Maxillary sagittal and vertical displacement induced by surgically assisted rapid palatal expansion

Sagittal and Vertical Changes of the Maxilla after Surgically Assisted Rapid Palatal Expansion: A Systematic Review and Meta-Analysis

Surgically assisted rapid palatal expansion (SARPE) is often performed to correct the transverse deficiency in the maxilla for skeletally mature patients. However, there is little consensus on the sagittal and vertical displacement of the maxilla after SARPE. This systematic review aims to analyze the position changes of the maxilla in the sagittal and vertical dimensions after the completion of SARPE. Registered with PROSPERO (registration number: CRD42022312103), this study complied with the 2020 PRISMA guideline and was conducted on 21 January 2023. Original studies were screened from MEDLINE (PubMed), Elsevier (SCOPUS), and Cochrane, and supplemented by hand-searching. Cephalometric changes of skeletal vertical and sagittal measurements were the focus. A fixed-effects model was applied in R for meta-analysis. After applying inclusion and exclusion criteria, seven articles were included in the final review. Four studies had a high risk of bias, and the other three had a medium risk of bias. Meta-analysis revealed that the SNA angle increased by 0.50° ± 0.08° (95% confidence interval, 0.33° to 0.66°), and the SN-PP angle increased by 0.60° ± 0.09° (95% confidence interval, 0.41° to 0.79°) after SARPE. In summary, the maxilla displayed statistically significant forward and clockwise downward movement after SARPE. However, the amounts were small and might not be clinically significant. Due to the high risk of bias of included studies, our results must be taken cautiously. Future studies are needed to discern the effects of direction and angulation of the osteotomies of SARPE on the displacement of the maxilla.

Evaluation of Masticatory Muscles in Adult Patients with Maxillary Hypoplasia Treated with Surgically Assisted Rapid Maxillary Expansion (SARME): A Retrospective Study

Aim: The aim of the present study was to investigate modifications in electromyographic activity of temporal and masseter muscles before and after surgically assisted rapid maxillary expansion (SARME) in adult subjects. Materials and Methods: Data from 20 patients with unilateral posterior crossbite were selected retrospectively from the Orthodontics Department of the University of Genoa and the Department of Biomedical Surgical and Dental Sciences of the University of Milan, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico Milan. Inclusion criteria were set as skeletal class I; adult patients (age > 18); good general health; patients with a transverse maxillary deficiency with unilateral posterior crossbite and maxillary constriction ≥ 5 mm; Superficial electromyographic (EMG) examinations at T0 and T1. Exclusion criteria were smoking, metabolic bone diseases (e.g., hyperparathyroidism, vitamin C deficiency), chronic use of corticoids before or during treatment, parafunctional habits (e.g., bruxism), and temporomandibular joint dysfunction. The Shapiro−Wilk test was performed to check whether the data were normally distributed. Differences for each variable before and after SARME were analyzed with a paired t-test (p < 0.05). Results: The statistical analysis demonstrated no statistically significant differences between the EMG values taken before and after SARME regarding the standardized electrical activity of the masticatory muscles (masseter and anterior temporalis (p > 0.05)). Conclusions: Considering the specific conditions of this study, it can be concluded that SARME did not alter the EMG activity of the masseter and temporal muscles. The present study has shown that the masticatory musculature evaluated after approximately 8 months of therapy can adapt well to SARME.

The Diagnosis Methods and Management Modalities of Maxillary Transverse Discrepancy

Transverse deficiency of the maxilla (TDM) is the most common skeletal change that involves the maxilla. The craniofacial skeletal assessment as early as possible is critical, as the early diagnosis of TDM influences the effectiveness of treatment. Methods for treating TDM have been reported since the mid-19th century and continue to evolve. This article puts forward a literature review on the topic, investigating the diagnosis and management of TDM, as well as stability after surgical and nonsurgical interventions. We conducted a literature search using a logical combination of the terms “palatal extension,” “maxillary transverse deficiency,” “diagnosis,” and “management.” More recent approaches include three-dimensional imaging, which has allowed for accurate depictions of the craniofacial region to be examined, allowing for evaluation of the spatial relationships between the jaw elements. The success of nonsurgical management compared to surgical management depends on the growth stage of the patient. Unfortunately, data comparing the stability of surgical and nonsurgical management is still lacking. However, for surgical intervention, surgically assisted palatal expansion (SARPE) appears to be the appropriate choice, especially when a large expansion is needed.

Stability of bimaxillary surgery involving intraoral vertical ramus osteotomy with or without presurgical miniscrew-assisted rapid palatal expansion in adult patients with skeletal Class III malocclusion

Objective

The aim of this study was to evaluate the stability of bimaxillary surgery involving bilateral intraoral vertical ramus osteotomy performed with or without presurgical miniscrew-assisted rapid palatal expansion (MARPE) in adult patients with skeletal Class III malocclusion.

