Case report: long term lingual arch - preventable iatrogenic damage.

Lingual arches are fixed space maintainers utilised for the preservation of leeway space in cases of mild mandibular crowding. They are normally bonded using glass-ionomer cement applied to the internal surface of molar bands. As with any fixed appliance/retainer, if molar bands are not sufficiently monitored they have the potential to pose a significant threat to an individual's dental health. Unconventionally, in our example a lingual arch was used as a long-term fixed retainer with harmful consequence to one of the banded first permanent molars. A general understanding of molar bands and fixed retainers is important for patients' general dental health by the prevention of discrete caries progression.

A discerning approach to simple aesthetic orthodontics.

There is currently considerable interest from general dental practitioners (GDPs) in the use of simple orthodontics to treat adult malocclusions. There is controversy in this, particularly in relation to 'quick fixes', simple orthodontics and 'straight teeth in six months' as opposed to more conventional treatment where the whole malocclusion is treated. This article will present a case for the use of simple aesthetic adult orthodontics in a measured and planned way. It will discuss the processes, planning and the importance of consent. It will also highlight how digital technology is used to preview, consent and execute an aesthetic result. Many of the recent systems emerging, have been as a result of the demand and supply of cosmetic dentistry. This, to a degree, has not helped since the implication of a 'quick-fix' is associated with this field. There has also been discussion on what the limits of GDP orthodontics should be. There is variability in how GDPs approach orthodontics, their experience, skill and ability to treat to an acceptable standard. Short courses may be one way of delivering orthodontic training but some of these courses are not regulated and the amount of internal mentoring is variable. This article highlights some of the systems in use, and potential upsides and downsides of this approach.

The prevalence of opportunistic pathogens associated with intraoral implants.

AIMS: The aim of this study was to determine the prevalence and proportions of opportunistic pathogens harboured on orthodontic retainers. METHODS AND RESULTS: First, Staphylococcus spp. and Candida spp. were isolated from the retainer's inner surface and from other mucosal surfaces of the subject's mouth by routine bacterial culture. The prevalence and proportions of these micro-organisms on retainers was compared in different areas of the mouth within a group of retainer wearers, and mucosal carriage was compared to a group of nonretainer wearers. Staphylococcus spp. were isolated from 50% of the retainers and comprised on average 8·4% of the viable microbiota. Candida spp. comprised 0·13% of the viable microbiota and were recovered from 66·7% of the retainers. Neither genus was isolated from nonretainer wearers. Second, the two most commonly worn retainers manufactured from different materials were sampled; again Staphylococcus spp. and Candida spp. were recovered; however, no statistical differences were observed between the devices. CONCLUSIONS: Opportunistic, nonoral, pathogenic micro-organisms were recovered from orthodontic retainers. SIGNIFICANCE AND IMPACT OF THE STUDY: It is possible that an orthodontic retainer could be a reservoir for opportunistic pathogens and act as a source of cross-, self- and re-infection.

Clinicians' knowledge and practice of data protection legislation and information management.

AIMS: The aim of this study was to review current legislation and guidance on information governance and to audit clinicians' management of confidential patient information and knowledge of published guidelines in a teaching hospital. MATERIALS AND METHODS: A questionnaire was developed based on published Department of Health, General Dental Council and National Health Service guidance. This was then piloted and distributed to clinicians to complete. RESULTS: A review of the current guidance revealed many confusing and unclear areas. However, clinicians' knowledge of information governance was generally good, with an overall correct response rate of 73%. CONCLUSIONS: All clinicians have an ethical and legal obligation to protect confidential patient data and to be aware of their responsibilities. Local guidelines need to be clarified to help clinicians to manage patient data effectively.

The effect of orthodontic bonding materials on dental plaque accumulation and composition in vitro.

The aim of this study was to investigate the accumulation and composition of microcosm dental plaque on different orthodontic bonding materials using an in vitro model. Microcosm plaques were grown on discs of a range of bonding materials in a constant depth film fermentor. The biofilms were derived from human saliva and supplied with artificial saliva as a source of nutrients. The number of viable bacteria in the biofilms was determined and the streptococci present were identified to species level. The results showed that there was no significant difference in bacterial accumulation between different bonding materials, however, biofilms grown on materials which were fluoride releasing, did not contain Streptococcus mutans. This in vitro study has shown that the use of fluoride-releasing bonding materials may support the growth of supragingival plaque, which does not contain S. mutans.

