Measuring instrument of carbon dioxide concentration in seawater

The Measuring instrument of carbon dioxide concentration in seawater (pCO(2)) is developed. The instrument consists of an equilibrator, a non-dispersive infrared gas analyzer (NDIR), a carrier gas generator and a processing signal generator. The equilibrator has a cross section of 3 c㎡ and is 15 cm tall. The principle of pCO(2) measurement is based on the equilibration of a carrier gas phase with a seawater sample and subsequent determination of the carbon dioxide concentration in the carrier gas. The carrier gas circuit of the NDIR is opened to the atmosphere to maintain the carrier gas line at a barometric pressure. The present instrument can measure pCO(2) within the measuring error of about 2 ppm with sample water of about 180ml every 20 min

Multiple Regression Analysis for Grading and Prognosis of Cubital Tunnel Syndrome:Assessment of Akahori’s Classification

The purpose of this study was to quantitatively evaluate Akahori's preoperative classification of cubital tunnel syndrome. We analyzed the results for 57 elbows that were treated by a simple decompression procedure from 1997 to 2004. The relationship between each item of Akahori's preoperative classification and clinical stage was investigated based on the parameter distribution. We evaluated Akahori's classification system using multiple regression analysis, and investigated the association between the stage and treatment results. The usefulness of the regression equation was evaluated by analysis of variance of the expected and observed scores. In the parameter distribution, each item of Akahori's classification was mostly associated with the stage, but it was difficult to judge the severity of palsy. In the mathematical evaluation, the most effective item in determining the stage was sensory conduction velocity. It was demonstrated that the established regression equation was highly reliable (R＝0.922). Akahori's preoperative classification can also be used in postoperative classification, and this classification was correlated with postoperative prognosis. Our results indicate that Akahori's preoperative classification is a suitable system. It is reliable, reproducible and well-correlated with the postoperative prognosis. In addition, the established prediction formula is useful to reduce the diagnostic complexity of Akahori's classification

Skeletal open bite with amelogenesis imperfecta treated with compression osteogenesis : a case report

Background: We successfully treated a 37-year-old male who had skeletal open bite with severe amelogenesis imperfecta (AI) with orthodontics, compression osteogenesis, and prosthodontics. Case presentation: The patient was diagnosed with severe anterior open bite caused by severe AI. Corticotomy was performed on both buccal and palatal sides of the molar regions, and anchor plates were placed onto the bilateral zygomatic buttress and the center of the hard palate. After corticotomy, posterior maxillary segments were moved 3.5 mm superiorly to correct skeletal open bite with elastic chains. After 8-month, overbite had decreased by 2.0 mm. After further 5 months of prosthodontic preparation, orthodontic appliances were removed, and provisional crowns were set on all teeth. The anterior open bite was corrected, and ideal occlusion with a Class I molar relationship was achieved. The upper first molars were intruded 3.5 mm, resulting in 3.0o counter-clockwise rotation of the mandible. The total active treatment period was 16 months. Acceptable occlusion with a good facial profile was well maintained throughout the 8-year retention period. Conclusions: Our results indicate long-term stability after interdisciplinary treatment combining orthodontics, oral surgery, and prosthodontics in a patient with severe anterior open bite and AI

Thread shape, cortical bone thickness, and magnitude and distribution of stress caused by the loading of orthodontic miniscrews : finite element analysis

Cortical bone thickness is assumed to be a major factor regulating miniscrew stability. We investigated stress distribution in two miniscrews with different thread shapes (type A and B) and in cortical bone of three different thicknesses using three-dimensional (3D) finite element (FE) models. More specifically, 3D FE models of two different miniscrews were created and placed obliquely or vertically into a cylindrical bone model representing different cortical bone thicknesses. When force was applied to the miniscrew, the stress distribution on the screw surface and in the peri-implant bone was assessed using FE methodology. Miniscrew safety was evaluated using a modified Soderberg safety factor. Screw head displacement increased with a decrease in cortical bone thickness, irrespective of screw type. The smallest minimum principal stresses on the screw surfaces remained constant in type A miniscrews on changes in cortical bone thickness. Minimum principal stresses also appeared on the cortical bone surface. Lower absolute values of minimum principal stresses were seen in type A miniscrews when placed vertically and with upward traction in obliquely placed type B miniscrews. Both miniscrews had acceptable safety factor values. Taken together, orthodontists should select and use the suitable miniscrew for each patient in consideration of bone properties

