A severe open bite case treated with orthodontics and tongue reduction surgery: 13-year followup. A case report.

BACKGROUND: The management of open bite malocclusions creates controversy when treatment approach and long-term stability are considered. Tongue size, posture and habits have been associated as aetiologic and compounding factors. Reduction tongue surgery has therefore been advocated as an aid in treatment, especially when the open bite is accompanied by perceived macroglossia. AIM: The present article describes a clinical case of a 10-year-old girl who started treatment in the mixed dentition with an excessive open bite and speech defects. METHODS: A combination of orthodontics and a partial glossectomy was necessary to successfully address the open bite associated with an enlarged tongue. RESULTS: The need for orthognathic surgery treatment was eliminated and the patient was satisfied with the post-treatment aesthetics, function and speech. CONCLUSION: After 13 years of follow-up, a stable occlusion was maintained with only minor relapse.

Factors influencing the accuracy of cephalometric prediction of soft tissue profile changes following orthognathic surgery.

The cephalometric prediction of orthognathic treatment outcome is an important part of the surgical planning and the process of informed consent. The orthodontic and surgical changes must be described accurately prior to treatment in order to assess the treatment's feasibility, to optimize case management and to increase patient's understanding and acceptance of the recommended treatment. The aim of the present article was to investigate on the factors that could influence the accuracy of cephalometric prediction in planning orthognathic surgery. Review of the literature revealed that, besides factors directly related to the prediction method and its use, there exist a considerable number of factors which could affect significantly the accuracy of soft tissue response. These factors could be biological ones such as relapse, centre of mandibular rotation and individual variation in response to treatment and others such as gender, race, pre-operative soft tissue thickness and data bases for mean ratios of soft to hard tissue movement changes. Some of the factors affecting the accuracy of prediction of soft tissue response following orthognathic surgery are inevitable and there are others, difficult to control and predict. However, patients should be informed that predictions are only a guide, may not represent the actual result of the surgical outcome, and as such they should be implemented.

Fluoride release from an orthodontic glass ionomer adhesive in vitro and enamel fluoride uptake in vivo.

INTRODUCTION: The objective of this study was to investigate the in-vitro fluoride release from a glass ionomer orthodontic bonding system (Fuji I, GC Corporation, Tokyo, Japan) over a 2-month period and the in-vivo enamel fluoride uptake after 6 months. METHODS: Ten metal brackets were bonded with either glass ionomer or composite resin (Transbond XT, 3M Unitek, Monrovia, Calif; Light Cure), which served as controls, to recently extracted molars. The bonded teeth, cut at the level of their roots, were stored in distilled water that was renewed after every fluoride measurement at 1, 3, 7, 30, and 60 days. The in-vitro fluoride release was measured by using a fluoride ion-selective electrode, connected to an ion analyzer. Fifteen pairs of premolars were bonded with metal brackets with either the Fuji or the Transbond adhesive. Six months later, the teeth were extracted for orthodontic purposes, embedded in resin, and cross-sectioned, and the fluoride compositions between the outer and bulk enamel surfaces were evaluated with scanning electron microscopy and energy dispersive analysis. The results were analyzed with nonparametric 1-way analysis of variance (ANOVA) on ranks for in-vitro fluoride release and nonparametric 2-way ANOVA on ranks for in-vivo fluoride enamel uptake; group differences were investigated with the Holm-Sidak test at the .05 level. The Spearman rank correlation coefficient test was used to investigate the association between fluoride and aluminum levels in the interfaces of the specimens bonded. RESULTS: The initial burst of fluoride release observed for the Fuji adhesive after the first day of the experiment had a significant decrease with time, and it persisted throughout the monitoring period (60 days) (P <0.05). Fluoride concentrations were found in both the outer and deeper enamel surfaces, with the outer sites having 4 times higher fluoride relative to the bulk for the glass ionomer (P <0.05), and higher fluoride was found in the outer layers for the glass ionomer bonded enamel specimens (P <0.05). However, the concurrent identification of aluminum and fluoride traces in the enamel implied that the source of this high fluoride concentration originated from cement particles and not from ionic uptake. CONCLUSIONS: The short-term fluoride release and the absence of documented enamel uptake suggest that the glass ionomer orthodontic adhesive tested might provide protective action only through the reservoir mechanism.

A severe reaction to ni-containing orthodontic appliances.

Exposure to nickel-containing orthodontic appliances may cause intra- or extraoral allergic reactions. Nickel is the most typical antigen implicated in causing allergic contact dermatitis, which is a Type IV delayed hypersensitivity immune response. This report presents an unusual reaction to nickel during the orthodontic treatment of an adult female patient. The patient had no previous history of allergy and had been wearing fixed metal upper appliances while in orthodontic treatment to assist the eruption of her impacted teeth. The adverse hypersensitivity reactions appeared only after the surgical exposure and included severe signs of eczematic and urticarial reactions of the face with redness, irritation, itching, eczema, soreness, fissuring, and desquamation as well as intraoral diffuse red zones. Diagnostic patch testing performed by the allergist revealed sensitization to nickel (++++ score). Treatment was achieved with nickel-free appliances.

Effect of in vivo aging on the shear bond strength of an orthodontic adhesive.

