Is there a correlation between dental and cervical vertebrae maturation stages in growing subjects? A systematic review with meta-analysis.

OBJECTIVE: To assess the evidence on the relationship between dental and cervical vertebrae maturation. MATERIALS AND METHODS: Searches were performed (up to December 2021) in seven databases, as well as in gray literature. Studies that included growing subjects, which evaluated the correlation between the stages of tooth formation and the maturation of cervical vertebrae, were eligible. The methodological quality of the selected reports was assessed using the JBI checklist for cross-sectional studies. Random-effects meta-analyses were implemented to calculate the pooled correlation coefficients between the maturation stages of cervical vertebrae and each tooth type. The GRADE approach was followed to assess the certainty of evidence. RESULTS: Seventy-seven studies were selected. Most of them had limitations related to sampling and reliability of the methods to evaluate maturation. The syntheses evidenced positive correlations between the maturation of cervical vertebrae and the formation/calcification stages of the following lower teeth: canine (n = 7318; r = 0.692; 95% CI: 0.656-0.724), first premolar (n = 6194; r = 0.689; 95% CI: 0.649-0.725), second premolar (n = 6194; r = 0.695; 95% CI: 0.659-0.729), and second molar (n = 7905; r = 0.698; 95% CI: 0.652-0.739). All estimates were affected by the risk of bias and the presence of unexplained statistical heterogeneity. CONCLUSIONS: The evidence points to an apparent positive correlation between dental and cervical vertebrae maturation. These results need to be carefully evaluated as the body of evidence is of very low quality. CLINICAL RELEVANCE: Dental maturation might be a potential indicator of skeletal craniofacial growth status. A routine dental x-ray could be sufficient, reducing radiation exposure by requesting additional radiographs.

Rates of tooth movement and bone remodeling activity: Self-ligating versus conventional brackets.

BACKGROUND: Bracket systems have been developed with the purpose of reducing frictional resistance between the archwire and accessories. The aim of this research was to compare rates of tooth movement and regions of cellular bone modeling activity along tooth root surfaces of teeth moved with conventional vs. self-ligating brackets. MATERIAL AND METHODS: The experiments were conducted in 20 male dogs. Bands were cemented in all intermediate incisors, with conventional brackets (Morelli) on the right side and hybrid self-ligating ones (T3-American Orthodontics) on the left side. A 0.019" x 0.025" stainless steel wire was inserted passively in the slot of these brackets with chain elastics (250 gf) to perform sliding mechanics. Clinical records of the orthodontic mechanics were made before and after 15 days of the tooth movement. The dental segments of the animals were prepared for light microscopy. Statistical analysis of variance and the Tukey correction with a P value at 5% were used. RESULTS: There were no significant differences in tooth movement rates between the two types of brackets but differences, in the bone modeling activity, suggested that tooth movement with the self-ligating brackets resulted in more tipping and less translational movement than tooth movement with the conventional brackets. CONCLUSIONS: The rates of tooth movement were similar between the two systems. The histological evaluation of cellular bone modeling activity along tooth root surfaces showed more translation movement of teeth with the conventional brackets, and more tipping movement of teeth with self-ligating brackets. Key words:Edgewise, histological reactions, orthodontic movement, self-ligating, brackets.

Development of a calcified odontogenic hamartoma following avulsion of a permanent central incisor.

The avulsion of a permanent immature tooth is a serious condition and a real emergency in dentistry. The management of a traumatized avulsed tooth is always a challenge to the clinician. This case report concerns the development of a calcified odontogenic hamartoma after the avulsion of an immature central incisor in an eight-year-old female. The patient presented for the treatment four months after the avulsion. Her intraoral examination showed complete healing of the area but an atypical appearance of the alveolar area of the missing tooth was observed in the periapical radiograph. A new radiographic scan performed six months later revealed the formation of a radiopaque irregular structure at the cervical level of the alveolar ridge at the site of the missing tooth. Surgical removal was performed, and the histopathological examination revealed a hamartomatous proliferation of odontogenic tissue with calcification. After healing, the lateral incisor was orthodontically moved mesially and restored to resemble the central incisor. An orthodontic device was installed to improve function and aesthetics of the patient.