Orthodontic Approach to Hemifacial Microsomia

Aim and objective: To present a growing patient with unilateral mandibular hypoplasia and microtia involved in the first and second branchial arch syndrome (FSBAS) treated with functional appliance. Background: The FSBAS comprises several developmental facial hypoplasia in ear and maxillofacial bones, resulting in hemifacial microsomia. Treatment for hemifacial microsomia varies greatly depending on the grade of mandibular deformities. Functional appliance treatment during growth period is available for mild to moderate mandibular deformities. However, there are few reports of hemifacial microsomia treated with functional appliance. Case description: The patient, an 8-year-and-5-month-old girl, had a chief complaint of mandibular deviation. She had been diagnosed with the FSBAS at birth. Her facial profile was straight and panoramic radiograph indicated that the mandibular ramal height of the affected side was about 60.4% compared to the unaffected side. The occlusal cant was 6°, and the right maxilla and mandible showed severe growth deficiency. At the age of 10 years, functional appliance with expander was used; for 2 years 6 months, the maxillomandibular growth was controlled and from panoramic radiograph, the ramus height of the affected side was increased to 65.0% compared to the unaffected left mandibular ramus. At the age of 12 years and 8 months, multibracket treatment was initiated. After 32 months of active treatment, proper occlusion with functional Class I canine and molar relationships was obtained, although facial asymmetry associated with the difference of ramus heights still existed. The resulting occlusion was stable during 1.5-year retention period. Conclusion: Our results indicated the importance of orthopedic treatment during growth period in the patient with hemifacial macrosomia involving the FSBAS. Clinical significance: This report proposes an efficacy of conventional orthodontic treatment for growing patients with hemifacial macrosomia involved in the FSBAS

埋伏歯による上顎切歯歯根吸収に対して下顎小臼歯の移植を行った歯性上顎前突症例

埋伏歯は外科的な開窓，牽引処置が必要となるだけでなく，萌出方向の異常による隣在歯の歯根吸収といった弊害も起こしうる．今回我々は，犬歯の埋伏によって上顎4 前歯に歯根吸収が生じた患者に対して，下顎小臼歯を移植し動的矯正治療を行い，良好な治療結果が得られたので報告する． 患者は初診時年齢12歳9 か月の男子であり，近医にて上顎両側犬歯の埋伏による上顎4 前歯の歯根吸収を指摘され，当科を紹介された．上顎4 前歯のうち，最も重度の歯根吸収を呈した上顎右側側切歯を抜去し，上顎両側犬歯の開窓，牽引処置を行った．13歳10か月時の再診断の結果，動揺が大きく保存困難であった上顎右側中切歯の抜去および下顎右側第一小臼歯の上顎右側中切歯部への移植を施行し，マルチブラケット治療を開始した． 2 年4 か月の動的治療により，わずかに上下顎歯列正中の右方偏位が認められたものの，緊密な咬合を獲得することができた．保定6 か月経過時に上顎右側中切歯部移植歯の最終補綴を行った．現在，保定1 年9 か月経過し下顎骨のわずかな晩期成長が認められたものの，咬合は安定しており，上顎右側中切歯部に移植した下顎小臼歯および歯根吸収が認められた上顎左側中，側切歯に関しても，著しい変化もなく経過良好である．今後，移植歯を含め長期間にわたる保定観察を継続していく予定である

A treatment case of Sotos syndrome

Sotos syndrome is a genetic disorder characterized by overgrowth in childhood, specific facial manifestations, advanced bone age, and mental retardation. Although only one case report of Sotos syndrome treated with surgical orthodontics has thus far been published, there have also been a few detailed reports of long-term observation of Sotos syndrome through total orthodontic treatment. This article aimed to present the case of a growing patient with skeletal mandibular protrusion and unilateral posterior crossbite as present in Sotos syndrome treated with a non-surgical orthodontic technique. A 10-year-old boy was diagnosed with skeletal mandibular protrusion and posterior crossbite associated with Sotos syndrome. After maxillary lateral expansion, the skeletal Class III relationship with an anterior crossbite improved owing to mandibular clockwise rotation, while the facemask had a marginal effect. At the completion of growth at 16 years, he had a skeletal Class I relationship, and thus, conventional orthodontic treatment with preadjusted edgewise appliances was initiated. After 41 months of multibracket treatment, acceptable occlusion with a functional Class I relationship was obtained. At 12 months postretention, no or few changes in occlusion and facial features were observed. Our results demonstrate that considering the maxillofacial vertical growth during peripubertal period associated with Sotos syndrome, much attention should be paid to the early orthopedic treatment with the facemask and/or chin cap

Management of Apert Syndrome

Aim and objective: To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery. Background: Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion. Case description: A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of −10.0 mm, an anterior open bite of −5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite. Conclusion: Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse. Clinical significance: The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome

Mechanical stability of orthodontic miniscrew depends on a thread shape

Background/purpose: Primary stability of orthodontic miniscrew system is of great importance in maintaining stable anchorage during a treatment period. Thus, this study aimed to examine whether the thread shape of orthodontic miniscrew had an effect on its mechanical stability in bone. Materials and methods: Three different types of miniscrews (type A and B with a regular thread shape; type C with a novel thread shape) were placed in artificial bone block with different artificial cortical bone thickness of 1.5, 2.0 and 3.0 mm. Values of maximum insertion torque (MIT), removal torque (RT), torque ratio (TR), screw mobility, static stiffness (K), dynamic stiffness (K∗) and energy dissipation (tan δ) ability were assessed for each miniscrew system. Results: The MIT, RT, TR and K of type C miniscrew were significantly greater than those of type A and B miniscrews when the miniscrews were placed in the thinner artificial bone. Furthermore, the TR value of type C miniscrew was more than 1, indicating the MRT value was larger than the MIT value in the novel miniscrew. The values of K∗ and tan δ were almost similar among the three types of miniscrews. Conclusion: The miniscrew with a novel thread shape showed a higher initial stability compared to those with a regular thread shape. Thus, in order to obtain a sufficient initial stability, it is important to select the type of screw thread that is appropriate for the thickness of the cortical bone