Global issues with orthodontic education: a personal viewpoint.
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Curriculum↗
Biomedical subjects
O P Kharbanda
Publications and source records attributed to O P Kharbanda.
Root resorption and its association with alterations in physical properties, mineral contents and resorption craters in human premolars following application of light and heavy controlled orthodontic forces.
OBJECTIVES: To study the effect of different orthodontic force levels on cementum, investigating from the point of view of its physical properties, alterations in the mineral components, type and location of the resorption craters and the exploration in 3D of space. DESIGN: In vivo human premolars subjected to heavy and light forces were employed for this study. After a period of movement they were analyzed for hardness and elasticity. Also, the mineral composition measuring Ca, P and F of the cementum root surface was investigated. A new method for volumetric analysis of resorption craters was developed. RESULTS: There were no significant differences for hardness and elastic modulus between the light and heavy force groups and no significant effects for different tooth positions. Significant inter-individual variation in the Ca, P and F concentrations was noted. Force-related data showed that mean volume of the resorption crater in light-force group was 3.49-fold greater than the control group, and the heavy-force group 11.59-fold more than control group. The heavy force group had 3.31-fold greater total resorption volume then light force group. Buccal cervical and lingual apical regions demonstrated significantly more resorption craters than the other regions. The 2D measurements were strongly correlated to 3D measurements. CONCLUSION: The application of light and heavy forces did not show any statistically significant differences in hardness and elastic modulus when compared with untreated teeth. The inconsistent increase or decrease of Ca, P and F contents between control and experimental teeth at sites of compression and tension were difficult to explain. There was more resorption by volume in the heavy force group as compared with the light group and controls. Our data also suggested that the high-pressure zones might be more susceptible to resorption after 28 days of force application.
Adolescent↗
Orthodontic treatment of a case of Aarskog syndrome.
Aarskog syndrome is a rare syndrome with a typical triad of facial, digital and genital characteristics. Orthodontic treatment of a patient with Aarskog syndrome has not been documented in literature till date. This case report shows that an individual with Aarskog syndrome can be an excellent orthodontic patient and should not be excluded from the general patient population. A stable occlusion can be achieved with acceptable profile and soft tissue contours in these patients as well.
Adolescent↗
Oral habits in school going children of Delhi: a prevalence study.
This study was conducted on 5554 children aged 5-13 years old with the objectives of recording the prevalence of oral habits among North Indian children according to sex. These children were selected from the schools of Delhi. The sample represented the entire school-going population of Delhi in the age group of 5-13 years. Statistical analysis was carried out using BMDP software and sex differences were calculated by using Fisher's exact test. The results showed that the prevalence of oral habits in Delhi school going children was 25.5%. Tongue thrust was the commonest habit (18.1%) followed by mouth breathing (6.6%). Thumb sucking was relatively less common habit and seen in only 0.7% of children. There were no significant differences between boys and girls for the prevalence of oral habits. However, for the specific habit types there was a sex difference. Thumb sucking was more common in girls (1.0%) when compared with boys (0.4%) and this difference was statistically significant (P < 0.001). There was a reverse trend for the mouth breathing, which was more common (P < 0.001) in boys (7.8%) than girls (5.3%). There were no differences for tongue thrust habit between boys (17.5%) and girls (18.6%).
Adolescent↗
Skeletal and dental changes with nonextraction Begg mechanotherapy in patients with Class II Division 1 malocclusion.
