[Archwire segmentation: a solution to the problems involved in treating atypical cases]. / La segmentation de l'arc, une réponse aux difficultés de traitement de cas atypiques.

INTRODUCTION: Asymmetrical orthodontic cases frequently prove very difficult to correct. Anchorage mini-screws are often needed to treat these cases when the malocclusion is of maxillary origin. Nonetheless, a precise biomechanical assessment must be made to avoid undesirable sideeffects resulting from the mechanics used. Whether one uses a continuous or a segmented archwire, adverse events can occur and must be planned for in order to contain them. MATERIALS AND METHODS: The authors will first give an overview of the possible undesirable effects using the continuous arch technique and the principles underlying the segmented archwire technique. Various clinical cases will also be described to support their argument. CONCLUSION: The advantage of the segmented techniques lies in the precision and speed of the movements obtained in the three dimensions of space. However, they can also present major drawbacks. In practice, these techniques seem best-suited to complex atypical cases, and particularly cases involving asymmetry of the frontal and transverse planes.

Digital evaluation of nasal changes induced by rapid maxillary expansion with different anchorage and appliance design.

BACKGROUND: Scientific evidence showed that rapid maxillary expansion (RME) affects naso-maxillary complex, increasing nasal width and volume. This study aimed to evaluate nasal changes induced by rapid maxillary expansion with different anchorage and appliance design by using low dose and cone beam computed tomography. METHODS: A total of 44 patients (20 males, mean age 8y 8 m ± 1y 2 m; 24 females mean age 8y 2 m ± 1y 4 m) were included in the investigation and divided into three groups according to the appliance: Hyrax-type expander anchored to permanent teeth, modified Hyrax-type expander anchored to deciduous teeth, modified Haas-type expander anchored to deciduous teeth. Maxillary expansion was performed until overcorrection and the expander was passively kept in situ for 7 months at least. All patients had three-dimensional imaging before expansion (T0) and after the retention period (T1). Nasal floor width, nasal wall width, maxillary inter-molar width were measured by means of Mimics software. The paired sample t-test was employed to assess the significance of the differences between the time points; the analysis of variance test (ANOVA) was used to compare differences between groups. RESULTS: The statistical analysis revealed significant differences between T0 and T1 for each recorded measurement in each group; no significant differences were found by comparing groups. CONCLUSIONS: Rapid maxillary expansion produces a significant skeletal transverse expansion of nasal region in growing patients. No significant differences in nasal effects are expected when the appliance is anchored onto deciduous teeth, with or without the palatal acrylic coverage.

Unexpected complications associated with mandibular fixed retainers: A retrospective study.

INTRODUCTION: The purposes of this retrospective study were to describe the types of unexpected complications associated with mandibular fixed retainers and to assess their prevalences and possible etiologic causes. METHODS: A total of 3500 consecutive patients (1423 male, 2077 female) treated with fixed appliances and a mandibular fixed retainer as a part of the retention protocol were screened during the retention period (2008-2013) for unexpected complications. Thirty-eight subjects (12 male, 26 female; mean age, 20.7 ± 8.9 years) with unexpected complications were identified and assigned to the unexpected complications group and compared with a randomly selected control group of 105 subjects (43 men, 62 women; mean age, 29.5 ± 9.7 years) without unexpected complications. Relationships between unexpected complications and cephalometric and clinical variables were evaluated. RESULTS: An opposite inclination of the contralateral canines (twist effect) was found in 21 subjects. In 89.5%, the left canines were tipped buccally. A torque difference of 2 adjacent incisors (X effect) was identified in 12 patients. In 5 subjects, nonspecific complications were noted. Subjects in the unexpected complications group were significantly younger at debonding (P = 0.03) and had higher mandibular plane angles (P <0.0001) and increased pretreatment ventral positions of the mandibular incisors (P = 0.029). No differences were found between the groups with regard to treatment duration, wire type, failure rate, treatment changes in incisor proclination, or intercanine distance. CONCLUSIONS: Unexpected complications of mandibular fixed retainers are relatively rare. Facial divergence was identified as a possible predictor. However, the etiology is most likely multifactorial. Strong asymmetry among the patients with the twist effect suggests that the mechanical properties of retention wires may play a role and should be examined in the future.