Escobar Syndrome-An Multidisciplinary Approach for an Excellent Outcome With 3 Years of Follow-Up.

This case report intends to provide the facial characteristics of Escobar syndrome and to describe the orthodontic treatment of a 12-year-old female patient diagnosed with it. Escobar syndrome, a variant of the multiple pterygium syndrome, is a rare disorder with many systemic, facial, and oral manifestations.The patient presented with mixed dentition, severe dolichofacial pattern, increased lower facial height, convex profile, severe anterior open bite, maxillary hypoplasia, and mandibular retrognatism. The multidisciplinary approach included soft cleft palate repair, orthodontic treatment, orthognathic surgery, restorative cosmetic dentistry, speech therapy, and physiotherapy. Despite the limitations imposed by the syndrome, this report illustrates how the multidisciplinary treatment approach aided in the correction of occlusal function and facial esthetics and improvement in the quality of life of the patient with Escobar syndrome.

Are self-ligating brackets related to less formation of Streptococcus mutans colonies? A systematic review.

OBJECTIVE: To verify, by means of a systematic review, whether the design of brackets (conventional or self-ligating) influences adhesion and formation of Streptococcus mutans colonies. SEARCH STRATEGY: four databases (Cochrane Central Register of Controlled Trials, Ovid ALL EMB Reviews, PubMed and BIREME) were selected to search for relevant articles covering the period from January 1965 to December 2012. SELECTION CRITERIA: in first consensus by reading the title and abstract. The full text was obtained from publications that met the inclusion criteria. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data using the following keywords: conventional, self-ligating, biofilm, Streptococcus mutans, and systematic review; and independently evaluated the quality of the studies. In case of divergence, the technique of consensus was adopted. RESULTS: The search strategy resulted in 1,401 articles. The classification of scientific relevance revealed the high quality of the 6 eligible articles of which outcomes were not unanimous in reporting not only the influence of the design of the brackets (conventional or self-ligating) over adhesion and formation of colonies of Streptococcus mutans, but also that other factors such as the quality of the bracket type, the level of individual oral hygiene, bonding and age may have greater influence. Statistical analysis was not feasible because of the heterogeneous methodological design. CONCLUSIONS: Within the limitations of this study, it was concluded that there is no evidence for a possible influence of the design of the brackets (conventional or self-ligating) over colony formation and adhesion of Streptococcus mutans.

Does cortical thickness influence the primary stability of miniscrews?: A systematic review and meta-analysis.

OBJECTIVE: To investigate whether there is evidence to support the association between cortical thickness (CtTh) and the primary stability of mini-implants (MI). MATERIALS AND METHODS: A search was performed including articles published until September 2013. The inclusion criteria comprised observational clinical studies conducted in patients who received monocortical MI for orthodontic anchorage and in vivo or ex vivo experimental studies performed to evaluate the primary stability of MI, studies that evaluated the association between CtTh and MI primary stability, CtTh measurement performed numerically, and MI primary stability evaluated by implant stability quotient value, Periotest value , pull-out strength, or insertion torque. Studies conducted exclusively in artificial bone or finite elements were excluded. RESULTS: Abstract and title reading identified 15 possible articles to be included. After reading the complete text, three were excluded. One article was found by hand searching and another excluded for an overlapping sample. Finally, 12 articles were selected. A positive correlation was found between primary stability and CtTh when studies that evaluated primary stability through PS were grouped (r  =  .409) and when studies that evaluated stability in humans were grouped (r  =  .338). CONCLUSIONS: There is a positive association between MI primary stability and CtTh of the receptor site. However, there is still a lack of well-designed clinical trials.

Is trabecular bone related to primary stability of miniscrews?

