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Biomedical subjects

R Nanda

Publications and source records attributed to R Nanda.

At least 19 recordsLinked to original sources
PubMed1992

Dental and orthopedic effects of high-pull headgear in treatment of Class II, division 1 malocclusion.

In the present study a prospective cephalometric investigation was undertaken to examine the skeletal and dental effects of the high-pull extraoral appliance, when the resultant force was directed through the level of trifurcation of the maxillary molars. Twelve adolescent patients with Class II, Division 1 malocclusions were selected for the study. Each patient wore the headgear for a 6-month period, an average of 12 hours a day. A group of untreated adolescent patients with Class II, Division 1 malocclusions who were in a similar age range, as well as skeletal and dental characteristics were chosen as controls. Lateral cephalometric films were taken before and after the 6-month treatment period, and before and after the observation period in the control group of patients. Our data indicate that by directing the force of the headgear approximately through the center of resistance of the maxillary molars, it is possible to accomplish simultaneously a substantial distal movement of the molars (2.6 +/- 0.6 mm), as well as significant intrusion (0.54 +/- 0.54 mm). In addition, our results demonstrate that the applied force of 500 gm was sufficient to initiate maxillary orthopedic changes in the treated patients. These changes include relative restriction of horizontal and vertical maxillary growth, as well as distal movement (mean: 0.8 mm) of the maxillary anterior border in the treatment group relative to an untreated control group. Such orthopedic changes have been previously described only in association with much higher force levels.

Adolescent↗
PubMed1990

Increase in vertical dimension by interpositional bone grafts and subsequent craniofacial growth in adolescent monkeys.

The purpose of this study was to investigate the relationship between craniofacial growth and total maxillary osteotomy in adolescent Macaca fascicularis monkeys. The monkeys' facial height was increased with the help of interpositional bone grafts. Four monkeys underwent surgical procedures, and five served as controls. The changes in growth after surgery were then assessed with the help of conventional cephalometry and osseous implants. Lateral cephalometric radiographs of all monkeys were taken before and immediately after implant placement, immediately after surgery, and every 4 weeks thereafter for 1 year. Analysis of the cephalometric head films revealed that the increases in facial height assisted by interpositional grafts were not stable. Postsurgical observations showed a relapse in total facial height.

Animals↗
PubMed1989

Effects of a fixed magnetic appliance on the dentofacial complex.

The purpose of the study was to design and evaluate the effects of a fixed magnetic appliance that hinged the mandible open and exerted an intrusive force on the teeth. Ten patients between the ages of 8 years and 10 years 6 months, with Class II, Division 1 malocclusion associated with mandibular retrusion and increased lower facial height, were treated with this appliance. The length of treatment was 4 months, after which the appliance was removed and the patients were followed up for 4 months. Ten children with similar age, sex, and dentofacial characteristics acted as controls and did not receive any appliance therapy. Changes in morphology of the dentofacial complex were evaluated by use of lateral cephalograms and study models. In addition temporomandibular joint and muscle functions were assessed. During treatment mandibular length increased 3.2 mm, angle of facial convexity decreased 2.8 degrees, the upper and lower teeth intruded an average of 1.5 mm each, and the mandibular plane angle decreased 1.3 degrees. In the follow-up period, some rebound eruption was noted; however, all other changes were stable.

Cephalometry↗
PubMed1989

Food intolerance and the irritable bowel syndrome.

Two hundred patients (156 women) with the irritable bowel syndrome were treated with dietary exclusion for three weeks. Of the 189 who completed this study, 91 (48.2%) showed symptomatic improvement. Subsequent challenge with individual foods showed that 73 of these 91 responders were able to identify one or more food intolerances and 72 remained well on a modified diet during the follow up period (mean (SD), 14.7 (7.98) months). Of the 98 patients who showed no symptomatic improvement after three weeks of strict exclusion only three were symptomatically well at follow up (mean (SD), 12.48 (8.09 months). There was no close correlation between response and symptom complex. There was a wide range of food intolerance. The majority (50%) identified two to five foods which upset them (range 1-14). The foods most commonly incriminated were dairy products (40.7%) and grains (39.4%).

Adolescent↗
PubMed1989

Longitudinal study on craniofacial growth following Le Fort I maxillary osteotomy in adolescent monkeys.