Methods

A total of 40 adult patients with skeletal Class III malocclusion were retrospectively divided into two groups (n = 20 each) according to the use of MARPE for the correction of transverse maxillomandibular discrepancy during presurgical orthodontic treatment. Serial lateral cephalograms and dental casts were analyzed until 6 months after surgery.

Results

Before presurgical orthodontic treatment, there was no significant differences in terms of sex and age between groups. However, the difference of approximately 3.1 mm in the maxillomandibular intermolar width was statistically significant (p < 0.001). Two days after surgery, the mandible had moved backward and upward without any significant intergroup difference. Six months after surgery, the maxillary intercanine (2.7 ± 2.1 mm), interpremolar (3.6 ± 2.4 mm), and intermolar (2.0 ± 1.3 mm) arch widths were significantly increased (p < 0.001) relative to the values before presurgical orthodontic treatment in the MARPE group; these widths were maintained or decreased in the control group. However, there was no significant difference in surgical changes and the postsurgical stability between the two groups. No significant correlations existed between the amount of maxillary expansion and postsurgical mandibular movement.

Conclusions

MARPE is useful for stable and nonsurgical expansion of the maxilla in adult patients with skeletal Class III malocclusion who are scheduled for bimaxillary surgery.

Assessment of pulp volume changes after surgically assisted rapid palatal expansion

Maxillary transverse deficiency is a common skeletal problem. When the patient is younger, it is treated by rapid palatal expansion by using orthodontic appliances. If this fails or the patient is older, which means skeletal growth is completed, surgically aided rapid palatal expansion (SARPE) becomes necessary. In this technique, after the osteotomies have been made, the two maxillary bones are distracted by tooth-borne device. Since a tooth-borne device will apply the distraction forces on the teeth, the pulp volumes may change. Our aim was to investigate the volume changes of the tooth pulps after SARPE in which a tooth-borne device was used. We scanned our database and included 20 patients (7 males and 13 females) aging between 16 and 30 (mean 19.5±3.97) to this retrospective study. All the patients had undergone SARPE surgeries and they had pre-surgery and postconsolidation cone beam computerized tomography (CBCT) images. All the surgeries had been done in similar ways; all the patients had used similar tooth-borne modified acrylic bonded expansion device. We divided the maxillary teeth into three groups: the incisors, the premolars and the molars. We imported the CBCT images of each patient into 3D Slicer software. We calculated volumes of pulps for all maxillary teeth. We compared volumes with paired t test. Statistical significance level was accepted as P< .05. The devices had been left in place between 83 and 179 days including distraction and consolidation periods (mean 121.35±27.83 days). Amount of the expansions varied between 6.03mm and 11.16mm (mean 7.19±1.18mm). We found a statistically significant decrease of the pulp volumes in incisor, premolar and molar teeth (P<.001) between pre-surgery and postconsolidation periods. When using tooth-borne devices in SARPE, their impacts on teeth pulps should also be considered.

Surgically assisted rapid palatal expansion using customized bone-borne devices

Correction of maxillary compression via palatal expansion is easy in children and adolescents, but more complicated once growth is finished. This correction may be performed by progressive expansion using orthopaedic appliances after osteotomy with more stable results, which facilitate a second phase to achieve larger expansions. We present a clinical case treated using a customized device that improves predictability. The stability of the device is ensured by multiple support points with 8 screws that fix it to the palate.

Key words:Surgically assisted rapid palatal expansion, stereolithographic model, customized, bone-borne, expansion device.

Adjustable selective maxillary expansion combined with one-stage maxillomandibular surgery: A prospective study of osseous widening in fifty-five consecutive patients

OBJECTIVE

SARME is often considered to be the only available treatment for significant or severe maxillary transverse palatal deficiencies (MTD) in skeletally-mature patients. Despite this observation, the aim of our study was to assess a new type of maxilla distraction osteogenesis. Using two innovative tools, we performed selective expansion: the site to be widened and the amount of increase were both pre-selected. Patients were treated in a single maxillomandibular procedure. Our study focuses primarily on the extent of osseous widening.

STUDY DESIGN

Post-expansion computed tomography data from 55 non-syndromic patients were included in a prospective study and analyzed in two planes for transverse skeletal widening. Of the 55 patients, 16 underwent isolated posterior distraction for severe posterior endognathia (group I), and 39 were treated in both segments (group II). Diastemas and anterior spaces permitted resolution of crowding and patients with a small, narrow, tapering arch were given a more rounded form. All patients underwent a complete Le Fort I with down fracture. Two novel devices were used: first, an adjustable distractor to achieve an angular opening; and secondly, in group II, new modular plates interlocked for osteosynthesis to provide stability and anterior expansion.

RESULTS

In group I, analysis of the width of the gain showed significant posterior values decreasing from back to front, a result never achieved with the SARME procedure. The mean osseous gain at first molars was 7.1 mm. When anterior space was required in group II, it was created as wide as needed (mean 4.2 mm, at canine level) with good preservation of the 1st molar space gain (mean 6.8 mm).

