Effect of different palatal expanders with miniscrews in surgically assisted rapid palatal expansion: A non-linear finite element analysis

ABSTRACT Introduction: Surgically assisted rapid palatal expansion (SARPE) has been the treatment of choice in subjects presenting skeletally mature sutures. Objective: The purpose of this study was to analyze stress distribution and displacement of the craniofacial and dentoalveolar structures resulting from three types of palatal expanders with surgical assistance using a non-linear finite element analysis. Material and Methods: Three different palatal expanders were designed: Model-I (tooth-bone-borne type containing four miniscrews), Model-II (tooth-bone-borne type containing two miniscrews), and Model-III (bone-borne type containing four miniscrews). A Le Fort I osteotomy was performed, and a total of 5.0 mm palatal expansion was simulated. Nonlinear analysis (three theory) method (geometric nonlinear theory, nonlinear contact theory, and nonlinear material methods) was used to evaluate stress and displacement of several craniofacial and dentoalveolar structures. Results: Regardless of the maxillary expander device type, surgically assisted rapid palatal expansion produces greater anterior maxillary expansion than posterior (ANS ranged from 2.675 mm to 3.444 mm, and PNS ranged from 0.522 mm to 1.721 mm); Model-I showed more parallel midpalatal suture opening pattern - PNS/ANS equal to 54%. In regards to ANS, Model-II (1.159 mm) and Model-III (1.000 mm) presented larger downward displacement than Model-I (0.343 mm). PNS displaced anteriorly more than ANS for all devices; Model-III presented the largest amount of forward displacement for PNS (1.147 mm) and ANS (1.064 mm). All three type of expanders showed similar dental displacement, and minimal craniofacial sutures separation. As expected, different maxillary expander designs produce different primary areas and levels of stresses (the bone-borne expander presented minimal stress at the teeth and the tooth-bone-borne expander with two miniscrews presented the highest). Conclusions: Based on this finite element method/finite element analysis, the results showed that different maxillary expander designs produce different primary areas and levels of stresses, minimal displacement of the craniofacial sutures, and different skeletal V-shape expansion.

RESUMO Introdução: A expansão rápida da maxila assistida cirurgicamente (ERMAC) tem sido o tratamento de escolha em indivíduos que apresentam suturas esqueleticamente maduras. Objetivo: O objetivo deste estudo foi avaliar, utilizando uma análise não linear com elementos finitos, a distribuição de tensões e os deslocamentos das estruturas craniofaciais e dentoalveolares gerados por três tipos de expansores palatinos usados na ERMAC. Material e Métodos: Três tipos de expansores palatinos foram projetados: Modelo I (dento-osseossuportado com quatro mini-implantes), Modelo II (dento-osseossuportado com dois mini-implantes) e Modelo III (osseossuportado com quatro mini-implantes). Uma osteotomia Le Fort I foi realizada e foi simulada uma expansão palatina total de 5,0 mm. Um método de análise não linear (três teorias - teoria da não-linearidade geométrica, teoria do contato não linear e métodos para materiais não lineares) foi utilizado para avaliar a tensão e o deslocamento de diversas estruturas craniofaciais e dentoalveolares. Resultados: Independentemente do tipo de aparelho expansor palatino, a ERMAC produziu maior expansão anterior da maxila do que posterior (ENA variou de 2,675 mm a 3,444 mm e ENP variou de 0,522 mm a 1,721 mm); o Modelo I apresentou padrão de abertura mais paralela da sutura palatina mediana, com ENP/ENA igual a 54%. Com relação à ENA, o Modelo II (1,159 mm) e o Modelo III (1,000 mm) apresentaram maior deslocamento para baixo do que o Modelo I (0,343 mm). A ENP deslocou-se mais para anterior do que a ENA com todos os aparelhos; o Modelo III apresentou o maior deslocamento para anterior da ENP (1,147 mm) e da ENA (1,064 mm). Os três tipos de expansores apresentaram deslocamento dentário semelhante e separação mínima das suturas craniofaciais. Como esperado, diferentes designs de expansores palatinos produzem diferentes áreas primárias e níveis de tensões (o expansor osseossuportado apresentou tensão mínima nos dentes, e o expansor dento-osseossuportado com dois mini-implantes apresentou o maior). Conclusões: Com base nesse estudo de elementos finitos, os resultados mostraram que diferentes designs de expansores palatinos produzem diferentes áreas primárias e níveis de tensão, com deslocamento mínimo das suturas craniofaciais e diferentes expansões esqueléticas em forma de V.

Effect of miniscrew-assisted rapid palatal expansion on mandibular position / 口腔医学

Objective@#To explore the effect of miniscrew-assisted rapid palatal expansion (MARPE) on mandible position in the treatment of adult skeletal Class Ⅰ malocclusion with maxillary transverse deficiency. @*Methods@#In this retrospective study, 20 cases of adult skeletal Class Ⅰ malocclusion with maxillary transverse deficiency treated with MARPE in our hospital from July 2019 to March 2022 were selected as research objects. CBCT data of three time points before treatment (T0), immediately after expansion (T1) and six months after retention (T2) were collected. The head position was standardized and calibrated by Dolphin software, and then mandible landmarks (left and right Condylion, left and right Gonion, Menton) were positioned. The linear distance changes of each landmark relative to the reference plane of coronal plane, axial plane and sagittal plane were measured, which represented the sagittal, vertical and horizontal displacement of mandible respectively. Repeated measurement ANOVA and LSD multiple comparison were used to evaluate the position change of each landmark.@*Results @#The Menton and right Gonion rotated clockwise at T1, and relapsed to the initial position at T2. No lateral displacement of Menton was found.@*Conclusion@#When MARPE is used to treat skeletal Class Ⅰ malocclusion with maxillary transverse deficiency, it causes a transient clockwise rotation of the mandiblar. The mandible does not show sagittal, vertical and horizontal position changes in long-term evaluation.