Cephalometric determinants of successful functional appliance therapy.

This retrospective study was undertaken to determine the presence of any features on a pretreatment lateral cephalogram that may be used to predict the success of improvement in the sagittal dental base relationship during functional appliance therapy in patients with a Class II skeletal pattern. Seventy-two patients judged to have been successfully treated with a functional appliance were selected for the study. Pre- and posttreatment radiographs were analyzed and the change in the ANB angle was used to determine the skeletal response to treatment. Within the total sample size of 72 patients, two groups were selected. One group of 13 patients who demonstrated a reduction in ANB angle of 3.0 degrees or more were identified as the skeletal group. A second group of 15 patients who demonstrated a change in ANB angle equal to or less than 0.5 degrees were identified as the nonskeletal group. Statistical analysis of these two groups revealed the presence of skeletal and dentoalveolar differences on the pretreatment lateral cephalogram. In the skeletal group, which responded with a favorable skeletal change, the mandible was smaller both in length (P < .01) and ramus height (P < .05) and the anterior and posterior lower face heights were smaller (P < .05). The cranial base was also smaller when compared with the respective lengths in the nonskeletal group.

A cephalometric inter-centre comparison of growth in children with cleft lip and palate.

AIM: To examine whether the treatment provided by the Mount Vernon Cleft Team produces craniofacial growth outcomes comparable with that of the Oslo Team. LOCATION: Mount Vernon Hospital, Middlesex, UK. DESIGN: A retrospective cephalometric investigation. SUBJECTS: Seventy-five Mount Vernon children and 150 Oslo children with complete unilateral or bilateral clefts of the lip and palate METHOD: The subjects were matched for age, gender, and cleft type, and their radiographs were digitized. The radiographs from each site were grouped according to patient age (9-11 or 14-16) and cleft classification (bilateral/unilateral). Patients with associated craniofacial anomalies were excluded from the study. RESULTS: Of the four variables studied (SNA, SNPg, NGn, sNANsPG) significant differences in maxillary growth were noted for bilateral and unilateral cleft groups at 14-16 years of age. The soft tissue profile was significantly flatter in bilateral and unilateral Mount Vernon cases at 14-16 years. The craniofacial growth exhibited by the Mount Vernon patients demonstrated 3.9-5.1 degrees reduction in maxillary prominence with respect to the Oslo sample. The bilateral cases from Mount Vernon had greater anterior face heights at 14-16 years. CONCLUSION: The treatment provided by the Mount Vernon Cleft team leads to a reduced maxillary prominence in children aged 14-16 years compared with the Oslo sample. This reduction is statistically significant in unilateral cleft lip and palate.

An orthodontic patient administration system (OPAS) for complete departmental management.

There is a requirement for effective management and audit in today's hospital environment. This paper discusses some of the principal requirements of a computer program for comprehensive orthodontic department management and describes in detail one system.

An investigation of the dentition of parents of children with cleft lip and palate.

OBJECTIVE: The aim of this investigation was to identify whether any dental features in parents of children with cleft lip and palate can be useful as predictors of clefting. METHODS: The dentition of 28 pairs of parents of children with complete unilateral (17) and bilateral (11) cleft lip and palate and 21 pairs of parents of noncleft children were evaluated. Clinical and radiographic examinations were carried out to identify abnormalities of tooth number and morphology. Study cast assessment was undertaken to evaluate incisor relationship, overjet, overbite, intercanine widths, and mesiodistal widths of individual teeth, and these data were subjected to statistical analysis. RESULTS: The prevalence of abnormalities of tooth number in parents of cleft children was similar to those reported elsewhere for general populations. In parents of children with unilateral clefts, there was no tooth-size asymmetry between teeth on the side corresponding to the child's cleft and noncleft sides, respectively. No differences were found in tooth widths and intercanine widths between parents of children with unilateral clefts and parents of children with bilateral clefts. The incisor relationship, overjet, overbite, and intercanine widths were found not to differ statistically between the parents of cleft children and parents of noncleft children. CONCLUSIONS: No predictors of clefting could be identified in the dentition of parents of children with cleft lip and palate.