OBJECTIVE: To compare the primary stability of miniscrews inserted into bone blocks of different bone mineral densities (BMDs) with and without cortical bone, and investigate whether some trabecular properties could influence primary stability. MATERIALS AND METHODS: Fifty-two bone blocks were extracted from fresh bovine pelvic bone. Four groups were created based on bone type (iliac or pubic region) and presence or absence of cortical bone. Specimens were micro-computed tomography imaged to evaluate trabecular thickness, trabecular number, trabecular separation, bone volume density (BV/TV), BMD, and cortical thickness. Miniscrews 1.4 mm in diameter and 6 mm long were inserted into the bone blocks, and primary stability was evaluated by insertion torque (IT), mini-implant mobility (PTV), and pull-out strength (PS). RESULTS: Intergroup comparison showed lower levels of primary stability when the BMD of trabecular bone was lower and in the absence of cortical bone (P≤.05). The Pearson correlation test showed correlation between trabecular number, trabecular thickness, BV/TV, trabecular BMD, total BMD, and IT, PTV, and PS. There was correlation between cortical thickness and IT and PS (P≤.05). CONCLUSION: Cancellous bone plays an important role in primary stability of mini-implants in the presence or absence of cortical bone.

Transverse effects on the nasomaxillary complex one year after rapid maxillary expansion as the only intervention: a controlled study.

The aim of this study was to assess by means of cone-beam computed tomography (CBCT) scans the transverse effects on the nasomaxillary complex in patients submitted to rapid maxillary expansion (RME) using Haas expander in comparison to untreated individuals. This prospective controlled clinical study assessed 30 subjects (18 boys and 12 girls) with mixed dentition and during pubertal growth. The treated group was submitted to RME with Haas expander, retention for six months and a six-month follow-up after removal. The control group matched the treated group in terms of age and sex distribution. CBCT scans were taken at treatment onset and one year after the expander was activated. Maxillary first molars (U6) width, right and left U6 angulation, maxillary alveolar width, maxillary basal width, palatal alveolar width, palatal base width, right and left alveolar angulation, palatal area, nasal base width, nasal cavity width and inferior nasal cavity area on the posterior, middle and anterior coronal slices were measured with Dolphin Imaging Software(r) 11.5, except for the first two variables which were performed only on the posterior slice. All transverse dimensions increased significantly (P < 0.05) in the treated group in comparison to the control, except for alveolar angulation and inferior nasal cavity area (P > 0.05). Results suggest that increase of molar, maxillary, palatal and nasal transverse dimensions was stable in comparison to the control group one year after treatment with RME.

Superficial morphology and mechanical properties of in vivo aged orthodontic ligatures.

INTRODUCTION: The degradation of elastic ligatures in the oral environment results in the need of periodic replacement to maintain the optimal force during the orthodontic treatment. The purpose of this study was to perform a clinical prospective randomized study of the degradation of orthodontic elastomeric ligatures in the oral environment by scanning electron microscopy (SEM) and tensile strength test. METHODS: Two hundred elastic ligatures were randomly selected and placed around the brackets of 5 volunteers and removed in groups of 10, at different times (1, 2, 3, and 4 weeks). The control group was performed by another fifty ligatures which were not submitted to the oral degradation. The analyses were done by scanning electron microscopy (SEM) and strength mechanical test. RESULTS: The tensile strength test results showed reduction in the ultimate strength values after four weeks ageing in the oral environment and no statistical difference in the yield strength values (p < 0.05). The orthodontic elastomeric ligatures surface was significantly degraded in the oral cavity after four weeks. The elastomeric degradation began in the first week when the increase in the roughness could be detected just in some areas. Afterwards, the surface became gradually rougher and, after 4 weeks, it was totally rough with some crack areas. CONCLUSIONS: The elastic ligatures aged in the oral environment showed higher superficial degradation and lower loss of mechanical properties after the maximum experimental period.