Short-term assessment of pain and discomfort during rapid maxillary expansion with tooth-bone-borne and tooth-borne appliances: randomized clinical trial

ABSTRACT Objective: The aim of this randomized clinical trial was to evaluate and compare, during the first week of rapid maxillary expansion (RME), the impact caused by two types of appliances: Hyrax and Hybrid Hyrax. Methods: Forty-two patients who met the eligibility criteria (aged 11-14 years, with transverse maxillary deficiency, posterior crossbite, and presence of maxillary first premolars and first permanent molars) were selected and randomly divided into two groups: TBB GROUP (tooth-bone-borne expander), treated with Hybrid Hyrax (12 females and 9 males, mean age 13.3 ± 1.3 years), and TB GROUP (tooth-borne expander), treated with Hyrax (5 females and 16 males, mean age 13.3 ± 1.4 years). Pain and discomfort were assessed in two times: after the first day of activation (T1) and four days after, by means of the numerical rate scale and the instrument MFIQ (Mandibular Functional Impairment Questionnaire). Descriptive statistics and the Mann-Whitney test were used for comparison between groups and between sexes. A 5% significance level was adopted. Results: Both appliances had a negative impact, generating pain and discomfort, and reducing functional capacity. However, the scores obtained were of low intensity and no significant differences were observed between the groups. Considering sexes, there were statistically significant differences, with the female sex presenting higher scores for pain and functional limitation. Conclusions: Despite causing impact in pain and increase in the functional limitation, these changes were of low intensity, with no statistical difference between the groups. Females were more sensitive to the impact caused by the RME.

RESUMO Objetivo: O objetivo deste ensaio clínico randomizado foi avaliar e comparar, durante a primeira semana de expansão rápida da maxila (ERM), o impacto causado por dois tipos de aparelhos: Hyrax e Hyrax Híbrido. Métodos: Quarenta e dois pacientes que atendiam aos critérios de seleção (idade de 11 a 14 anos, com deficiência transversal da maxila, mordida cruzada posterior e presença de primeiros pré-molares e primeiros molares permanentes superiores) foram selecionados e divididos aleatoriamente em dois grupos: Grupo DOS (expansor dento-osseossuportado), tratado com Hyrax Híbrido (12 mulheres e 9 homens, idade média 13,3 ± 1,3 anos), e Grupo DS (expansor dentossuportado), tratado com Hyrax (5 mulheres e 16 homens, idade média de 13,3 ± 1,4 anos). A dor e o desconforto foram avaliados em dois momentos: após o primeiro dia de ativação (T1) e após quatro dias, por meio da escala de frequência numérica e do instrumento MFIQ (Questionário de Limitação Funcional Mandibular). A estatística descritiva e o teste de Mann-Whitney foram utilizados para comparação entre os grupos e entre os sexos. Adotou-se nível de significância de 5%. Resultados: Ambos os aparelhos tiveram impacto negativo, gerando dor e desconforto e reduzindo a capacidade funcional. No entanto, os escores obtidos foram de baixa intensidade e não foram observadas diferenças significativas entre os grupos. Considerando os sexos, houve diferenças estatisticamente significativas, com o sexo feminino apresentando maiores escores para dor e limitação funcional. Conclusões: Apesar de causar impacto na dor e aumento na limitação funcional, essas alterações foram de baixa intensidade, sem diferença estatística entre os grupos. As mulheres foram mais sensíveis ao impacto causado pela ERM.

Alveolar defects before and after surgically assisted rapid palatal expansion (SARPE): a CBCT assessment

ABSTRACT Introduction: Surgically Assisted Rapid Palatal Expansion (SARPE) promote maxillary expansion in skeletally mature patients. This technique is effective; however, some side effects are still unknown. Objectives: evaluate the presence of alveolar defects (dehiscences and fenestrations) in patients submitted to the SARPE. The null hypothesis tested was: SARPE does not influence the number of dehiscences and fenestrationss. Methods: A retrospective quasi-experiment study of a convenience sample of 279 maxillary teeth, in 29 patients evaluated with Cone Beam Computed Tomography (CBCT) at T1 (before SARPE), T2 (after expansion) and T3 (after retention), was performed. The examined teeth were: canines, first and second premolars, first and second molars. in axial, coronal, and cross-sectional views. The evaluations involved viewing slices from mesial to distal of the buccal roots. Results: All statistical analyses were performed using SAS 9.3 and SUDAAN softwares. Alpha used in the study was 0.05. Alveolar defects increased statistically from T1 (69.0%) to T2 (96.5%) and T3 (100%). Dehiscences increased 195% (Relative Risk 2.95) at the end of expansion (T2). After retention (T3), individuals were on average 4.34 times more likely to develop dehiscences (334% increase). Fenestrations did not increase from T1 to T2 (p = 0.0162, 7.9%) and decreased from T2 to T3 (p = 0.0259, 4.3%). Presence of fenestrations at T1 was a significant predictor for the development of dehiscences in T2 and T3. Dehiscences increased significantly in all teeth, except second molars. Conclusion: The null hypothesis was rejected. After SARPE the number of dehiscences increased and fenestrations decreased. Previous alveolar defects were predictor for dehiscences after SARPE.

