Kazuhiro Ono

Clinical study on prognostic factors for autotransplantation of teeth with complete root formation

Autotransplantation is often performed to replace a missing tooth, but tooth autotransplantation has been reported in fewer teeth with complete root formation than those with incomplete root formation. The aim of this prospective study was to evaluate the factors that affect the prognosis of autotransplantation of teeth with complete root formation. 109 patients with 117 transplants were studied. Of the 117 transplants investigated, 14 (12%) failed during the observation period. The overall 1-year survival rate was 96%; the 5-year survival rate was 84%. The major causes of failure were unsuccessful initial healing and replacement root resorption with periodontal inflammation. Factors significantly associated with unsuccessful transplantation, in single factor analysis, were age 40 years or more, molar tooth as donor, probing pocket depth to 4mm or more, history of root canal treatment, multi-rooted teeth and fixation with sutures. Pocket depth of 4mm or more and history of root canal treatment appeared to increase the risk of unsuccessful transplantation in multivariate analysis. It is suggested that the pocket depth of the donor tooth and history of root canal treatment are related to the healing of paratransplantal tissue and root resorption.

Partial monosomy 5p and partial trisomy 5q due to paternal pericentric inversion of chromosome 5

SummaryA male infant with partial monosomy 5p and partial trisomy 5q due to paternal pericentric inversion of chromosome 5 (46,XY,rec(5), dup q,inv(5)(p15.1q35.1)pat) is reported together with the oral findings. The phenotype was chiefly the cri-du-chat syndrome. Severe retardation of mental and motor development, microencephaly, cardiac malformation, crying and facial appearance unique to the cri-du-chat syndrome were observed. Perioral and intraoral findings included thin upper lip, downturning corners of mouth, micrognathia, shallow palate, and cleft of soft palate. Anterior deciduous teeth were small and canine deciduous teeth were conic. The row of deciduous teeth showed a flat arch-like shape that was very wide but short in length. No abnormality was noted in the number of deciduous teeth or the timing of eruption.

Blepharo-Cheilo-Dontic (BCD) Syndrome: Case Report

Objective To report a case of blepharo-cheilo-dontic (BCD) syndrome, to compare with the previous cases, and to discuss the possible treatment. Patient The patient was a 14-day-old boy born uneventfully on August 7, 2002. His scalp hair was sparse and curly. A tumor on the top of his head, which was thought to be a dermoid cyst, and a nevus on the back of his left hand were observed. All typical symptoms of blepharo-cheilo-dontic syndrome, such as euryblepharon with ectropion of the lower eyelids, distichiasis, bilateral cleft lip and palate, severe oligodontia, and conical teeth, were observed. Because there was no fatal complication, and growth and development were about normal, it was recommended that a long and active treatment plan be considered for this patient.

Relapse tendency in maxillary arch width in unilateral cleft lip and palate patients with different maxillary arch forms.

Objective: The aim of this study was to investigate the relapse tendency in the maxillary dental arch widths in unilateral cleft lip and palate patients with different types of maxillary arch form. Subjects: Thirty-two unilateral cleft lip and palate patients treated by one-stage surgical palatal closure were included. The subjects were divided into three groups according to the types of the maxillary arch forms: group A, symmetrical arch form; group B, collapse of minor segment; group C, collapse of both segments. Methods: Using dental casts obtained at three different times, relapse in the intercanine, interpremolar, and intermolar widths in each group was assessed and differences between groups were investigated. Results: Patients in group A showed stable results in all measurements. Patients in group B showed posttreatment relapse in the intercanine width only, whereas patients in group C demonstrated significant posttreatment relapses in the interpremolar and intermolar widths. Comparison between groups showed more significant relapse in the interpremolar and intermolar widths of group C than in those of group B. Conclusion: The types of the maxillary arch forms in unilateral cleft lip and palate patients might play a stronger role in the stability of the maxillary dental arch widths after orthodontic treatment in patients with collapse of both segments and a severe degree of maxillary narrowness.

Phenotypes of articular disc cells in the rat temporomandibular joint as demonstrated by immunohistochemistry for nestin and GFAP

The articular disc is a dense collagenous tissue containing disc cells that are phenotypically described as chondrocyte‐like cells or fibrochondrocytes. Despite the possible existence of these phenotypes in systemic joints, little is known about the detailed classification of the articular disc cells in the temporomandibular joint. In this immunocytochemical study we examined the localization and distribution patterns of nestin and glial fibrillary acidic protein (GFAP) in the articular disc of the rat temporomandibular joint at postnatal day 1, and weeks 1, 2, 4 and 8, based on the status of tooth eruption and occlusion. Nestin and GFAP are intermediate filament proteins whose expression patterns are closely related to cell differentiation and cell migration. Both types of immunopositive cell greatly increased postnatally to a stable level after postnatal week 4, but they showed different distribution patterns and cell morphologies. Nestin‐reactive disc cells, which were characterized by a meagre cytoplasm and thin cytoplasmic processes, were scattered in the articular disc, whereas GFAP‐positive cells, characterized by broader processes, existed exclusively in the deeper area. In mature discs, the major proportion of articular disc cells exhibited GFAP immunoreactivity. Furthermore, a double‐immunostaining demonstrated that the nestin‐negative cells, consisting of GFAP‐positive and ‐negative cells, exhibited immunoreactions for heat shock protein 25. These findings indicate that the articular disc cells comprise at least three types in the rat temporomandibular joint and suggest that their expressions closely relate to mechanical loading forces within the joint, including occlusal force, as observed through postnatal development.