The present study was conducted to investigate the effects of Le Fort I maxillary osteotomy on craniofacial growth in adolescent monkeys. Twenty monkeys were used, of which eight served as control and twelve for experiment. All monkeys received tantalum implants, whereas experimental monkeys underwent Le Fort I osteotomy. Serial lateral cephalograms were taken before and immediately after surgery, and thereafter every month. Craniofacial growth was investigated by evaluating both repositionings of anatomical landmarks and implants, and dimensional changes. No significant differences between the experimental and control groups were observed in midfacial growth. Maxillary growth was not significantly affected excluding the posterior region of the maxilla. Condylar growth of the mandible was significantly influenced, and the overall length of the mandible in the experimental group was much less as compared to the controls. However, the length of the body of the mandible was not significantly affected, indicating a catch up growth of the mandible. It is shown that craniofacial growth is somewhat retarded, however, the maxilla and mandible experience harmonious growth even after surgery. Thus, it is indicated that the maxillary osteotomy is applicable to growing patients as well as adults, in terms of the craniofacial growth after surgery.

Animals↗
PubMed1988

Endoscopic sclerotherapy in the treatment of gastric varices.

Of 309 patients with portal hypertension, gastric varices were found in 48 (16 per cent). While the majority (88 per cent) of the patients had gastric varices in association with oesophageal varices, 6 (12 per cent) patients had 'isolated' gastric varices. Gastric varices were seen significantly (P less than 0.01) more often with grade 4 than with grade 3 varices. In 11 (28 per cent) of the 40 patients who completed sclerotherapy for oesophageal varices, gastric varices disappeared concurrently on eradication of oesophageal varices or during the following 6 months. Of the initial five patients with gastric varices who received direct intravariceal injections, four rebled; this technique was therefore replaced by combination (paravariceal + intravariceal) gastric variceal sclerotherapy. Emergency combination sclerotherapy successfully controlled bleeding from gastric varices in six of the eight treated patients. Thirty-two patients entered a programme of elective combination gastric variceal sclerotherapy. Variceal obliteration was achieved in 12 cases (38 per cent) and reduction in size was noted in another 7 patients (22 per cent) after a minimum of four courses. There were 11 (23 per cent) deaths, 8 due to uncontrolled bleeding from gastric varices and 3 due to hepatic coma. The other complications of gastric variceal sclerotherapy were minor and included retrosternal pain, fever and dysphagia. It is concluded that gastric varices often coexist with large oesophageal varices. If they persist for 6 months after eradication of oesophageal varices, a combination of paravariceal and intravariceal sclerotherapy should be attempted for their obliteration.

Emergencies↗
PubMed1988

Temporomandibular joint adaptations following maxillary osteotomy in adolescent monkeys.

The purpose of this study was to investigate the histologic appearance of temporomandibular joints of monkeys who had undergone total maxillary osteotomy. The specific aim of the study was to seek clues that might explain the inhibition in the mandibular growth 27 months following the surgery performed on adolescent monkeys. Eighteen female adolescent Macaca fascicularis monkeys were used. Eight served as control and ten were experimental. All experimental animals underwent 3.0 to 5.0 mm superior and 0.5 to 2.5 mm anterior repositioning of the maxilla. All animals were killed 27 months after the surgical procedure. Qualitative and quantitative histologic evaluations of the temporomandibular joints were done and results were compared with the cephalometric data. The findings showed no pathologic changes, although the histologic appearance of the temporomandibular joints of the experimental animals was more mature than that of the controls. The histologic results support cephalometric findings and the data are discussed in relationship to the role of maxilla, maxillary teeth, and occlusion in regulating mandibular growth.

Animals↗
PubMed1988

Response of tuberculous stricture to antituberculous treatment.

Tuberculous infection of the gastrointestinal tract results in a variety of histopathological lesions. Some patients develop intestinal strictures and present with subacute intestinal obstruction. The treatment is controversial and vary from a trial of antituberculous drugs to early surgery:the response to medical therapy is not clear. To examine this issue the present prospective therapeutic trial was carried out on 39 patients with symptoms of bowel obstruction and radiological evidence of intestinal stricture. All patients were treated with conventional antituberculous drugs (streptomycin, rifampicin, and isoniazid) under close supervision. Thirty four (87%) patients completed the trial, five were lost to follow up. Thirty one (91%) of these showed significant clinical improvement:26 became completely symptom free, while the remaining five complained of only vague abdominal discomfort. Only three (8%) patients failed to respond to treatment and were subjected to surgery. Barium series were repeated in 23 of 31 who completed the treatment; the remaining eight refused further investigations. Complete resolution of the radiological abnormality was seen in 16 (70%) patients. In the remaining seven (30%) the stricture persisted; in two of these the treatment was continued for another year and both showed substantial radiological improvement. It is concluded that most patients with tuberculous strictures respond well to medical treatment and surgery should be resorted to only if drug therapy fails.