In situ evaluation of orthodontic elastomeric chains.

The hypothesis tested in this study was that intraoral exposure of elastomeric chains alters their tensile strength. For such purpose, it was evaluated the in situ behavior of different elastomeric chains stretched for 3 weeks. Three kinds of elastomeric chains, Plastic chain (PC), Memory chain (MC) and Super slick chain (SSC), were randomly placed in 3 quadrants of 13 patient in a fixed distance of 16 mm and mean initial force of 180 g. Tensile testing was performed in an universal testing machine at different intervals: initial, 1 h, 24 h, 1 week, 2 weeks and 3 weeks. A two-way ANOVA test was performed to identify the influence of both material and time on the force decrease. A subsequent one-way ANOVAtest with the Tukey's post hoc test was used to identify statistically significant intragroup and intergroup remaining force (g and %) differences at 5% significance level. The effect of both the material and the time factors were significant. All groups showed significant force decrease after the 1-h period (23% for PC and 14% for MC and SSC). At the end of the 3-week period, the remaining force was 57% (96 g), 67% (129 g) and 71% (125 g) for PC, MC and SSC, respectively. In conclusion, intraoral exposure of elastomeric chains altered their tensile strength. In general, the greater force decrease occurred within the first hour. The remaining force of the enhanced chains measured at each time interval was greater than the conventional one (PC). After 3 weeks, only the enhanced chains maintained the force applied over 100 g.

Does rapid maxillary expansion have long-term effects on airway dimensions and breathing?

INTRODUCTION: In this systematic review, we identified and qualified the evidence of long-term reports on the effects of rapid maxillary expansion (RME) on airway dimensions and functions. METHODS: Electronic databases (Ovid, Scirus, Scopus, Virtual Health Library, and Cochrane Library) were searched from 1900 to September 2010. Clinical trials that assessed airway changes at least 6 months after RME in growing children with rhinomanometry, acoustic rhinometry, computed tomography, or posteroanterior and lateral radiographs were selected. Studies that used surgically assisted RME and evaluated other simultaneous treatments during expansion, systemically compromised subjects, or cleft patients were excluded. A methodologic-quality scoring process was used to identify which studies would be most valuable. RESULTS: Fifteen articles fulfilled the inclusion criteria, and full texts were assessed. Three were excluded, and 12 were assessed for eligibility. Four articles with low methodologic quality were not considered. The remaining 8 were qualified as moderate. The posteroanterior radiographs showed that nasal cavity width increases; in the lateral radiographs, decreased craniocervical angulation was associated with increases of posterior nasal space. Cone-beam computed tomography did not show significant increases of nasal cavity volume. Rhinomanometry showed reduction of nasal airway resistance and increase of total nasal flow, and acoustic rhinometry detected increases of minimal cross-sectional area and nasal cavity volume. CONCLUSIONS: There is moderate evidence that changes after RME in growing children improve the conditions for nasal breathing and the results can be expected to be stable for at least 11 months after therapy.

Long-term fluoride release from resin-reinforced orthodontic cements following recharge with fluoride solution.

The aim of this study was to test the hypothesis that there is no difference in the fluoride release behavior of resin-reinforced glass ionomer cements before or after fluoride recharge. The materials were divided into 5 groups: 2 resin-reinforced glass ionomer cements used for attaching orthodontic bands, that is, group FOB (Fuji Ortho Band) and group MCB (Multi-Cure Glass Ionomer Orthodontic Band Cement); 2 resin-reinforced glass ionomer cements and a composite used for bonding orthodontic brackets, that is, group OGLC (Ortho Glass LC), group FOLC (Fuji Ortho LC), and group TXT (Transbond XT), respectively. Fluoride release was measured during a 60-day period by using selective ion electrodes connected to an ionic analyser. After 4 weeks, the samples were exposed to 0.221% sodium fluoride solution. The results showed that cements achieved a maximum fluoride release 24 h after initial setting. No statistically significant differences were observed between groups FOB and OGLC regarding the amount of released fluoride following fluoride recharge from day 31 to day 36 (p>0.05). In conclusion, FOB and OGLC cements showed a higher capacity of capturing and releasing fluoride compared to the other cements studied.