This prospective cephalometric study was undertaken to assess the mode and magnitude of Class II correction with nonextraction Begg mechanotherapy in growing children. The sample comprised subjects with similar malocclusion and age range (9-12 years) who were specifically selected for nonextraction Begg mechanotherapy. Cephalograms were analyzed to assess the skeletal, dental, and soft tissue changes that occurred after correction of the molar relationship, the overjet, and the overbite during the 9-month treatment period. The results revealed a significant improvement in the anteroposterior jaw relationship, suggested by the significant reduction in the ANB angle (1.62 degrees ) and in Wits AO-BO (1.42 mm). The mandibular length increase of 0.56 mm suggests that the Class II elastics used in nonextraction Begg mechanotherapy had a minimal stimulatory effect on mandibular growth. There was a significant increase in the anterior and posterior facial heights and the ramal height. Almost all of the dental changes were significant. The most striking feature were a significant retraction and extrusion of the maxillary incisors and proclination and intrusion of the lower incisors accompanied by extrusion of the mandibular molars. The maxillary incisors extruded by 1.64 mm under the influence of the undesirable downward component of the Class II elastic forces. The major contribution to overjet and molar correction was predominantly dentoalveolar.
Cephalometry↗
Muscle response to the twin-block appliance: an electromyographic study of the masseter and anterior temporal muscles.
An electromyographic study was performed on 10 young growing girls in the age group of 9 to 12 years with Class II Division 1 malocclusion and retruded mandible, who were under treatment with Twin-block appliances. Bilateral EMG activity of elevator muscles of the mandible (ie, anterior temporalis and masseter) was monitored longitudinally with bipolar surface electrodes to determine changes in postural, swallowing, and maximal voluntary clenching activity during an observation period of 6 months. The changes were noted at the start of treatment (0 month), within 1 month of Twin-block insertion, at the end of 3 months, and at the end of 6 months. The results revealed a significant increase in postural and maximal clenching EMG activity in masseter (P <.01) and a numeric increase in anterior temporalis activity during the 6 month period of treatment. The increased electromyographic activity can be attributed to an enhanced stretch (myotatic) reflex of the elevator muscles, contributing to isometric contractions. The main force for Twin-block treatment appears to be provided through increased active tension in the stretched muscles (motor unit stimulation) and from initiation of myotatic reflex activity and not through passive tension (viscoelastic properties) of jaw muscles. The results of this study reaffirm the importance of full-time wear for functional appliances to exert their maximum therapeutic effect by way of neuromuscular adaptation.
Adaptation, Physiological↗
Dental and craniofacial features of Aarskog syndrome: report of a case and review of literature.
Aarskog syndrome is a rare syndrome with a typical triad of facial, digital and genital characteristics. The characteristic cephalometric finding in this patient was the unusually large upward slant of SN plane and a steep Ba-N plane. Though the patient presented with a class I skeletal pattern, both the maxilla and mandible were hypoplastic and retruded with respect to the cranial base. Other characteristic features regarding the mandibular morphology were a large FMA (37 degrees) and Sn-GoGn (44 degrees) angles, a large gonial angle (138 degrees), an increase in total anterior facial and lower anterior facial height.
Abnormalities, Multiple↗
A study of dental caries in school children from rural Haryana.
The prevalence of dental caries among rural school children (688 boys and 331 girls) in the age group of 12-16 years in Haryana was found to be 39.4%. It was 37.9% in boys and 42.6% in girls. The difference between males and females was statistically not significant. A significant increase in prevalence of dental caries with age was observed (i.e. 33.1% in 12-year-old children to 45.8% in 14-year-old children). The mean DMFT per child was found to be 1.03 and DMFT per affected child was 2.6. The mean of D, M and F was found to be 1.0, 0.03 and 0.0 respectively.
Adolescent↗
Dental and skeletal changes after intraoral molar distalization with sectional jig assembly.
The present study was conducted on 10 subjects to evaluate dental and skeletal changes after intraoral molar distalization. The maxillary molars were distalized with a sectional jig assembly. Sentalloy open coil springs were used to exert 150 gm of force for a period of 12 weeks. A modified Nance appliance was the main source of anchorage. The pre- and postdistalization records included dental study casts, clinical photographs, and cephalograms. A total of 665 readings recorded from lateral cephalograms and dental casts were subjected to statistical analysis. The mean distal movement of the first molar was 2.78 mm, which was highly significant (o < 0.001). It moved distally at the rate of 0.86 mm/month. There was clinically some distal tipping (3.50 degrees) and distopalatal rotation (2.40 degrees). These changes were statistically significant (p < 0.001). The second molars accompanied the first molars and moved distally by nearly the same amount. There was 1.00 mm increase in the overjet and 2.60 degrees mesial tip of second premolar. The changes in the facial skeleton and dentition bases were minimal and statistically not significant. However, there was clockwise rotation of the mandible of 1.30 degrees that was statistically significant. This was the result of molar extrusion (1.60 mm).