Alterações produzidas na fala por contenções superiores ortodônticas - ensaio clínico randomizado prospectivo / Alterations produced in speech due to upper orthodontic restraints - prospective randomizes clinical trial

Objetivo: Avaliar e comparar a influência das diferentes contenções ortodônticas superiores na fala e as percepções dos voluntários às diferentes condições provocadas pela sua utilização. Correlacionar as percepções entre si e com as dimensões do arco superior. Material e Métodos: Selecionou-se 21 (n) voluntários para utilizar 4 tipos de contenções removíveis superiores (Placa wrap-around convencional, em U e com orifício anterior e contenção termoplástica transparente-CTT) por 21 dias cada, com intervalos de 7 dias sem utilização entre elas. Durante a pesquisa, alguns voluntários desistiram ou não compareceram às avaliações, sendo excluídos. As percepções dos pacientes aos aparelhos foram avaliadas com a Escala Visual Analógica de 100 mm (n final=19), e correlacionou-se estas entre si. A avaliação da fala (n final=18) foi realizada em gravações de trechos vocais realizadas antes e imediatamente após a instalação das 4 contenções, assim como após 21 dias de uso destas. Para isto empregou-se a Análise Perceptiva Auditiva da fala e a Análise Acústica da frequência dos formantes F1 e F2 das vogais. Aplicou-se a ANOVA para dados repetidos e teste de Friedman com post hoc de Tukey, além das Correlações de Pearson e de Spearman para as avaliações. O nível de significância estatística estabelecido foi de 5%. Resultados: Os variados desenhos das contenções wrap-around não diferiram de forma significante em nenhuma das percepções e a CTT recebeu notas estatisticamente piores em todos os quesitos, com exceção da estética onde não diferiu estatisticamente das demais. Correlações positivas importantes foram encontradas entre alterações na fala e desconforto em todos os aparelhos. A interferência oclusal na CTT correlacionou-se muito positivamente a outras percepções, como alterações na fala e desconforto. Na avaliação perceptivo-auditiva, as alterações na fala aumentaram significantemente no momento imediato após a instalação do wrap-around com orifício e da CTT, e continuaram significantemente elevadas após 3 semanas. A frequência dos formantes das vogais foi prejudicada no momento inicial da instalação e as Alterações mantiveram-se presentes no wrap-around convencional, em U e na CTT após 3 semanas. Conclusões: A CTT prejudicou mais a fala que os wrap-around. Entre estes, os wrap-around convencional e em U interferiram menos na fala. O período de 3 semanas de uso dos aparelhos não foi totalmente suficiente para a readaptação da fala. A CTT foi pior classificada que as placas wrap-around em todas percepções avaliadas, exceto na estética, onde não diferiram significantemente. A cobertura oclusal da CTT pareceu ser a causadora da sua reprovação e das maiores alterações à fala nesta contenção. As dimensões do arco superior pouco influenciaram as percepções. Considerando as alterações na fala e as percepções dos pacientes, as contenções wrap-around apresentaram melhor desempenho e devem ser a primeira escolha quando a opção de contenção do arco superior for um aparelho removível.(AU)