RESUMO Introdução: A expansão rápida da maxila assistida cirurgicamente (ERMAC) promove expansão em pacientes esqueleticamente maduros. Essa técnica é efetiva; entretanto, alguns efeitos colaterais ainda são desconhecidos. Objetivos: Avaliar a presença de defeitos alveolares (deiscência e fenestração) em pacientes submetidos à ERMAC. A hipótese nula testada foi que a ERMAC não influenciaria o número de deiscências e fenestrações. Métodos: Foi realizado um estudo quase-experimental de uma amostra de conveniência de 279 dentes superiores, de 29 pacientes que foram avaliados por meio de tomografia computadorizada de feixe cônico (TCFC) em T1 (antes da ERMAC), T2 (após expansão) e T3 (após contenção). Caninos, primeiros e segundos pré-molares, primeiros e segundos molares foram examinados em cortes axiais, coronais e sagitais. As raízes vestibulares desses dentes foram avaliadas da face mesial até a distal. Resultados: Todas as análises estatísticas foram realizadas usando os softwares SAS 9.3 e SUDAAN. O alfa usado no estudo foi de 0,05. Os defeitos alveolares aumentaram significativamente de T1 (69,0%) para T2 (96,5%) e T3 (100%). Deiscências aumentaram 195% (risco relativo de 2,95%) no final da expansão (T2). Após contenção (T3), os pacientes tiveram, em média, 4,34 vezes mais chance de desenvolver deiscência (334% de aumento). As fenestrações não aumentaram de T1 para T2 (p= 0.0162, 7.9%) e diminuíram de T2 para T3 (p = 0.0259, 4,3%). A presença de fenestrações em T1 foi um preditor significativo para o desenvolvimento de deiscências em T2 e T3. Deiscências aumentaram significativamente em todos os dentes, exceto nos segundos molares. Conclusão: A hipótese nula foi rejeitada. Após a ERMAC, o número de deiscências aumentou e o de fenestrações diminuiu. Defeitos alveolares prévios foram preditores de deiscências após a ERMAC.

Endotracheal tube damage during surgically assisted rapid palatal expansion surgery; a case report

Endotracheal tube damage is a well-known complication of maxillary surgery. We report a case of failure to ventilate due to superficial damage to the tubing between the cuff and pilot balloon in the nasal portion of a north facing Ring, Adair and Elwyn pre-formed endotracheal tube during Surgically Assisted Rapid Palatal Expansion surgery. The endotracheal tube was replaced uneventfully and surgery completed successfully. On reflection, we feel that that the vulnerable position of the cuff-pilot tubing significantly contributed to this critical incident and suggest that increased recognition of this is vital for the prevention of such cases in the future.

Advances and applications of the maxillary expansion technique / 口腔疾病防治

@#Transverse maxillary deficiency is a common malocclusion in the clinic. Palatal expansion techniques are commonly used in the treatment of maxillary transverse deficiency. Traditional palatal expansion techniques have good effects on the treatment of children and adolescents whose palatal suture has not yet closed, but the effects on adult patients are unsatisfied. New palatal expansion techniques, such as miniscrew-assisted rapid palatal expansion and surgical-assisted maxillary expansion, have increased the age-related indications for palatal expansion, and their bone expansion effect has been strengthened. With the development of CAD/CAM technology and 3D printing technology, techniques such as Invisalign and personalized appliances have been developed and have promising application prospects. To provide references for the clinical treatment of maxillary transverse deficiency, palatal expansion techniques are reviewed from the following aspects: mechanism and indications, expansion pattern, traditional and new palatal expansion appliances, stability and retention of palatal expansion, outlook of future expanders, etc.

Maxillary skeletal expander for maxillary transverse deficiency: Application and strengths / 中国组织工程研究

BACKGROUND: Maxillary skeletal expander is a non-surgical expansion technique of the maxilla. It is different from the traditional maxillary rapid expander, micro-implant assisted rapid palatal expansion, and surgically assisted rapid palatal expansion. It provides new ideas and methods for the correction of maxillary transverse deficiency, and especially for adult patients with the growth finished, provides an efficient and minimally invasive bone expansion. OBJECTIVE: To review the application and advantage of the maxillary skeletal expander in the treatment of maxillary transverse deficiency, providing scientific reference for the clinical therapeutic schedule in such patients. METHODS: A computer search for Cochrane Library, PubMed, Embase, Web of Science, CNKI, WanFang Database, and CBM databases was performed for Chinese and English literature related to the maxillary expansion device published before May 31st, 2019. RESULTS AND CONCLUSION: The maxillary skeletal expander is an effective method for correcting the maxillary transverse deficiency, and the expansion of the arch is not limited by age. This device also has a good outcome in bone expansion for adults. The maxillary skeletal expander expands the entire mid-face structure, causing the mid-sacral suture to be parallel, followed by ruptured palatine suture, increased width between the zygomatic bones, as well as the entire nasal cavity involving the upper nasal bone area is widened. This device also causes less adverse reactions, for example, the teeth are inclined buccally and the height of the alveolar bone is reduced.

