Resident evaluation of orthodontic programs in Canada

The purpose of this study was to investigate the satisfaction of Canadian orthodontic residents with their programs and determine the scope of their training. An anonymous online questionnaire was sent to all Canadian orthodontic residents in November 2006. Data were assembled and categorized by different variables, and chi-square comparative analyses were performed. Forty-four out of fifty-four residents responded, giving a participation rate of 81.48 percent. Overall, 86.36 percent of responding residents were satisfied with their program. Respondents said they felt they received the appropriate amount of formal didactic teaching sessions and dedicated and protected academic time. All residents indicated their programs offered training in numerous treatment philosophies: 93.18 percent said they have sufficient clinically based training, and 72.73 percent indicated that their research-based training was sufficient. All responding residents indicated they will complete more than thirty patients from start to finish, and 25 percent estimated completion of more than seventy patients by graduation. Residents said they will complete on average five orthognathic surgery, twenty-four extraction, thirty-one non-extraction, eight adult, and thirteen patients in the mixed dentition. Only 50 percent said their programs contained care for disabled or underserved patients. Most (86.36 percent) said they feel they will be adequately prepared to provide unsupervised orthodontic care after graduation. These orthodontic residents indicated they collaborate most with the disciplines of oral surgery, periodontics, and prosthodontics. However, only 52.27 percent indicated they have a formal interdisciplinary program for treating patients. We conclude from the study that Canadian orthodontic residents are satisfied with the didactic, clinical, and research aspects of their programs. They receive comprehensive instruction with the opportunity to complete a significant number of patients, employing a variety of treatment approaches.

Profile changes in orthodontic patients treated with mandibular advancement surgery

INTRODUCTION

The potential to improve facial esthetics is often the deciding factor in treatment planning of borderline orthodontic patients who can be treated with either orthognathic surgery or dental camouflage. The purpose of this study was to determine the degree of skeletal and soft-tissue Class II disharmony necessary before a significant esthetic benefit is derived from mandibular advancement surgery.

METHODS

Twenty laypeople, 20 orthodontists, and 20 oral surgeons rated the attractiveness of before and after treatment profiles of 20 mandibular advancement patients using a 5-point Likert scale. The Spearman rank correlation tested for relationships between amount of profile change and varying pretreatment ANB and profile angles. Plots of the distribution of profile changes with varying ANB and profile angles were then examined.

RESULTS

There was a tendency for inverse correlations between profile change and profile angle, and for positive correlations between profile change and ANB angles, but only the relationship between profile change and ANB angles judged by the orthodontists was statistically significant (P <0.05). Orthodontists, oral surgeons, and laypeople found that profiles consistently improved when profile angles were < or = 159 degrees, < or = 158 degrees, and < or = 157 degrees, respectively. Orthodontists and oral surgeons found profiles consistently improved when ANB angles were > or = 5.5 degrees and > or = 6.5 degrees, respectively, whereas laypeople showed no trend between ANB angle and profile change. The incidence of having less desirable profiles after treatment was 2.6 to 5.0 times higher when the pretreatment profile angles were larger than the threshold profile angles, and 4.5 to 7.9 times higher when the pretreatment ANB angles were less than threshold ANB angles.

CONCLUSIONS

Pretreatment profile angles < 160 degrees and ANB angles > 6 degrees are necessary for profiles to be consistently perceived as improved after surgery and to minimize the incidence of the profile worsening after treatment.

Healing of periodontal tissues following transplantation of cells in a rat orthodontic tooth movement model

OBJECTIVE

To determine the fate and differentiation of transplanted periodontal ligament (PL) precursor cells and mouse embryonic stem (ES) cells and their relative capacity to regenerate wounded periodontium.

MATERIALS AND METHODS

Orthodontic tooth movement was introduced 24 hours before transplantation of PL or ES cells, and rats were euthanized either 24 hours or 72 hours after cell transplantation. The control rats received either no tooth movement and no cell transplantation or tooth movement and no cell transplantation. Differentiation of transplanted cells was assessed from mandibular periodontal histological tissue sections by immunohistochemical methods using monoclonal antibodies against PL cell differentiation markers. Data were analyzed using Student's t-test at a significance level of P = .05.

