PubMed Health⌕ Search

Biomedical subjects

G Chaushu

Publications and source records attributed to G Chaushu.

At least 37 records · Page 2Linked to original sources
PubMed2000

Anterior loop of the mental canal: an anatomical-radiologic study.

This study sought to characterize the anatomical dimensions of the anterior mental loop and to determine the accuracy of conventional radiographs in identifying its presence and dimensions. The study group consisted of 46 hemimandibles fixed in formalin. Radiographs of the area between the mental foramen and the midline were obtained and evaluated for each hemimandible, followed by dissection and physical examination of the same area. Anatomically, an anterior loop of the mental nerve was observed in only 13 hemimandibles (28%). The anterior extension of the loop ranged from 0.4 to 2.19 mm. No correlation was found between the radiographic image and the anatomical shape of the loop. Of the radiographically diagnosed loops, 40% were not seen in anatomical examination. In cases with a false radiologic loop, a correlation was found between the diameter of the origin of the incisive canal and the radiologic interpretation of the loop. The radiologic appearance or diagnosis of the anterior mental loop in cadaver mandibles does not disclose the true ramification of the inferior alveolar nerve to the mental and incisive nerve.

Cadaver↗
PubMed2000

Relationship of blood glucose level to community periodontal index of treatment needs and body mass index in a permanent Israeli military population.

BACKGROUND: The goal of this study was to find a possible link between blood glucose levels and periodontal disease. METHODS: In a prospective study the dental health of 10,590 military service men and women was examined. The relationships of periodontal condition, expressed as CPITN index, and blood glucose levels were tested. The effect of gender, body mass index (BMI), and smoking was also evaluated. RESULTS: Blood glucose levels were significantly and positively associated with severe periodontal disease, men, and higher BMI. Smoking did not affect blood glucose levels. CONCLUSIONS: Blood glucose levels might be associated with severe periodontal disease.

Adult↗
PubMed2000

Emergency tracheostomy following life-threatening hemorrhage in the floor of the mouth during immediate implant placement in the mandibular canine region.

BACKGROUND: The edentulous interforaminal mandibular area is frequently the preferred area for implant placement. METHODS: A case of emergency tracheostomy following life-threatening hemorrhage in the floor of the mouth during immediate implant placement in the mandibular canine region is described. The probable cause was bleeding from the sublingual artery or a branch of that artery following implant perforation of the lingual cortex. RESULTS: Healing was uneventful and the patient was released from the hospital after 11 days. Three years later, CT showed a well-osseointegrated implant with a severe buccolingual inclination. CONCLUSIONS: It is stressed that short implants (14 mm or less) should be used in the mandibular canine region and that effective treatment of this complication is essential.

Arteries↗
PubMed2000

The clinical effectiveness of implants placed immediately into fresh extraction sites of molar teeth.

BACKGROUND: Studies concerning immediate implantation describe its use in the anterior and premolar regions. However, its clinical effectiveness in immediately replacing molar teeth has rarely been challenged. The purpose of this study was to evaluate the survival rate of implants placed immediately after extraction of molar teeth to support a fixed ceramo-metal prosthesis. METHODS: From 1989 to 1996, 56 immediate implants were placed in 43 patients following extraction of 51 molars; 46 molars were replaced by 1 implant and 5 molars replaced by 2 implants. All implants were restored with fixed prostheses (4 single crowns and 52 splinted). Mean follow-up period was 15 months (range, 4 to 60 months). The influence of the following parameters on implant failure was evaluated: gender, arch, smoking, pre-extraction vertical bone loss, implant length, and severity of complications between the two stages of surgery. RESULTS: The 5-year cumulative survival rate (5-year CSR) was 89%. The 5-year CSR among men was 84% compared to 93.5% among women. The maxillary 5-year CSR was 82% and the mandibular 92%. Among non-smokers (50 implants), the 5-year CSR was 90% compared to 83% among smokers (6 implants). Complications were evident in 8 (6 minor, 2 major) out of 50 non-failing implants compared to 2 (minor) of the 6 failing implants. No differences were evident in the other study variables. CONCLUSIONS: Immediate implantation in the molar region is an alternative, predictable surgical treatment. Immediate implantation in the posterior mandible has a better prognosis than in the posterior maxilla.

Adolescent↗
PubMed2000

Immediate versus non-immediate implantation for full-arch fixed reconstruction following extraction of all residual teeth: a retrospective comparative study.