Non-surgical treatment of transverse deficiency in adults using Microimplant-assisted Rapid Palatal Expansion (MARPE)

ABSTRACT Introduction: Maxillary transverse deficiency is a highly prevalent malocclusion present in all age groups, from primary to permanent dentition. If not treated on time, it can aggravate and evolve to a more complex malocclusion, hindering facial growth and development. Aside from the occlusal consequences, the deficiency can bring about serious respiratory problems as well, due to the consequent nasal constriction usually associated. In growing patients, this condition can be easily handled with a conventional rapid palatal expansion. However, mature patients are frequently subjected to a more invasive procedure, the surgically-assisted rapid palatal expansion (SARPE). More recently, researches have demonstrated that it is possible to expand the maxilla in grown patients without performing osteotomies, but using microimplants anchorage instead. This novel technique is called microimplant-assisted rapid palatal expansion (MARPE). Objective: The aim of the present article was to demonstrate and discuss a MARPE technique developed by Dr. Won Moon and colleagues at University of California - Los Angeles (UCLA). Methods: All laboratory and clinical steps needed for its correct execution are thoroughly described. For better comprehension, a mature patient case is reported, detailing all the treatment progress and results obtained. Conclusion: It was concluded that the demonstrated technique could be an interesting alternative to SARPE in the majority of non-growing patients with maxillary transverse deficiency. The present patient showed important occlusal and respiratory benefits following the procedure, without requiring any surgical intervention.

RESUMO Introdução: a deficiência transversa da maxila é uma má oclusão com alta prevalência em todas as faixas etárias, da dentição decídua à permanente. Se não for corrigida, pode agravar-se com o passar do tempo, prejudicando o crescimento e desenvolvimento facial. Além dos prejuízos oclusais, essa deficiência pode trazer problemas respiratórios também severos, devido à consequente constrição da cavidade nasal. Em pacientes em crescimento, a sua resolução é relativamente simples, por meio da expansão rápida convencional da maxila. Porém, os pacientes já maduros geralmente são encaminhados para um procedimento mais invasivo, a expansão rápida de maxila assistida cirurgicamente (SARPE). Mais recentemente, pesquisadores têm demonstrado que é possível executar a expansão palatal esquelética em pacientes adultos sem auxílio de osteotomias, mas sim com auxílio de mini-implantes. Essa técnica é denominada Microimplant-Assisted Rapid Palatal Expansion, ou MARPE. Objetivo: o objetivo do presente artigo é demonstrar e discutir uma das técnicas disponíveis de MARPE, desenvolvida por Won Moon e colaboradores, na University of California, Los Angeles (UCLA). Métodos: a técnica encontra-se detalhadamente descrita, com as etapas laboratoriais e clínicas que devem ser seguidas para sua correta execução. Para descrevê-la, é apresentado o caso clínico de uma paciente adulta, detalhando toda a sequência do tratamento e os resultados obtidos. Conclusão: a técnica apresentada pode ser uma alternativa não invasiva à SARPE na resolução da deficiência transversa de maxila, podendo ser empregada na maioria dos pacientes com crescimento facial finalizado. A paciente apresentada demonstrou benefícios significativos nos aspectos oclusal e respiratório, sem a necessidade de intervenção cirúrgica.

Three dimensional evaluation of alveolar bone changes in response to different rapid palatal expansion activation rates

ABSTRACT Introduction: The aim of this multi-center retrospective study was to quantify the changes in alveolar bone height and thickness after using two different rapid palatal expansion (RPE) activation protocols, and to determine whether a more rapid rate of expansion is likely to cause more adverse effects, such as alveolar tipping, dental tipping, fenestration and dehiscence of anchorage teeth. Methods: The sample consisted of pre- and post-expansion records from 40 subjects (age 8-15 years) who underwent RPE using a 4-banded Hyrax appliance as part of their orthodontic treatment to correct posterior buccal crossbites. Subjects were divided into two groups according to their RPE activation rates (0.5 mm/day and 0.8 mm/day; n = 20 each group). Three-dimensional images for all included subjects were evaluated using Dolphin Imaging Software 11.7 Premium. Maxillary base width, buccal and palatal cortical bone thickness, alveolar bone height, and root angulation and length were measured. Significance of the changes in the measurements was evaluated using Wilcoxon signed-rank test and comparisons between groups were done using ANOVA. Significance was defined at p ≤ 0.05. Results: RPE activation rates of 0.5 mm per day (Group 1) and 0.8 mm per day (Group 2) caused significant increase in arch width following treatment; however, Group 2 showed greater increases compared to Group 1 (p < 0.01). Buccal alveolar height and width decreased significantly in both groups. Both treatment protocols resulted in significant increases in buccal-lingual angulation of teeth; however, Group 2 showed greater increases compared to Group 1 (p < 0.01). Conclusion: Both activation rates are associated with significant increase in intra-arch widths. However, 0.8 mm/day resulted in greater increases. The 0.8 mm/day activation rate also resulted in more increased dental tipping and decreased buccal alveolar bone thickness over 0.5 mm/day.

RESUMO Introdução: o objetivo do presente estudo retrospectivo multicêntrico foi quantificar as alterações na altura e na espessura do osso alveolar após o uso de dois diferentes protocolos de ativação na expansão rápida da maxila (ERM), bem como determinar se uma taxa de expansão mais rápida tem maior probabilidade de causar mais efeitos adversos, tais como inclinação dos dentes e do processo alveolar, fenestração e deiscência dos dentes de ancoragem. Métodos: a amostra consistiu de registros pré- e pós-expansão de 40 indivíduos (com idades entre 8 e 15 anos) que se submeteram à expansão rápida da maxila usando o aparelho Hyrax com quatro bandas como parte de seu tratamento ortodôntico para correção da mordida cruzada posterior. Os indivíduos foram divididos em dois grupos, de acordo com a taxa de ativação na expansão rápida da maxila (0,5 mm/dia e 0,8 mm/dia; n = 20 cada grupo). Imagens tridimensionais de todos os indivíduos da amostra foram avaliadas com o uso do software Dolphin Imaging v. 11.7 Premium. Foram analisadas as seguintes medidas: largura da base da maxila, espessura das corticais ósseas vestibular e lingual, altura do osso alveolar, angulação e comprimento das raízes. A significância das alterações nessas medidas foi avaliada com o teste não paramétrico de Wilcoxon e as comparações entre os grupos foram feitas usando a ANOVA. A significância foi definida como p ≤ 0,05. Resultados: as taxas de ativação na ERM de 0,5mm/dia (Grupo 1) e 0,8mm/dia (Grupo 2) causaram aumento significativo na largura da arcada após o tratamento. Porém, o Grupo 2 apresentou maior aumento, se comparado ao Grupo 1 (p < 0,01). A altura e a largura do osso alveolar vestibular diminuíram significativamente em ambos os grupos. Ambos os protocolos de tratamento resultaram em aumento significativo na inclinação vestibulolingual dos dentes. Porém, o Grupo 2 apresentou maior aumento, em comparação ao Grupo 1 (p < 0,01). Conclusão: ambas as taxas de ativação estão associadas a um aumento significativo nas larguras intra-arcada; entretanto, a taxa de 0,8mm/dia resultou em maior aumento. Essa mesma taxa de ativação também resultou em maior inclinação dos dentes e em redução mais acentuada da espessura do osso alveolar vestibular.