RESULTS

Transplantation of PL and ES cells resulted in a higher number of osteopontin, bone sialoprotein, and alpha-smooth muscle actin labeled transplanted cells, predominantly around the blood vessels of the periodontium in study rats compared with control rats (cell transplantation but no orthodontic tooth movement, P = .05). Combined treatments of tooth movement and cell transplantation resulted in enhanced regeneration of the periodontium as a result of tooth movement. Transplantation of PL cells induced a higher number of differentiating cells in the PL and alveolar bone than did transplantation of ES cells.

CONCLUSIONS

Orthodontic tooth movement promotes the differentiation of transplanted cells, and the differentiation occurs predominantly in the paravascular areas of the periodontium. In terms of regeneration of wounded periodontium, transplantation of PL cells produced a higher level of regeneration than ES cells, possibly because of PL cell plasticity and the capacity to undergo effective differentiation in the periodontal cellular microenvironment.

In Vivo Bonding of Orthodontic Brackets to Fluorosed Enamel using an Adhesion Promotor

Objectives: To determine the success of bracket retention using an adhesion promoter with and without the additional microabrasion of enamel.

Materials and Methods: Fifty-two teeth with severe dental fluorosis were bonded in vivo using a split-mouth design where the enamel surfaces of 26 teeth were microabraded with 50 μm of aluminum silicate for 5 seconds under rubber dam and high volume suction. Thirty-seven percent phosphoric acid was then applied to the enamel, washed and dried, and followed by placement of Scotchbond Multipurpose Plus Bonding Adhesive. Finally, precoated 3M Unitek Victory brackets were placed and light cured. The remaining teeth were bonded using the same protocol but without microabrasion.

Results: After 9 months of intraoral service, only one bond failure occurred in the control group where microabrasion was used. Chi-square analysis revealed P = .31, indicating no statistical significance between the two groups.

Conclusions: Bonding orthodontic attachments to fluorosed enamel using an adhesion promoter is a viable clinical procedure that does not require the additional micro-mechanical abrasion step.

Diagnosis and management of the infraerupted primary molar

An infraerupted tooth is a tooth that has failed to erupt to be in line with adjacent teeth in the vertical plane of occlusion. The general dentist may be faced with this predicament which requires careful attention and thoughtful consideration in terms of long-term patient goals. It is important to diagnose infraerupted teeth and treat them in a timely fashion to help prevent unwelcome sequelae. Important interdisciplinary communication is vital between the dentist and the orthodontist to ensure that precious space and time are not lost. Here we present a review article of complications and considerations that must be taken into account when faced with a patient who has an infraerupted tooth.

Diagnosis and clinical management of patients with skeletal Class III dysplasia

This paper summarizes the current literature on the diagnosis and treatment of a patient with Class III skeletal dysplasia. It also includes a report of two siblings with Class III skeletal dysplasia, although each received different treatment due to different causes of the condition. This review illustrates that early appropriate diagnosis, including cephalometric analysis, is important for identifying the location of the dysplasia. If the dysplasia is in the maxilla, treatment may prevent the need for future orthognathic surgery. Treatment for mandibular prognathism usually involves waiting for the patient's growth to complete (this could occur past the age of 18 in women and the age of 20 in men) and performing orthognathic surgery at that time.

Shear/peel bond strength of orthodontic attachments to moist and dry enamel

INTRODUCTION

The purpose of this study was to evaluate the in-vitro shear-peel bond strength of orthodontic attachments bonded to moist and dry enamel surfaces with orthodontic resin.

METHODS

Two stainless-steel mesh-based buttons were bonded to pumiced and etched enamel of each of 60 human molars mounted in cylindrical molds with Transbond XT (3M/Unitek, St Paul, Minn) (control), Smartbond (Gestenco International, Goteborg, Sweden), or Assure (Reliance Orthodontic Products, Itasca, Ill) according to each manufacturer's instructions. Half of the teeth were bonded under dry conditions, and half were given a thick layer of whole, unstimulated, fresh human saliva just before bonding. The teeth were stored in distilled deionized water at 37 degrees C. The shear-peel bond strength of 1 button on each tooth was evaluated in a testing device (Zwick, Ulm, Germany) at 24 hours; the remaining button on each tooth was evaluated at 6 months.

RESULTS

Statistically significant differences (P < .05) were evident in button adhesion to the tooth surface between moisture variations for Transbond XT, but not for Assure and Smartbond. Superior bond strengths were obtained for Transbond XT on dry enamel; the bond strength of Assure to saliva-contaminated enamel was better than that of the other materials.