Adolescent↗
A cephalometric evaluation of the dental and facial-skeletal effects using the Bionator with stepwise protrusive activations.
A study was conducted to ascertain dental effects of step-wise mandibular advancement with Bionator therapy. A sample of 24 girls in the age group of 9 to 12 years having Class II Division 1 malocclusion was well matched for age, severity of malocclusion and craniofacial morphology. The sample was divided into three groups. Eight girls underwent step-wise mandibular advancement in three stages, while eight were treated with single step advancement. Eight girls acted as control who did not undergo any treatment. The total treatment/observation period was 9 months. The cephalometric analysis revealed that the progressive mandibular advancement enhances favorable facio-skeletal changes, more so in the mandible. The sagittal correction was predominantly of skeletal type with step-wise advancement, while with single step advancement it was due to both skeletal and dental changes.
Activator Appliances↗
Cephalometric analysis of changes produced by a modified Herbst appliance in the treatment of Class II division 1 malocclusion.
This study investigated treatment changes produced by the Herbst appliance in a sample of severe Class II division 1 cases, over a period of 8 months. The sample consisted of 16 girls, of whom eight were treated by the Herbst appliance, whilst eight served as controls. All cases were matched with respect to age, sex, skeletofacial morphology, and length of treatment/observation period. Twenty-two skeletal and 19 dental parameters were recorded on pre- and post-treatment cephalograms. The net treatment effect of Herbst therapy was evaluated, taking into account the growth that occurred in the control sample. The study revealed that during 8 months of Herbst therapy there was a significant increase in mandibular length, along with sagittal repositioning. The skeletal changes in the mandible were mainly responsible for overjet and molar relation correction. A slight, favourable forward rotation of the mandible was identified. Dentoalveolar features included flaring of lower incisors and distalization of upper molars. The appliance did not have any retrusive effect on the maxilla. The modified splint design differed from the original and was cemented rather than bonded.
Case-Control Studies↗
Accidental swallowing of a gold cast crown during orthodontic tooth separation.
Accidental swallowing of a gold cast crown that became loose after separation with brass wire for orthodontic band placement, is reported. The intervention to remove the ingested crown subsequent to its location in the GI tract on immediate radiographic examination of chest and abdomen included endoscopic examination. Since the crown had past distal to the duodenum it was decided to keep a watch on its movement by daily radiographic examination. The crown passed with excreta on the 5th day uneventfully. Literature on ingestion of foreign bodies of dental origin is reviewed. Possible emergencies and their management is discussed.
Adolescent↗
Hyoid bone and atlas vertebra in established mouth breathers: a cephalometric study.
The position of hyoid bone and atlas vertebra in 29 established mouth breathers (17 boys and 12 girls) in the age group of 10-14 years were cephalometrically evaluated and compared with 23 nose breathers (11 boys and 12 girls). The children of both the groups were selected on the basis of history and clinical examination. The comparisons were made using univariate analysis for male and female groups separately as well as combined. It was observed that mouth breathers do maintain an extended head posture, which was evident from a decrease in distance between the occiput and dorsal arch of atlas vertebra. However the results of the present study did not reveal any distinct characteristics of hyoid bone and atlas vertebra that can be used to predict or associate the craniofacial pattern of mouth breathers.
Adolescent↗
Craniofacial pattern of parents of children having cleft lip and/or cleft palate anomaly.
