The Complexity of Skeletal Transverse Dimension: From Diagnosis, Management, and Treatment Strategies to the Application of Collaborative Cross (CC) Mouse Model.

This study investigates the significance of skeletal transverse dimension (STD) in orthodontic therapy and its impact on occlusal relationships. The primary goal is to enhance understanding and promote the integration of transverse skeletal diagnostics into routine orthodontic assessments. To achieve this aim, the study employs a comprehensive approach, utilizing model analysis, clinical assessments, radiographic measurements, and occlusograms. The initial step involves a meticulous assessment of deficiencies in the maxilla, mainly focusing on transverse dimension issues. Various successful diagnostic methods are employed to ascertain the type and presence of these deficiencies. Furthermore, the study compares surgically assisted maxillary expansion (SARME) and orthopedic maxillary expansion (OME) in addressing skeletal transverse issues. Stability assessments and efficacy analyses are conducted to provide valuable insights into the superiority of SARME over OME. The findings reveal that proper evaluation of STD is crucial in orthodontic diagnosis, as overlooking transverse dimension issues can lead to complications such as increased masticatory muscle activity, occlusal interferences, and an elevated risk of gingival recession. Surgically assisted maxillary expansion emerges as a more stable solution than orthopedic methods. In conclusion, incorporating skeletal transverse diagnostics into routine orthodontic assessments is imperative for achieving optimal occlusal relationships and minimizing negative consequences on dentition, periodontium, and joints. The study emphasizes the significance of accurate three-dimensional assessments and recommends the consideration of SARME over OME for addressing skeletal transverse deficiencies. Finally, the Collaborative Cross (CC) mouse model is also a novel mouse model for studying complex traits. Exploring the Collaborative Cross mouse model opens avenues for future research, promising further insights into transverse skeletal issues in orthodontics.

Surgically assisted maxillary expansion with or without pterygoid disjunction alters maxillomandibular positioning.

PURPOSE: This study aimed to analyze alterations in mandibular positioning after surgically assisted maxillary expansion (SARME) with and without pterygoid disjunction (PD). METHODS: Cone-beam computed tomography scans of 24 healthy individuals (18-45 years old) with transverse deficiency, superior to 5 mm, underwent SARME with or without PD. The aspects prospectively assessed were (1) alignment and position of the head (ITK-Snap and 3D Slicer software); (2) McNamara's and Steiner-Tweed-Wits' cephalometric analysis (Dolphin Imaging®); and (3) colorimetric evaluation based on 3D correspondence analysis (3D Slicer software). RESULTS: A decrease in 1-NA and 1-SN angles as well as an increased occlusal plane in both groups was observed. Superior-inferior and anteroposterior spatial displacements of the chin were statistically significant in the PD group. Altered colorimetric patterns were also observed in the PD group. CONCLUSIONS: This study found more evident tooth inclination in the group without PD; mandibular alterations were more evident in the PD group. Further studies with 3D analysis are strongly recommended for more comprehensive results.

Volumetric upper airway changes following a new technique for Surgically-Assisted Maxillary Expansion (SAME).

