Orlando Tanaka

Nailbiting, or onychophagia : A special habit

Onychophagia, or nailbiting, is a common oral habit, observed in both children and adults. The etiologies suggested for nailbiting include anxiety, stress, loneliness, imitation of other family member, heredity, inactivity, transference from a thumb-sucking habit, and poorly manicured nails. Treatment should be directed at the causes; punishment, ridicule, nagging and threats, and application of bitter-tasting commercial preparations on the nail are a variety of reminders, but are not appropriate approaches to treatment. The key to success is the nailbiters consent and cooperation.

Insertional torque and axial pull-out strength of mini-implants in mandibles of dogs.

INTRODUCTION The objectives of this study were to evaluate insertional torque of mini-implants (MI) for orthodontic anchorage, to compare their axial pull-out strength at 0 (T0), 15 (T15), and 60 (T60) days after placement, to determine initial and peri-implant cortical bone thickness, and to analyze the correlations among these variables. METHODS Sixty MI were placed in the mandibles of 10 dogs. Peak insertional torque values were recorded, and, after the animals were killed, specimens were prepared. The MI were aligned with a testing machine to register axial pull-out strength. Cortical bone thickness was measured after removal of the MI. Statistical analyses were conducted with ANOVA and Tukey HSD tests. RESULTS Pull-out strength and peri-implant cortical bone thickness had differences (P <0.01) at the various times. The T0 value showed the highest pull-out strength, and the smallest peri-implant cortical bone thickness was at T60. There was a regular correlation between pull-out strength and peri-implant cortical bone thickness at T0 (r = 0.44, P = 0.05). There was no correlation between insertional torque and pull-out strength, and insertional torque and initial cortical bone thickness. CONCLUSIONS Pull-out strength is greater immediately after placement of MI, cortical bone thickness decreases because of bone resorption, and insertional torque is not an efficient method for predicting the retention of MI.

Evaluation of skeletal and dental asymmetries in Angle Class II subdivision malocclusions with cone-beam computed tomography

INTRODUCTION The purpose of this study was to determine whether Angle Class II subdivision malocclusions have skeletal or dental asymmetries between the Class II and Class I sides. METHODS A sample of 54 untreated Angle Class II subdivision patients with pretreatment photos and cone-beam computed tomography (CBCT) scans was used. The photos were used to identify the Class II subdivision malocclusion and to record the amount of crowding per quadrant. Landmarks were plotted on each CBCT volume so that direct 3-dimensional measurements could be made to compare the positions and dimensions of the skeletal and dental structures on the Class II side vs the Class I side. RESULTS Significant differences were found for 2 skeletal measurements: the position of the maxilla relative to the cranial base, and the mandibular dimension from the mandibular foramen to the mental foramen. Statistically significant dental differences were found for the position of the mandibular first molars and canines in relation to the maxilla and the mandible. Statistically significant differences were found for the maxillary first molars and canines in relation to the mandible. CONCLUSIONS There were significant skeletal and dental differences between the Class I and Class II sides. The dental asymmetries accounted for about two thirds of the total asymmetry.

Sliding resistance with esthetic ligatures: an in-vitro study.

INTRODUCTION This study was developed to evaluate in vitro the properties related to sliding resistance of esthetic ligatures. METHODS Frictional force of 6 ligatures--2 conventional, 2 specially coated elastomeric, Teflon-coated (Dupont, Wilmington, Del) stainless steel, and stainless steel (control) ligatures--were studied by sliding 0.019 x 0.025-in stainless steel wire through the 0.22-in slot of stainless steel bracket. Elastomeric ligatures were tested for frictional and tensile forces under 3 experimental conditions: recent stretching, after 21 days of simulated stretching in artificial saliva, and a demineralizing/remineralizing regimen. Statistical analysis was conducted with ANOVA and Games-Howell tests. RESULTS There was high correlation between frictional and tensile forces of elastomeric ligatures, with reduction of both after 21 days. The demineralizing/remineralizing regimen reduced the frictional forces of ligatures to the same level as the ligatures in artificial saliva. Teflon-coated and stainless steel ligatures showed the lowest initial frictional forces, but there was no difference in friction of stainless steel and post-stretched elastomeric ligatures. CONCLUSIONS Frictional forces generated by esthetic elastomeric ligatures under simulated oral environments are not stable and are more related to tensile force than to surface characteristics of the ligatures.

Spontaneous eruption of a canine after marsupialization of an infected dentigerous cyst

A dentigerous cyst is the most common developmental odontogenic cyst. It is a benign and asymptomatic intraosseous lesion that affects the bones of the maxillofacial complex, interfering with tooth eruption. This article reports the spontaneous eruption of a canine after marsupialization of an infected dentigerous cyst and extraction of the deciduous teeth. A radiograph showed a large cyst with a radiolucent area involving the mandibular left deciduous canine and first molar, and the permanent canine and first premolar. Although enucleation is the treatment of choice, marsupialization is the best option for large cysts involving an unerupted permanent tooth, as in this case. The patient was followed for 1 year, and eruption of the permanent canine and first premolar and gradual reduction of the radiolucent area were observed.

Multiloop edgewise archwire in the treatment of a patient with an anterior open bite and a long face.

An adolescent girl with an Angle Class III malocclusion, excessive lower facial height, and anterior open bite sought nonsurgical treatment. She was treated with a multiloop edgewise archwire (MEAW). In association with a chincup, MEAW mechanics allowed the successful correction of the anterior open bite and the molar relationship, without major alterations of the patients profile. Combined orthodontic and surgical treatment should be considered for patients with skeletal anterior open-bite malocclusion. For patients who do not want surgery, however, MEAW treatment is an alternative that can have excellent results.