The craniofacial patterns of 38 sets of parents who had children with cleft lip and/or cleft palate anomalies (experimental group) were compared with the 24 sets of parents of healthy (noncleft) children (control group). Using a computerized program, 248 cephalograms (124 lateral and 124 frontal) were digitized and analyzed. The parents in the experimental group exhibited a distinct craniofacial morphology, including a significant decrease in upper anterior facial height (N-Ans) and total anterior face height (V-Gn). Anterior nasal spine (Ans) and maxillary alveolar process (A) were positioned more anteriorly and superiorly in the experimental group, which contributed to a significant increase in the length of the palate (Ans-Pns) and an anterosuperior rotation of the palatal plane. The cranial base angle in the experimental group was significantly obtuse and the articular angle was smaller than that of the controls. The counterclockwise rotation of the mandible was mitigated by a significant increase in the gonial angle. Parents in the experimental group also tended to have faces which were smaller in both transverse and vertical dimensions.
Adult↗
Extreme transmigration of mandibular cuspid: report of two cases.
Transmigration of impacted mandibular cuspid to the opposite side seems unhypothetical due to the presence of symphyseal cartilage. Two such rare cases of extreme transmigration were radiographically discovered when patient reported for orthodontic therapy.
Child↗
A study of the etiological factors associated with the development of malocclusion.
The prevalence of malocclusion among 1608 children (777 boys and 831 girls) in the age group of 5-7 years, selected from different schools of varied locations of Delhi was observed as 18.4%. A number of factors that could influence the normal development of occlusion during early mixed dentition stage were recorded. These included spacing in anterior teeth, attrition of primary teeth and deleterious oral habits. The socio-demographic variables included occupation of parents, family size, location type and the school type. The age of the child and sex were also considered. In order to find out the contribution and importance of above mentioned occlusal characteristics and socio-demographic factors in the development of malocclusion, the data were subjected to univariate analysis. Further a stepwise logistic regression analysis was done to know whether any association exists between the occurrence of malocclusion and combination of these factors. Four factors were found to contribute significantly in the occurrence of malocclusion explaining 15.5% variation in case of boys and 22% in case of girls. More significant factors were absence of spacing, effect of habits and lack of attrition of primary teeth. About 80% of the total variation was independent of these factors and could not be explained by this analysis. It further testifies possible predominance of genetic influences in the development of occlusion.
Adolescent↗
A cephalometric appraisal of dento-facial and soft tissue pattern in Indo-Aryans.
Cephalometric characteristics of various races and ethnic groups have been described by several investigators as this information is essential for clinical and research purposes. The objective of this study was to describe the dentofacial and soft tissue pattern of Indo-Aryans and to compare it with accepted standards for Caucasians and other North Indian population groups. Lateral cephalometric radiographs of 30 females with pleasing profile and good occlusion, aged 16-21 years, were used. A computer aided cephalometric analysis was performed and the basic descriptive statistics for the various cephalometric variables were obtained. Indo Aryans have shown a mild convex Dental Pattern as compared to Caucasians but similar to North Indians. Their soft tissue pattern is characterised by increased thickness of upper lip and a thin lower lip.
Adolescent↗
Status of dental caries and treatment needs in tribal children of Mandu (Central India).
Study was conducted in 1016 tribal children 6-13 years of age, living in remote villages of Mandu in district Dhar of Madhya Pradesh., to find out the status of dental caries and treatment needs. The tribal children exhibited a low prevalence of dental caries, both in primary and permanent dentitions, compared to rural as well as urban Indian children of the same age. The point prevalence of dental caries in primary teeth was 28-37% in 6-8 years age group and in the permanent teeth was 6-17% in 8-12 years children. The mean dmf ranged between 0.8-1.25 in six and eight year old children. The DMF hovered around 0.5-1.4 in 6-12 years old children. Nearly 30% children needed conservative care. Only a negligible percentage of children needed extraction/s of primary or permanent teeth. They showed less caries both in terms of dmf/DMF as well in its severity.
Adolescent↗