BACKGROUND: Immediate implants placed into fresh extraction sites are considered a predictable and acceptable procedure. The main biological advantage is the preservation of bone height and width. However, there is no direct proof of the clinical and surgical importance of this. The purpose of this study was to evaluate the correlation between implant dimensions, anatomic factors, and survival rates of immediate versus non-immediate implants. METHODS: From 1989 to 1996, 380 implants (117 immediate and 263 non-immediate) were placed in 43 patients (50 jaws) following extraction of all residual teeth. A total of 253 implants were placed in the maxilla and 127 in the mandible, with a mean of 7.65 and 7.9 per jaw, respectively. Of the implants, 31% were placed immediately into fresh extraction sites. RESULTS: Total 5-year cumulative survival rate (CSR) was 92%, mandibular 96% and maxillary 90%. Immediate implants had a better 5-year CSR (96%) versus non-immediate implants (89.4%). The maxilla mainly contributed to this difference (95% versus 88%). The mean potential contact surface area (PCSA) was 230 mm2. Implants with significantly higher values yielded a higher 5-year CSR in the maxilla (96.6% versus 82.9%). Immediate implants in the posterior maxilla had a 100% 5-year CSR versus 72% with the non-immediate implants. CONCLUSIONS: 1) Implant-supported fixed ceramo-metal prosthesis is a predictable treatment modality for edentulous patients; 2) factors favorably affecting the survival of implants placed to support full-arch ceramo-metal prosthesis include immediate implantation, higher PCSA values, and implant location; 3) immediate implantation exerts its effect through higher PCSA values and by a compensatory effect to bone quality; 4) immediate implantation does not carry additional morbidity; and 5) potential contact surface area (PCSA) is a reliable mean that accurately represents implant dimensions and may replace length and diameter in future studies.

Adult↗
PubMed2000

The use of hydroxyapatite bone cement for sinus floor augmentation with simultaneous implant placement in the atrophic maxilla. A report of 10 cases.

BACKGROUND: Dental implant placement associated with sinus floor augmentation in a severely atrophic maxilla can be performed in a 1- or 2-stage surgical procedure, depending on the height of the residual alveolar bone. A minimum of 4 to 5 mm is recommended for a 1-stage procedure. METHODS: This clinical study describes the use of hydroxyapatite (HA) bone cement to stabilize HA-coated cylindrical implants placed simultaneously during sinus augmentation in 100 patients where insufficient bone volume did not allow primary implant stability. A total of 26 HA-coated dental implants were inserted in 100 grafted sinuses of 10 patients. RESULTS: None of the cases presented any difficulty in achieving initial stabilization and parallelism. No clinical complications of the sinuses were evident. Prior to exposure, radiographic evaluation revealed the implants embedded in a densely homogeneous radiopaque mass. At second-stage surgery, there was no clinical evidence of crestal bone loss around the implants. All implants were clinically osseointegrated. All patients received fixed implant-supported prostheses. Mean follow-up was 18 months (range 12 to 24 months). CONCLUSIONS: According to this preliminary study, the hydroxyapatite bone cement appears to hold great promise as a grafting alloplastic material for sinus floor augmentations. Its main advantage is its ability to provide initial stability required for osseointegration and proper implant location and parallelism. Further clinical and histological studies are required before it can be recommended for routine use in sinus lift procedures.

Adult↗
PubMed1999

Risk factors contributing to symptomatic plate removal in orthognathic surgery patients.

PURPOSE: This study analyzed the fate of miniplates in orthognathic surgery and defined risk factors that eventually result in plate removal. PATIENTS AND METHODS: The outpatient clinic files of 70 patients who had undergone orthognathic surgery were reviewed. All osteotomies were rigidly fixed with stainless steel or titanium miniplates. Study variables included age, gender, plate material, site of plates, and reasons for plate removal. RESULTS: Of 260 plates used for fixation, 31 were removed (12%). When all factors were considered together, only age was statistically significant. Patients older than 30 years of age were more likely to have plate removal (22% vs. 9%). Only when each factor was considered separately were gender and plate material statistically significant. Females (15.4% vs. 6.7%) and stainless steel plates (15.5% vs. 6.7%) were more prone to plate removal. Although more plates were removed from the buttress (15.5%) and chin (14.5%) compared with the piriform area (6.4%), this was not statistically significant. CONCLUSIONS: Age can be defined as a primary risk factor for plate removal, whereas gender and plate material are secondary. Although age and gender are not controllable, the use of titanium plates and infection control may lower the number of symptomatic plates and the need for their removal.

Adolescent↗
PubMed1999

The use of panoramic radiographs to localize displaced maxillary canines.