CONCLUSIONS

Bonding to moist and dry enamel appears to be material-specific. Adequate in-vitro bonding to moist, saliva-contaminated enamel is possible with certain bonding materials.

Preventive and interceptive orthodontic treatment needs of an inner-city group of 6- and 9-year-old Canadian children

OBJECTIVE

Early recognition of developing malocclusions and the potential for uncomplicated orthodontic treatment procedures can minimize or eliminate future costly treatment. This study was designed to assess the potential for this approach in children living in a limited-income environment. A modified index for preventive and interceptive orthodontic needs (IPION) was used to determine the need for such treatment in schoolchildren aged 6 and 9 years.

METHODS

Two calibrated examiners examined each child independently and assessed several components of his or her occlusion, including molar relationship, crossbite, open bite, overbite and overjet. Dental variables such as presence of caries and early loss of teeth were also noted. Informed consent was obtained and all children present at school on the day of the field study were included. A total of 395 children were divided into 2 groups, aged 6 and 9 years.

RESULTS

A high prevalence of caries in the deciduous dentition (30.4% for 6 year olds; 20.6% for 9 year olds) and early loss of primary teeth (11.9% for 6 year olds; 29.4% for 9 year olds) was observed. A large percentage of children had crossbite in the anterior or posterior segments, or both. Open bites were also a common finding. Future orthodontic problems were identified in 28% of this population by using the modified IPION. No statistically significant differences (p > 0.05) were found between sexes or age groups using the chi2 test.

CONCLUSIONS

Most of the developing malocclusions identified in this study would be amenable to interceptive orthodontics, consisting of space maintenance, crossbite correction and arch expansion.

Increasing general dentists' provision of care to child patients through changes in the undergraduate pediatric dentistry program

Reduced caries rates and an increased percentage of children with dental insurance have made it more difficult for dental schools to provide undergraduates with sufficient numbers of pediatric dental patients requiring restorative procedures. This may result in graduates who are not competent and are reluctant to treat children after graduation. To ensure the quality of the undergraduate clinical training program, the Division of Pediatric Dentistry at the University of Manitoba changed from a comprehensive-based clinic to a block system in 1998-99. Specific communities with limited access to dental care (neighboring core area schools and Hutterite colonies) were specifically targeted as potential sources for child patients. This format increased the exposure of students to patient management as well as to complex pediatric dentistry procedures. To assess the learning experiences before and after the changes to the clinical pediatric dentistry program, sixty general dentists who had graduated from the University of Manitoba were randomly selected using the Manitoba Dental Association Directory. Surveys were sent to twenty general dentists who graduated in each of the following years: 1993, 2000, and 2002. Forty-five dentists responded, fifteen from each of the three surveyed classes. Dentists who graduated after the changes to the program (2000, 2002) reported that they performed a greater number of complex pediatric dentistry procedures and treated more toddler and preschool children than the group that graduated before the changes (1993). Referrals to pediatric dentistry specialists were higher in the 1993 group than in the 2000 and 2002 groups. In conclusion, an adequate pool of pediatric patients is critical to provide dental students with sufficient learning experiences. The dentists who graduated from the program after the changes were implemented are providing more comprehensive treatment to younger children.

Performance measures to improve the quality of orthodontic services and control expenditures

One of the most critical and contentious issues for specialist and nonspecialist professionals in the coming decades will be to evaluate the outcomes of health care services. Performance measures are imperative for elective orthodontics, because of the relatively weak evidence that they lead to significant improvements in dental and oral health, occlusal function, and psychological well-being of patients. Such measures are particularly crucial for orthodontic treatment eligible for benefit payments, because they will assure third-party dental insurers that the annual premiums levied from governments (taxes), employers (in lieu of salary increments), and individuals (in lieu of other discretionary expenditures) are well spent (ie, not wasted). Performance measures will also improve the "standards of orthodontic practice," so the continued integrity of the profession is contingent on their development.