CONCLUSION

Total Le Fort I osteotomy associated with two innovative devices provides a new, segmental and adaptable approach for transverse distraction osteogenesis. We demonstrate a good match with the dental enlargement required. All patients were managed in a single orthognathic procedure for all the anomalies to be treated. Long-term results show good stability.

Effects of surgically assisted rapid maxillary expansion on mandibular position: a three-dimensional study

Background

This study aimed to evaluate three-dimensional changes in mandibular position after surgically assisted rapid maxillary expansion (SARME).

Methods

A retrospective study was carried out with tomographic records of 30 adult patients with maxillary transverse deficiency who underwent SARME. Cone beam computed tomography scans were obtained preoperatively (T1), after expansion (T2) and 6 months after expansion (T3). Mandibular landmarks were measured with respect to axial, sagittal, and coronal planes. Repeated measures ANOVA was used for statistical analysis.

Results

Clockwise rotation and lateral displacement of the mandible were observed immediately after SARME. However, mandibular displacements tended to return close to their initial values at T3.

Conclusions

Clockwise rotation and lateral shift of the mandible are transient effects of SARME.

Evaluations of sagittal and vertical changes induced by surgically assisted rapid palatal expansion

INTRODUCTION

Class II, anterior open bite and/or a steep mandibular plane angle are frequently considered a contraindication to the use of surgically assisted rapid palatal expansion (SARPE). Nevertheless, few studies have investigated the maxillary and mandibular effects after SARPE on the sagittal and vertical planes, with dissimilar results and small samples of patients.The aim of the current study was to evaluate the sagittal and vertical effects after SARPE.

METHODS

Twenty-one consecutive adult patients (7 males, 14 females; mean age, 25.6 ± 6.3 years) who required SARPE were included in this study. All patients were subjected to subtotal LeFort I osteotomy with pterygomaxillary disjunction. Lateral cephalometric radiographs were taken during the preoperative assessment (T0) and 6 months after the end of the expansion (T1). Cephalometric measurements were realized at T0 and T1 for all the patients. Independent-sample t test and analysis of variance were used.

RESULTS

Statistically significant changes were observed only in upper incisor^NA (P = 0.04). No skeletal sagittal or vertical variation was found after SARPE.

CONCLUSIONS

Class II, anterior open bite and/or a steep mandibular plane angle cannot be considered an outright contraindication to its use. Upper incisor palatal inclination could result after SARPE.

Effects of rapid palatal expansion on the sagittal and vertical dimensions of the maxilla: a study on cephalograms derived from cone-beam computed tomography

INTRODUCTION

The purpose of this study was to use cone-beam computed tomography imaging to examine the skeletal and dental changes in the sagittal and vertical dimensions after rapid palatal expansion.

METHODS

Twenty-eight healthy children (mean age, 9.9 years; range, 7.8-12.8 years; 17 boys, 11 girls) who required rapid palatal expansion treatment were included. For each patient, a bonded Haas-type expander with full occlusal and palatal acrylic coverage was cemented in place. Cone-beam computed tomography images were obtained as part of the pretreatment orthodontic records and at the completion of rapid palatal expansion for all patients. The mean interval between pretreatment and completion of rapid palatal expansion was 52 days (range, 19-96 days). The average skeletal age of the patients, determined from hand-wrist films also obtained before treatment, was 10.1 years. The mean expansion of the expander was 8.0 mm (range, 5.9-9.6 mm). Each cone-beam computed tomography image was compressed from the outer portion of the right side of the patient's head to the center of the left central incisor into a 2-dimensional synthesized cephalogram, which was then traced and measured.

RESULTS

The results showed that from pretreatment to completion of rapid palatal expansion, SNA, FH-NA, and A-Nperp increased by means of 1.04°, 0.92°, and 0.87 mm, respectively (P <0.05). In addition, 1/-NA, 1/-SN, 1/-NA, 1/-Nperp, and 1/-PP showed mean decreases of 3.74°, 2.53°, 1.17 mm, 0.49 mm, and 2.69°, respectively (P <0.05). Both ANS and PNS moved significantly downward (ANS, 2.05 mm; PNS, 1.16 mm).

CONCLUSIONS

There was forward movement of the maxilla as a result of rapid palatal expansion treatment. Bonded rapid palatal expansion treatment resulted in downward displacement of the maxilla with a greater displacement of ANS than PNS and posterior movement of the maxillary central incisors.

Three-dimensional computed tomographic analysis of changes to the external features of the nose after surgically assisted rapid maxillary expansion and orthodontic treatment: a prospective longitudinal study

INTRODUCTION

The aim of this prospective, longitudinal study was to evaluate changes to the external shape and form of the nose after surgically assisted rapid maxillary expansion and orthodontic treatment. The changes were registered using a 3-dimensional computer tomography technique, based on superimposition on the anterior base of the skull.

METHODS

The subjects comprised 35 patients (mean age, 19.7 years; range, 16.1-43.9 years). Low-dose, helical computerized tomography images were taken at treatment start and after orthodontic treatment, about 18 months postsurgery. The 3-dimensional models were registered and superimposed on the anterior cranial base.