Display of the incisors as functions of age and gender.

BACKGROUND: Older subjects usually show less of their upper incisors and more of their lower incisors than younger subjects. OBJECTIVES: To determine how much of the upper and lower central incisor crowns are visible in Brazilian subjects with their lips at rest. METHODS: The subjects were 240 white Brazilian subjects divided into four age groups: Group 1, 12 to 15 years of age; Group 2, 20 to 30 years of age; Group 3, 31 to 50 years of age and Group 4, 51 years of age and older. Each group contained 30 males and 30 females. The vertical display of the incisors was measured in millimetres from the midpoints of the incisal edges of the upper and lower central incisors to the borders of the upper and lower lips. RESULTS: In females, the mean upper central incisor display reduced from 4.45 mm in Group 1 to 1.32 mm in Group 4, and in males it reduced from 3.35 mm in Group 1 to 0.57 mm in Group 4. Less of the lower central incisor crowns were displayed in Group 1 females (Mean: 0.47 mm) than in Group 4 females (Mean: 2.22 mm), and in Group 1 males (Mean: 0.61 mm) than in Group 4 males (Mean: 3.05 mm). Brazilian women showed significantly more of their upper incisor crowns than Brazilian men in Groups 1, 2 and 4, whereas Brazilian men showed significantly more of their lower central incisors than Brazilian women in Group 4. CONCLUSIONS: With the lips at rest, older Brazilians display less of their upper central incisors and more of their lower central incisors than young Brazilians. Women show more of their upper incisors than men, while men display more of their lower central incisors than women.

The use of lidocaine as an anti-inflammatory substance: a systematic review.

OBJECTIVE: To investigate existence of evidence that supports the therapeutical use of lidocaine as an anti-inflammatory substance. METHODS: A search on health sciences databases was performed, including only papers published in English until May 2007 which reported in vivo experimental studies that tested lidocaine as an anti-inflammatory substance and used morphological and/or biochemical analysis. The keywords used were: "lidocaine & inflammation", "lidocaine & neutrophils" and "lidocaine & prostaglandin". The search results were previous selected by title and abstract, and then articles were read and those that met inclusion criteria were carefully analyzed and classified. RESULTS: Only 10 articles met the inclusion criteria, and were carefully read. They were ranked (A, B, and C) according to the level of evidence produced. Seven articles were classified as C, two classified as B, and one classified as A. Despite methodological differences, all of them, except for one, reported that lidocaine showed anti-inflammatory effects. CONCLUSIONS: According to the reviewed literature, lidocaine has a potential as an anti-inflammatory agent. However, there is still a lack of well-designed studies to support its clinical use, and none of them evaluated its effects on a mucous epithelium.

Selective alveolar corticotomy to intrude overerupted molars.

Orthodontic intrusion of overerupted molars in adults is challenging for most clinicians. Efficient intrusion can be achieved by combining selective alveolar corticotomies with a modified full-coverage maxillary splint to reduce surgical risks, treatment time, and costs for both orthodontists and patients.

Orthodontic treatment of patients with sickle-cell anemia.

Sickle-cell anemia is a genetic blood disease characterized by a hemoglobin gene mutation. The genetic failure is basically constituted by replacement of the hemoglobin beta chain in the sixth position so that the amino acid valine is encoded instead of glutamic acid. As a result, the erythrocytes have their normal biconcave discoid shape distorted, generally presenting a sicklelike shape, which reduces both their plasticity and lifetime. Because a complete blood supply is so important during application of both intraoral and extraoral forces, this article addresses the general and oral aspects associated with sickle-cell anemia. This will guide the clinician regarding such patients who seek orthodontic treatment by making references to literature on multidisciplinary management.