Three-dimensional analysis of maxillary changes associated with facemask and rapid maxillary expansion compared with bone anchored maxillary protraction.

INTRODUCTION: Our objectives in this study were to evaluate in 3 dimensions the growth and treatment effects on the midface and the maxillary dentition produced by facemask therapy in association with rapid maxillary expansion (RME/FM) compared with bone-anchored maxillary protraction (BAMP). METHODS: Forty-six patients with Class III malocclusion were treated with either RME/FM (n = 21) or BAMP (n = 25). Three-dimensional models generated from cone-beam computed tomographic scans, taken before and after approximately 1 year of treatment, were registered on the anterior cranial base and measured using color-coded maps and semitransparent overlays. RESULTS: The skeletal changes in the maxilla and the right and left zygomas were on average 2.6 mm in the RME/FM group and 3.7 mm in the BAMP group; these were different statistically. Seven RME/FM patients and 4 BAMP patients had a predominantly vertical displacement of the maxilla. The dental changes at the maxillary incisors were on average 3.2 mm in the RME/FM group and 4.3 mm in the BAMP group. Ten RME/FM patients had greater dental compensations than skeletal changes. CONCLUSIONS: This 3-dimensional study shows that orthopedic changes can be obtained with both RME/FM and BAMP treatments, with protraction of the maxilla and the zygomas. Approximately half of the RME/FM patients had greater dental than skeletal changes, and a third of the RME/FM compared with 17% of the BAMP patients had a predominantly vertical maxillary displacement.

Tratamento do sorriso gengival / Treatment of the gummy smile

Este estudo constitui-se de uma revisão da literatura referente às principaisopções de tratamento para a correção do sorriso gengival, baseado em sua etiologia. Aexposição de mais de 2 mm de gengiva durante o sorriso é denominada de sorriso gengivale sua etiologia está atribuida a vários fatores como: erupção passiva alterada, hiperfunçãodos músculos levantadores do lábio superior, excesso vertical da maxila ou uma combinaçãodestes. Por esta razão, é essencial desenvolver um diagnóstico diferencial, baseado emconhecimentos sobre altura facial, espaço interlabial em repouso, comprimento do incisivocentral superior, comprimento do lábio superior e quantidade de exposição da gengivaqueratinizada durante o sorriso, para definir o correto planejamento da correção do sorrisogengiva I. As alternativas de tratamento incluem ortodontia, cirurgia ortognática, aplicaçãode toxina botulínica, terapia periodontal ou cirúrgica, dependendo da etiologia do sorrisogengival. Para o sorriso gengiva I por erupção passiva alterada, o tratamento de escolha éa cirurgia plástica periodontal. Diante do diagnóstico de hiperfunção dos músculos levantadoresdo lábio superior, a opção de tratamento é a cirurgia de tecido mole ou a aplicaçãode toxina botulínica; para o tratamento de excesso vertical da maxila, o tratamento deescolha é ortodontia associada à cirurgia ortognática. No caso de etiologia combinada, otratamento inicial é a correção do comprimento dental (diante de erupção passiva alterada),com posterior correção da alteração esquelética ou de tecido mole.

This study consisted af a literature review an the major treatment aptians forcarrectian af gummy smile, based an its etialagy. Twamillimeters ar more af maxillary gingival expasure while full smiling can be treated as gummy smile. The etialagical factars includes altered passive eruptian, hyper functianal upper lip elevatar muscles, vertical maxillary excess,skeletal and dental, ar a cambinatian af any af these, which requires a differential diagnasis based an clinical knowledge af facial height, interlabial gap at rest, maxillary incisar height,upper lip length and amaunt af the marginal gingival during smiling, in arder to define themast appropriate treatment plan for correction af the gummy smile. Therapeutic options include orthodontics, orthognatic surgery, botulinum toxin, surgical ar periodontal therapy, depending an the causative agent af the gummy smile. The periodontal plastic surgery is the treatment af chaice for the gingival smile by altered passive eruptian. The surgery af sotttissue ar the application af batulinum taxin is indicated for the treatment for hyperactivity af upper lip elevatar muscles. For the treatment af vertical maxillary excess, the treatment of choice is assaciated with arthagnathic surgery. In case af combined etiology, the initialtreatment is the carrectian af taath length (if in the presence af altered passive eruptian)with subsequent correction af skeletal change ar soft tissue.

Effect of low-level laser therapy (GaAlAs) on bone regeneration in midpalatal anterior suture after surgically assisted rapid maxillary expansion.

OBJECTIVE: The aim of this study was to evaluate the effects of laser therapy on bone regeneration in the midpalatal anterior suture (MPAS) after surgically assisted rapid maxillary expansion (SARME). METHODS: Thirteen patients aged between 18 and 33 years old with maxillary transverse deficiency (> or =7.0 mm) were evaluated. All patients underwent subtotal Le Fort I osteotomy with separation of the pterygomaxillary suture with the use of Hyrax expander, and were divided into 2 groups: control group (n = 6) and laser group (n = 7). A GaAlAs laser (P = 100 mW, lambda = 830 nm, Ø = 0.06 cm(2)) was used. The laser was applied in 8 treatment sessions with intervals of 48 hours. Each treatment session consisted of laser applications, per point (E = 8.4J, ED = 140J/cm(2)), at 3 points on the MPAS, and total dose of E = 25.2 J, ED = 420 J/cm(2). Digital radiographs were taken before the surgical procedure and at 1-, 2-, 3-, 4-, and 7-month follow-up visits. Optical density analysis of the regenerated bone was performed using Adobe Photoshop 8.0 software. RESULTS: Bone regeneration associated with the use of laser after SARME showed a statistically significant difference. A higher mineralization rate was found in the laser group (26.3%, P < .001) than the control group. CONCLUSION: Low-level laser irradiation (GaAlAs) accelerates bone regeneration in MPAS after SARME. However, the optical density measurements after 7 months of follow-up were lower in comparison with the preoperative measurements.

