Quantity and distribution of plaque in orthodontic patients treated with molar bands

Objective

The placement of orthodontic bands usually increases plaque accumulation due to numerous mechanical retention sites. The purpose of this investigation was to evaluate the amount and distribution pattern of biofilm in the oral (palatal and lingual) and interproximal regions surrounding orthodontic bands.

Materials and Methods

We evaluated the formation of biofilm on 32 orthodontic bands which had been placed intraorally for 6?C37?months. Two parameters were measured: the percentage of surface covered by biofilm (quantity) and the biofilm distribution pattern of accumulation. We measured these two parameters in four regions of interest: the mesial and distal interproximal regions, as well as the mesial and distal regions of the oral attachment.

Results

The quantity of biofilm formation was similar in all four regions of interest, ranging from 13.3% to 16.8%. In contrast to biofilm quantity, distribution patterns differed in the four regions. In the mesial and distal interproximal regions it appeared as extensive insular areas in 87.5% and 71.9%, respectively, whereas it appeared more often supragingival and linear in nature in regions adjacent to the oral attachment, i.e. in 65.6% and 68.8%, respectively.

Conclusion

Our results indicate that firstly, oral hygiene in the palatal and lingual regions of orthodontic bands seems as difficult as it is in the interproximal areas, thus requiring thorough hygiene in both areas. Secondly, orthodontic patients with a history of periodontal disease require special attention regarding the use of orthodontic bands.     

Vertical palatal bone dimensions on lateral cephalometry and cone-beam computed tomography: implications for palatal implant placement

Objectives: To evaluate the necessity of three‐dimensional imaging (computed tomography [CT]/cone‐beam computed tomography [CBCT]) for paramedian insertion of palatal implants. Material and methods: Lateral radiographs and CBCT scans were performed from 18 human skulls. For lateral cephalometry, the nasal floor (right/left) and the oral hard palate of all skulls were lined with a tin foil for contrast enhancement. The quantity of vertical bone as measured on lateral radiographs was compared with CBCT measurements obtained in median and parasagittal planes and at minimum bone height. Spearman's rank correlation coefficients were determined for bivariate correlation analysis. Results: The median palatal bone height on CBCT (mean 8.98 mm; standard deviation [SD] 3.4) was markedly higher than the vertical height seen on lateral radiographs (mean 6.6 mm; SD 3.2). Comparing lateral cephalometry with CBCT, the strongest association was observed at the minimum palatal bone height (r=0.926; P<0.001; Spearman's rank correlation coefficient). Conclusions: Lateral radiographs allow accurate and adequate assessment of vertical bone before paramedian insertion of palatal implants. The vertical bone dimension as displayed on lateral cephalometry reflects the minimum bone height rather than maximum bone in the median plane. Therefore, a preoperative CT or CBCT is only indicated when the lateral cephalometry reveals a marginal quantity of bone. To cite this article:
Jung BA, Wehrbein H, Heuser L, Kunkel M. Vertical palatal bone dimensions on lateral cephalometry and cone‐beam computed tomography: implications for palatal implant placement.
Clin. Oral Impl. Res. 22 , 2011; 664–668
doi: 10.1111/j.1600‐0501.2010.02021.x     

Anatomic site evaluation of the palatal bone for temporary orthodontic anchorage devices

Objectives: The aim of the present study was to assess the micromorphologic characteristics of the palatal bone from an implantologic standpoint.
Materials and Methods: The material consisted of tissue blocks of autopsy material from 22 subjects (18 males, three females) between 18 and 63 years of age. The specimens comprised the anterior median palatal region from 5 to 10 mm behind the incisive foramen. They were prepared in the transversal plane according to ground thin-section technology. The midpalatal area as well as an area of 3 mm bilateral to the midline were assessed, and a classification of quantitative palatal bone availability was developed.
Results: The findings could be divided into three classes: (1) class I palatal bone consists almost of compact bone; (2) class II cortical bone layer on oral and nasal sides of palate, broad compact bone in the suture area (≥3 mm), loose trabecular bone lateral to the suture area; and (3) class III cortical bone on oral and nasal side, thin compact bone in the suture area (<3 mm) and loose-structured trabecular bone lateral to the suture area. In most sections (72.7%), class I characteristics were found (16 subjects). 18.2% of sections were assigned to class II (four subjects) and only 9.1% of sections were assigned to class III (two subjects).
Conclusion: These results document that in most cases a good primary stability of temporary orthodontic anchorage devices should be achieved in the midpalatal and paramedian area of the anterior palate, as the bone quantity available is high.     

Oral health impact in patients wearing removable prostheses: relations to somatization, pain sensitivity, and body consciousness

PURPOSE: Previous studies investigating associations between patient personality traits and complaints related to wearing dental prostheses have been inconclusive. From the perspective of cognitive behavioral theory, the current study investigated whether pain sensitivity, body consciousness, and somatization affected the oral health of patients wearing removable dentures. MATERIALS AND METHODS: Eighty-eight patients were supplied with removable partial and complete dentures. The Oral Health Impact Profile (OHIP), with six subscales measuring oral health impairment and disability during daily living, the Pain Sensitivity Index, the Private Body Consciousness scale, and the Somatization Scale of the SCL-90-R, were used. RESULTS: The variables pain sensitivity, body consciousness, and somatization correlated significantly with all six OHIP subscales in removable denture wearers. In multiple hierarchic regression analyses, patient personality accounted for 38.0% of functional limitation and 41.5% of physical pain. CONCLUSION: Pain sensitivity and bodily preoccupation might be important factors in explaining the subjective oral health effects of removable denture wearing.     