Skeletal and dentoalveolar changes after miniscrew-assisted rapid palatal expansion in young adults: A cone-beam computed tomography study / 대한치과교정학회지

OBJECTIVE: The aim of this study was to evaluate the skeletal and dentoalveolar changes after miniscrew-assisted rapid palatal expansion (MARPE) in young adults by cone-beam computed tomography (CBCT). METHODS: This retrospective study included 14 patients (mean age, 20.1 years; range, 16–26 years) with maxillary transverse deficiency treated with MARPE. Skeletal and dentoalveolar changes were evaluated using CBCT images acquired before and after expansion. Statistical analyses were performed using paired t-test or Wilcoxon signed-rank test according to normality of the data. RESULTS: The midpalatal suture was separated, and the maxilla exhibited statistically significant lateral movement (p < 0.05) after MARPE. Some of the landmarks had shifted forwards or upwards by a clinically irrelevant distance of less than 1 mm. The amount of expansion decreased in the superior direction, with values of 5.5, 3.2, 2.0, and 0.8 mm at the crown, cementoenamel junction, maxillary basal bone, and zygomatic arch levels, respectively (p < 0.05). The buccal bone thickness and height of the alveolar crest had decreased by 0.6–1.1 mm and 1.7–2.2 mm, respectively, with the premolars and molars exhibiting buccal tipping of 1.1°–2.9°. CONCLUSIONS: Our results indicate that MARPE is an effective method for the correction of maxillary transverse deficiency without surgery in young adults.

Stability of dental, alveolar, and skeletal changes after miniscrew-assisted rapid palatal expansion / 대한치과교정학회지

OBJECTIVE: Miniscrew-assisted rapid palatal expansion (MARPE) is a means for expanding the basal bone without surgical intervention in young adults. Here, we assessed the differences in dental, alveolar, and skeletal measurements taken before (T0), immediately after (T1), and 1 year after (T2) MARPE. METHODS: Twenty-four patients (mean age, 21.6 years) who had undergone MARPE and cone-beam computed tomography at T0, T1, and T2 were included. Changes in the following parameters were compared using paired t-tests: intercusp, interapex, alveolar, nasal floor, and nasal cavity widths; inclination of the first molar (M1) and its alveolus; and thickness and height of the alveolar bone. A linear mixed-effects model was used to determine variables that affected periodontal changes in the M1. RESULTS: MARPE produced significant increases in most measurements during T0–T2, despite relapse of some measurements during T1–T2. The alveolar thickness decreased on the buccal side, but increased on the palatal side. The alveolar crest level at the first premolar moved apically. Changes in the thickness and height of the alveolar bone were affected by the corresponding initial values. CONCLUSIONS: MARPE can be used as an effective tool for correcting maxillomandibular transverse discrepancy, showing stable outcomes 1 year after expansion.

Investigation of the effects of miniscrew-assisted rapid palatal expansion on airflow in the upper airway of an adult patient with obstructive sleep apnea syndrome using computational fluid-structure interaction analysis / 대한치과교정학회지

OBJECTIVE: The objective of this study was to investigate the effects of miniscrew-assisted rapid palatal expansion (MARPE) on changes in airflow in the upper airway (UA) of an adult patient with obstructive sleep apnea syndrome (OSAS) using computational fluid-structure interaction analysis. METHODS: Three-dimensional UA models fabricated from cone beam computed tomography images obtained before (T0) and after (T1) MARPE in an adult patient with OSAS were used for computational fluid dynamics with fluid-structure interaction analysis. Seven and nine cross-sectional planes (interplane distance of 10 mm) in the nasal cavity (NC) and pharynx, respectively, were set along UA. Changes in the cross-sectional area and changes in airflow velocity and pressure, node displacement, and total resistance at maximum inspiration (MI), rest, and maximum expiration (ME) were investigated at each plane after MARPE. RESULTS: The cross-sectional areas at most planes in NC and the upper half of the pharynx were significantly increased at T1. Moreover, airflow velocity decreased in the anterior NC at MI and ME and in the nasopharynx and oropharynx at MI. The decrease in velocity was greater in NC than in the pharynx. The airflow pressure in the anterior NC and entire pharynx exhibited a decrease at T1. The amount of node displacement in NC and the pharynx was insignificant at both T0 and T1. Absolute values for the total resistance at MI, rest, and ME were lower at T1 than at T0. CONCLUSIONS: MARPE improves airflow and decreases resistance in UA; therefore, it may be an effective treatment modality for adult patients with moderate OSAS.