RESULTS

There were in general significant widening and overall anterior and inferior displacement of the nasal soft tissues. The changes varied in size and direction. No correlation was found between the initial and final widths of the nose, or between the initial and final widths of the nostrils.

CONCLUSIONS

After surgically assisted rapid maxillary expansion, the most obvious changes to the external features of the nose were at the most lateral alar bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. Patients with narrow and constrained nostrils can benefit from these changes. The 3-dimensional superimposition applied in this study is a reliable method, circumventing projection and measurement errors.

Orthodontic measurements and nasal respiratory function after surgically assisted rapid maxillary expansion: an acoustic rhinometry and rhinomanometry study

The present study sought to assess nasal respiratory function in adult patients with maxillary constriction who underwent surgically assisted rapid maxillary expansion (SARME) and to determine correlations between orthodontic measurements and changes in nasal area, volume, resistance, and airflow. Twenty-seven patients were assessed by acoustic rhinometry, rhinomanometry, orthodontic measurements, and use of a visual analogue scale at three time points: before surgery; after activation of a preoperatively applied palatal expander; and 4 months post-SARME. Results showed a statistically significant increase (p<0.001) in all orthodontic measurements. The overall area of the nasal cavity increased after surgery (p<0.036). The mean volume increased between assessments, but not significantly. Expiratory and inspiratory flow increased over time (p<0.001). Airway resistance decreased between assessments (p<0.004). Subjective analysis of the feeling of breathing exclusively through the nose increased significantly from one point in time to the next (p<0.05). There was a statistical correlation between increased arch perimeter and decreased airway resistance. Respiratory flow was the only variable to behave differently between sides. The authors conclude that the SARME procedure produces major changes in the oral and nasal cavity; when combined, these changes improve patients' quality of breathing.

Lateral cephalometry changes after SARPE

Surgically assisted rapid palatal expansion (SARPE) is associated with postoperative cephalometric changes. In this study we analyse these changes in the sagittal plane in orthognathic patients undergoing SARPE followed by orthodontic treatment and Le Fort I, bilateral sagittal split osteotomy (BSSO), or bimaxillary surgery. This is a retrospective review of 50 patients (20 males, 30 females) undergoing orthognathic treatment with SARPE to correct transversal deficiency of the maxilla as part of a comprehensive treatment plan. PP-SN, SNA, and ANB angles were increased and U1-SN and U1-PP angles were decreased. All changes were statistically significant. Changes of SNB, PP-Mand plane angle, and SN-Mand. plane angle were not statistically significant. Surgically assisted rapid palatal expansion using a bone-borne appliance as a preparative step for later orthognathic surgery results in clockwise rotation of the maxilla.

Effect of surgically assisted rapid maxillary expansion on masticatory muscle activity: A pilot study

Background:

The aim of the present study was to analyze the electromyographic (EMG) activity of masseter and temporal muscles of adult patients submitted to surgically assisted rapid maxillary expansion (SARME) before and after the surgery.

Materials and Methods:

The sample consisted of 19 adults, with ages ranging from 20 to 47 years (mean 25.4 years), with bilateral posterior cross bite requiring SARME treatment. The electromyographic activity of masseter and temporal muscles was analyzed before treatment (T1) and after the surgical procedure (T2). The mean interval between the two electromyographic analyses was 15 days.

Results:

The muscular active was electromyographically analyzed during the clinical situation of habitual gum chewing (10 sec), dental clenching (4 sec), mouth opening and closing (10 sec), rest (10 sec), protrusion (10 sec), and right and left laterality (10 sec). The measured differences between T1 and T2 data were evaluated using the paired t-test (SPSS 17.0 for Windows). The electromyographic analysis showed that the activity of the masseter and temporal muscles decreased significantly after the SARME in all the clinical situations after the surgery.

Conclusion:

According to the results of the present study, individuals after SARME surgery presented patterns of electromyographic contraction similar to those developed by dentate individuals during the movements of mandibular excursion.

Changes in nasopharyngeal airway following orthopedic and surgically assisted rapid maxillary expansion

INTRODUCTION

The aim of this study was to compare changes in soft-palate morphology and nasopharyngeal relations after orthopedic rapid maxillary expansion (RME) and surgically assisted RME (SARME).

METHODS

A group of 10 patients received RME, a second group of 10 patients received SARME, and a third group of 10 patients served as an untreated control group. Lateral and posteroanterior cephalograms were obtained for each individual at preexpansion/precontrol and postexpansion/postcontrol. In addition to descriptive parameters, the angulation, length, and thickness of the soft palate and superior and inferior pharyngeal spaces and the ratios of the length of the soft palate to the length of the superior and inferior pharyngeal spaces were evaluated. Paired t-tests were performed to analyze changes within groups, and analysis of variance and Duncan tests were used to compare changes among groups.