Long-term in vitro fluoride release and rerelease from orthodontic bonding materials containing fluoride

The purpose of this study was to compare in vitro long-term (30 month) fluoride release and rerelease rates (after fluoride exposure) from 3 orthodontic bonding materials containing fluoride and 1 without fluoride. Ten samples of each material (Python, TP Orthodontics, LaPorte, Ind; Assure, Reliance Orthodontic Products, Itasca, Ill; Fuji Ortho LC, GC America, Alsip, Ill; and Transbond XT, 3M Unitek, Monrovia, Calif) were fabricated and stored in deionized distilled water at 37 degrees C. Five samples had fluoride-release rates measured at days 546, 637, 730, 821, and 913 after initial fabrication, and 5 samples were exposed to fluoride (Nupro 2% NaF gel, Dentsply Canada, Woodbridge, Ontario, Canada) for 4 minutes at day 535 and had measurements taken on days 546, 548, 552, 575, 637, 730, 821, and 913. To prevent cumulative measurements, the storage solutions were changed 24 hours before measurement. Statistically significant differences were found in fluoride-release rates (P <.0001), with Fuji Ortho LC releasing the most fluoride, followed by Python and Assure at all time points in the nonfluoride exposed group. In the fluoride-exposed group, there were significant differences in fluoride release (P <.0001), with Fuji Ortho LC releasing the most fluoride. A "burst-effect" pattern of fluoride release was seen after fluoride exposure for all materials. It was concluded that Fuji Ortho LC, Assure, and Python might have sufficient long-term fluoride-release rates to reduce white spot formation, and all are recommended as suitable fluoride-releasing orthodontic bonding materials.

Rapid palatal expansion in the young adult: time for a paradigm shift?

A 19-year-old man presented for correction of a malocclusion that included a transverse maxillary deficiency. The patient was informed that he required orthognathic surgery to expand his upper jaw and correct his malocclusion, but he refused surgical expansion. Recent evidence indicates that rapid palatal expansion can be used without surgery in young adults; the decision was therefore made to treat the patient nonsurgically. Rapid palatal expansion of the maxillary arch was accomplished by means of a Hyrax appliance, with post-treatment radiographs revealing an opening of the midpalatal suture. The belief still persists among some clinicians that young adult patients require orthognathic surgery for palatal expansion, despite recent evidence supporting a nonsurgical approach after closure of the midpalatal suture.

Controlling third-party expenditures and improving quality assurances: a plea for change

Growing demands to contain health care's inflationary expenditures have particular relevance for elective (eg, orthodontic) services, because their progressively increasing provision will ultimately jeopardize the resources for others (eg, restorative dentistry). Some form of rationalization is therefore inevitable, especially in services eligible for payments from third-party benefits. These are central concerns of the ongoing debate on whether rationalization should be driven by service efficiency and cost efficiency and who should make such decisions. The adaptation of contemporary computer-based technology could resolve this dilemma, especially if real-time comprehensive assessments of 3-dimensional craniofacial forms before and after treatment are incorporated into local and national databases. Such a facility would then help to develop clinical guidelines to optimize the provision of specific orthodontic services for particular malocclusions. Referring individual cases to these databases would subsequently help to control service expenditures and maintain or even improve their outcomes to the ultimate benefit of both the profession and the public.

Treatment and long-term follow-up of a patient with hereditary gingival fibromatosis: a case report

This report addresses the complex nature of oral diagnosis, treatment and long-term case management in the hereditary form of recurrent gingival fibromatosis. Case management is discussed in relation to a 13-year-old girl who presented with recurrent, progressive gingival enlargement requiring consecutive periodontal and orthodontic treatment. The initial course of treatment included 4-quadrant gingivectomy with reverse bevel incisions, followed by orthodontics. Microscopic examination of the gingivectomy specimens supported the clinical diagnosis. Three years later, recurrence of the condition was observed in all quadrants. To facilitate orthodontic tooth movement and to achieve optimal esthetics, another full-mouth gingivectomy was performed. There was no recurrence of the condition a year later. It is recommended that patients with this condition be monitored closely after gingivectomy, so that the treatment requirements of localized areas can be addressed as needed.

