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Biomedical subjects

M Sakuda

Publications and source records attributed to M Sakuda.

At least 55 records · Page 3Linked to original sources
PubMed1997

Palatal configuration in complete bilateral cleft lip and palate infants before and after cheiloplasty.

OBJECTIVE: The purpose of this study was to analyze the three-dimensional configuration of the premaxilla, vomer, and lateral segments in bilateral cleft lip and palate (BCLP) infants and to investigate the early changes in the configuration following one- and two-stage cheiloplasty. METHODS: This study consisted of 10 complete BCLP infants. One-stage operations were performed in five patients according to Manchester's method at 4 months of age. Two-stage operations were done for the remaining five patients using a triangular flap according to Tennison's method, at 4 and 8 months of age. Serial plaster models before and after the cheiloplasty were measured with a computer-controlled, highly accurate, contact-type measuring apparatus. Temporal changes in the configuration and form of the premaxilla were observed using an automatic superimposition method. The inclination and deviation of the vomer were evaluated using an approximation technique to a straight line with least squares. The distance between the lateral segments and a three-dimensional coordinate of the incisal point were also measured. RESULTS AND CONCLUSIONS: The following differences in palatal configuration between the one- and two-stage cheiloplasties were observed: 1) In the two-stage group, the premaxilla shifted toward the cleft edge where the cheiloplasty was performed in both first- and second-stage operations. After the two-stage operation, the premaxilla did not shift greatly, and the premaxilla in cases 4 and 5 shifted downward and toward the cleft edge of the lateral segments where the first operation was performed. Protrusion of the premaxilla remained in the two-stage group. 2) In the one-stage group, the premaxilla in case 4 descended downward and backward without twisting or bending. The premaxilla of the other patients descended downward with twisting and bending. 3) Patients in the two-stage group had a stronger tendency toward medial collapse of the lateral segments than did those in the one-stage group.

Calcium Sulfate↗
PubMed1996

Stress distribution in the temporomandibular joint produced by orthopedic chincup forces applied in varying directions: a three-dimensional analytic approach with the finite element method.

Stress distribution in the temporomandibular joint (TMJ) during chincup therapy was investigated by means of a three-dimensional finite element model of the mandible, including the TMJ. An orthopedic chincup force of 400 gf (3.92 N) was applied at the pogonion of the mandible in the directions ranging from -50 degrees to 40 degrees, relative to the line connecting the pogonion and condyle. Compressive stresses, widely distributed on the condyle and glenoid fossa and in the articular disk, were larger in the posterior area than in the anterior and middle regions, when the force direction was from -50 degrees to 0 degree, whereas the forces applied in the remaining directions produced relatively uniform stress distributions. An interesting finding was that tensile stresses were induced in the anterior region of the articular disk, irrespective of force direction, although the remaining areas experienced compressive stresses. It is shown that changes in stresses in the TMJ are highly pertinent to the direction of chincup forces. When the directional angle was around -50 degrees, the variation in stresses in the TMJ was greatest. As the angle was changed to 30 degrees or 40 degrees, the stresses approached a certain level of compressive stress, which indicated the force direction as an optimal application of orothopedic chincup force in terms of biomechanically balanced stress distribution for the TMJ components.

Chin↗
PubMed1996

Three cases of oblique facial cleft.

Three patients with an oblique facial cleft are described. One patient displayed ring constriction, lymphoedema, distal pseudosyndactyly and an occipital encephalocele to which an amniotic band was attached at birth. Therefore, it was obvious that the oblique facial cleft was accompanied by an amnion rupture sequence. These signs were not apparent in the other patients. However, one of the patients demonstrated various anomalies, amongst which syndactyly on the right foot, scoliosis, microcephaly, microphthalmia and corneal opacity suggested that the patient may have been affected by the amnion rupture sequence, except for polydactyly on the left foot, cleft hand and vertebra plana.

Abnormalities, Multiple↗
PubMed1996

Case report: hypoglossia-hypodactylia syndrome.

A case of hypoglossia-hypodactylia syndrome is described. The infant was characterized by micrognathia, accompanied by a defect of the gingiva, and hypoplasia of the tongue. There was defect in the right arm below the elbow. The right foot manifested syndactyly of the great, second and third toes and osseous fusion of the first and second metatarsi and proximal phalanges. In the left foot brachydactyly of the great and fifth toes, syndactyly of the second, third and fourth toes, hypoplasia of the first and second metatarsi and defect in the first phalanx were evident.

Abnormalities, Multiple↗
PubMed1996

Gigantic dense bone island of the jaw.

