Hyrax Expander Research Articles

Evaluation of the effects of maxillary expansion and protraction on facial soft tissue profile in unilateral cleft lip and palate patients using cone beam computed tomography

Aim: The aim of this study was to evaluate 3 dimensionally the influence of maxillary expansion and protraction on the facial soft tissue profile in unilateral cleft lip and palate patients with skeletal Class III malocclusion. Materials and Methods: This retrospective study included 2 groups. The first treatment group included randomly selected CBCT scans of 15 unilateral cleft lip and palate patients (8 males and 7 females, mean age 8.3±1 years) with skeletal Class III treated with Hyrax expander for rapid expansion and face mask appliance for maxillary protraction. The CBCT scans for each patient were available before starting the treatment (T1) and after a positive overjet was achieved (T2). The soft tissue profile changes in the treatment group were compared with a closely matched second control group with skeletal Class I relation (7 males and 8 females, mean age of 8.5± 1.1 years). Results: Upper lip protrusion, H angle, prominence of the nose and soft tissue facial height showed statistically significant increase in the first than the second group (P < 0.001). Lower lip protrusion, angle of facial convexity, nasolabial angle and soft tissue chin prominence showed statistically significant decrease in the first than the second group (P < 0.001). Conclusions: Unilateral cleft lip and palate patients with skeletal Class III malocclusion showed significant improvement in the facial soft tissue profile when treated with hyrax expander and face mask.

Factors related to maxillary expander loss due to anchoring deciduous molars exfoliation during treatment in the mixed dentition phase.

The aim was to identify factors associated with maxillary expander loss due to anchoring deciduous molars exfoliation and assess the diagnostic accuracy of the upper second premolar cusp position as a prognostic factor for the exfoliation of its corresponding deciduous molar. Ninety-two subjects aged 8.4 ± 1.1 years, treated with a Haas or hyrax expander, and using the same expansion protocol and deciduous teeth as anchorage were included. The position of the upper second premolar cusp, according to the half pulp chamber (HPC) line of the ipsilateral upper first permanent molar, was assessed on pre-treatment panoramic radiographs. A significant association between anchoring deciduous molar exfoliation and the position of the upper second premolar cusp according to the HPC line (P = 0.002; odds ratio = 5.7) was seen, while there was no association with gender, age, treatment duration, and type of expander. The median survival time for an anchoring deciduous molar, when the underlying premolar cusp was touching/crossing the HPC line, was 13.0 (11.7; 14.2) months. The upper second premolar cusp position to the HPC line showed high accuracy (at least 76.11 per cent) and substantial repeatability (at least 0.7) as a prognostic factor for the corresponding second deciduous molar exfoliation. Applicability in the mixed dentition phase with fully erupted upper first permanent molars. The probability of a second deciduous molar to be successfully used as maxillary expander anchorage for at least 16 months is above 94 per cent; when at baseline, the corresponding premolar cusp is apical to the HPC line.

Comparison of skeletal maxillary transverse deficiency treated by microimplant-assisted rapid palatal expansion and tooth-borne expansion during the post-pubertal growth spurt stage:

To investigate the efficacy of microimplant-assisted rapid palatal expansion (MARPE) to treat skeletal maxillary discrepancies during the post-pubertal growth spurt stage. Sixty patients with skeletal maxillary transverse deficiency during the post-pubertal growth spurt stage were randomly divided into MARPE and Hyrax groups. Thirty patients (mean age: 15.1 ± 1.6 years) were treated using the four-point MARPE appliance; 30 patients (mean age, 14.8 ± 1.5 years) were treated using the Hyrax expander. Cone beam computed tomography scans and dental casts were obtained before and after expansion. The data were analyzed using paired t-tests and independent t-tests. The success rates of midpalatal suture separation were 100% and 86.7% for MARPE and Hyrax groups, respectively. Palatal expansion and skeletal to dental ratio at the first molar level were greater in the MARPE group (3.82 mm and 61.4%, respectively) than in the Hyrax group (2.20 mm and 32.3%, respectively) (P < .01). Reductions in buccal alveolar bone height and buccal tipping of the first molars were less in the MARPE group than in the Hyrax group (P < .01). MARPE enabled more predictable and greater skeletal expansion, as well as less buccal tipping and alveolar height loss on anchorage teeth. Thus, MARPE is a better alternative for patients with skeletal maxillary deficiency during the post-pubertal growth spurt stage.