Three-dimensional analysis of the child cleft face.

OBJECTIVE: This study examined the facial surfaces of cleft children and unaffected children aged 8-11 years with the aim of identifying and assessing differences in their facial surface morphology. The investigation was carried out using an Optical Surface Scanner, an instrument that utilizes laser light to construct and archive a three-dimensional image of the face suitable for linear measurement and direct surface comparisons. DESIGN, SETTING, AND PATIENTS: Thirty-nine cleft lip and palate (CLP) patients and 25 unaffected subjects were voluntarily recruited from two southeast England hospitals. A range of linear facial measurements was compared. Three-dimensional differences between the cleft subgroups and the control group were visualized by superimposition of averaged cleft scans over the averaged control group images. RESULTS: Statistically significant dimensional differences (p < or = .05) in interocular width, nose base widths, mouth widths, and nose base/mouth width ratios were found between the cleft group and the control group. Qualitative differences over the whole of the face were readily demonstrated between the groups by superimposition. Face width and submandibular area depth differed consistently between the groups, the cleft face appearing narrower with a deeper submandibular area. CONCLUSION: Significant differences exist between the facial surface morphology of CLP patients and control subjects.

The use of a face mask for postoperative retention in cleft lip and palate patients.

Surgical relapse in cleft lip and palate patients following Le Fort I osteotomy can be pronounced due to the presence of scar tissue from previous surgical episodes. This article reviews the literature on the use of protraction face masks. It describes the use of a face mask in the postoperative management of osteotomy patients undergoing surgery for the correction of severe skeletal Class III relationships. The management of a patient with repaired unilateral cleft lip and palate is illustrated.

The physical characteristics of neodymium iron boron magnets for tooth extrusion.

Impaction and non-eruption of teeth is a common problem encountered in orthodontics and many techniques have been proposed for the management of this condition. It has been advocated that a system utilizing magnets would supply a continuous, directionally sensitive, extrusive force, through closed mucosa and thus provide not only a physiological sound basis for successful treatment, but also reduce the need for patient compliance and appliance adjustment. This ex vivo investigation examined in detail the physical characteristics of neodymium iron boron magnets employed in attraction in order to assess their usefulness in the clinical situation. Attractive force and magnetic flux density measurements were recorded for nine sets of magnet pairs with differing morphologies. The effect of spatial relationship on force was assessed by varying vertical, transverse and horizontal positions of the magnets relative to each other, and by altering the pole face angles. The data obtained suggest that magnets with larger pole face areas and longer magnetic axes provide the best performance with respect to clinical usefulness. It was possible to formulate a specific relationship between force and flux density for each magnet pair. This relationship can be used in the clinical management of unerupted teeth to predict the force between the magnets by measuring the magnetic flux density present at mucosal level. The results indicate that magnetic systems may, indeed, have a place in the treatment of unerupted teeth.

Rare earth magnets in orthodontics: an overview.

Magnets have been used in dentistry for many years. They can be made to push or pull teeth. The force they deliver can be directed, and they can exert their force through mucosa and bone, as well as within the mouth. In orthodontics they are used for intrusion of teeth, tooth movement along archwires, expansion, retention, in functional appliances, and in the treatment of impacted teeth. New 'high energy' magnets are capable of producing very high forces relative to their size. Although magnets are potentially very useful there are a number of problems that severely affect their performance; the force produced between any two magnets falls dramatically with distance, significant irreversible loss in force is seen if the magnets are heated and a dramatic reduction in force is seen if the magnets are not ideally aligned to one another. In addition, magnets corrode badly in the mouth and a robust coating is required to protect them. This paper outlines the background to high energy magnets used in orthodontics, discusses the relevant physical and biological properties of them, and reviews their applications.

The durability of parylene coatings on neodymium-iron-boron magnets.