Adolescent↗
PubMed1987

Longitudinal study of craniofacial growth in Macaca fascicularis.

This paper is an analysis of normal craniofacial growth in adolescent crab-eating macaques (Macaca fascicularis). Eight female adolescent monkeys were used in this study. Their individual craniofacial growth was studied for a 24-month period utilizing tantalum implants and roentgenographic cephalograms. Throughout the observation period, each monkey consistently showed a class I molar relationship with a good overjet and overbite. The amount of anterior displacement of the maxilla and the mandible was significantly dominant compared to the vertical displacements at every observation period. The midface exhibited a maxillary differential growth pattern in which the premaxilla displaced superiorly and the posterior maxilla moved inferiorly, resulting in a counterclockwise rotation of the entire maxilla. Growth of the lower anterior teeth and alveolar bone compensated for the incremental vertical spaces which were induced by superior displacement of the premaxilla and inferior repositioning of the chin. In addition, the amount of anterior displacement of the upper and lower anterior teeth were significantly larger than that of the premaxilla and the chin. The dentocraniofacial growth pattern in Macaca fascicularis was quite similar to that seen in Macaca mulatta.

Aging↗
PubMed1987

Facial growth subsequent to Le Fort I osteotomies in adolescent monkeys.

The study goal was to assess qualitatively and quantitatively the craniofacial adaptations following total maxillary osteotomy with and without mandibular autorotation. Six adolescent female Macaca fascicularis monkeys were randomly divided into two surgical groups, and eight others served control. Prior to surgery, metallic implants were inserted in the anterior part of the cranial base, on opposite sides of craniofacial sutures, and in multiple sites of the maxilla and mandible. Group I animals underwent a Le Fort I advancement of 4 mm, while Group II animals had a 5-mm advancement and a 2.5-mm impaction. Lateral cephalometric head-films were taken at monthly intervals for a total follow-up of 12 months after surgery. At least two cephalograms were taken on each occasion, one with the teeth in occlusion and the other with the mouth wide open. The latter was used to ascertain accurately the outline of the mandibular condyle. Cephalometric superimposition methods were used to quantify the growth changes. The findings indicated that the growth changes in the maxilla and mandible were related to the extent of injury caused by maxillary surgery. The largest increments and rates of growth were observed respectively in the control animals, Group I animals (anterior maxillary repositioning), and Group II animals (anterior and superior maxillary repositioning). The most interesting finding was that mandibular growth pattern followed maxillary growth pattern in both experimental groups, and the immediate postsurgical occlusion in Class II molar relationship was maintained with increased overjet in both experimental groups throughout the postsurgical observation period.

Animals↗
PubMed1987

Effect of tensile force magnitude on release of cranial suture cells into S phase.

An in vitro model was used to study the effect of tensile force magnitude and duration on cell proliferation in cranial suture tissue. Helical springs were calibrated to deliver specific magnitudes of force to rat midsagittal suture in organ culture. The explants were incubated for time periods ranging from 1 to 48 hours. The in vitro model system facilitates study of the effects of a single parameter of an applied force on suture tissue without the interference of the complicated craniofacial anatomy. Specifically, the influence of tensile force magnitude and duration on DNA synthesis was investigated. Using autoradiography, cells incorporating tritiated thymidine were counted, indicating cells released into DNA synthesis (S) phase.

Animals↗
PubMed1987

Relative efficacy and safety of absolute alcohol and 50% alcohol as variceal sclerosants.

Absolute alcohol and 50% alcohol were compared as sclerosants in 79 patients who underwent sclerotherapy for esophageal varices every 3 weeks with either of the solutions. Active variceal bleeding could be controlled more often (p less than 0.05) with absolute alcohol (93.3%) compared with 50% alcohol (53.8%). Variceal eradication could be achieved with absolute alcohol in a significantly shorter time with smaller amounts and fewer sclerotherapy sessions than with 50% alcohol. Except for a higher incidence of retrosternal pain and fever noted with the use of absolute alcohol, there was no significant difference in the incidence of various complications, rebleeding rate, or mortality between the two sclerosants. Absolute alcohol is a more effective and equally safe sclerosant compared with 50% alcohol.

Adolescent↗