A prospective cohort study on the effects of RME in the mandibular dentition of cleft subjects

PurposeRapid maxillary expansion (RME) is the most frequent orthopedic procedure in cleft subjects. However, little is known about its effects on the mandible. The aim of this study was to investigate the spontaneous response of the mandibular teeth following RME. MethodsThis prospective cohort study was carried out with a sample of thirty participants with unilateral cleft lip and palate (UCLP), 8–15 years old, who had transverse maxillary deficiency. Two participants were excluded. They were allocated into three groups: G1 (n = 10), G2 (n = 10), and G3 (n = 8). G1 was treated with a Fan-type expander; G2 with an iMini expander; and G3 with a Hyrax expander. Measurements were performed in Cone Beam CT scans obtained before treatment (T1) and 3 months post-expansion (T2). The primary outcomes were buccolingual inclination of mandibular first molars and canines, and intercanine and intermolar width at different levels. ResultsDental changes were significant (P < 0.05) for intercanine width, increasing in G1 and G2, and for intermolar width, increasing in G2 and G3. There were no significant differences among groups (P > 0.05). ConclusionRME in UCLP subjects performed with these expanders may lead to significant spontaneous changes in both anterior and posterior region of the mandible.

Evaluation of photobiomodulation therapy to accelerate bone formation in the mid palatal suture after rapid palatal expansion: a randomized clinical trial.

To evaluate the efficiency of photobiomodulation therapy (PBMT) in the midpalatal suture (MPS) and pain sensation in patients undergoing rapid palatal expansion (RPE). Thirty-four individuals with the diagnosis of skeletal maxillary hypoplasia were divided in two groups: laser (n = 18) and control (n = 16). Treatment plan consisted of the use of the Hyrax expander in all patients. Subjects in the laser group were irradiated with diode laser (980nm, 0.3W) in six spots bilaterally distributed along the MPS for 10s during the active phase of treatment and after overcorrection (passive phase of RPE). Control group received sham irradiations with the laser in standby mode to characterize the placebo effect. Digital occlusal radiographs were performed at different time-points for bone formation evaluation in both groups. The effects of laser irradiation on pain were assessed by the visual analog scale (Wong-Baker Faces Pain Scale). Bone formation between groups was not significantly different (p = 0.2273). At 3months, bone formation was not yet complete in both groups. Pain sensation was similar between groups (p = 0.3940). However, pain was significantly higher for the first 7days of treatment compared with the 14th day. PBMT did not accelerate bone regeneration in the MPS and pain sensation was similar.

Evaluation of mandibular changes after rapid maxillary expansion: a CBCT study in youngsters with unilateral posterior crossbite using a surface-to-surface matching technique.

The purpose of this study was to evaluate mandibular asymmetry in youngsters with posterior unilateral crossbite (PUXB), through cone-beam computed tomography and reverse engineering technique, before and after rapid maxillary expansion (RME) treatment. Forty cone-beam computed tomography (CBCT) images were obtained from all patients at two time points, namely T0 acquired before the placement of a Hyrax expander and T1 after appliance removal. The CBCT scans were segmented and volume rendered into a surface there-dimensional (3D) mesh model. Thereafter, mandibular models were digitally registered by using a "best-fit" algorithm. Surface and volumetric changes, between T0 and T1, were compared by using Student's t tests. A slight increase of 0.45 cm3 of the total mandibular volume was found at T1 when compared with T0 (p < 0.001). The mandibular hemi-volume on the crossbite side (CB) was slightly smaller than the non-crossbite side both at T0 and T1. However, the mean differences of hemi-volume from the CB (crossbite) and non-CB side between T0 and T1 show a decrease of 0.26 cm3 (p < 0.001). Findings for the surface-to-surface deviation analysis demonstrated a fine percentage of matching at T0 which slightly improved at T1 (p < 0.001). Youngsters affected by PUXB showed a very slight and not statistically significant volumetric and morphological asymmetry between CB side and non-CB side at T0. However, the change in mean differences of 0.26 cm cannot be considered clinically relevant. Mandibles in young PUXB patients exhibit only a very mild mandibular asymmetry. Although the statistically significant mean change found right after RME removal cannot be considered clinically relevant, a more consistent sample and a longer follow-up could be of interest in explaining the short-term findings.