A parylene coating is frequently used to prevent corrosion of neodymium-iron-boron magnets when they are used intra-orally. This in vitro study was designed to test the durability of parylene coating in a simulated oral environment. Single and double parylene-coated magnets were subjected to grinding and crushing forces in an industrial ball mill. The results demonstrate that abrasion and wear was visible around the edges after 1 hour of testing, with a breach of the coating noted under high magnification scanning electron microscopy (SEM). The conclusion of the study is that parylene coating is unlikely to withstand intra-oral forces. The shape of the magnets, the manufacturing process involved in their production, and the thickness of the parylene coating are important factors to consider with respect to the durability of magnets used in the mouth.

Effect of chlorhexidine on multi-species biofilms.

With human saliva as an inoculum, microcosm dental plaques were grown on dental amalgam in a constant-depth film fermentor (CDFF) in the presence (suc +ve) and absence (suc -ve) of sucrose. The biofilms were then exposed to 0.2% chlorhexidine gluconate (CHG) for 1, 5, or 60 min and the survivors enumerated. Suc +ve biofilms had higher proportions of streptococci but lower proportions of veillonellae than suc -ve biofilms. Exposure to CHG for 1 min reduced the viable count of suc -ve and suc +ve biofilms by 53% and 89% respectively. In both cases, reductions were mainly attributable to killing of streptococci and actinomyces. After 60 min of exposure, 4% of the bacteria in the suc -ve and 2% in the suc +ve biofilms remained viable. This study has shown that large numbers of bacteria in microcosm dental plaques can survive a 1-min exposure to 0.2% CHG and that even after a 60-min exposure, substantial numbers of bacteria remain viable.

Corrosion of the intra-oral magnets by multi-species biofilms in the presence and absence of sucrose.

The purpose of this study was to determine the corrosive effects of multi-species biofilms on intra-oral magnets in the presence and absence of sucrose. Using pooled human saliva as an inoculum, biofilms were grown on the surfaces of 90 neodymium-iron-boron (Nd2Fe14B) magnets in a constant depth film fermentor under aerobic conditions at 37 degrees C. The fluid phase was a mucin-containing artificial saliva (delivered at a rate of 0.72/litres day-1), and, after 15 days, 100 ml of 10% (w/v) sucrose was added (as three pulses of 33.3 ml) each day for a further 15 days. Six magnets with attached biofilms were removed periodically. On each sampling occasion the numbers of aerobes, anaerobes, streptococci, veillonellae and actinomyces in each biofilm, the pH of the fermentor effluent and the dry mass of the magnets were determined. Addition of sucrose to the fermentor resulted in a fall in pH (from a mean of 6.94 to a mean of 4.96), an increase in the proportion of streptococci and a decrease in the proportion of veillonellae comprising the biofilms. The decrease in mass of the magnets was 28-fold greater in the presence of sucrose than in its absence. The results of this study have shown that the presence of sucrose affects the microbial composition of multi-species biofilms growing on Nd2Fe14B magnets and results in a marked increase in corrosion of the magnets.

A comparison of crown size dimensions of the permanent teeth in a Nigerian and a British population.

This investigation was undertaken to compare the mesio-distal and bucco-lingual crown dimensions of the permanent teeth in Nigerian and British populations. The study sample consisted of 30 pairs of study models of children from each of the two populations. The children were matched for sex. The mean age for the Nigerian and British samples was 12.5 +/- 1.4 years and 12.9 +/- 1.2 years respectively. No left-right side differences were observed (P > 0.05). The results indicate that the mesio-distal crown diameters were consistently larger in the Nigerian sample. With the exception of mandibular central incisors and maxillary canines there were no statistically significant differences in bucco-lingual crown diameters in the two populations.

Variability in recording and grading the need for orthodontic treatment using the handicapping malocclusion assessment record, occlusal index and dental aesthetic index.

This investigation evaluates three malocclusion treatment need indices, the Handicapping Malocclusion Assessment Record (HMAR), the Occlusal Index (OI) and the Dental Aesthetic Index (DAI), for reliability and inter-index correlation. Pretreatment study models of 30 cases (mean age 12.9 years, SD 1.2) were assessed using each index. All the indices demonstrated a high level of reliability and non could be selected over the other with regards intra-examiner differences. The DAI, however, was more time-saving (2.68 mins, SD 0.41) and simple to use. The highest correlation was between HMAR and OI (r = 0.87, P < 0.001) which is a reflection of the similarity in their design. This study also discusses the limitations of the three indices.