Effectiveness of varnish with CPP-ACP in prevention of caries lesions around orthodontic brackets: an OCT evaluation

OBJECTIVE To evaluate the in vitro efficiency of applying varnish containing casein phosphopeptide (CPP) and amorphous calcium phosphate (ACP) in prevention of caries lesions around orthodontic brackets. MATERIALS AND METHODS For this purpose, brackets were bonded to the vestibular surface of bovine incisors, and eight groups were formed (n = 15) according to exposure of oral hygiene substances and enamel varnish: 1 (control) brushing only performed, 2 (control) brushing + use of mouth wash with fluoride, 3 Duraphat varnish application only (Colgate-Palmolive Ind. E Com. Ltda, São Paulo, SP, Brazil), 4 Duraphat + brushing, 5 Duraphat + brushing + mouth wash, 6 MI Varnish application (GC America, USA), 7 MI + brushing, and 8 MI + brushing + mouth wash. The experimental groups alternated between pH cycling and the procedures described and were kept in an oven at temperature of 37°C. Both brushing and immersion in solutions was performed in a time interval of 1 minute, followed by washing in deionized water three times a day for 28 days of experimentation. Afterwards, evaluation by optical coherence tomography (OCT) of the special type (Ganymede OCT/Thorlabs, Newton, USA) was performed. In each group, a scanning exam of the white spot lesion area (around the region where brackets were bonded) and depth measurement of caries lesions were performed. RESULTS Groups 1 and 3 were shown to differ statistically from groups 5, 6, 7, and 8 (p = 0.000). MI Varnish was shown to be more effective in diminishing caries lesion depth, compared with Duraphat, irrespective of being associated with brushing and mouth wash, or not. LIMITATIONS The major limitation of this study is that it is a study in which demineralization was obtained with the use of chemical products, and did not occur due to the presence of Streptococcus mutans and its acid byproducts. CONCLUSION Application CPP-ACP-containing varnish irrespective of being associated with brushing and mouthwash, or not, reduced depth of caries lesions around orthodontic brackets.

Metal and ceramic bracket effects on human buccal mucosa epithelial cells.

OBJECTIVE To test the null hypothesis that metal and ceramic brackets have no effect on the epithelial cells of the buccal mucosa. MATERIALS AND METHODS Two metal and two ceramic brackets were bonded in 21 individuals of both sexes. With the use of liquid-based exfoliative cytology, morphometric and morphologic changes in buccal mucosa cells adjacent to these brackets were determined and were compared at three time points: baseline (T0), 60 days after placement (T1), and 30 days after removal of the brackets (T2). RESULTS A decrease in nuclear area and an increase in cytoplasmic area occurred in the buccal mucosa cells adjacent to the brackets at T1 (P < .01). At T2, this altered morphometry persisted only in cells adjacent to the metal brackets, although to a lesser degree than at T1 (P < .01). A greater decrease in nuclear area was noted in cells adjacent to the metal brackets than in those next to the ceramic brackets (P < .01). At T0, the proportions of surface and subsurface cells were similar, but at T1, a predominance of surface cells was observed (P < .05). At all time points, smears of cells appeared normal or normal with some inflammatory changes. CONCLUSION The hypothesis is rejected. Placement of metal and ceramic brackets in the buccal cavity induces cellular alterations. These alterations do not suggest malignancy.

Conservative treatment of unicystic ameloblastoma.

INTRODUCTION Ameloblastomas are benign asymptomatic intraosseous lesions that affect the bones of the maxillomandibular complex, interfering both in function and facial esthetic appearance. A 14-year-4-month-old girl was referred by her clinician complaining her anterior teeth were crooked and inclined forward. The lower left mandibular tooth presented with increased pericoronal space compatible with dentigerous cyst. METHODS AND RESULTS The aim of this report is to relate a case of unicystic ameloblastoma with conservative treatment and with indication for orthodontic treatment. The conservative therapy was performed and the lesion had been completely removed. The need for radiographic and clinical follow-up for up to 10 years, initially performed every 6 months during the first 2 years and afterwards annually, in addition to the risk of late recurrence were explained for patient and her guardian. CONCLUSION The histopathologic exam of the surgical tissue provided the final diagnosis of ameloblastoma, as the lesion had not presented in its classical form and in atypical locations, as in this case involving a tooth that had not yet erupted.

Organization and quantification of the collagen fibers in bone formation during orthodontic tooth movement

The organic matrix of alveolar bone is composed fundamentally of type I collagen. Polarized light microscopy provides unique information about the structure, composition and polymerization degree of a variety of organic and inorganic tissues that is not available with other techniques. The aim of this research was to compare two methodologies of polarized light analysis for collagen organization in bone formation during orthodontic tooth movement and determined maturity of collagen over the time. Thirty Wistar rats were euthanized 3, 7 and 14 days after the NiTi unilateral closed-coil spring was stretched between the upper right first molar and the incisors. The control consisted by contra-lateral site. The first molar area was fixed, decalcified and histologically processed using picrosirius pigment. The collagen birefringence of bone turnover was analyzed by color percentage and phase retardation. We observed an increase in collagen fiber organization over time with two methodologies. The Pearson coefficient correlation indicated a strong relationship (0.76) among the two polarized light analyses. In summary, there is collagen maturation over 3, 7 and 14 days. We successfully evaluated the molecular organization, arrangement, degree of polymerization and maturation process of collagen fibers in bone turnover through color percentages and phase retardation.