The upper airway volume effects produced by Hyrax, Hybrid-Hyrax, and Keles keyless expanders: a single-centre randomized controlled trial.

To assess upper airway volume changes after rapid maxillary expansion (RME) with three different expanders. Three-arm parallel randomized clinical trial. Sixty-six patients, 10-16 years old, in permanent dentition, with maxillary transverse deficiency were recruited and assigned with block randomization (1:1:1 ratio) and allocation concealment to three groups of 22 patients each (Hyrax, Hybrid-Hyrax, and Keles keyless expander). The primary outcome (overall upper airway volume change) and secondary outcomes (volume changes in the nasal cavity, nasopharynx, oropharynx, and hypopharynx) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone beam computed tomography. Differences across groups were assessed with crude or adjusted for confounders (gender, age, growth stage, skeletal pattern, baseline airway volume, and amount of expansion) linear regression models. Fifty-one patients were analysed (19, 19, and 13 in the Hyrax, Hybrid-Hyrax, and Keles groups). Maxillary expansion resulted in considerable increases in total airway volume in the Hybrid-Hyrax group (+5902.1 mm3) and less in the Hyrax group (+2537.9 mm3) or the Keles group (+3001.4 mm3). However, treatment-induced changes for the primary and all secondary outcomes were of small magnitude and no significant difference was seen among the three expanderes in the total airway volume in either crude or adjusted analyses (P > 0.05 in all instances). Finally, among pre-peak patients (CVM 1-3), the Hybrid-Hyrax expander was associated with significantly greater increases in total airway volume compared to the Hyrax expander (P = 0.02). RME resulted in relatively small increases in total upper airway volume and its separate compartments, with mostly no statistically significant differences across the Hyrax, Hybrid-Hyrax, and Keles groups. Significantly greater attrition was found in the Keles group due to appliance failure. The current trial might possibly be under-powered to detect differences between groups, if such exist. Keles expanders blocked during activations and required substitution for completion of treatment. The protocol was not published before trial commencement. Australian and New Zealand Clinical Trial Registry (ACTRN12617001136392).

Shelter availability and human attitudes as drivers of rock hyrax (Procavia capensis) expansion along a rural-urban gradient.

While anthropogenic land‐use changes threaten wildlife globally, some species take advantage of such changes and disperse into urban areas. The wildlife in urban areas often promotes conflicts with humans, notably when the animals are associated with the spread of zoonotic diseases. In Israel, current urban invasion of rock hyraxes (Procavia capensis) draws public attention, since the species is a reservoir host of cutaneous leishmaniasis, a serious skin disease. The rock hyrax, however, has seldom been studied in densely populated areas, and the drivers for its urban expansion, as well as its abilities to live and spread in core urban areas, are relatively unknown. Here, we explore the rock hyrax expansion to urban areas process by examining the availability, characteristics and use of shelter along an urban gradient. Our findings suggest that a series of factors determines shelter availability and quality for the rock hyrax, which facilitates its dispersion across the urban gradient. We found that rock hyraxes from the Judean Desert expand to the peri‐urban region of Jerusalem by colonizing new rocky shelters formed as by‐products of urban development. With their populations reaching extreme densities in this area and saturating the available shelters, there is some spill over to the adjacent core urban areas where they colonize littered sites, which are made available due to the local socio‐economic conditions and cultural norms of waste disposal and illegal placement of temporary structures. Our work emphasizes the significance of the urban gradient approach for studying the mechanisms promoting wildlife expansion to cities. Our findings suggest that changes in shelter availability and quality due to urban development, and cultural norms promote shifts of the hyrax population by pushing from the already established areas and pulling into new environment across the urban gradient.