BACKGROUND: Skeletal maxillary constriction (SMC) is one of the common skeletal discrepancies which are associated with alterations in the respiratory function. Today, many surgical techniques are used to expand the maxilla in adult patients with no consensus about the optimal technique. OBJECTIVES: The present study aimed to investigate the changes of the upper airway volume resulting from the use of a new, minimally invasive surgically-assisted maxillary expansion (SAME) technique, and compare the results with the conventional SAME technique. MATERIAL AND METHODS: A prospective study was conducted between September 2015 and July 2018. A total of 28 adult patients (11 males, 17 females; mean age: 19.1 ±2.7 years) with SMC underwent SAME. The sample was divided according to the applied surgical technique into 2 groups: the conventional osteotomy SAME (CO­SAME) group consisted of 13 patients (18.7 ±2.2 years) and the selective osteotomy SAME (SO-SAME) group consisted of 15 patients (19.4 ±3.2 years). Cone beam computed tomography (CBCT) scans were initially obtained preoperatively (T1) and 3 months post expansion (T2). The upper airway was divided into 2 segments: retropalatal and retroglossal. The volume of each segment and the total airway volume (TAV) were assessed using the OnDemand3D® software. RESULTS: The total upper airway volume showed a significant increase after both CO­SAME and SO-SAME (1.29 ±0.26 cc and 1.21 ±0.19 cc, respectively), with significant increases in retropalatal and retroglossal airway volumes (RPAV and RGAV) after both CO­SAME and SO-SAME (RPAV - 0.73 ±0.10 cc and 0.83 ±0.10 cc, and RGAV - 0.56 ±0.23 cc and 0.38 ±0.23 cc, respectively). No significant differences were observed in the maxillary width (MW), TAV or RGAV between the 2 SAME techniques, whereas the increase in RPAV in the SO-SAME group was significantly greater than that of the CO­SAME group. CONCLUSIONS: The new, minimally invasive SAME technique was an effective procedure to increase MW and the upper airway volume.

Surgical management of cross-bites in orthognathic surgery: Surgically assisted rapid maxillary expansion (SARME) versus two-piece maxilla.

PURPOSE: The surgical treatment of cross-bites includes surgically-assisted maxillary expansion (SARME) or maxillary-bipartition during bimaxillary surgery. This study evaluates and compares the changes in the teeth and lower nasal passage, as well as the stability of the expansion. PATIENTS AND METHODS: The measurements were performed on the cone-beam computed tomography (CBCT) scans of 32 patients with transverse (width) deficiencies of the maxilla. To expand the maxilla, 12 patients underwent the two-piece maxilla method, while 20 patients received SARME. RESULTS: The mean distraction width for SARME was 6.8 mm (SD 3.7), while that for the two-piece maxilla was 4.1 mm (SD 1.6). The expansion with SARME was over the entire length of the maxilla, from anterior to posterior, whereas the expansion of the two-piece patient group was only in the posterior part of the maxilla. The segments of the maxilla opened nearly parallel in SARME, while they were reverse V-shaped in the two-piece maxilla, from anterior to posterior. CONCLUSION: A key point in the planning of combined orthodontic-orthognathic therapy with surgical correction of a cross-bite is the precise determination of the area where the width needs to be increased, and the amount of correction needed to treat the patient using minimal surgical procedures.

Estudo comparativo dimensional tomográfico do côndilo mandibular de indivíduos com deficiência transversal de maxila / Comparative dimensional tomographic study of the mandibular condyle of individuals with transversal maxillary deficiency

A deficiência transversal de maxila, caracteriza-se por mordida cruzada posterior uni ou bilateral, dentes apinhados e ou rotacionados, e pelo formato ogival do palato. O tratamento em indivíduos adultos tem sido realizado a partir da expansão de maxila cirurgicamente assistida (EMCA), que resulta em efeitos esqueléticos e dentários no arco superior, com expectativa de efeitos no arco inferior. Neste estudo nos propusemos avaliar a ocorrência de alterações dimensionais nos côndilos mandibulares, de pacientes com deficiência transversal de maxila, e submetidos a expansão cirurgicamente assistida em imagens obtidas por tomografias computadorizadas de feixe cônico (TCFC) de catorze indivíduos com deficiência transversal de maxila, sendo cinco homens e nove mulheres, com idades entre 24 e 28 anos. Na reformatação axial as medidas foram obtidas no sentido, látero-medial, póstero-anterior lateral, póstero-anterior central e pósteroanterior medial da superfície articular. Nas reformatações coronais, mensurou-se os sentidos látero-medial superior, látero-medial inferior, látero-medial médio e súperoinferior. Dentre as medidas obtidas e submetidas à análise estatística pelo teste t pareado, somente as medidas axial póstero-anterior lateral esquerda (-0,90mm), coronal médio direita (-1,24mm), coronal inferior esquerda (1,78mm), coronal súpero-inferior direita (0,76mm), axial póstero-anterior lateral (-0,74mm) e coronal inferior (-1,13mm) foram estatisticamente significativas. Os resultados obtidos na amostra estudada nos permitiram concluir que: em indivíduos com deficiência transversal de maxila e submetidos a EMCA, ocorreram alterações dimensionais nos côndilos mandibulares, que puderam ser entendidas por remodelação, uma vez que caracterizaram-se por aumento e redução, dependendo da localização da medida realizada.