Miniscrew-assisted rapid palatal expander (MARPE): the quest for pure orthopedic movement

ABSTRACT The midpalatal suture has bone margins with thick connective tissue interposed between them, and it does not represent the fusion of maxillary palatal processes only, but also the fusion of palatal processes of the jaws and horizontal osseous laminae of palatal bones. Changing it implies affecting neighboring areas. It has got three segments that should be considered by all clinical analyses, whether therapeutic or experimental: the anterior segment (before the incisive foramen, or intermaxillary segment), the middle segment (from the incisive foramen to the suture transversal to the palatal bone ) and the posterior segment (after the suture transversal to the palatal bone ). Rapid palatal expansion might be recommended for patients at the final pubertal growth stage, in addition to adult patients with maxillary constriction. It represents a treatment solution that can potentially avoid surgical intervention. When performed in association with rapid palatal expanders, it might enhance the skeletal effects of the latter. Of the various designs of expansion appliances, MARPE (miniscrew-assisted rapid palatal expander) has been modified in order to allow its operational advantages and outcomes to become familiar in the clinical practice.

RESUMO A sutura palatina mediana tem margens ósseas interpostas por tecido conjuntivo denso e não representa apenas a união dos processos palatinos da maxila, mas também a dos processos alveolares das maxilas e das lâminas horizontais dos ossos palatinos. Modificá-la implica em influenciar outras áreas vizinhas. Ela tem três segmentos a serem considerados em todas as análises clínicas, terapêuticas e experimentais: anterior (antes do forame incisivo, ou intermaxilar), médio (do forame incisivo até a sutura transversa com o osso palatino) e posterior (após a sutura transversa com o osso palatino). A expansão rápida da maxila pode ser indicada para pacientes que se encontram no final da fase de crescimento da puberdade, além de pacientes adultos com atresia maxilar, representando uma solução de tratamento, possivelmente evitando uma intervenção cirúrgica. Quando associada a aparelhos de protração maxilar, pode maximizar os efeitos esqueléticos desses. Entre os vários designs de aparelhos disjuntores, ultimamente encontra-se o MARPE (Miniscrew-Assisted Rapid Palatal Expander), que tem sido modificado para que ocorra, na rotina clínica, uma familiarização com suas vantagens operatórias e resultados obtidos.

Transverse Discrepancy in Orthodontics: A Review.

In today’s orthodontic practice esthetics is a primary concern both for patient and the orthodontist. The perception of esthetics for a lay person largely depends on the symmetry of the face. Hence, diagnosis and correction of the transverse discrepancy are imperative for optimum result. Some occlusal relations can result from skeletal jaw relation or from tooth positions. Malocclusion can occur in three planes of space, i.e., sagittal, transverse, and vertical plane. Transverse discrepancy is “An abnormality of development in transverse plane.” In orthodontic diagnosis and treatment planning, the emphasis is placed on recognizing asymmetry and achieving symmetric results with dental midlines coincident with each other and with the facial midline. Humans, like most other animals, are considered to display bilateral symmetry. By strict definition, this implies that mirror-image mathematical identity exists between right and left halves. In orthodontic diagnosis and treatment planning, emphasis is placed on recognizing asymmetry and achieving symmetric results. Treatment of an asymmetry can be challenging. The 1st treatment step is to diagnose if the asymmetry is of functional, dental or skeletal cause. The treatment options for transverse problem may include arch coordination, asymmetric extraction, asymmetric mechanics, and skeletal correction by orthopedic or surgical procedure. However, it is crucial to determine that the observed asymmetry is genuine and not the product of a functional or habitual shift of the mandible as is often the case with unilateral cross-bites due to reduced width of the maxillary arch.

Nasal septum changes in adolescent patients treated with rapid maxillary expansion

Objective: To analyze cone-beam computed tomography (CBCT) scans to measure changes in nasal septal deviation (NSD) after rapid maxillary expansion (RME) treatment in adolescent patients. Methods: This retrospective study involved 33 patients presenting with moderate to severe nasal septum deviation as an incidental finding. Out of these 33 patients, 26 were treated for transverse maxillary constriction with RME and seven, who did not undergo RME treatment, were included in the study as control group. CBCT scans were taken before appliance insertion and after appliance removal. These images were analyzed to measure changes in nasal septum deviation (NSD). Analysis of variance for repeated measures (ANOVA) was used. Results: No significant changes were identified in NSD regardless of the application or not of RME treatment and irrespective of the baseline deviation degree. Conclusion: This study did not provide strong evidence to suggest that RME treatment has any effect on NSD in adolescent patients; however, the results should be interpreted with caution, due to the small sample size and large variation amongst individual patient characteristics.

Objetivo: analisar imagens de tomografia computadorizada de feixe cônico (TCFC) para mensurar as alterações no desvio de septo nasal (DSN) após o tratamento com expansão rápida da maxila (ERM) em pacientes adolescentes. Métodos: o presente estudo retrospectivo incluiu 33 pacientes com desvio de septo nasal de moderado a severo, diagnosticado como um achado incidental. Dos 33 pacientes analisados, 26 tiveram a constrição maxilar transversal tratada por meio de ERM; 7 pacientes não foram submetidos à ERM, sendo incluídos no estudo como grupo controle. As imagens de TCFC foram obtidas antes da instalação do aparelho e após sua remoção, sendo analisadas para mensurar as alterações no DSN. A análise de variância para medidas repetidas (ANOVA) foi empregada. Resultados: não foram identificadas alterações significativas no DSN, independentemente da realização ou não do tratamento com ERM e do grau inicial de desvio. Conclusão: esse estudo não fornece evidências suficientes para sugerir que o tratamento com ERM produza qualquer efeito sobre o DSN em pacientes adolescentes. Porém, esses resultados devem ser interpretados com cautela, em virtude do tamanho reduzido da amostra e da grande variação das características individuais dos pacientes.