Objective: To evaluate and compare the influence of different upper removable orthodontic retainers on speech and volunteers' perceptions to different conditions caused by their use. To correlate perceptions with each other and with upper arch dimensions. Material and Methods: 21 (n) volunteers were selected to use four types of upper removable retainers (conventional wrap-around, horseshoe-shaped wrap-around, wrap-around with an anterior "hole" and transparent thermoplastic retainer - TTR) for 21 days each, with intervals of 7 days without use between them. During the search, some volunteers dropped out or did not attend the evaluations and were excluded. Patients perceptions (final n=19) were evaluated with a visual analogue scale of 100 mm, and these were correlated with each other. Speech evaluation (final n=18) was performed in vocal excerpts recordings made before, immediately after and 21 days after the installation of each appliance, with Perceptual Auditory Analysis Auditory and Acoustic Analysis of formant frequencies F1 and F2 of the vowels. ANOVA for repeated measures and Friedman test with post hoc Tukey, in addition to Pearson and Spearman correlation for the evaluations were applied for statistics evaluation. The level of statistical significance was set at 5%. Results: Different designs of wrap-around retainers did not differ significantly in any of the perceptions and TTR received significantly worse grades in all aspects, except for esthetics, which did not statistically differ from the others. Significant positive correlations were observed between changes in speech and discomfort on all appliances. Occlusal interference in TTR was very positively correlated to other perceptions, such as changes in speech and discomfort. Speech changes, evaluated by Perceptual Auditory Analysis, increased immediately after conventional wraparound and TTR installation, and reduced after 3 weeks of use, but not back to normal levels observed without device. However, this increase was statistically significant only for the conventional wrap-around and TTR, remaining significant high after 3 weeks. Formant frequencies of vowels were altered at initial time and the changes remained present in conventional, horseshoe-shaped and TTR appliances after 3 weeks. Conclusions: TTR was more harmful to speech than the wrap-around appliances. Among these, conventional and horseshoe-shaped has interfered less in speech. The 3-week period with retainers was not fully sufficient for speech adaptation. TTR was worse classified than the wrap-around retainers in all evaluated perceptions, except in esthetics, which did not differ significantly. Occlusal coverage of TTR seems to be the cause of its rejection and its major changes to speech. Upper arch dimensions little influence volunteers perceptions. Considering speech changes and volunteers perceptions, the wrap-around retainers had better performance and should be the first choice when retainer option is a removable device in the upper arch.(AU)

Periodontal Side Effect During Orthopedic Face Mask Therapy.

A 7-year-old patient exhibited gingival recession of tooth #41 and severe plaque accumulation after 3 months of face mask therapy. The recession improved only slightly after appropriate oral hygiene instructions and motivation. Decisive improvement began when the vertical chin pad extension was reduced to avoid pressure on the affected area.

Retrospective study of clinical complications during orthodontic treatment with either a removable mandibular acrylic splint Herbst or with a cantilever Herbst.

OBJECTIVE: To compare the clinical complications during treatment with either a removable mandibular acrylic splint (RMS) or with a cantilever (HC) Herbst appliance. METHODS: Records from 159 Class II, division 1, consecutively treated patients with a Herbst appliance were examined. The sample was composed of 82 male and 77 female patients with a mean age of 11.8 years. The Herbst appliance was used for a mean of 12 months (standard deviation 2.15 months). Two main Herbst groups were analyzed: group RMS (n  =  125) and group HC (n  =  34). They were further subdivided according to the telescopic system used (Dentaurum type 1 or PMA) and fixation mode (splint with crowns or Grip Tite bands). Patients' clinical records were assessed to identify clinical complications. RESULTS: The incidence of complications during treatment was 85.3% for the HC group and 88.0% for the RMS group, with no statistically significant difference (Mann-Whitney test, P > .05). The fixation mode (crown or band) also did not show a statistically significant difference (P > .05). Regarding the telescopic system used, the Dentaurum group had 2.9 times more susceptibility to complications than the PMA group, regardless of the Herbst type. CONCLUSIONS: On average, approximately 2.5 complications per patient were reported. Most patients had a maximum of three complications during Herbst treatment. Herbst appliance type (RMS or HC) and fixation mode (crowns or Grip Tite bands) did not influence the number of complications. The PMA (without screws) telescopic system seemed to be more reliable (regarding the number of complications) than Dentaurum type 1, regardless of the appliance design (RMS or HC).

Analysis of pain level in cases treated with Invisalign aligner: comparison with fixed edgewise appliance therapy.