Transverse maxillary deficiency is characterized by posterior uni or bilateral crossbite, crowded and rotated teeth, as well as high palate. Its treatment in adult individuals is surgically assisted rapid palatal expansion (SARPE). This procedure not only has skeletal and dental effects in the upper arch, but also expresses effects in the lower arch. The objective of this study was to verify the occurrence of dimensional alterations in the mandibular condyles of patients with transversal maxillary deficiency submitted to surgically assisted maxillary expansion. Measurements by cone beam computed tomography (CBCT) of the mandibular condyles, axial plains, lateromedial sizes, posterior-anterior lateral, posterior anterior central, and posterior-anterior medial of the articular surface were performed. In the coronal reformats, the superior lateral medial, inferior lateral medial, medium lateral medial, and superior inferior sizes were measured. CBCT images of fourteen individuals with transversal maxillary deficiency were used, five male and nine female with an average age of 24.28 years. Among the values obtained and submitted to statistical analysis by the paired t-test, only the left posterior-lateral anterior axial measurements (-0.90mm), right middle coronal (-1.24mm), left inferior coronal (1.78mm), right superior-inferior coronal (0.76mm), axial anterior-posterior lateral (-0.74mm) and inferior coronal (-1.13mm) were statistically significant. It was concluded that in individuals with maxillary transversal deficiency that underwent surgically assisted rapid palatal expansion (SARPE), dimensional alterations occurred in the mandibular condyles, which can be understood by remodeling, once they are characterized by an increase and reduction, depending on the location where the measurement was performed.

Avaliação tridimensional das vias aéreas de pacientes submetidos à expansão maxilar cirurgicamente assistida / Tridimensional assessment of airway in patients submitted to surgically assisted rapid maxillary expansion

Neste estudo comparamos o volume dos seios maxilares dos pacientes submetidos à expansão rápida de maxila cirurgicamente assistida (EMCA), por meio da tomografia computadorizada de feixe cônico (TCFC). Foram avaliados 10 pacientes submetidos a expansão rápida de maxila cirurgicamente assistida (EMCA) pela técnica da osteotomia Le Fort I subtotal, que possuíam tomografias pré e pós-operatórias de 180 dias. As imagens foram analisadas utilizando software Dolphin Imaging® (versão 11.0.03.32) que permite a avaliação do espaço aéreo, delimitando-se áreas de interesse e realizando o calculo do volume correspondente. As imagens dos seios maxilares direito (SMD) e esquerdos (SME) foram analisadas nas tomografias pré e pós-operatórias. A média das medidas de volume foi de 13,760mm³ para o SMD e 14,499mm³ no SME, nas imagens pré-operatórias e de 14,779mm³ para o SMD e 14,435mm³ para o SME, nas pós-operatórias. Os volumes pré e pós-operatórios foram avaliados estatisticamente através do teste t pareado para significância maior que 0,05. Após as cirurgias, a média de volume dos SMD apresentou um aumento significante. Este aumento também foi observado nos SME, porem não foi estatisticamente significante. A partir destes resultados, é possível concluir que existe influencia da EMCA sobre o volume dos seios maxilares.