Quantitative evaluation of midpalatal suture maturation via fractal analysis / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to determine whether the results of fractal analysis can be used as criteria for midpalatal suture maturation evaluation. METHODS: The study included 131 subjects aged over 18 years of age (range 18.1–53.4 years) who underwent cone-beam computed tomography. Skeletonized images of the midpalatal suture were obtained via image processing software and used to calculate fractal dimensions. Correlations between maturation stage and fractal dimensions were calculated using Spearman's correlation coefficient. Optimal fractal dimension cut-off values were determined using a receiver operating characteristic curve. RESULTS: The distribution of maturation stages of the midpalatal suture according to the cervical vertebrae maturation index was highly variable, and there was a strong negative correlation between maturation stage and fractal dimension (−0.623, p < 0.001). Fractal dimension was a statistically significant indicator of dichotomous results with regard to maturation stage (area under curve = 0.794, p < 0.001). A test in which fractal dimension was used to predict the resulting variable that splits maturation stages into ABC and D or E yielded an optimal fractal dimension cut-off value of 1.0235. CONCLUSIONS: There was a strong negative correlation between fractal dimension and midpalatal suture maturation. Fractal analysis is an objective quantitative method, and therefore we suggest that it may be useful for the evaluation of midpalatal suture maturation.

Surgically assisted rapid palatal expansion with tent screws and a custom-made palatal expander: a case report / 대한악안면성형재건외과학회지

Rapid palatal expansion(RPE) with the tooth-born appliance is not sufficient to apply to the patients with periodontal problem or insufficient tooth anchorage, and it leads to tipping of the anchorage teeth and increasing teeth mobility and root resorption. To avoid these disadvantages, we present the case using palatal screws and custommade palatal expander. A 23-year-old patient underwent surgically assisted rapid maxillary expansion with the Hyrax expansion using 4 tent screws. The study models were used to measure the pre-/-post surgical width of the anterior and posterior dental arches with a digital sliding caliper. In the result, the custom-made palatal expander with 4 tent screws is suitable for delivering a force to the mid-palatal suture expansion. And it is low cost, small sized and simply applied. The results indicated that maxillary expansion with the custom-made palatal anchorage device is predictable and stable technique without significant complications in patients.

Icariin inhibits TNF-αexpression in periodental tissue during root resorption induced by rapid palatal expansion / 实用口腔医学杂志

Objective:To evaluate the effect of icariin on TNF-αexpression in periodental tissue during root resorption induced by ropid palatal expansion in rats.Methods:24 male Wistar rats were divided randomly into 3 groups(n =8)as group A(none-expansion control group),B(expansion group)and C(icariin and expansion group).In group B and C,an initial force of 50 g was applied to the area between the right and left upper first molars of the rats for 2 weeks for palatal expansion.The rats of group C were given intragastric administration of icariin at 2.5 mg/(kg·d)while the rats of group A and B were given the same dose place-bo.The centered buccal-lingual root and peridentium tissue slices were generated from the upper first molars of the rats.HE stai-ning of the slices was performed.The expression of TNF-αprotein at the compression sites was detected by irnmunohistochemistry. Results:The A values of TNF-αof group A,B and C were 0.030 2 ±0.001 7,0.241 0 ±0.002 4 and 0.088 6 ±0.002 8 respec-tively(B vs A or C,P <0.05).Conclusion:Icariin may inhibit TNF-αexpression in periodental tissue during root resorption in-duced by rapid palatal expansion.

Avaliação da influência do septo nasal na expansão de maxila cirurgicamente assistida por meio de tomografia computadorizada de feixe cônico / Evaluation of the influence of the nasal septum in surgically assisted maxillary expansion using cone computed tomography

A expansão da maxila cirurgicamente assistida (EMCA) é um procedimento cirúrgico indicado para a correção da atresia maxilar em pacientes que já atingiram a maturação óssea. Os efeitos da EMCA são observados não só nos arcos dentários, maxilas e mandíbula, mas também na cavidade nasal, já que o septo nasal encontra-se localizado no centro do assoalho nasal, apoiado sobre a sutura palatina mediana. O objetivo deste estudo foi identificar a posição do septo nasal antes e após a separação cirúrgica das maxilas e avaliar sua influência na movimentação da maxila do lado que foi deslocado. Foram avaliadas 56 tomografias computadorizadas de feixe cônico (TCFC) adquiridas no tomográfo i-CAT Classic®, com voxel de 0,3mm, de 14 indivíduos submetidos à EMCA nos períodos préoperatório e pós-operatório de 15, 60 e 180 dias. Inicialmente, as imagens pósoperatórias foram visualizadas nas reformatações multiplanares, para identificar a qual maxila, direita ou esquerda, o septo nasal permaneceu ligado após a EMCA. Numa segunda etapa, foram realizadas medidas lineares nas imagens correspondentes aos períodos pré e pósoperatórios. Essas medidas foram realizadas na reformatação axial imediatamente acima do aparelho expansor, de forma padronizada para cada paciente, e consistiram da distância entre uma linha de referência central, que passava na espinha nasal anterior e no centro do forame incisivo, dividindo o paciente em lado direito e esquerdo, até os caninos e molares direitos e esquerdos. O índice kappa intraexaminador foi > 0,9. Para comparar as diferenças entre as médias dos dois grupos (lado ligado ao septo nasal e não ligado ao septo nasal) foi utilizado o teste t. Em 78,6% dos pacientes o septo nasal permaneceu ligado à maxila esquerda e em 21,4%, ligado à maxila direita. Em relação às medidas lineares, tanto na região de caninos como na região de molares, observouse que, no período pré-operatório, não havia diferença entre os lados direito e esquerdo...