Long term skeletal and dental changes between tooth-anchored versus Dresden bone-anchored rapid maxillary expansion using CBCT images in adolescents: Randomized clinical trial

The aim of this study was to determine long-term skeletal and dental changes in tooth-anchored versus Dresden bone-anchored rapid maxillary expansion using CBCT images in adolescents. In all, 29 adolescent patients (11-17 years of age) needing skeletal expansion were randomly allocated to two different groups treated by either a Dresden bone-anchored expander or a conventional hyrax expander. Patients included did not have previous orthodontic treatment, were non-syndromic and had all teeth present in mouth. CBCT images were taken before expansion and two or more years after expansion. An independent T-test was used to determine the statistical significance between treatment groups and paired T-test was used to compare the results before and after expansion in each group. Neither treatment group showed overall long-term different skeletal and dental changes in the transverse, anterior-posterior and vertical planes (P<0.05). Both treatment groups showed mild asymmetric skeletal expansion, but these were clinically insignificant. Both expanders had similar skeletal and dental results. The greatest changes were in the transverse plane. Changes in vertical and anterior-posterior were negligible.

Quad-helix compression to decompensate molar inclination prior to skeletal expansion.

To demonstrate that patients without posterior crossbite (PCB) but with maxillary transverse deficiency, not previously observed due to an increased curve of Wilson, can benefit from the same palatal expansion as patients with PCB, after correction of the buccal inclination. A total of 41patients presenting amaxillary skeletal transverse deficiency were treated: 26 without PCB and 15 with PCB. In the non-PCB group, quad-helix compression was followed by aHyrax expander (QH+HY), whereas the PCB group only underwent Hyrax expander treatment (HY). The maxillary intercanine, interpremolar, intermolar widths (cusp tips and gingival level) and molar inclination were measured at baseline and at the end of treatment in both groups. No significant differences were found between groups at the end of treatment, and no PCBs remained. The same maxillary expansion was achieved in the QH+HY and HY groups in the region of the canines, at both the gingival (3.4 ± 2.0 vs. 3.4 ± 2.7 mm; P = 0.999) and cusp tip levels (4.5 ± 3.1 vs. 3.8 ± 2.2 mm; P = 0.981). The molar inclination in the QH+HY group decreased, while there was a slight increase in the HY group (-6.50° ± 5.34° vs. 2.3° ± 4.1°; P < 0.001). Some patients with maxillary transverse deficiency do not present with PCB, due to an increased curve of Wilson. However, these patients require skeletal expansion similar to that of patients with abilateral PCB. The curve of Wilson should be flattened prior to expansion in order to increase the amount of maxillary skeletal expansion.

A multicenter, prospective, randomized trial of pain and discomfort during maxillary expansion: Leaf expander versus hyrax expander.

Pain suffered by the young patient is the most frequent symptom during orthodontic treatment and is the one that most frightens children and causes worry in their families. To investigate pain perception and function impairment during the first week of activation of two palatal expansion screws. A total of 101 subjects were randomly divided into two groups: RME group included patients treated with the standard hyrax expansion screw and LEAF group included patients treated with Leaf Expander appliance. Pain intensity was assessed via the Wong-Baker scale. A questionnaire on oral function impairments was also compiled by the patients. The Pain Scale analysis showed that patients in the RME group suffered from a significantly higher level of pain than those in the LEAF group (88.6% vs 25%, P<.01). RME group showed highest pain indexes from day 1 to day 4 (51.4% RME vs 9.7% LEAF suffered at least once from strong pain in the first 4days, P<.01). Furthermore, oral functions were similarly affected in both groups. Pain reported during maxillary arch expansion is influenced by clinical activation protocol and by the screw type. Patients treated with Leaf Expander reported significantly lower pain level in the first 7days of treatment.