The aim of this study was to compare the volume of the maxillary sinuses of patients undergoing surgically assisted rapid maxillary expansion (SARME), by cone beam computed tomography (CBCT). Were evaluated 10 patients submitted to surgically assisted rapid maxillary expansion (SARME) by the technique of subtotal Le Fort I osteotomy, which had pre and postoperative CT scans of 180 days. The images were analyzed using Dolphin Imaging® (version 11.0.03.32) software that enables the assessment of airspace, delimiting up areas of interest and performing the calculation of the corresponding volume. The images of the right maxillary sinus (RMS) and left (LMS) were analyzed in the pre -and postoperative CT scans. The average measure of volume was 13.760mm³ for the RMS and 14.49mm³ in the LMS, for the preoperative images and 14.779mm³ for the RMS and 14.435mm³ for the LMS, in postoperative. The pre-and postoperative volumes were evaluated statistically by the "t" test. After surgery, the mean volume of RMS showed a significant increase. This increase was also observed in LMS, however it was not statistically significant. From these results, we conclude that there SARME influence on the volume of the maxillary sinuses.

Avaliação da expansão de maxila cirurgicamente assistida (EMCA) por meio da tomografia computadorizada de feixe cônico / Evaluation of surgically assisted rapid maxillary expansion (SARME) using cone beam computed tomography

O objetivo deste estudo foi avaliar por meio da tomografia computadorizada de feixe cônico (TCFC) o padrão de abertura e o processo de neoformação óssea da sutura intermaxilar em pacientes submetidos à expansão de maxila cirurgicamente assistida (EMCA). Foram avaliados 14 indivíduos submetidos à expansão de maxila cirurgicamente assistida (EMCA) pela técnica da osteotomia Le Fort I subtotal utilizando tomografia computadorizada de feixe cônico (TCFC) nos períodos préoperatório e pós-operatório de 15, 60 e 180 dias. A partir da observação do padrão de abertura da sutura intermaxilar, após a cirurgia, pôde-se classificá-la nos tipos I e II. O Tipo I corresponde à abertura da sutura intermaxilar desde a espinha nasal anterior até a espinha nasal posterior, o Tipo II, à abertura desde a espinha nasal anterior até a sutura transversal palatina. Este padrão foi relacionado à técnica cirurgica, idade do paciente e tipo de aparelho expansor. As médias de densidade da óssea na região da sutura intermaxilar foram comparadas entre os períodos estudados (pré e pós-operatório de 15, 60 e 180 dias) para acompanhar a neoformação óssea. Os dados foram tabulados e submetidos à análise estatística. Os resultados mostraram a ocorrência do padrão de abertura tipo I em 12 indivíduos e o padrão tipo II em 2 indivíduos. A média de densidade óssea encontrada no período pós-operatório de 180 dias (PO 180) foi de 49,9% em relação a media do período pré-operatório (Pré). Concluiu-se que o padrão de abertura da sutura intermaxilar está mais relacionado à idade do paciente, que nesse estudo foi de 23,9 anos para o tipo I e 33,5 anos, para o tipo II, e à técnica cirúrgica empregada e que ao final do período de contenção estudado (PO 180) não foi possível observar a total neoformação óssea na região da sutura intermaxilar.

The aim of this study was to evaluate using cone beam computed tomography (CBCT) the opening pattern and process of bone formation in the intermaxillary suture in patients with transverse maxillary deficiency undergone surgically assisted rapid maxillary expansion (SARME). Fourteen patients were evaluated whom submitted to surgically assisted maxillary expansion (SARME) by the technique of subtotal Le Fort I osteotomy using beam computed tomography (CBCT) in the preoperative and postoperative periods of 15, 60 and 180 days. From the observation of the opening pattern of the intermaxillary suture, after surgery, were classifie in types I and II. Type I corresponds to the opening of the intermaxillary suture from the anterior nasal spine to posterior nasal spine, and Type II corresponds to opening from the anterior nasal spine to the transverse palatine suture. This pattern was related to surgical technique, patient age and type of expander device. The average density of the bone in the region of the intermaxillary suture were compared between the studied periods (pre-and postoperative 15, 60 and 180 days) to evaluate bone formation. Data were tabulated and analyzed statistically. The results showed the occurrence of the opening pattern type I in 12 subjects and the standard type II in 2 individuals. The mean value of density found in the postoperative period of 180 days (PO 180) was 49.9% compared to the mean of the preoperative (Pre). It was concluded that the pattern of opening the intermaxillary suture is related to patients age, that was 23,9 years in type I and 33,5 years in type II and the surgical technique, furthermore, at the end of the retention period studied (PO 180) was not possible to observe the complete bone formation in the region of the intermaxillary suture.