The Surgically assisted rapid palatal expansion (SARPE) is a surgical procedure indicated for the correction of maxillary constriction in adult patients. The effects of EMCA are observed not only in dental, maxillary, and mandibular arches, but also in the nasal cavity, since the septum is located in the center of the nasal floor and rests on the median palatine suture. The purpose of this study the position of the nasal septum before and after surgical separation of the maxillary, was to identify and evaluate their influence on the movement of the jaw which remained attached. Fifty six cone beam computed tomography (CBCT) scanner acquired i-CAT Classic, with 0.3 mm voxel. Fourteen individuals submitted to SARPE in the preoperative and postoperative periods of 15, 60, and 180 days which were evaluated. Initially, postoperative images were visualized using multiplanar reformatting to identify which jaw, right or left, the nasal septum remained bound after the SARPE. In a second step, linear measurements in the images corresponding to the pre- and postoperative periods were performed. These measurements were performed in the axial immediately above the expander reformatting, standardized form for each patient, and consisted of the distance from a central reference line, passing the anterior nasal spine and the center of the incisive foramen, dividing the patient's right side and left to the canines and molars on the right and left. The intraobserver kappa index was > 0.9. To compare the differences between the means of two groups (side connected to the nasal septum and not connected to the nasal septum) a t test was used. In 78.6% of patients, the nasal septum remained attached to the left maxilla and 21.4% on right jaw. Regarding linear measurements, both in the region of canines as in the molar region, it was observed that, in the preoperative period, there was no difference between the right and left sides. After the SARPE, a statistically...

Avaliação da influência do septo nasal na expansão de maxila cirurgicamente assistida por meio de tomografia computadorizada de feixe cônico / Evaluation of the influence of the nasal septum in surgically assisted maxillary expansion using cone computed tomography

A expansão da maxila cirurgicamente assistida (EMCA) é um procedimento cirúrgico indicado para a correção da atresia maxilar em pacientes que já atingiram a maturação óssea. Os efeitos da EMCA são observados não só nos arcos dentários, maxilas e mandíbula, mas também na cavidade nasal, já que o septo nasal encontra-se localizado no centro do assoalho nasal, apoiado sobre a sutura palatina mediana. O objetivo deste estudo foi identificar a posição do septo nasal antes e após a separação cirúrgica das maxilas e avaliar sua influência na movimentação da maxila do lado que foi deslocado. Foram avaliadas 56 tomografias computadorizadas de feixe cônico (TCFC) adquiridas no tomográfo i-CAT Classic®, com voxel de 0,3mm, de 14 indivíduos submetidos à EMCA nos períodos préoperatório e pós-operatório de 15, 60 e 180 dias. Inicialmente, as imagens pósoperatórias foram visualizadas nas reformatações multiplanares, para identificar a qual maxila, direita ou esquerda, o septo nasal permaneceu ligado após a EMCA. Numa segunda etapa, foram realizadas medidas lineares nas imagens correspondentes aos períodos pré e pósoperatórios. Essas medidas foram realizadas na reformatação axial imediatamente acima do aparelho expansor, de forma padronizada para cada paciente, e consistiram da distância entre uma linha de referência central, que passava na espinha nasal anterior e no centro do forame incisivo, dividindo o paciente em lado direito e esquerdo, até os caninos e molares direitos e esquerdos. O índice kappa intraexaminador foi > 0,9. Para comparar as diferenças entre as médias dos dois grupos (lado ligado ao septo nasal e não ligado ao septo nasal) foi utilizado o teste t. Em 78,6% dos pacientes o septo nasal permaneceu ligado à maxila esquerda e em 21,4%, ligado à maxila direita. Em relação às medidas lineares, tanto na região de caninos como na região de molares, observouse que, no período pré-operatório, não havia diferença entre os lados direito e esquerdo...

The Surgically assisted rapid palatal expansion (SARPE) is a surgical procedure indicated for the correction of maxillary constriction in adult patients. The effects of EMCA are observed not only in dental, maxillary, and mandibular arches, but also in the nasal cavity, since the septum is located in the center of the nasal floor and rests on the median palatine suture. The purpose of this study the position of the nasal septum before and after surgical separation of the maxillary, was to identify and evaluate their influence on the movement of the jaw which remained attached. Fifty six cone beam computed tomography (CBCT) scanner acquired i-CAT Classic, with 0.3 mm voxel. Fourteen individuals submitted to SARPE in the preoperative and postoperative periods of 15, 60, and 180 days which were evaluated. Initially, postoperative images were visualized using multiplanar reformatting to identify which jaw, right or left, the nasal septum remained bound after the SARPE. In a second step, linear measurements in the images corresponding to the pre- and postoperative periods were performed. These measurements were performed in the axial immediately above the expander reformatting, standardized form for each patient, and consisted of the distance from a central reference line, passing the anterior nasal spine and the center of the incisive foramen, dividing the patient's right side and left to the canines and molars on the right and left. The intraobserver kappa index was > 0.9. To compare the differences between the means of two groups (side connected to the nasal septum and not connected to the nasal septum) a t test was used. In 78.6% of patients, the nasal septum remained attached to the left maxilla and 21.4% on right jaw. Regarding linear measurements, both in the region of canines as in the molar region, it was observed that, in the preoperative period, there was no difference between the right and left sides. After the SARPE, a statistically...