Fluoride release from new light-cured orthodontic bonding agents

The purpose of this study was to compare the rates of fluoride release with time from 1 nonfluoridated and 3 fluoride-containing orthodontic bonding materials in distilled water and artificial saliva. Materials tested were Assure (Reliance Orthodontic Products, Itasca, Ill), Fuji Ortho LC (GC, Tokyo, Japan), Python (TP Orthodontics, LaPorte, Ind), and Transbond XT (3M Dental Products, Monrovia, Calif). Ten specimens of each material type were stored in distilled water, and 10 of each type were stored in artificial saliva at 37 degrees C. Fluoride release was measured with an ion-specific electrode. Readings were taken periodically for a total time period of 6 months. At day 1, Assure released the most fluoride into distilled water (66.2 microg/cm(2)) and into artificial saliva (65.8 microg/cm(2)), followed by Fuji Ortho LC (25.9 microg/cm(2); 18.8 microg/cm(2)), Python (6.3 microg/cm(2); 4.2 microg/cm(2)), and Transbond (0.1 microg/cm(2); 0.1 microg/cm(2)). The fluoride release rates were highest during the first days of testing, declining to lower but more stable levels. At the end of 6 months, Fuji Ortho LC released the most fluoride (3.8 microg/cm(2); 3.5 microg/cm(2)) followed by Assure (3.1 microg/cm(2); 2.8 microg/cm(2)), Python (2.6 microg/cm(2); 1.7 microg/cm(2)), and Transbond (0.1 microg/cm(2); 0.1 microg/cm(2)). The type of storage medium did not dramatically affect fluoride release. The second part of the study, undertaken after a year of sample storage, tested the 20 samples of Assure for a further 2-week period, after exposure to running and still distilled water. Although fluoride release rates declined with time, they were still higher than the 1.5 microg/cm(2) level that is referenced as inhibiting decalcification of enamel in a clinical environment. Release rates were similar in running and still water at all time points. Throughout the 6-month period, all 3 fluoride-containing materials had rates of fluoride release that could theoretically inhibit decalcification of enamel.

Occlusal and oral health status of a group of 3-8-year-old South African black children

This study determined the oral health status of a group of 3-8-year-old South African black children, comprising a total of 214 children from the townships of Garankuwa, Shosanguwe, Mabopane, Hebron and Erasmus who attended a school in Akasia, Greater Pretoria Metropolitan Substructure. The decayed, missing and filled teeth (dmft), oral hygiene status, dental IQ and malocclusion status were determined. The study found that the children's oral health status and occlusal status were unacceptable. The level of their dental IQ scores was low, their oral hygiene poor, and they were in urgent need of primary and secondary dental care. In addition they were in need of both preventive and interceptive orthodontic care. A national strategy to address primary dental health care is recommended.

In vitro and in vivo fluoride release from orthodontic elastomeric ligature ties

Clinically, demineralization of enamel around orthodontic attachments can occur after only 1 month. Fluoride incorporation into elastomeric ligature ties may provide additional protection against decalcification through fluoride release. This study compared the fluoride release of fluoride-impregnated and nonfluoride elastomeric ligature ties (Ortho Arch Company) both in vitro and in vivo. A total of 260 fluoride-impregnated and 260 nonfluoride elastomerics were evaluated in this study, 400 in vitro and 120 in vivo. For the in vivo part of the study, six patients had fluoride and nonfluoride elastomerics placed in cross-quadrant fashion in their mouths; these were removed and tested for residual fluoride release after 1 month. With the use of the potentiometric analytical method, the fluoride release of the elastomerics was determined in distilled water as the 24-hour residual release, to compare the in vitro and in vivo fluoride leached into solution. The data was analyzed with the Wilcoxon matched-pairs signed ranks test. The distilled water control yielded an F- reading of 0.03 +/- 0.01 microgram/F/mL. In the in vitro part of the study, an average of 0. 38 microgram/F/mL/elastomeric was released over the 1 month period by the fluoride-impregnated elastomerics; this decreased significantly (P <. 05) to a 24-hour residual value at 1 month of 0.02 microgram/F/mL/elastomeric ligature, which is in the same order of magnitude as the distilled water control solution. The nonfluoride ties produced a calculated 24 hour residual fluoride release of 0. 003 microgram/F/mL/elastomeric after 1 month; this is much less than the distilled water control and would not be possible to measure accurately. After 1 month in vivo, significantly greater (P >.05) amounts of 24-hour residual fluoride were apparent: F- elastomerics = 1.43 microgram/F/mL/elastomeric and nonfluoride elastomerics = 0.44 microgram/F/mL/elastomeric. Fluoride ties gained weight intra-orally. Residual, leachable fluoride was present in fluoride-impregnated and nonfluoride elastomeric ligature ties after 1 month of intraoral use, due to imbibition. The clinical efficacy of fluoride-impregnated elastomeric ligature ties to prevent decalcification in the presence of plaque needs to be investigated.