Utilização da ancoragem esquelética na distalização de molares superiores / Use of skeletal anchorage in distal movement of maxillary molars

A correção da má oclusão de classe II constitui um procedimento comum na prática ortodôntica. Um dos métodos para sua correção compreende a distalização de dentes posteriores superiores. Com esse fim, diversos tipos de aparelhos podem ser empregados, inclusive a ancoragem esquelética com os dispositivos de ancoragem temporária (DAT). O objetivo do presente artigo foi abordar a utilização desses dispositivos na região do tuber da maxila com finalidade de distalização dos dentes posteriores superiores. Concluiu-se que o emprego dos dispositivos temporários de ancoragem foi eletivo para a distalização dos molares e manutenção da ancoragem durante a mecânica subsequente.

Effects of surgically assisted rapid maxillary expansion on nasal dimensions using acoustic rhinometry.

OBJECTIVE: The objective of this study was to evaluate the effects of surgically assisted rapid maxillary expansion (SARME) on nasal dimensions using acoustic rhinometry. STUDY DESIGN: Twenty-seven patients ranging in age from 18 to 53 years were evaluated as having a maxillary transverse deficiency larger than 7 mm, a bilateral cross-bite, and no evidence of nasal obstruction. All patients underwent evaluation of the nasal cavity by acoustic rhinometry both before and 6 months after SARME. The Wilcoxon test was used to evaluate minor cross-sectional areas (MCA) and the nasal volume of the right and left nasal cavities, and these parameters were measured with and without the application of topical nasal decongestant before and after SARME. RESULTS: In comparison with preoperative measurements, minor cross-sectional areas and nasal volumes were significantly larger after SARME. There was a statistically significant difference associated with the use of nasal decongestant; the minor cross-sectional areas and nasal volume of the right and left nasal cavities were smaller when nasal decongestants were not used. CONCLUSIONS: Surgically assisted rapid maxillary expansion increases the minor cross-sectional areas and volume of the nasal cavities. Acoustic rhinometry is an objective method for evaluating the geometry of the nasal cavity in patients with transverse maxillary deficiency.

Prediction of transverse maxillary dimension using orthodontic models.

The main objective of this study was to quantify the transverse maxillary dimensions using orthodontic cast models of individuals with natural normal occlusion. Sixty-eight pairs of orthodontic models were evaluated with the respective posteroanterior radiographies of white adults (38 women and 30 men; mean age, 17 years and 5 months). The models were placed in Class I molar occlusion, and on each pair, 4 points were marked on the alveolar buccal ridge (2 on the premolar region and 2 on the molar), determining the upper and lower transverse interpremolar and intermolar dimensions. The variables analyzed in the 3 measurements, obtained from the cephalometric radiographies and the cast models, showed no statistical differences. The upper intermolar distance was 57.20 +/- 2.60 mm; the lower intermolar, 55.16 +/- 2.40 mm; the upper interpremolar, 42.17 +/- 2.19 mm, and the lower interpremolar; 39.67 +/- 1.77 mm. On the posteroanterior cephalograms, the maxillary width was 65.97 +/- 3.42 mm and the mandibular width was 87.92 +/- 4.60 mm. There was intraresearcher and interresearcher correlation. There was no sexual dimorphism. The method proposed in this study can predict the transverse maxillary dimension, applying the formula ym = 8.62 + 0.88xm (ym = expected upper intermolar distance, xm = lower intermolar distance) for the molar region, and ypm = 4.87 + 0.94xpm (ypm = expected upper interpremolar distance, xpm = lower interpremolar distance) for the premolar region.

Transverse effects of surgically assisted rapid maxillary expansion: a comparative study using Haas and Hyrax.

BACKGROUND: Surgically assisted rapid maxillary expansion is the treatment of choice for correcting transverse maxillary deficiency in patients with skeletal maturity, although the influence of the expander type on these alterations has not been elucidated yet. OBJECTIVE: Determine the skeletal and dental transverse effects on the maxilla after completion of surgically assisted rapid maxillary expansion, with Haas and Hyrax expanders. METHODS: Thirty-eight patients (aged between 18 and 39 years) were submitted to subtotal Le Fort I osteotomy and divided into Hass and Hyrax groups (19 patients each). Measurements of maxillary width, upper intermolar width, and its inclination on the posteroanterior cephalometric radiographs were obtained in the preoperatory period (T1), after the completion of the expansion (T2), and 4 months after the completion of the expansion (T3). The intercusp and intergingival distances measured on the plaster models were obtained from the first premolars and molars, before expander cementation (M1) and after the expander removal (M2). RESULTS: Both groups revealed statistically significant increase in the maxillary width, upper intermolar width, and inclination of the molars in T2 (P<0.001); T3 showed a statistically significant decrease in the maxillary width and inclination of the molars (P<0.001). The expansion presented an increment on the maxillary width of 71% from the upper intermolar width (T1-T3), and molars had vestibular inclination (P<0.05). The ratio of width increase of maxilla by the amount of device activation was of 69% for Haas and 74.5% for Hyrax. CONCLUSION: Clinically, the transversal effects were similar for both groups.