BACKGROUND: The aim of this study was to evaluate and compare the difference in the level of pain using the visual analog scale (VAS) between cases treated with the edgewise appliance and Invisalign. In addition, the cause of pain and discomfort in the Invisalign cases was identified. METHODS: The sample consisted of 145 cases for the edgewise group (EG; n=55), Invisalign group (IG; n=38), and edgewise and Invisalign group (EIG; n=52). VAS scores were collected during the first three stages (first stage: 0 to 7 days, second stage: 14 to 21 days, and third stage: 28 to 35 days) and at the end of the treatment (overall VAS score). Evaluation of the cause of pain was categorized into three different types of problem (category 1: non-smoothed marginal ridge or missing materials, category 2: deformation of attachments, and Category 3: deformation of the tray). Statistical comparison of VAS scores between groups was performed by two-way analysis of variance. RESULTS: A significantly higher VAS score was observed at 3 and 4 days after, at 1, 2, and 3 days after, and at 2 and 3 days after in stages 1, 2, and 3, respectively, in EG compared to EIG and IG. A significant difference was observed in overall VAS scores between EG and IG in intensity of pain, number of days that pain lasted, and discomfort level. Only intensity of pain resulted in a significant difference between EG and EIG. Most of the causes of problem in the Invisalign cases were deformation of the tray. CONCLUSIONS: Invisalign may offer less pain compared to the edgewise appliance during the initial stages of treatment. In the use of Invisalign, deformation of tray must be carefully checked to avoid pain and discomfort for the patients.

Efficacy and compliance in treatment of sleep apnea with Herbst mandibular advancement splints (OHA version).

The benefits of the Herbst thermoformed advancement splint in the treatment of obstructive breathing disorders during sleep have been assessed in numerous studies. Unfortunately, like all other mandibular advancement devices, patients fail to wear it regularly in the long-term. Injuries, discomfort or pain caused by errors in manufacture or adjustment are generally blamed for this. After a critical review of the literature, some solutions are proposed to improve production of the orthesis and patient management.

A prospective randomized split-mouth study on pain experience during chairside archwire manipulation in self-ligating and conventional brackets.

OBJECTIVE: To investigate patient discomfort during archwire engagement and disengagement in patients treated with self-ligating and conventional brackets using a split-mouth design. MATERIALS AND METHODS: Eighteen consecutive patients (15 female, 3 male; age: 22.2 ± 6.4 years) who requested treatment with fixed orthodontic appliances were randomly assigned for bonding with SmartClip self-ligating brackets on one side of the dentition and conventional standard edgewise brackets on the other. During the course of treatment, patients rated the discomfort experienced during every archwire engagement and disengagement using a numeric rating scale. Results were evaluated for round and rectangular nickel titanium and rectangular stainless steel, titanium molybdenum, and Elgiloy archwires. Patients also rated their overall experience retrospectively for both bracket systems. RESULTS: Regardless of archwire type, disengagement was rated as being significantly more painful on the SmartClip side (P  =  .027). For rigid, rectangular archwires, engagement and disengagement were rated as being significantly more painful on the SmartClip side (P  =  .031; P  =  .004). Retrospective ratings favored conventional brackets beyond ratings recorded during treatment. CONCLUSION: Engagement and disengagement of rigid rectangular archwires caused more pain with SmartClip self-ligating brackets than with conventional ones. Careful archwire manipulation and patience during full alignment are essential for limiting chairside pain. Low pain levels will help ensure treatment satisfaction and compliance.

Pressure-induced alopecia from orthodontic headgear.

UNLABELLED: Every treatment in the dental specialty has its own set of complications, Orthodontic therapy being no exception. Such a problem during the course of treatment puts the specialist in a dilemma as to whether to continue or stop the treatment. One such case in which during headgear therapy, a rare complication such as alopecia was encountered has been dealt with in this paper. This case report shows its effective management while still continuing treatment, thus leading to the desired result. It emphasizes on the importance of maintaining a balance between the benefts and risks of a treatment. CLINICAL RELEVANCE: The use of headgear can lead to the rare complication of alopecia and the clinician should be aware of it. OBJECTIVE: The reader should understand the psychological implications of alopecia and also to carry out the treatment after assessing the risk/beneft ratio.

Correlation of the arch forms of male and female subjects with those of preformed rectangular nickel-titanium archwires.