AIMS: To assess the effect of intra-oral aging on the shear bond strength of a composite resin orthodontic adhesive (Transbond XT, 3M Unitek, Monrovia, CA, USA) after 6 months in the oral cavity and to compare it with control specimens not subjected to intra-oral aging. METHODS: The sample consisted of patients aged 13-36 years, in need of premolar extractions for orthodontic purposes. Ten premolars were bonded with Transbond XT. After 6 months in vivo, the teeth were carefully extracted, sectioned at the amelo-cemental junction, mounted in cold cure acrylic resin cylinders and subjected to shear bond strength testing using a universal testing machine. The debonded bracket base surfaces were then studied under light microscope, photographed digitally and analysed with SigmaScan Image Measurement Software (Jandel GmbH, Erkrath, Germany) for the percentage of coverage of the debonded brackets with the orthodontic adhesive. The same procedure was followed for 14 premolars from the same patients bonded in vitro with the same adhesive. RESULTS: No statistically significant differences were found in the shear bond strength between the two groups of composite resin adhesive systems (with and without clinical aging) or in the adhesive remnant coverage following debonding. No significant correlation was detected between the shear bond strength and the adhesive remnant coverage in the test specimens with and without aging. CONCLUSIONS: Laboratory studies of shear bond strength appear to be clinically relevant.

Allergic reactions to nickel-containing orthodontic appliances: clinical signs and treatment alternatives.

Nickel is the most common contact allergen. Nickel-containing orthodontic appliances are implicated in allergic reactions, which represent a type IV delayed hypersensitivity immune response. Nickel hypersensitivity is diagnosed through the patient's history, clinical findings, and biocompatibility testing (patch skin tests). While testing the level of nickel in mucosa and blood does not have diagnostic value, the in vitro cell proliferation assays could be an important diagnostic tool. Allergic hypersensitivity reactions may involve intra- and extraoral clinical signs, comprising diffuse erythema, edema, eczema, fissuring, desquamation, and symptoms such as itching and soreness. Caution and close monitoring should be exercised when placing nickel-containing orthodontic appliances in patients with known histories of nickel contact dermatitis, as the original treatment approach might need modification. The aim of this article is to provide orthodontists with the necessary knowledge about the biologic mechanisms, diagnostic tools, and clinical signs, as well as the treatment alternatives to nickel-induced allergic reactions.

Conservative treatment of isolated condylar fractures in growing patients.

Traumas to the mandible in children, due to falls or traffic accidents, can involve fractures in the condylar area. Without timely and proper diagnosis, such fractures may give rise to serious problems, such as growth disturbances of the face and disorders of the temporomandibular joint. Orthodontists are often involved in the diagnosis of condylar fractures but, more importantly, they should be involved in the successful conservative management of the fracture. The aim of this article is to present 5 cases of isolated condylar fractures in children (2 boys, 3 girls; age range 4.5 to 10 years) who were diagnosed and treated solely by a conservative orthopedic approach, involving the use of a functional appliance (activator). After a follow-up period of 1 year, clinical and radiologic examination indicated, due to the growth potential of the condyles during childhood, successful healing and remodeling had occurred in all 5 cases and no discomfort or complications were reported. A conservative treatment approach for an isolated condylar fracture, using a functional appliance during the growth period, can lead to complete restoration of the fractured area and re-establishment of physiologic function of the stomatognathic system with no signs of disturbance in dentofacial development.

Predisposing factors to formation of cleft lip and palate: inherited craniofacial skeletal morphology.

OBJECTIVE: To identify inherited craniofacial morphologic features in individuals at high risk for cleft of the lip, cleft palate, or both. SUBJECTS: Twins without cleft from 33 pairs of monozygotic twins discordant for cleft lip, cleft palate, or both were studied. There were 17 males and 16 females of Caucasian origin, ranging from 3 to 18 years (15 with cleft lip and palate [CLP], 10 with cleft lip [CL], and 8 with cleft palate [CP]), collected from five craniofacial centers (United States and Canada). DESIGN: The twin without cleft (noncleft) from each set was compared with an age- and sex-matched control individual from the Burlington Growth Centre, Toronto, Ontario. Posteroanterior and lateral cephalograms were traced and digitized using a computer custom analysis. Descriptive statistics, Student's t tests, and analysis of variance were used to test 40 variables in a pilot study comparing the noncleft twin groups with the controls. Preliminary analysis permitted pooling of the CLP and CL groups (n = 25). To minimize false-positive significance, only 14 variables (from the maxillofacial area) were tested. RESULTS: Using the raw probabilities, eight variables showed significant differences between the pooled noncleft CLP and CL (CL[P]) twin group and the controls. However, when the level of significance was adjusted, only four (nasal width [p < .01], cranial base length [p < .05], cranial base width/length ratio [p < .001], and maxillary width/length ratio [p < .05]) were significantly different. No significant differences were confirmed between the noncleft CP twin group and the controls. CONCLUSIONS: The noncleft member of a discordant monozygotic pair has a number of facial characteristics that differ from the general population. These may predispose to the formation of a cleft lip or palate and may result from a deficiency or distortion of the mesenchyme that forms the craniofacial structures.