Nasal Chamber Changes Following Rapid Maxillary Expansion in Children with Bilateral Cleft Lip and Palate

Purpose: The aim was to study the skeletal effect of rapid palatal expansion (RPE) on the anterior and posterior nasal width in a sample of Egyptian children (age range 9.4-14.3 years, mean 11.16 years) with bilateral cleft lip and palate (BCLP). Methods: Twenty Egyptian children with complete BCLP exhibiting maxillary transverse deficiency were divided randomly into; Group 1 received a fixed fan expander and Group 2 a hyrax expander. Cone-beam computed tomography (CBCT) images were taken before T1 and 3 months after expansion T2, just before the alveolar cleft grafting (ACG) surgical procedure. Linear and angular measurements were assessed to measure the degree of change on the anterior and posterior nasal chamber widths, dentition, and dental arch. Results: Repeated measure ANOVA with a between variable analysis was used to examine the effect of the two expanders on the dental arch and anterior nasal width as well as posterior nasal width. Statistically significant increase in dentoalveolar measurements were found in each group, nasal widths showed no statistically significant differences before and after expansion. Conclusion: increase in nasal width were found to be statistically insignificant following RME.

Maxillary expander with differential opening vs Hyrax expander: A randomized clinical trial

The aim of this 2-arm parallel trial was to compare the dentoskeletal effects of the expander with differential opening (EDO) and the Hyrax expander in the mixed dentition. Patients aged 7-11years with maxillary dental arch constriction and Class I or Class II sagittal relationships were randomly allocated into 2 study groups. The experimental group comprised 22 patients (10 males, 12 females) with a mean age of 8.46years treated with the EDO. The comparison group was composed of 24 patients (6 males, 18 females), mean age of 8.92years treated with the conventional Hyrax expander. One complete turn per day for 6days was performed for the posterior screw of the EDO and for the Hyrax expander. The anterior screw of the EDO was activated 1 complete turn per day for 10days. The primary outcomes were the anterior opening of the midpalatal suture, changes on the interincisal diastema width, maxillary dental arch widths, arch perimeter, arch length, palatal depth, inclination of maxillary posterior teeth and on dental arch shape, and the amount of differential expansion in the anterior region compared with the posterior region of the maxillary dental arch. Computer-generated randomization was used. Allocation was concealed with sequentially, numbered, sealed, and opaque envelopes. Blinding was applicable for outcome assessment only. Occlusal radiographs of the maxilla were obtained at the end of the active expansion phase (T2). Intraoral photographs were obtained immediately pre-expansion (T1) and at T2. Digital dental models were obtained at T1 and 6months after the active expansion period (T3). Intergroup comparisons of T1-T2 changes were performed using multiple linear regression analysis (P<0.05). The independent variables were both treatment and the starting forms. Bonferroni correction for multiple tests was applied. The experimental group showed a significantly greater opening of the anterior region of the midpalatal suture, a greater increase of the interincisal diastema width, and greater increases of the intercanine distance and inter-first deciduous molar distance than the Hyrax expander. The experimental group showed a significant differential expansion between the anterior and posterior regions, whereas the Hyrax group produced a similar expansion in the canine and molar regions. Serious harm was not observed. The EDO was capable of promoting greater orthopedic and dental changes in the anterior region of the maxilla than the conventional Hyrax expander. Similarity between the 2 expanders was observed for changes in the posterior region width, arch perimeter, arch length, palatal depth, and posterior teeth inclination.

The assessment of rapid palatal expansion using a remote monitoring software

ObjectiveDental Monitoring (DM) is a software system that allows orthodontists to remotely monitor a patient's treatment. This study evaluated the accuracy of DM software in assessing the achievement of treatment goals in patients undergoing rapid palatal expansion treatment and patient acceptance of DM. MethodsConsecutively treated patients undergoing rapid palatal expansion were invited to participate. Participants were trained to capture intraoral photos/videos using the DM app. Maxillary intermolar width (mm) and posterior crossbite correction measured by DM were compared with digital models and intraoral measurements. Patient acceptance of the DM app was evaluated with a survey. ResultsOf the 30 patients enrolled, 20 patients completed the study. DM accurately assessed the correction of posterior crossbite. There was no significant difference in intermolar width measurements obtained with DM, digital model, or intraoral examination. Overall, 71% of the participants found the DM app “easy” to work with and 43% of the patients preferred DM over a clinical visit. ConclusionIn-person evaluation of maxillary expansion with a Hyrax expander can be replaced with remote monitoring using the DM software, yet challenges associated with digital imaging hinder the use of this remote evaluation for some patients.