OBJECTIVE: The purpose of this investigation was to develop a reliable method of diagnosing the position of a displaced maxillary canine on the basis of a single panoramic radiograph. STUDY DESIGN: A total of 115 panoramic radiographs depicting 164 displaced maxillary canines were evaluated. The ratio of the width of the displaced canine to the width of the homolateral central incisor (the canine-incisor index) and the ratio of the width of the displaced canine to the width of the contralateral canine (the canine-canine index) were calculated. The height of the crown of each displaced canine was classified in the vertical plane, relative to the adjacent incisor, as apical, middle, or coronal. RESULTS: There was an overlap in the canine-incisor index ranges of the buccal (0.94-1. 45) and palatal (1.15-1.29) canines in the apical zone. In the middle and coronal zones, a clear difference could be seen between the canine-incisor indices of labially (0.78-1.11) and palatally (1.15-1.7) located canines. A cut-off point of 1.15 was determined. CONCLUSIONS: Provided that vertical restriction and the canine-incisor index are used, the panoramic radiograph can serve as a useful indicator for determining the position of an unerupted maxillary canine.

Adolescent↗
PubMed1999

Comparative study of splenic wound healing in young and adult rats.

BACKGROUND: Nonoperative management (NOM) of splenic injuries is a common practice in stable trauma patients. Nevertheless, age-related differences in the success rate of NOM have prompted inclusion of age among the criteria of patient selection. Elucidation of the cellular mechanism of splenic wound healing in the young versus that of adults may explain why age can be related to the success of NOM in splenic injuries. METHODS: A laceration was made in the splenic antihilar surface of 40 young and 40 adult male rats. Postoperatively, at specified intervals extending until day 21, spleens were removed, fixed, and examined by routine histopathology. In addition, sections were stained histochemically for collagen fibers and immunohistochemically for myofibroblast histomorphometry. RESULTS: The intense local hemorrhage was resorbed within 48 hours in the young rats, and within 7 days in the adults. Disappearance of germinal centers and other splenic alterations started on the first day in both groups, but regeneration of splenic parenchyma was accomplished after 14 days in the young, whereas in the adults, on day 21 it was still incomplete. Maximal myofibroblast accumulation at the laceration site was seen after two days in the young, whereas in adults only on day 4 (p < 0.0001). Collagen scars were not present in either group. Thickening of the damaged capsule, composed of collagen fibers with yellowish-green polarization colors, was observed only in adult rats. CONCLUSION: Splenic wounds heal by regeneration and not by collagen scarring. In the young, myofibroblasts accumulate in the site of injury faster than in adults. These cells may enhance contraction and increase the rate of wound healing until parenchymatic regeneration is completed. Our results may indirectly explain the higher success rate of NOM of splenic injury in young patients.

Aging↗
PubMed1999

Reliability of a method for the localization of displaced maxillary canines using a single panoramic radiograph.

The present study was initiated to determine the validity and reproducibility of a method previously reported for localization of displaced maxillary canines by panoramic radiographs. Eleven dental specialists (five orthodontists, five surgeons, and one radiologist) and five (final year) dental students were asked to interpret initial panoramic radiographs of 20 patients with 26 unerupted canines. The method contends that, provided that the radiographic image of the unerupted canines superimposes on the root of the lateral incisor at a height coronal to the apical third, a ratio between the widest mesiodistal dimension of the affected canine and the homolateral central incisor [Canine-Incisor Index (CII)] of more than 1.15 indicates palatal displacement. Among the observers, the measurement error was small, insufficient to cause overlap between the ranges of values for the CII of buccal and palatal canines. Inter-observer reproducibility was high. Without exception, all observers correctly diagnosed the location of each of the impacted canines. The CII cut-off point of 1.15, which was arbitrarily chosen in the previous work, was shown to be valid to differentiate buccal from palatal displacement. The present method is rapid, simple, accurate, and easily taught to dental students or dental specialists, with the simplest of initial instruction. While confirmations with other radiographic techniques is strongly advised before a definitive treatment is undertaken, this method has merit in providing more information than has been available from the panoramic radiograph hitherto, to satisfy the needs of an initial orthodontic consultation.

Adolescent↗
PubMed1999

Full-arch restoration of the jaw with fixed ceramo-metal prosthesis: late implant placement.

BACKGROUND: The completely edentulous patient has few treatment options in conventional dentistry. When implants are considered, treatment plans range from a 2-implant overdenture to a completely implant-supported prosthesis. Fixed prosthesis is often the preferred selection of the edentulous patient. This study assesses the 5-year cumulative survival rate of implants placed to support full-arch fixed restoration. METHODS: During 1990 to 1995, 171 implants were placed in 22 completely edentulous jaws of 20 patients. All patients were discharged wearing immediate dentures. The implants were analyzed as to the number of implants per jaw, implant location, length, and diameter. RESULTS: The 5-year cumulative survival rate was 89.9%. The mean number of implants per jaw was 7.7 for the maxilla and 8 for the mandible. In the maxilla, the preferred implant locations were the canines, centrals, laterals, and first premolars; in the mandible, they were the canines, laterals, and first molars. The mean implant length was 14.2 mm for the mandible and 13.2 mm for the maxilla. The mean implant diameter was 3.6 mm for the maxilla and 3.8 for the mandible. CONCLUSIONS: The results of the present study indicate that fixed full-arch ceramo-metal restorations can be a predictable implant treatment modality for the edentulous patient.