RESULTS

No statistically significant differences were found in changes in measurements related to soft-palate morphology or nasopharyngeal dimensions among the SARME, RME, and control groups; however, increases in soft-palate angulation and superior and inferior pharyngeal spaces after expansion/control were greater in the SARME group than in other groups.

CONCLUSIONS

No statistically significant differences were found between changes in the nasopharyngeal airway after RME and SARME.

Cephalometric study of slow maxillary expansion in adults

INTRODUCTION

The purpose of this retrospective study was to evaluate the dentoskeletal changes after slow maxillary expansion in adults.

METHODS

Three kinds of maxillary expanders (Haas [Dyna Flex, Laboratory, St Louis, Mo], MAX-2000 [Dyna Flex], and DMAX-2000 [Dyna Flex]) were used randomly in 3 study groups of 65 adults treated with nonsurgical slow maxillary expansion, followed by full straight-wire appliance therapy. A control group of 22 adults, meeting the same inclusion criteria, were treated only with full straight-wire appliance therapy without expansion. Posteroanterior and lateral cephalometric records were taken before the start of treatment (T1) and after fixed orthodontic treatment (T2). The data were analyzed statistically by using paired t tests and Kruskal-Wallis H tests.

RESULTS

From T1 to T2, there was no significant change in nasal width, maxillary width, and mandibular width in the 3 groups. The sella-nasion-mandibular plane angle increased 0.97 degrees (P <0.05) in the DMAX-2000 group. The mandibular incisor-mandibular place angle in the Haas, MAX-2000, DMAX-2000, and control groups had mean increases of 4.90 degrees, 4.42 degrees, 4.55 degrees, and 5.20 degrees (P <0.05 for each), respectively. The maxillary incisor-nasion-A-point angle increased 3.04 degrees (P = 0.05), and the distal root of the maxillary first molar-nasion perpendicular decreased 1.48 mm (P <0.05) in the control group. The distal facet of the maxillary first molar-nasion perpendicular decreased 3.57 mm (P <0.05), and the distal root of the maxillary first molar-nasion perpendicular decreased 2.50 mm (P <0.05) in the MAX-2000 group.

CONCLUSIONS

After expansion treatment, there were no evident transverse or significant sagittal and vertical skeletal maxillary changes in the 3 groups.

Surgically assisted palatine expansion in adult patients: evaluation of a conservative technique

PURPOSE

This study was conducted to assess a conservative technique for surgically assisted palatine expansion (SAPE) done under local anesthesia and conscious sedation in adults. Dental inclination, uniformity of expansion, and satisfaction of orthodontist were evaluated.

PATIENTS AND METHODS

Twenty-seven consecutive patients, ranging in age from 25 to 42 years, underwent SAPE under local anesthesia. The surgical procedure involved osteotomy of the lateral wall of the maxilla, from the maxillary tuberosity to the nasal cavity, with the nasal septum and the ptyerigoid plates left intact. Cast models were obtained before surgery and 1 year after surgery. Cuspid inclinations were assessed, with intercanine distance in 2 points, the incisal and cervical borders, measured before and after surgery. Molar inclination was obtained by measuring intermolar distance at the cervical margin and occlusal table. The results were statistically analyzed by analysis of variance. A questionnaire with 4 questions was addressed to the orthodontists to evaluate the level of satisfaction with the procedure.

RESULTS

Cuspid and molar inclination occurred, but there was no statistically significant difference (P < .05) in dental inclination before and after surgery. The expansion was greater at the molar level than at the canine level, but this difference also was not statistically significant (P > .05). According to the questionnaire, 100% of the procedures allowed the expansion, 100% of the orthodontists were satisfied, and 68.75% observed dental inclination, but this inclination was not excessive in 100% of the cases.

CONCLUSIONS

The proposed technique is a safe, predictable, and reliable method for SAPE in adult patients. Although ptyerigoid plate and nasal septum fractures were not performed, the maxillary bone exhibited uniform expansion. Dental inclination was not significant, either clinically or during cast model analysis. Orthodontists could achieve treatment objectives with this surgical procedure.

Transpalatal distraction using bone-borne distractor: clinical observations and dental and skeletal changes

PURPOSE

The aim of this clinical study was to analyze the outcome, complications, and long-term results of transpalatal distraction for the correction of maxillary transverse deficiency (MTD) and assess skeletal and dental changes in the sagittal, vertical, and transverse planes through cephalograms and dental casts.

PATIENTS AND METHODS

Ten adult patients with MTD were treated with a Transpalatal Distractor (Surgi-Tec, Bruges, Belgium). Lateral and posteroanterior cephalometric films and dental casts were taken before surgery and at the end of the consolidation period. The statistical analysis of cephalometric film and dental cast measurements was undertaken with paired t tests.