INTRODUCTION: This investigation was carried out to correlate the normal arch forms of male and female subjects derived mathematically by the beta function with commercially available preformed rectangular nickel-titanium archwires. METHODS: The mathematical beta function was used to derive planar projections of natural archforms by using the spatial coordinates of the labial bracket interfacing surfaces in the maxillary and mandibular arches of both sexes. Graphic planar representations of corresponding bracket base spatial coordinates of archforms of 30 popular rectangular nickel-titanium archwire-bracket assemblies (derived through the same mathematical function) were superimposed on relevant maxillary and mandibular arches. RESULTS: The rectangular nickel-titanium archwire-bracket assemblies exceeded the intercanine width by averages of 7.159 mm in the maxillary arches of females, 6.289 mm in the maxillary arches of males, 6.667 mm in the mandibular arches of females, and 5.337 mm in the mandibular arches of males. The average intermolar width exceeded the natural width by 2.893 mm in the maxillary arches and 1.861 mm in the mandibular arches. The average intermolar-intercanine width ratios for natural arches (2.11 for mandibular and 1.75 for maxillary) were greater than the ratios for the wire-bracket assemblies (1.78 for mandibular and 1.53 for maxillary). CONCLUSIONS: The prefomed rectangular nickel-titanium archwires might result in wider arch forms. The intercanine width difference is greater than the intermolar width. The differences were more pronounced for arches in female subjects compared with those in males. These findings influence posttreatment retention, stability, and facial esthetics. A subsequent change to stainless steel wires to restore a more natural form and size can lead to round tripping and increased treatment duration.

Accidental ingestion of a fractured Twin-block appliance.

Orthodontic appliances that become dislodged can cause problems in the airway or the gastrointestinal tract. Accidental ingestion of an appliance during a chair-side procedure or because of inadequate retention of the appliance can create a medical emergency with potentially serious complications, including death from aspiration of the foreign body. This article reports the accidental ingestion of a fractured Twin-block appliance. The ease with which removable appliances can become dislodged if retention is inadequate is discussed, and some serious complications that can arise are described. Precautions the orthodontist can take to prevent such accidents are presented.

Apical root resorption is associated with comprehensive orthodontic treatment but not clearly dependent on prior tooth characteristics or orthodontic techniques.

SYSTEMATIC REVIEW CONCLUSION: Increased incidence and severity of external apical root resorption (EARR) occurred in patients undergoing comprehensive orthodontic therapy, especially when therapy involved higher levels of force than those commonly used for orthodontic tooth movement. CRITICAL SUMMARY ASSESSMENT: Results from a high-quality systematic review of 11 randomized clinical trials (RCTs) suggests that EARR has a multifactorial etiology; is associated with comprehensive orthodontics; supports the clinical use of light forces, especially during intrusion of teeth; and requires higher-quality research. EVIDENCE QUALITY RATING: Limited.

Anterior tooth wear and retention type until 5 years after orthodontic treatment.

OBJECTIVES: To study occlusal wear of anterior teeth in orthodontic patients retained with different retainers until 5 years post-treatment, and to investigate whether type of retention influences occlusal wear. MATERIAL AND METHODS: Orthodontic patients (n=222), aged 15 years maximally at the start of treatment, were followed until 5 years post-treatment. In the maxilla, a retainer bonded on all six teeth or a removable retainer was used; in the mandible, a lingual retainer was bonded on all anterior teeth or on canines only. Dental casts were analyzed before treatment (T(0)), after treatment (T(1)), and 5 years post-treatment (T(5)). Incisal and canine wear were scored by applying a grading scale. Intercanine width, overjet, and overbite were measured with an electronic caliper. Statistics used were: Paired samples t-test for differences over time; Pearson correlation coefficients for associations between wear and retention type; and backward linear regression for influence of retention type on wear. RESULTS: There was an increase in wear during all time periods and for all teeth. From T(0) to T(5) an increase in maxillary intercanine width and maxillary retention had an effect on changes in canine wear. Incisal wear was associated with an increase in upper intercanine width (T(1)-T(5)). For both arches, an increase in maxillary intercanine width during treatment was associated with less progression of canine and incisal wear, but the explained variance was low, 13.4% and 19.3%, respectively. CONCLUSIONS: Retention type and, occasionally, an increase in intercanine width influence anterior teeth wear post-treatment. However, the clinical significance and impact of the examined retention methods on occlusal wear are small.

