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Biomedical subjects

R Nanda

Publications and source records attributed to R Nanda.

At least 37 records · Page 2Linked to original sources
PubMed1994

Endoscopically guided placement of nasogastric tubes in patients with esophageal carcinoma with absolute dysphagia: report of a 3-year experience.

Esophageal cancer often leads to total or near-total dysphagia, necessitating placement of nasogastric tubes for nutritional support. In patients with failed blind intubation or even failed fluoroscopic-guided tube placement, endoscopic guidance has a role to play. The catheter-over-guidewire technique is simple, safe, and easy to use. Over a period of 3 years, it was used in 28 patients who had esophageal cancer with absolute dysphagia. Successful placement of Levin tubes was achieved in 21 (75%) of these patients. Failure was more common in upper third lesions. The procedure was done on an outpatient basis, and no procedure-related complications were recorded in this series. To summarize, endoscopically assisted nasogastric tube placement is a useful option in esophageal cancer when blind intubation has failed, and it should be considered in preference to fluoroscopic assistance if endoscopic facilities are available.

Adult↗
PubMed1994

Biomechanical basis of vertical dimension control during rapid palatal expansion therapy.

Rapid palatal expansion (RPE) is recognized as a very successful orthopedic therapy to correct maxillary transverse deficiencies in growing patients. However, the transverse forces delivered during RPE have been shown to create undesirable orthodontic and orthopedic side effects in patients exhibiting skeletal open bite tendency, large interlabial gap, or severe Class II skeletal patterns, with long lower facial height and increased facial convexity. The application of extraoral forces during RPE therapy by the concomitant use of a high-pull chincap is described and clinically illustrated as a method to control the vertical dimension.

Biomechanical Phenomena↗
PubMed1993

Long-term stability and prediction of soft tissue changes after LeFort I surgery.

Many evaluations of soft tissue changes after orthognathic surgery have been undertaken, and many correlations of soft tissue to hard tissue movements have been established. These studies have not, however, specifically discussed the long-term stability or characteristics of the soft tissue changes. The objectives of this study were (1) to determine the long term stability of soft tissue changes 5 years after LeFort I osteotomy, (2) to determine reliable correlations, if any, of soft tissue changes to bony movements effected in surgery, and (3) to determine the predictability of soft tissue changes as an aid to orthodontic treatment planning. Cephalometric data from 25 patients who were treated with LeFort I osteotomy with or without a concurrent mandibular procedure were analyzed retrospectively. Cases were selected from the patient records of the Department of Oral Surgery of the Vrije Universiteit in Amsterdam, the Netherlands. These patients were followed up at four time points, the last being a mean of 6.1 years after surgery. Analysis of stability data revealed that most horizontal and vertical soft tissue change after LeFort I surgery occurred in the first year after surgery. Significant (> 10%) change continued to occur for subnasale, labrale inferius, upper lip protrusion, lower lip protrusion, and soft tissue convexity during the subsequent 5 years. Hard tissue to soft tissue correlations were calculated and ratios of soft tissue to hard tissue movement were determined for appropriate hard and soft tissue landmarks at four time intervals. Reliable correlations of hard tissue change at surgery to 5-year soft tissue change could be made for 10 variables, which was considerably less frequently than for 1-year soft tissue change. The relatively low reliability of long-term prediction correlations suggests that soft tissue movements may be more independent of hard tissue over time. One-year prediction values were similar to 5-year values and thus could be used for prediction purposes in orthodontic treatment planning. Most short-term hard to soft tissue correlations found in the present study were in the range of those established by previous authors. Long-term hard tissue to soft tissue correlations gave higher ratios of soft tissue movement secondary to maxillary surgery, approaching ratios of 1.0:1.0 for some variables. This finding, as well as the long-term stability data, suggest that soft tissue settling or equilibrium after surgery may take several years to complete.

Adolescent↗
PubMed1993

Evaluation of horizontal and vertical differences in facial profiles by orthodontists and lay people.

A novel video image processing technique was used to evaluate changes in the facial profile mimicking the effects of various orthognathic surgical techniques. Incremental changes were introduced in male and female images simulating the effects of mandibular advancement or set-back, maxillary advancement or set-back, and maxillary impaction. Twenty-two clinicians and 22 lay people completed questionnaires evaluating their level of sensitivity to changes in the facial profiles and their preferences regarding alternative profiles. The results indicate that in judging realistic color video images, both orthodontists and lay people are sensitive to relatively small horizontal changes in the facial profile. In contrast, orthodontists are less sensitive to relatively large vertical changes but more sensitive to horizontal mandibular changes.

Cephalometry↗
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↗