RESULTS

The intraoperative and postoperative problems encountered were damage to the central incisive teeth as a result of vertical osteotomy, wound dehiscence after the latent period, pain during the distraction period, and loosening of the distractor and buccal displacement of the left alveolar segment during the consolidation period. Model analysis showed that the greatest amount of transverse increase was in the premolar region (7.07 mm for first premolar and 7.10 mm for second premolar). Frontal cephalometric analysis indicated that transverse distances increased more at the alveolar level (7.75 mm) than in the maxillary base (5.25 mm) and nasal region (4.3 mm). The asymmetries between the left and right sides in both dental and skeletal expansions were statistically nonsignificant. The changes in the Sella-nasion-point A, Sella-nasion-point B, Sella-nasion and gonion-gnasion angles were statistically significant.

CONCLUSIONS

According to the results of this study, transpalatal distraction was found to be a clinically effective technique for palatal expansion in adult patients with MTD. However, treatment planning and regular clinical follow-up visits are necessary for long-term clinical success.

Hyrax appliance opening and pattern of skeletal maxillary expansion after surgically assisted rapid palatal expansion: a computed tomography evaluation

OBJECTIVE

The objective of this study was to evaluate, using computed tomography, correlations between Hyrax appliance opening and post-SARPE skeletal changes.

STUDY DESIGN

Fifteen patients underwent SARPE according to a specific protocol and were followed. Linear and angular measurements of the anterior, intermediate, and posterior portions of the maxilla were evaluated. The correlation between maxillary expansion and appliance opening was investigated.

RESULTS

Significant overall expansion was observed. In the anterior and intermediate portions of the maxilla, the increase in maxillary width was greater than that observed in the posterior portion. The degree of appliance opening was significantly greater than that of the skeletal expansion. Also, no linear correlation between appliance opening and regional maxillary expansion was established.

CONCLUSION

The transverse expansion of the maxilla was less than uniform. The lack of linear correlation between appliance opening and skeletal expansion is attributable to multiple factors, including those related to the device, the surgical technique, and the craniofacial deformity itself.

Closer look at the stability of surgically assisted rapid palatal expansion

PURPOSE

To assess the amount of dental and skeletal expansion and stability after surgically assisted rapid maxillary expansion (SARPE).

PATIENTS AND METHODS

Data from 20 patients enrolled in this prospective study were collected before treatment, at maximum expansion, at the removal of the expander 6 months later, before any second surgical phase, and at the end of orthodontic treatment, using posteroanterior cephalograms and dental casts.

RESULTS

With SARPE, the mean maximum expansion at the first molar was 7.48 +/- 1.39 mm, and the mean relapse during postsurgical orthodontics was 2.22 +/- 1.39 mm (30%). At maximum, a 3.49 +/- 1.37 mm skeletal expansion was obtained, and this expansion was stable, such that the average net expansion was 67% skeletal.

CONCLUSION

Clinicians should anticipate a loss of about one third of the transverse dental expansion obtained with SARPE, although the skeletal expansion is quite stable. The amount of postsurgical relapse with SARPE appears quite similar to the changes in dental-arch dimensions after nonsurgical rapid palatal expansion, and also quite similar to dental-arch changes after segmental maxillary osteotomy for expansion.

Dentoalveolar changes after surgically assisted maxillary expansion: a three-dimensional evaluation

OBJECTIVES

Surgically assisted rapid palatal expansion (SARPE) is a common procedure to correct maxillary transverse deficiency of >5 mm in patients with closed midpalatal suture. The aim of this study was to three-dimensionally analyze skeletal and dentoalveolar changes after SARPE.

STUDY DESIGN

Eighteen mature patients (mean age 26 years) with a palatal transverse deficiency underwent SARPE. The surgical procedure consisted of a lateral osteotomy combined with an interradicular osteotomy between the roots of the upper central incisors. Measuring points were defined on teeth as well as facial skeleton. Computerized tomography scans were performed preoperatively and immediately after the expansion period.

RESULTS

Changes of the dentoalveolar and maxillofacial complex were analyzed.

CONCLUSIONS

Bilateral osteotomy combined with a sagittal osteotomy between the roots of the upper central incisors is a safe method of surgically assisted maxillary expansion. The amount of dentoalveolar tipping was smaller than reported in literature. The expansion was mostly achieved by maxillary expansion.

Transverse effects after surgically assisted rapid maxillary expansion in the midpalatal suture using computed tomography

Surgically assisted rapid maxillary expansion is the treatment of choice for correcting maxillary transverse deficiency in adults. Traditionally, the appliance for expansion is tooth-borne and tissue-tooth-borne devices (Hyrax and Haas). Although a number clinical and radiographic studies have evaluated the surgically assisted rapid maxillary expansion, only limited information is available to study the transverse movement of the midpalatal suture with computed tomography. Forty adult patients of both sexes, ranging in age from 18 to 38 years, with bilateral transverse maxillary deficiency were operated on. Twenty patients had Hyrax expander, and 20 had Haas expander. Under general anesthesia, subtotal Le Fort I osteotomy was performed including pterygomaxillary dysjunction. The width of the midpalatal suture opening was measured at the anterior edge of the midpalatal suture and at the junction of the midpalatal suture and palatal bones, using computed tomography in axial acquisition, obtained in the preoperative period and immediately after the end of expansion. A digital caliper was used to measure Haas and Hyrax distance on the central jackscrew preoperatively and postoperatively. The proportion between the midpalatal suture expansion and the amount of expansion on the jackscrew was evaluated. The mean of midpalatal suture opening and screw opening for Haas group was 5.19 and 8.78 mm, and for the Hyrax group, 5.85 and 8.51 mm, respectively. Both groups showed parallel-shaped separation of the midpalatal opening with no significant difference in the anterior and posterior portion. Midpalatal/jackscrews opening proportion was greater in the Hyrax group (69,2%) than in the Haas group (60%).