The clinical and radiographic features of gigantic dense bone islands of the jaw were reviewed in 21 subjects to better determine the pathogenesis of this condition. Most of the islands were asymptomatic. They showed a striking predilection for occurrence in the premolar to molar region of the mandible. The greatest dimension of gigantic dense bone islands measured on panoramic radiographs ranged from 2.5 to 7.0 cm, and they were most commonly structureless radiopaque areas. None showed bony expansion buccolingually, nor did they displace adjacent teeth or bony anatomic structures. It is concluded that gigantic dense bone island is not a benign bone neoplasm and is perhaps merely a large counterpart of smaller dense bone islands or idiopathic osteosclerosis.

Adolescent↗
PubMed1996

Radiographic investigation of mandibular periostitis ossificans in 55 cases.

The radiographic and clinical features of periostitis ossificans in 55 patients with mandibular osteomyelitis were studied. On the basis of whether the original mandibular contour was preserved or not, the lesions could be classified radiographically into two major types, each with two subtypes. Type I lesions were of shorter duration than Type II. Type 1-2 and Type II-1 periostitis ossificans were characteristically observed in patients under 25 years of age. Extraction of the lower third molar with pericoronitis was the most frequent cause of periostitis ossificans. An unerupted third molar tooth bud was found in close proximity to the area of periostitis ossificans in six patients. With adequate treatment there can be complete resolution of periostitis ossificans in Type I cases; however, when there has been loss of mandibular contour (Type II cases), mandibular deformity remains even when normal bony architecture has been restored.

Adolescent↗
PubMed1996

Application of a new method for anthropometric analysis of the nose.

An accurate, quantitative method of measuring external nasal forms was developed in which facial plaster models were measured with a highly accurate contact-type three-dimensional coordinate measurement apparatus. Subsequently, we have developed techniques to identify the landmarks of a face automatically from the three-dimensional data and to superimpose two sets of data automatically for the purpose of sectional and longitudinal analyses, respectively. These techniques were applied to patients with unilateral cleft lip nasal deformities. Consequently, we were able to observe shifts in the facial landmarks and subtle three-dimensional changes.

Adolescent↗
PubMed1996

Tongue, jaw, and lip muscle activity and jaw movement during experimental chewing efforts in man.

The electromyographic (EMG) activity of the human genioglossus (GG) muscle during chewing efforts is not fully understood. In this study, the EMG activity of the human GG muscle during unilateral gum chewing was illustrated and correlated with the activities in the anterior temporalis (AT), the anterior digastric (DG), and the inferior orbicularis oris (OI) muscles. GG muscle activity was measured with customized surface electrodes, while other muscles were recorded with conventional surface electrodes. EMG activities during tongue displacement and the articulation of long vowels, recorded by the customized electrodes, were consistent with the recordings obtained by fine wire electrodes placed in the GG muscle. Jaw displacement was monitored by means of a kinesiograph with a transducer attached to the mandibular central incisors. Mean normalized GG muscle activity showed an onset in the last one-fifth of the intercuspal phase, gradually increasing during jaw-opening, and at its greatest immediately before the maximum jaw-opening position. It then decreased during jaw-closing and ceased in intercuspation but showed a small rebound in the third fifth of the intercuspal phase. The GG muscle burst showed phase lags with the DG and OI muscles and an opposite phase with the AT muscle (all P < 0.0001). All correlations were statistically significant (all P < 0.0001, r values between 0.88 and 0.97). The results suggest central coordination of the timing of the activities of the jaw, lip, and tongue muscles in chewing.

Adolescent↗
PubMed1996

Tongue volume in human female adults with mandibular prognathism.

It has often been hypothesized that a large tongue leads to an enlargement of the mandible and therefore contributes to the development of mandibular prognathism. We examined (1) whether the tongue volume in human subjects with mandibular prognathism was larger than that in subjects with good occlusion and (2) whether the tongue volume and the pharyngeal capacity correlated with the morphological characteristics of dento-skeletal structures. Magnetic resonance images of the tongue and its surrounding structures were recorded for female adult volunteers with good occlusion (control group, n = 10) and patients with mandibular prognathism (test group, n = 16). Lateral cephalograms were obtained for the patients. No significant differences were determined for the tongue volume or the pharyngeal capacity between the two groups. The tongue volume did not correlate with the pharyngeal capacity (r = 0.280, p = 0.166). The tongue volume correlated with the facial angle (r = 0.548, p = 0.028), the Y-axis (r = 0.539, p = 0.031), and the angle nasion-A point-pogonion (r = 0.540, p = 0.031). These results suggest that the tongue volume is accounted for by the combined horizontal and vertical location of the chin and symphysis, but do not support the conventional clinical surmise that large tongue volume is inherent in patients with mandibular prognathism.

Adult↗
PubMed1996

Three-dimensional comparison between the palatal forms in infants with complete unilateral cleft lip, alveolus, and palate (UCLP) with and without Hotz's plate.