Alterations in intermediate filaments expression in disc cells from the rat temporomandibular joint following exposure to continuous compressive force

The articular disc in the temporomandibular joint (TMJ) that serves in load relief and stabilizing in jaw movements is a dense collagenous tissue consisting of extracellular matrices and disc cells. The various morphological configurations of the disc cells have given us diverse names, such as fibroblasts, chondrocyte‐like cells and fibrochondrocytes; however, the characteristics of these cells have remained to be elucidated in detail. The disc cells have been reported to exhibit heterogeneous immunoreaction patterns for intermediate filaments including glial fibrillary acidic protein (GFAP), nestin and vimentin in the adult rat TMJ. Because these intermediate filaments accumulate in the disc cells as tooth eruption proceeds during postnatal development, it might be surmised that the expression of these intermediate filaments in the disc cells closely relates to mechanical stress. The present study was therefore undertaken to examine the effect of a continuous compressive force on the immunoexpression of these intermediate filaments and an additional intermediate filament – muscle‐specific desmin – in the disc cells of the TMJ disc using a rat experimental model. The rats wore an appliance that exerts a continuous compressive load on the TMJ. The experimental period with the appliance was 5 days as determined by previous studies, after which some experimental animals were allowed to survive another 5 days after removal of the appliance. Histological observations demonstrated that the compressive force provoked a remarkable acellular region and a decrease in the thickness of the condylar cartilage of the mandible, and a sparse collagen fiber distribution in the articular disc. The articular disc showed a significant increase in the number of desmin‐positive cells as compared with the controls. In contrast, immunopositive cells for GFAP, nestin and vimentin remained unchanged in number as well as intensity. At 5 days after removal of the appliance, both the disc and cartilage exhibited immunohistological and histological features in a recovery process. These findings indicate that the mature articular cells are capable of producing desmin instead of the other intermediate filaments against mechanical stress. The desmin‐positive disc cells lacked α‐smooth muscle actin (α‐SMA) in this study, even though desmin usually co‐exists with α‐SMA in the vascular smooth muscle cells or pericytes. Because the precursor of a pericyte has such an immunoexpression pattern during angiogenesis, there is a further possibility that the formation of new vessels commenced in response to the extraordinary compressive force.

Craniosynostosis with joint contractures, ear deformity, cleft palate, scoliosis, and other features.

A case of craniosynostosis with joint contractures, ear deformity, cleft palate, scoliosis, and many other features is presented. The patients skull was round with craniosynostosis of the coronal suture. The fingers were slender and long; the finger joints were contracted. Trismus was also present. Contracture of the temporomandibular joint was suspected. The helices were flat, antihelices were minimal, and the ears protruded. Furthermore, the facial and cranial features of this patient included mild hypertelorism, ocular proptosis, short pons nasi, flat radix nasi, mild retrognathia, and small oral fissure. In the oral cavity, a relatively wide cleft extended from the soft palate to the uvula. A frontal chest radiograph revealed a mild scoliosis. Differential diagnoses are discussed in reported syndromes with craniosynostosis.

PBL Tutorial Linking Classroom to Practice: Focusing on Assessment as Learning

In this paper we discuss the implementation of PBL at the Niigata University Faculty of Dentistry and the development of the modified triple jump as a means of directly assessing problem-solving ability. We observe that, in order for PBL to have an educational effect, learning outcomes need to be properly assessed, and the assessment process needs to comprise more than just assessment of learning. It should also be a learning experience for the student—in other words, assessment as learning.

Cephalometric evaluation after two-stage palatoplasty combined with a Hotz plate: a comparative study between the modified Furlow and Widmaier–Perko methods

The effects on craniofacial growth of two different soft palate repair techniques in two-stage palatoplasty were investigated. This was a retrospective, cross-sectional cohort study of 68 children with non-syndromic, complete unilateral cleft lip and palate. Thirty-four patients were treated with the modified Furlow method (F-group) and the remaining 34 with the Widmaier-Perko method (P-group). Craniofacial growth was assessed by analyzing 12 angular and 12 linear measurements on lateral cephalograms. Composite facial diagrams from the two groups were compared with those of a control non-cleft group. Angular and linear measurements did not differ significantly between the two groups, implying that the craniofacial morphology was not affected by the difference in soft palate repair technique. However, small differences in anterior nasal spine and posterior nasal spine were found in cleft patients compared with controls. These findings suggest that the modified Furlow and Widmaier-Perko methods have a similar impact on craniofacial growth. Considering speech function, the modified Furlow method provides better craniofacial growth and speech function. However, the long-term effects of both methods on craniofacial growth after growth cessation remain to be determined.

Correction of Mandibular Asymmetry Due to Hemifacial Microsomia Using a Custom-made Implant

Abstract Custom-trade artificial bone produced by the figurative lithographic method based on 3-dimensional computed tomography data is now available as a compatible and reliable implant. We describe a patient with hemifacial microsomia who was treated with custom-made artificial bone, trade from hydroxyapatite, for facial symmetry. Using the implant was less invasive surgically and shortened the operating time. A full-scale model and template were created using the binder jet method and 3-dimensional computed tomography images reformatted with single-helical scan data. These technologies were useful for producing the custom-made implant and explaining the procedure to the patient perioperatively. A symmetrical profile of the patients face has been maintained without any resorption of the implant and graft bed for 3 years. The hydroxyapatite custom-made implant was effective for facial rehabilitation in the treatment of mandibular asymmetry due to hemifacial microsomia.