[The use of bone distraction in the treatment of the transverse direction in adults]

Crowding and mal-positioning of teeth in the dental arch are problems frequently encountered with adult patients. These discrepancies are associated with a lack of development of basal bone, a shortcoming whose etiology is difficult to discern. Treating these problems with expansion assisted by surgery depends on osseous distraction, the separating of segments of bone to create new bone and the movement of whole groups of teeth and their periodontium, a technique that assures excellent stability. It is important to define precisely the indications for this technique as well as our therapeutic protocols, both in the maxilla and in the mandible. For an expander we use a single thread expansion screw welded to two molar bands. To be sure it works effectively; the surgeon first opens the maxillary suture to liberate the two portions of the maxilla. After a ten day wait, the expansion screw is opened daily for up to two weeks depending on how much expansion is required. When the desired point is attained, the expansion device is locked, and the patient returns for check-up visits every ten days. During this period the patient is outfitted with a false tooth to mask the large and unsightly diastema that has appeared between the central incisors. Three months after the original intervention the patient receives a full-banded strap-up. The orthodontist usually employs centripetal forces to level the teeth and to correct rotations in an effort to minimize the risk of periodontal complications. The results that we have obtained with this treatment have fulfilled our expectations with significant improvement in arch form, full respect for the periodontium, an improvement in facial balance, and the appearance of a generous and pleasing smile.

Surgically assisted rapid palatal expansion: a literature review

Transverse maxillomandibular discrepancies are a major component of several malocclusions. Orthopedic and orthodontic forces are used routinely to correct a maxillary transverse deficiency (MTD) in a young patient. Correction of MTD in a skeletally mature patient is more challenging because of changes in the osseous articulations of the maxilla with the adjoining bones. Surgically assisted rapid palatal expansion (SARPE) has gradually gained popularity as a treatment option to correct MTD. It allows clinicians to achieve effective maxillary expansion in a skeletally mature patient. The use of SARPE to treat MTD decreases unwanted effects of orthopedic or orthodontic expansion. Our aim in this article is to present a comprehensive review of the literature, including indications, diagnosis, guidelines for case selection, a brief overview of the surgical techniques, orthodontic considerations, complications, risks, and limitations of SARPE to better aid the clinician in the management of MTD in skeletally mature patients.

Facemask therapy with and without expansion

INTRODUCTION

The aim of this study was to compare the effects of facemask treatment with and without expansion in patients with skeletal Class lll malocclusion.

METHODS

The material for this study consisted of the pretreatment and posttreatment lateral cephalograms of 28 subjects with skeletal and dental Class lll malocclusions, divided into 2 groups of 14. In the facemask with expansion group (FMEXP; 8 girls, 6 boys; mean age, 11 years 1 month), each subject wore a Delaire-type facemask and a bonded rapid maxillary expansion appliance. In the facemask only group (FM; 8 girls, 6 boys; mean age, 11 years 6 months), each subject wore a Delaire-type facemask with a removable appliance. A third group of untreated children with Class lll malocclusion (7 girls, 7 boys; mean age, 10 years 2 months) was used as the control sample.

RESULTS

The forward displacement of the maxilla in both treated groups was significantly greater than in the control group. The forward displacement of pogonion and increase in facial depth in the control group showed significant differences compared with the treatment groups. Extrusion of the maxillary molars was significantly greater in the FM group than in the control group. The increase in the mandibular plane angle and the decrease in the facial axis were significantly different between the FMEXP group and the control group. Molar relationship increased more in the FM group than in the FMEXP group; this was the only significant difference between the treatment groups. In both treatment groups, dental and skeletal treatment of subjects with Class lll malocclusion were achieved.

CONCLUSIONS

If the treatment indications are appropriate, facemask therapy can be an effective method for Class III treatment.