A three-dimensional measuring system was developed to analyze changes in palatal forms of UCLP infants. This system quantified the change of the curved surface on a palate by automatically superimposing two wireframe models obtained from casts at different stages of growth. It also analyzed the curvature of the palatal surface. This system was used to study the palates of 20 infants with unilateral cleft lip and palate (UCLP), from the first to fourth months after birth (12 with Hotz's plate and 8 without, selected at random). Both major and lesser maxillary segments without Hotz's plate remained anterior and lateral although those with Hotz's plate moved mesially during the fourth month after birth. In addition, the degrees of curvature on the palatal surfaces with Hotz's plate were less than those without Hotz's plate.

Alveolar Process↗
PubMed1996

Three-dimensional comparison between the palatal forms in infants with complete unilateral cleft lip, alveolus, and palate (UCLP) with and without Hotz's plate.

A three-dimensional measuring system was developed to analyze changes in palatal forms of UCLP infants. This system quantified the change of the curved surface on a palate by automatically superimposing two wireframe models obtained from casts at different stages of growth. It also analyzed the curvature of the palatal surface. This system was used to study the palates of 20 infants with unilateral cleft lip and palate (UCLP), from the first to fourth months after birth (12 with Hotz's plate and 8 without, selected at random). Both major and lesser maxillary segments without Hotz's plate remained anterior and lateral although those with Hotz's plate moved mesially during the fourth month after birth. In addition, the degrees of curvature on the palatal surfaces with Hotz's plate were less than those without Hotz's plate.

Analog-Digital Conversion↗
PubMed1996

Three-dimensional comparison between the palatal forms in complete unilateral cleft lip and palate with and without Hotz plate from cheiloplasty to palatoplasty.

The palatal forms in 20 infants with a complete unilateral cleft lip, and palate (12 with a Hotz palate and 8 without, selected at random) were studied from birth until 18 months of age. Using techniques developed previously, the degree of curvature in the palate and the magnitude of migration of the maxillary segments were measured three-dimensionally. Furthermore, using a newly developed method to approximate a set of the points on the alveolar ridge to a circle in a plane, the form of the alveolar arch was evaluated. Results from the group with a Hotz plate revealed that the plate possesses four effects not seen in the group without a Hotz plate. The size of the palate was larger, and the sagittal gap between the two segments of the maxilla was smaller. These results suggest that the appliance could stimulate the growth of the segments and could prevent collapse of the maxillary arch from the force of lip closure. Third, the steepness of the segments toward the nasal cavity was smaller, possibly occurring because the appliance prevents tongue intrusion into the cleft. Fourth, the magnitude of migration of the lesser segment toward the cleft edge of the major segment was larger. This result suggests that the appliance could guide the growth of the maxillary segments to narrow the cleft width until 18 months of age.

Alveolar Process↗
PubMed1995

Induction of teratocarcinoma F9 cell differentiation with cis-diammine dichloroplatinum(II) (CDDP).

cis-Diammine dichloroplatinum(II) (CDDP) is the salt of a platinum compound which has been noted to have a wide spectrum of activity against malignant disorders. We have studied the effects of CDDP on embryonal carcinoma F9 cell differentiation. In the presence of this agent in vitro, the cells showed rapid morphological changes, a marked increase in the mRNA expression of various differentiation markers accompanied by a loss of tumorigenicity. These results indicate that the differentiation of F9 cells is induced with CDDP.

Animals↗
PubMed1995

The kinetics of induction of Hox1.6 and C-jun mRNA during three different ways of inducing differentiation in teratocarcinoma F9 cells.

Changes in Hox1.6 and c-jun gene expression were examined upon F9 cell differentiation that was induced by three independent methods: a drug treatment with retinoic acid (RA), that with sodium butyrate (NaB), and a genetic approach using the ts mutant. To obtain further information on the mechanism of teratocarcinoma cell differentiation we have examined the kinetics of the induction of Hox1.6 and c-jun mRNA whose gene products have been demonstrated to have specific roles in gene regulation. Expression of Hox1.6 mRNA was induced more rapidly than c-jun mRNA by all the above three inducing methods. Furthermore, protein synthesis was not required for the induction of Hox1.6 mRNA as well as of c-jun mRNA synthesis in all three methods. The data suggested that the transcriptional increase in the Hox1.6 mRNA was a primary response and could play an important role in F9 cell differentiation.

Butyrates↗
PubMed1995

Healing after removal of benign cysts and tumors of the jaws. A radiologic appraisal.

A retrospective review of the radiographic findings after removal of benign jaw cysts (n = 31) and ameloblastomas (n = 24) was carried out. The radiographic features of the site margins and interior contents were classified into four categories. In most patients radiographic changes were detected between 1 and 4 months after removal of the lesion, and complete bone healing was found 4 months or more after surgery. Radiographic changes included "spiculed" or "trabecular" contents within the interior of the surgical site. The fourth month was found to be the optimum time for follow-up radiographic examination for the early detection of residual lesions. In nine (53%) of the patients who had ameloblastoma, recurrent lesions were noted within or at the periphery of the original surgical sites 6 to 10 years after the initial tumor removal.

Adult↗