Analysis of cephalometric head films taken at monthly intervals shows that both the maxillas and the mandibles of the experimental monkeys grew harmoniously, although the amount and direction of growth showed significant changes compared to the controls. The mandibles of experimental monkeys that underwent autorotation immediately following the surgical procedures showed 36 to 60 percent less growth as measured from condylion to menton, condylion to gonion, and gonion to menton. Similarly, the anterior dental-alveolar-symphyseal height showed 75 percent less increase as compared to the controls. The results show that, although the surgical procedure was performed on the maxilla, the mandibular growth showed significant modulation to adapt to the surgically changed maxillary environment. The role of occlusion and function is discussed in the context of the present findings.

Animals↗

PubMed1978

Intrauterine growth retardation. Antenatal diagnosis by ultrasound.

Serial cephalometry is useful not only in defining the risk for intrauterine growth retardation (IUGR) in relation to each fetus' growth potential but also in identifying symmetric versus asymmetric undergrown fetuses. It is suggested that all fetuses with biparietal diameters falling below the 25th percentile or dropping to a lower percentile division undergo biophysical and biochemical monitoring for detection of the affected fetus. The value of the head-to-abdomen circumference ratio close to term in delineating asymmetric undergrown fetuses is discussed.

Cephalometry↗

PubMed1980

The influence of simultaneous cleft lip and palate repair on facial growth in rabbits.

This study was designed to test the influence of simultaneous cleft lip and palate repair on facial growth in rabbits. Three groups of rabbits were used. Group I consisted of control rabbits who had no surgery; Group II had surgically created, but unrepaired, clefts of the lip, alveolus, and palate; and Group III had surgically created clefts of the lip, alveolus, and palate followed by immediate simultaneous lip and palate repair. In Group III, the lip was repaired using the Millare technique and the palate using two-flap palatoplasty, leaving no bare bone exposed. All animals were sacrificed after twenty weeks. Results of the direct cephalometry of the skulls confirmed that simultaneous lip and palate repair results in inhibition of anterior-posterior and transverse maxillary growth. Some significant changes were also found in mandibular length and nasal deflection. All 15 rabbits with simultaneous cleft lip and palate repair developed anterior crossbites and functional shifts to the left or cleft side. Further analysis comparing the results of facial growth inhibition in this study with inhibition following lip repair only or palate repair only will be necessary to assess the severity of secondary maxillo-facial deformities resulting from lip and palate repair.

Animals↗

PubMed1980

Biometric and dynamic ultrasound assessment of small-for-dates infants: report of 260 cases.

The accuracy of 4 ultrasonic parameters and their combined use of detecting fetal growth retardation in a group of 260 small-for-dates infants are analyzed. Abdominal circumference measurement was the most accurate single ultrasonic technique. By combining this measurement with fetal cephalometry, it was possible to diagnose antenatally 96.8% of the small-for-dates infants. Fetal urinary production was below the normal mean in 94.3% of these infants. All except 1 asymmetric growth-retarded fetus had a fetal breathing movement rate lower than that of a normal fetus. The perinatal mortality was significantly decreased in a group of ultrasonically detected growth-retarded fetuses, as compared with the group of unrecognized small-for-dates fetuses.

Cephalometry↗

PubMedDate not supplied

Facial growth and development in unilateral cleft lip and palate from the time of palatoplasty to the onset of puberty: a longitudinal study.

X-ray cephalometry was used for the assessment of facial growth and development from the time of palate surgery to the onset of puberty (from 5 to 11 years) in 24 boys with unilateral cleft lip and palate treated with primary periosteoplasty (at 8 months) and palatal pushback supplemented by pharyngeal flap surgery (at 5 years). The lowest growth showed the depth of the maxilla and the height of the upper lip. An increasing protrusion of the mandible and in particular the increasing retrusion of the maxilla resulted in a flattening of the face and in an impairment of sagittal jaw relations. However, it was possible to attain an improvement of overjet produced by a substantial increase of the proclination of upper incisors and of the alveolar process. There was a deterioration of the prominence of the upper lip. Anterior growth rotation was absent during the development of the face, though a rotation in both directions was quite common in individual cases. The steepness of the mandibular body, vertical jaw relations, and facial vertical proportions remained unchanged. As compared to the pubertal period, the growth and development differed only by a more marked proclination of the dentoalveolar component of the maxilla and by an improvement of overjet. Facial convexity and sagittal jaw relations deteriorated in more than 90% of the patients, the overjet only in 20%, yet the prominence of the lip in 70%. Facial convexity and sagittal jaw relations were not correlated with mandibular rotation but they affected the overjet and the prominence of the upper lip.(ABSTRACT TRUNCATED AT 250 WORDS)

Cephalometry↗

PubMed1995

[Cephalometric indices in patients with sleep apnea syndrome].

The cephalometric indexes of 16 patients with obstructive sleep apnea syndrome (OSAS) were compared with those of 12 controls in order to determine if fundamental anatomical changes were present in the patients and to identify a pattern of facial features that might be characteristic of individuals with OSAS. Our results point to micrognathia of the upper maxilla in OSAS patients (indicated by significantly lower indexes for convexity, Mx 1, and the angles SNA and ANB). We also found a longer soft palate and a functionally shallower pharynx. Together theses features reduce the permeability of the posterior pharyngeal air space. Additionally, we observed a dolichocephalic facial pattern in OSAS patients, along with a tendency to morbid anterior opening. We analyze the limitations of conventional cephalometry. While recognizing its usefulness in establishing baseline indexes before treatment and in postsurgical assessment, we nevertheless point out that it cannot be relied upon as the only test for evaluating surgical correction in OSAS patients.

Adult↗