The Effect of Debonding and/or Bleaching on Enamel Color – an In-vitro Study

AIM: There are various studies in the literature on bonding brackets to bleached teeth and on the effect of bleaching material on the color of compomers. The purpose of this study was to investigate changes in tooth color depending on the process of bonding - debonding and/or bleaching. MATERIAL AND METHODS: Ninety crowns of lower bovine permanent incisors were divided into nine subgroups. Three bonding materials (chemical, light- and pressure-cured) and three bleaching materials (15% CP, 35% CP, or 38% HP) were applied to the teeth, whereby each tooth was divided into quarters: untreated, bleached only, bonded-debonded only, and bleached after a bonding-debonding procedure. The Easyshade spectrophotometer was used to determine CIELCh coordinates (lightness, color, and hue) three times for each area. The areas' differences in color were expressed as the Euclidian distance DeltaE. Four examiners (two orthodontists and two dentists) rated each tooth concerning color differences in the four areas. The data collected was subjected to the sign and Wilcoxon or the Kruskal-Wallis and Mann-Whitney U tests using the SPSS 12.0 program. RESULTS: Examiners found significant differences between those areas with and those without bleaching within each group of specimens (p < 0.05), but there were no differences concerning the bonding and debonding procedures (p > 0.05). Furthermore, digital tooth-shade measurements revealed no statistically-significant group-associated differences between those areas treated with bonding material and those not so treated, nor between bonded and debonded areas (p > 0.05). Nor did we observe any statistically-significant differences between bleached areas and those areas bleached after bonding and debonding procedures (p > 0.05). CONCLUSION: The processes of bonding and debonding alone do not seem to have any statistically-significant influence on the tooth color of bovine enamel using these testing materials, nor does the subsequent bleaching procedure.     

Effects of Orthodontic Bands on Marginal Periodontal Tissues A Histologic Study on Two Human Specimens

Eight banded teeth on two human specimens (9 years, male; 19 years, female) were analyzed regarding the fit of the orthodontic bands and periodontal reactions. Five teeth (three molars, two premolars) were evaluated histologically in the horizontal plane and three (one molar, two premolars) in the sagittal plane using the micro-section method according to Donath. The fit of the bands varied in occluso-apical direction. The mean of marginal gaps was x = 0.23 mm in the occlusal, x = 0.03 mm in the equatorial, and x = 0.28 mm in the cervical area. In the equatorial area the thin cement layer was largely homogeneous, whereas porosities and microfissures were found predominantly in thicker cement layers. 85% of the occlusal and cervical band margins revealed cement defects and/or erosions which were colonized by felted, partially densely compacted microbial plaque. With regard to the periodontal effects, the signs of inflammation in the buccolingual gingival areas were markedly less severe due to the supramarginal position of the band margins. The interdental gingiva of all teeth presented the histological pattern of an established gingival lesion. Leukocyte infiltration and inflammatory exudation in the area of the transseptal fibers were exceptionally pronounced in one lower molar (band exposure time: 6 months). At this site the connective tissue attachment close to the cementoenamel junction was severely damaged on the mesial surface and the pocket epithelium proliferated towards the apex, meaning progression from established gingivitis to an initial periodontal lesion. The histologic findings on these human periodontal tissues confirm that the application and hygiene control of orthodontic bands have to be performed with great care to avoid permanent periodontal destruction.     

Palatal implant anchorage reinforcement of posterior teeth: A prospective study

A new orthodontic implant anchor system (Orthosystem) has been developed. This 1-piece device made from titanium consists of a screw-type endosseous section (lengths of 4 and 6 mm), a cylindrical transmucosal neck, and an abutment. Clamp caps with slots provide for attachment of square orthodontic wires (transpalatal bars) to the implant. The aim of the present prospective study was to evaluate the anchorage capacity of palatally inserted Orthosystem implants for anchorage reinforcement of posterior teeth. The sample consisted of 9 dental Class II patients (age 15 to 35 years) whose treatment plan included extraction of the maxillary first premolars. Each of the patients received 1 implant inserted into the center of the anterior palate. After a mean unloaded implant healing period of 3 months, transpalatal bars were inserted to connect the posterior teeth to the implant. Retraction of the canines and incisors was accomplished without the use of compliance-dependent headgear or Class II elastics. The degree of anchorage loss as well as the amount of canine and incisor retraction were evaluated by measurements of the casts and lateral cephalograms. The mean anchorage loss was 0.7 mm on the right side and 1.1 mm on the left (P <.05). The right and left canines were retracted 6.6 and 6.4 mm, respectively, and the mean overjet reduction was 6.2 mm. Because clinical assessment and postremoval histologic assessment both revealed stability of the short implant, the small anchorage loss was most likely from the deformation of the transpalatal bars by the orthodontic forces. Nevertheless, the treatment goal was achieved in all patients without the use of compliance-dependent auxiliaries. The clinical experience during and after implant insertion, active orthodontic treatment, retrieval of the implant, and subsequent wound healing are described.