Stability of the Transverse Dimension of the Maxilla After Surgically Assisted Rapid Expansion

The aim of this study was to evaluate the behavior of the transverse dimension of the maxilla after surgically assisted rapid expansion with and without using a transpalatal arch fixed retention. Sixty cast models of the maxilla and 60 posteroanterior radiographs from 30 adult subjects, 16 male subjects and 14 female subjects, were evaluated. The subjects were 18.1 to 53.2 years old (mean age, 27.3 years), had been submitted to surgically assisted rapid maxillary expansion, and were using the expansion appliance for four months. The subjects were randomly assigned into two groups of 15 subjects. One group, called the group with retention, received a transpalatal arch fixed retention and another group, which received no retention, was called the group without retention. The assessments were performed at two time points: at the removal of the expansion appliance (T1) and 6 months after the removal of the expansion appliance (T2). In the cast models, interpremolar distances (A-A1) and intermolar distances (B-B1) were measured and in the posteroanterior radiographs, maxillomandibular discrepancy was used. A reduction in the distances A-A1 (-0.76 mm) and B-B1 (-1.54 mm) was observed among the time points studied in the group without retention and this difference was statistically significant. In the group with retention, the difference between the time points T1 and T2 was not statistically significant. The assessment of the maxillomandibular difference showed an increase between the time points T1 and T2 in the group with retention (1.54 mm) and the group without retention (0.84 mm), which means a reduction in the maxillary width in the posteroanterior radiograph. In the comparison between the groups, the assessment of the cast models and the assessment of the posteroanterior radiograph showed no statistically significant difference in any of the variables studied.

Using Computed Tomography to Evaluate Maxillary Changes After Surgically Assisted Rapid Palatal Expansion

Surgically assisted rapid palatal expansion (SARPE) is the procedure of choice for treating transverse maxillary deficiency in adult patients. The use of computed tomography (CT) as a method of evaluating the efficiency of this procedure has not been yet reported. Consequently, few landmarks for use in evaluating maxillary expansion have been defined. The goals of the present study were to define parameters to assess skeletal changes after SARPE and to use CT to evaluate those parameters. From June of 2004 to May of 2005, 15 patients underwent SARPE (a modified Le Fort I maxillary osteotomy without pterygomaxillary separation, together with a sagittal palatal osteotomy) according to a defined protocol. To determine the pattern of transversal expansion, linear and angular measurements of the anterior, intermediate, and posterior portions of the maxilla were evaluated in axial and coronal views. The cross-sectional area of the maxilla was calculated to obtain general information about maxillary expansion. The reliability of the method was confirmed. Significant overall expansion was observed. However, different patterns of expansion were seen in the three regions analyzed. In the anterior and intermediate portions of the maxilla, the increase in maxillary width was greater than that observed in the posterior portion. The transverse expansion of the maxilla achieved through SARPE without pterygoid plate separation was less than uniform. The accurate evaluation of the postoperative changes was heavily dependent upon images acquired through CT.

Surgically assisted rapid maxillary expansion (SARME): a review of the literature

Transverse maxillary hypoplasia, in adolescents and adults, is frequently seen in non-syndromal and syndromal patients including cleft patients. In skeletally matured patients, the uni- or bilateral transverse hypoplasia can be corrected by means of a surgically assisted rapid maxillary expansion. The treatment is a combination of orthodontics and surgical procedures and provides dental arch space for alignment of teeth. The procedure also causes a substantial enlargement of the maxillary apical base and of the palatal vault, providing space for the tongue for correct swallowing and thus preventing relapse. In addition, a distinct subjective improvement in nasal breathing associated with enlargement of the nasal valve towards normal values is seen with an increase of nasal volume in all compartments. In this article we give a review on surgically assisted rapid maxillary expansion. We conclude that there is no consensus in the searched literature regarding either the surgical technique, the type of distractor used (tooth-borne or bone-borne), the existence, cause and amount of relapse and whether or not overcorrection is necessary. A proposal for a prospective randomized patient study in order to find answers to the lacunas in knowledge regarding this treatment is done.

Skeletal and dental changes in the sagittal, vertical, and transverse dimensions after rapid palatal expansion

The purpose of this study was to examine the maxillary and mandibular responses to rapid palatal expansion (RPE) in all 3 dimensions. Twenty children (average age, 11.7 years) who required RPE treatment were included in this study. Pre- (T1) and post-RPE (T2) lateral and posteroanterior (PA) cephalograms and study models were taken for all patients. For each patient, lateral and PA cephalograms at T1 and T2 were traced, and the sagittal, vertical, and transverse measurements were made. In addition, on the pre- and postexpansion models, the widths between the first premolars, the first molars, and the two acrylic halves of the Haas-type expander were measured. Results showed that from T1 to T2, the mean SNA increased 0.35 degrees (P < .05) and ANB increased 1.00 degrees (P < .05). Both the ANS and PNS moved downward (1.30 mm and 1.43 mm, respectively, P < .05), and the mandibular plane angle (MP-SN) increased 1.72 degrees (P < .05). The maxillary and mandibular incisors did not change significantly after RPE. After RPE, the mean increase of maxillary interpremolar width, maxillary intermolar width, maxillary width (J-J), nasal width, and interorbital width were found to be 110.7%, 104.5%, 30.1%, 23.1%, and 3.3% of the screw expansion, respectively. After RPE treatment in children, the maxilla displaced slightly forward and downward (P < .05); the mandible rotated downward and backward, and the anterior facial height increased significantly (P < .05); and the widths of the maxilla and nasal cavity increased significantly (P < .05).