Expansão cirúrgica da maxila ancorada em implantes dentários: relato de caso clínico / Surgical maxillary expansion anchored on dental implants: case report

As deformidades transversais fazem parte das alterações dentofaciais mais encontradas. Entre elas, a mais comum é a deficiência maxilar transversal. O tratamento indicado nesses casos é a Expansão Rápida da Maxila (ERM). Em pacientes adultos parcialmente edêntulos, a dificuldade em obter-se ancoragem, muitas vezes, contraindica esse tipo de tratamento ortodôntico. O presente estudo faz uma breve revisão da literatura e apresenta um método para a expansão ortopédica da maxila, assistida cirurgicamente, utilizando implantes dentários como ancoragem. No caso clínico apresentado, foram colocados dois implantes de titânio na região dos dentes ausentes e, sobre suas respectivas coroas provisórias, foi cimentado um aparelho expansor tipo Hyrax, conforme protocolo estabelecido pela literatura. Conclui-se que os implantes de titânio podem ser considerados apropriados para realizar a ancoragem ortodôntica, fornecendo apoio para a expansão da maxila, pois, quando submetidos a diferentes níveis de forças, se mantiveram estáveis e osseointegrados.

One of the most common transverse discrepancies and a frequent dentofacial abnormality is the transverse maxillary deficiency. Rapid maxillary expansion (RME) is the indicated treatment in these cases, but satisfactoryanchorage is difficult to obtain in partially edentulous adult patients, which is a frequent contraindicationof this type of orthodontic treatment. This study reviewed studies about surgically assisted methods of orthopedic expansion of the maxilla using dental implants as anchorage and described a clinical case, in which two titanium implants were placed in the edentulous segment and a Hyrax expander was cemented to the provisional crowns, following a protocol described in the literature. Titanium implants remained stable and osseointegrated when forces were applied, which suggests that they may be suitable for orthodontic anchorage and support for maxillary expansion.

Repercussions of surgically assisted maxillary expansion on nose width and position of septum and inferior nasal conchae.

The aim of the present study was to assess the clinical and radiographic repercussions of surgically assisted maxillary expansion on the septum, nasal cavity and nasal conchae. The sample was made up of 15 patients with skeletal maturity (9 females and 6 males between 16 and 45 years of age) and maxillary transverse deficiency. Assessments were performed through anterior rhinoscopy and frontal cephalometric radiographs on three occasions: (T0) preoperative period, (T1) locking of the expander and (T2) six months following the locking procedure. An increase was observed in the basal portion of the pyriform aperture and distances between the lateral wall of the basal portion of the pyriform aperture and the septum. The radiographic exam revealed that the nasal septum did not undergo any statistically significant change in its position. Moreover, no significant changes in the position of the nasal septum or nasal conchae were detected throughout the three evaluation times. The results suggest that surgically assisted maxillary expansion is capable of widening the basal portion of the pyriform aperture, with little repercussion on the anterior position of the nasal septum and inferior nasal conchae.

Maxillary Expansion.

Maxillary transverse discrepancy usually requires expansion of the palate by a combination of orthopedic and orthodontic tooth movements. Three expansion treatment modalities are used today: rapid maxillary expansion, slow maxillary expansion and surgically assisted maxillary expansion.This article aims to review the maxillary expansion by all the three modalities and a brief on commonly used appliances.

Surgically Assisted Rapid Maxillary Expansion: Report Of 5 Cases