Adult↗
PubMed1999

Radiological findings of the post-sinus lift maxillary sinus: a computerized tomography follow-up.

The purpose of this paper is to present radiological findings of a short-term (8 to 10 months) computerized tomography (CT) follow-up study on 1-stage maxillary sinus lift cases. Pre- and postoperative dental CT scans of 21 patients (24 sinuses) after sinus lift procedures were compared. CT scans were used to assess newly formed bone and its interface with the implants, condition of the sinus membrane, evidence of buccal window cortication, and presence of any sinus pathology. Of the 57 implants placed, 28 had bone fully covering the implant on all sides which did not extend above the apical portion; 20 had bone fully covering the implant which did extend above the apex; and 9 exhibited incomplete bone coverage. All implants supported a fixed ceramo-metal prosthesis, and no implant failures were recorded after 3 years of follow-up. There was evidence of cortication of the buccal window in 10 sinuses; in the 14 remaining sinuses, bone consolidation on the buccal aspect was evident, but no evidence of cortication was seen. All sinuses healed without complications or clinical signs of sinusitis. In 11 sinuses, no changes in membrane thickness were noted. Membrane thickness decreased postoperatively in 12 sinuses, and in one, there was evidence of membrane thickening. Bone cortication in the anterior wall window may serve as an indicator for the remodeling status of the entire graft. Postoperative findings showed a significant improvement in overall membrane thickness. No clinical symptoms of sinusitis were evident, indicating that sinus lift procedures can be considered safe and do not predispose the sinus to acute or chronic sinusitis.

Adult↗
PubMed1999

Use of lyodura for bone augmentation of osseous defects around dental implants.

BACKGROUND: Lyodura has been used in periodontology and maxillofacial surgery to overcome different clinical conditions. The use of lyodura to induce new bone formation in humans has not been widely reported. The purpose of this article is to describe the use of lyodura as a resorbable barrier to promote bone formation in osseous defects around dental implants. METHODS: The study group consisted of 22 healthy patients (12 women and 10 men), with a mean age of 32 (range 20 to 45). A total of 44 implants (9 titanium screw-type and 35 hydroxyapatite-coated cylinder implants) were placed. Of these, 27 implants were placed in the maxilla and 17 in the mandible. At 27 extraction sites bony vertical defects were measured on the buccal, lingual, mesial and distal sides of the implant. In the remaining 17 cases, where either immediate or staged implantation was performed, and a dehiscence was present, its vertical length was measured from the alveolar crest. All bony defects were grafted with autogenous bone harvested from the tuberosity. Each site was covered with lyodura. RESULTS: Healing was uneventful; no inflammation, infection, or soft tissue dehiscence was observed. At all extraction sites and in 76% of the dehiscence defects, hard tissue appearing clinically similar to bone completely filled the defect. Of those defects not completely filled, a mean vertical bone increase of 2.5 mm was recorded. A mean vertical bone increase of 2.6 mm was achieved at extraction sites and a mean increase of 2.79 mm was achieved at dehiscence sites. CONCLUSIONS: Lyodura can safely and effectively be used for guided bone regeneration at both extraction sites and for dehiscence defects.

Absorbable Implants↗
PubMed1998

The influence of the osteotomy slope on bony changes after advancement genioplasty.

PURPOSE: The purpose of this study was to develop a prediction method for advancement genioplasty that would result in accurate preoperative cephalometric planning of the osteotomy slope and that could be transferred to the patient during the surgical procedure. PATIENTS AND METHODS: Serial cephalometric tracings of 20 patients who underwent advancement genioplasty were retrospectively analyzed. The osteotomy slope angle was defined as the angle between the osteotomy and a line perpendicular to the occlusal plane. The measured angle was compared with the calculated angle deduced from the horizontal and vertical genial postoperative changes. RESULTS: The measured osteotomy slope angle closely resembled the calculated angle. CONCLUSIONS: The close similarity between the calculated and measured osteotomy slope angles in this study shows that simple mathematical calculations can be applied clinically to aid surgeons in achieving a more predictable result. The osteotomy slope can be determined early in the prediction stage as a calculated figure based on the desired horizontal and vertical movements of the chin and can be transferred to the patient's chin during the surgical stage.

Adolescent↗