A comparison of white spot lesion formation between a self-ligating bracket and a conventional preadjusted straight wire bracket.

AIM: Demineralization following removal of orthodontic appliances is a common problem. Presence of archwires, especially those with loops and different types of ligatures, complicate cleaning around bands and brackets during orthodontic treatment. These factors led clinicians to develop self-ligating brackets. The purpose of this study was to compare the incidence of white spot lesion formation with the use of a self-ligating bracket with conventional preadjusted straight wire brackets. METHODS: Twenty patients were randomly divided into 2 groups. In the first group (aged 13.4 ± 2.5 years), the teeth were bonded with In-ovation brackets; the second group's (aged 14 ± 3.34 years) teeth were bonded with conventional preadjusted straight wire brackets. The patients were followed throughout treatment, and the number of white spot lesions was noted at debonding. RESULTS: The results revealed no statistically significant differences in white spot lesion development between conventional straight wire and self-ligating brackets. CONCLUSION: No differences in terms of white spot lesion formation were found between conventional straight wire and self-ligating brackets, and white spot lesion formation does depend largely on patients' oral hygiene status, not the type of bracket or ligation used.

Quadhelix appliance therapy resulting in pyogenic granuloma of the tongue.

This paper describes the examination, diagnosis and treatment of a rapidly enlarging tongue mass presenting in a healthy 12-year-old girl. This mass caused distress to both the patient and her parents and diagnostic uncertainty for her general medical and dental practitioners. The lesion was in fact caused by an orthodontic quadhelix appliance and responded to simple treatment.

Reabsorción radicular después del tratamiento ortodóncico con o sin corticotomía alveolar / Reabsorption radicule after of the orthodontic treatment with without corticotomy alveolar

La literatura sugiere que la reabsorción radicular, un efecto desfavorable del tratamiento ortodóntico, puede ser disminuida bajo condiciones de osteopenia, una condición caracterizada por la disminución de la densidad ósea y producida secundariamente a la cirugía de corticotomía alveolar. El propósito de este estudio fue comparar la reabsorción radicular de los incisivos centrales superiores después de una terapia sin extracciones con o sin el procedimiento de corticotomía, usando radiografías periapicales y cefalometrías laterales. La muestra fue compuesta por 2 grupos: 27 pacientes sometidos a un tratamiento ortodóntico sin extracción facilitado por corticotomía y 27 pacientes sometidos a un tratamiento ortodóntico convencional sin extracciones. Todas las radiográfias periapicales fueron tomadas con la técnica paralela. La longitud total de los incisivos derecho e izquierdo fue medida proyectando y magnificando las radiografías periapicales 8 veces. El test de Student fue usado para determinar las diferencias dentro de los grupos en pre-tratamiento (T1), post tratamiento (T2) y retención (T3). El test ANOVA de una sola cola combinado con Turkey hsd fue usado para determinar las diferencias entre los grupos. El análisis de ANOVA de una cola reveló una disminución significante en el tiempo de tratamiento (T1 a T2) entre los casos de ortodoncia facilitada con corticotomía y los casos de ortodoncia convencional. La longitud radicular de la muestra antes del tratamiento no era diferente significativamente (p = .11). Después del tratamiento hubo una reabsorción radicular significativa en los 2 grupos, p<0.01: CONV 0.7, CORT 0.3 mm. La muestra con el tratamiento convencional mostró raíces más cortas después del tratamiento al compararla con los casos de corticotomía (p = .02). El promedio de reabsorción radicular en T2 fue significativamente mayor en los casos de tratamiento convencional al compararse con los casos de ortodoncia facilitada por corticotomía (p = .03). La medición del ángulo SNA aumentó significativemente en los casos de ortodoncia facilitada por corticotomía (p = .001) y disminución significativamente en los casos de tratamiento convencional (P<.001)