Rapid Arch Expansion in Cleft Lip and Palate Children: Comparison Between Fan-Shaped Expander and Hyrax-Type Expander by Using Cone Beam Computed Tomography

Purpose: The aim of the current study was to evaluate the skeletal and dentoalveolar effects of rapid palatal expansion (RPE) in children with cleft lip and palate (CLP), ages 8 to 12 years treated with 2 expanders. Methods: Twenty Egyptian children with complete bilateral CLP exhibiting maxillary transverse deficiency were divided randomly into 2 groups according to the appliance used for expansion: (A) fan expander group. (B) hyrax expander group. Cone-beam computed tomography (CBCT) images were taken before and immediately after expansion procedure. Results: There was non-significant vertical movement of the maxilla for the 2 groups. On the transverse plane, there was more anterior expansion and posterior restriction for the fan group. However, the hyrax group showed significant posterior as well as anterior expansion. Both groups showed significant tipping between both sides posteriorly and anteriorly. Mandibular expansion was non-significant. Conclusion: Fan expander showed better results for children with cleft palate requiring anterior expansion only. Hyrax expander is better used for cases seeking for posterior and anterior expansion.

Comparative Study of Maxillary Expansion by Alternate Rapid Maxillary Expansion and Constriction Versus Hyrax Expansion

Aim of study: was to evaluate the skeletal and dental effects of maxillary expansion by alternate rapid maxillary expansions and constrictions technique in comparison to conventional RME expansion by Hyrax by using PA cephalometry. Material and methods: Twenty patients with constricted maxillary arch represented with an unilateral or bilateral posterior cross bite were selected with ages ranged from 12-15 years. Patients were divided randomly into two equal groups by computer aided randomization according to the protocol of expansion into (Group I): who received alternate rapid maxillary expansions and constrictions (Alt-RAMEC) protocol and (Group II): who received conventional RME protocol. Results: Skeletally, the Latero-Nasal Width and the Maxillary width recorded higher mean values in Alt-RAMEC group than RME group with statistical significance. Dentally, all linear and angular measurements recorded higher mean values postoperatively in Alt-RAMEC group than RME group with no statistical significance except upper inter-incisal width mesial. Conclusions: Alt-RAMEC protocol produces highly skeletal effects by increasing the nasal width and the maxillary width.

LABOR AND FINANCIAL COSTS IN TREATMENT OF DENTOALVEOLAR ANOMALIES IN THE PERIOD OF THE MIXED OCCLUSION

The aim of the present study is to analyze the complexity and cost of modern methods of orthodontic treatment of children during the period of replacement bite. The study of the duration and frequency of visits to the doctor the orthodontist with the use of technology 2x4, removable plates with artificial teeth, ring spacer, plate from the front Nakonechny pad and plate valve for the language of the Twin-block appliance, mask dilara combined with the expanding apparatus, plate screw, machine screw hyrax expansion. Based on the complexity of the calculated salary orthodontist doctor, medical and other personnel. The cost of consumables at the clinical and dental stages was determined by taking into account the purchase prices and the cost of a specific manipulation by weighing or measuring. Calculated the expenditure on maintenance of workplaces of the doctor and dental technician in the calculations of the required funding early orthodontic treatment used more information about the structure and prevalence of orthodontic pathology in children in the period of the mixed occlusion. It was found that the complexity of modern orthodontic treatment during the period of replacement bite varies from 5.55 hours (spacer with a ring in case of premature loss of a temporary tooth) to 10.73 hours in the treatment of distal bite with the twin-block device. The cost of orthodontic treatment during the period of replacement bite ranges from 12.6 thousand rubles (spacer with a ring in case of premature loss of a temporary tooth) to 33.4 thousand rubles in the treatment of mesial bite using a dilyar mask in combination with an expanding apparatus. Taking into account the prevalence of dentoalveolar anomalies in children during the period of replacement bite, the necessary financial costs for orthodontic treatment per one examined child and per child with a dentoalveolar anomaly reach 30 and 40 thousand rubles, respectively.

Nonsurgical maxillary expansion in adults: report on clinical cases using the Hyrax expander.

