ABSTRACT
In this paper, we analyze the sudden change from chaos to oscillation death generated by the Bonhoeffer-van der Pol (BVP) oscillator under weak periodic perturbation. The parameter values of the BVP oscillator are chosen such that a stable focus and a stable relaxation oscillation coexist if no perturbation is applied. In such a system, complicated bifurcation structure is expected to emerge when weak periodic perturbation is applied because the stable focus and the stable relaxation oscillation coexist in close proximity in the phase plane. We draw a bifurcation diagram of the fundamental harmonic entrainment. The bifurcation structure is complex because there coexist two bifurcation sets. One is the bifurcation set generated in the vicinity of the stable focus, and the other is that generated in the vicinity of the stable relaxation oscillation. By analyzing the bifurcation diagram in detail, we can explain the sudden change from chaos with complicated waveforms to oscillation death. We make it clear that this phenomenon is caused by a saddle-node bifurcation.
Subject(s)
Biophysics/methods , Oscillometry/methods , Algorithms , Animals , Axons , Decapodiformes/physiology , Electricity , Models, Neurological , Models, Statistical , Models, Theoretical , Neurons/physiologyABSTRACT
OBJECTIVE: Documentation of the application of maxillary distraction osteogenesis using rigid external distraction (RED) with skeletal anchorage combined with predistraction alveolar bone grafting (ABG) in cleft maxilla. DESIGN: Case report. PATIENT: A patient with numerous congenital missing teeth and severe maxillary deficiency related to complete bilateral cleft lip and palate with large alveolar bone defect. INTERVENTION: The patient received preoperative orthodontic treatment, predistraction ABG, and maxillary distraction osteogenesis using RED with skeletal anchorage. RESULTS: Predistraction ABG completely united the cleft maxilla. The united maxilla was successfully advanced by the RED system with skeletal anchorage, despite unsound dentition with numerous congenital missing teeth. CONCLUSION: The present study demonstrates that the combination of predistraction ABG and RED system with skeletal anchorage is effective for the treatment of severe maxillary deficiency related to complete bilateral cleft lip and palate with large bone defect and numerous congenital missing teeth.
Subject(s)
Jaw Abnormalities/surgery , Maxilla/abnormalities , Maxilla/surgery , Oral Surgical Procedures , Osteogenesis, Distraction/methods , Adolescent , Anodontia/etiology , Anodontia/rehabilitation , Bone Transplantation , Cephalometry , Cleft Lip/complications , Cleft Palate/complications , Dental Implants , Female , Humans , Jaw Abnormalities/complications , Occlusal Splints , Orthodontics, Corrective , Osteogenesis, Distraction/instrumentation , Retrognathia/surgeryABSTRACT
OBJECTIVE: Documentation of the application of mandibular widening by distraction osteogenesis and orthodontics. PATIENTS: Three patients with telescopic bite resulting from an extremely constricted mandible related to hypoglossia-hypodactyly syndrome. INTERVENTION: Mandibular widening by distraction osteogenesis using an extraoral device and subsequent orthodontic treatment. RESULTS: The extremely constricted mandible and telescopic bite were dramatically improved by mandibular widening using distraction osteogenesis and subsequent orthodontics. Two of the three patients had transient complications; one reported temporomandibular joint pain and the other showed evidence of periodontal damage. CONCLUSION: Mandibular widening by distraction osteogenesis is an effective technique for the treatment of telescopic bite resulting from an extremely constricted mandible.
Subject(s)
Malocclusion/surgery , Mandible/surgery , Micrognathism/surgery , Oral Surgical Procedures , Osteogenesis, Distraction , Child , Female , Foot Deformities, Congenital , Hand Deformities, Congenital , Humans , Malocclusion/therapy , Mandible/abnormalities , Micrognathism/therapy , Orthodontics, Corrective , Syndrome , Tongue/abnormalitiesABSTRACT
OBJECTIVES: To clarify the need for secondary alveolar bone grafting (ABG) in incomplete alveolar clefts identified clinically from its appearance and test the usefulness of alveolar ridge notching in the edentulous stage as a predictor for ABG. DESIGN: A prospective, cross-sectional study comparing three groups of patients at two stages. PATIENTS: Twenty-four patients with unilateral incomplete cleft of primary palate who underwent either no surgery or cheiloplasty only. METHODS: Cleft severity was assessed at two stages. Initially, the appearance of untreated clefts was assessed before cheiloplasty or at 3 months of age in the patient without cheiloplasty and graded by severity into three groups. Later alveolar bone defects were assessed with computed tomography in the primary or mixed dentition period. A decision regarding the requirement for ABG was then made. Finally, the relationship between untreated clefts and the need for ABG was determined. MAIN OUTCOME MEASURES: Nine (75%) of 12 patients with alveolar ridge notching in the edentulous stage were diagnosed as fulfilling the criteria for ABG. RESULTS: The alveolar bone defects correlated with the severity of untreated cleft conditions (Spearman r = 0.65, p =.002). The need for ABG was greater in patients with alveolar ridge notching, compared with those without notching (9/12 versus 0/12, p =.00034). CONCLUSIONS: Most patients with incomplete alveolar clefts clinically identified in the edentulous stage required ABG, and alveolar ridge notching in the edentulous stage could therefore serve as a predictor for ABG.