Maxillary expansion in adults is object of intense controversy and is still considered an unreliable procedure within the orthodontic community. Therefore, the surgically assisted rapid maxillary expansion is still considered the elective treatment nowadays. The aim of this study is to evaluate the efficacy of a nonsurgical maxillary expansion treatment in adult patients with unilateral or bilateral crossbites and to assess the occurrence of related complications, such as pain and tissue swelling, tipping of the posterior teeth and gingival recessions. Maxillary expansion using a Hyrax appliance on the upper first premolars and first molars was performed in 29 patients ranged between 18 and 32 years, mean age of 22±4 years. The sample included 13 patients with unilateral crossbite and 16 with bilateral crossbite. The statistical analysis was carried out using the SPSS Statistics version 23.0. An analysis of the paired data obtained on dental casts before and after treatment was performed using the Student's t-test. The posterior crossbite was fully corrected in all patients. The procedure was well tolerated, and pain, swelling or discomfort was not significant. Statistically significant differences were found between the interdental widths for all pairs, with a P<0.001 for all of them, except in the measurements of canines, in which P=0.001. Measurements of clinical crown height at the beginning (T0) and at the end (T1) of treatment were performed for the same teeth. An increase of the clinical crown height between 0.14 and 0.44 mm was found for premolars and molars. The results indicate that nonsurgical maxillary expansion in adult patients is an efficient method for correcting transverse deficiency in the maxillary arch. Similarly, the level of complications during treatment was not clinically significant, thus this procedure may be considered a safe treatment.

Buccal bone graft with surgically assisted rapid maxillary expansion in young adults; A cone beam computerized tomographic comparative study

Objectives: The aim of this study was to evaluate the dentoskeletal effect of buccal bone graft with buccal surgically assisted rapid maxillary expansion in young adults using cone beam computed tomography. Methods: The current randomized clinical study was conducted on a total sample of 21 orthodontic patients. The sample with mean age 20 Y. CBCTs were taken before and after orthodontic expansion. The patients were divided in to three groups, group I: consisted 7 patients treated with Hyrax expander, in conjunction with selected Buccopalatal corticotomy, group II: consisted 7 patients treated with Hyrax expander, in conjunction with selected Buccal corticotomy only, group III consisted 7 patients treated with Hyrax expander, in conjunction with selected Buccal corticotomy only, followed by immediately placement of bone graft directly over the decorticated plate. Results: The results showed high significant increase in buccal bone thickness in the group III. On the other hand, there was a significant decrease increase in buccal bone thickness in groups I&II. Conclusion: The buccal bone graft with surgically assisted RME in young adult leads to increase in buccal bone thickness than the other technique without bone graft. The other two techniques without bone graft showed significant reduction in buccal bone thickness.

Evaluation of palate area before and after rapid maxillary expansion, using cone-beam computed tomography.

ABSTRACTObjective: The aim of this study was to estimate the changes in the palate area after rapid maxillary expansion (RME) with the Hyrax expander in growing subjects, using cone beam computed tomography (CBCT). Methods: Fourteen patients (9 girls and 5 boys; mean age = 11.7 ± 2.4 years) who required RME as part of their orthodontic treatment were included in this study. CBCT records had been taken before RME treatment (T0), at the end of active expansion (T1) and after a 6-month retention period (T2). The CBCT scans were manipulated with Dolphin Imaging® version 11.7 Premium software, in which landmarks were positioned and measured in relation to sagittal, coronal and axial planes, to verify the palate surface area. In addition, linear measurements of the palatal depth and width were assessed. These measurements were compared by using analysis of variance (ANOVA) for repeated measures. A p-value smaller than 0.05 was considered statistically significant. Results: The palatal surface area and width significantly increased from T0 to T1, respectively by 9.27% and 9.71%, and both decreased in a non-significant manner from T1 to T2. The palatal depth had non-significant differences at T0, T1 and T2. Conclusions: RME promotes a significant gain in the surface area of the palate and an increase in intermolar width. The Hyrax appliance was effective for the treatment of maxillary atresia in growing patients. There was no vertical alteration of the palate. After a 6-month retention period, the maxilla transverse dimension and the surface area of the palate remained stable.