Transverse Maxillary Hypoplasia Research Articles

28. Comparison of Furlow and Straight Line Repair Techniques on Transverse Dental Arch Dimensions and Extent of Orthodontic Intervention

PURPOSE: While the Furlow and straight line repair are the most commonly performed palatoplasty techniques, studies have advocated for the Furlow technique as it provides an increase in palatal lengthening. However, the Furlow technique’s impact on the transverse axis of the dental arch has yet to be explored. This study aims to compare the impact of the Furlow and straight line repair techniques on the transverse dental arch dimensions and the extent for postoperative orthodontic interventions. METHODS: A retrospective chart review of patients with cleft palate with or without a cleft lip at an urban pediatric medical center receiving care from senior surgeons between 1997-2022 was completed. Variables including cleft characteristics, repair type, and orthodontic evaluation and interventions were collected. Patients undergoing straight line repairs (SLR) were compared to those undergoing Furlow palatoplasty. Data were analyzed using Wilcoxon and Chi-Squared analyses in R Studio 4.2.1. RESULTS: Of 1,552 patients with cleft lip and palate deformities, 53% underwent Furlow repair and 47% underwent SLR. SLR was associated with increased rates of maxillary narrowing (orthodontist reported) when compared to Furlow repairs (47% vs 33%, p=.013). Additionally, patients undergoing SLR demonstrated higher rates of orthodontic transverse palatal expansion compared to the Furlow cohort (45.88% vs 30.19%, p=.002). Sub-analysis by cleft type demonstrated that this relationship was only maintained in Veau IV clefts and not in Veau I-III, where the repair technique did not influence rates of transverse palatal expansion. CONCLUSION: This data associates SLR with increased prevalence of maxillary narrowing and transverse palatal expansion, particularly in veau IV cleft phenotypes. A potential explanation is that the greater width of bilateral clefts may require more extensive dissection, contributing to increased scarring and transverse maxillary hypoplasia when completing straight line repair. When counseling patients and families on benefits of various repair techniques, Veau IV clefts should be advised that more extensive orthodontic interventions may be required with straight line repair techniques.

Maxillary Expansion and Its Effects on Circummaxillary Structures: A Review.

Transverse maxillary discrepancies are the most common. The narrowed upper arch is the most prevalent problem an orthodontist encounter while treating adolescent and adult patients.Maxillary expansion is a technique used to increase the upper arch's transverse dimension to apply forces to widen the upper arch. For young children, a narrow maxillary arch has to be corrected using orthopedic and orthodontic treatments. In an orthodontic treatment plan, it is crucial to update transverse maxillary defeat. There are various clinical manifestations associated with a transverse maxillary deficiency which include a narrow palate, crossbite mainly seen in posteriors (unilateral or bilateral), severe crowding in anterior teeth, and cone-shaped hypertrophy can be seen. Some frequently used therapies for constricted upper arch include slow maxillary expansion, rapid maxillary expansion, and surgically assisted rapid maxillary expansion. Slow maxillary expansion requires light and constant force, whereas rapid maxillary expansion needs heavy pressure for activation. The surgical-assisted rapid maxillary expansion has gradually become popular to correct transverse maxillary hypoplasia. The maxillary expansion has various consequences on the nasomaxillary complex. There are multiple effects of maxillary expansion on the nasomaxillary complex. Mainly, the effect is seen on the mid-palatine suture along with the palate, maxilla, mandible, temporomandibular joint, soft tissue, and anterior and posterior upper teeth. It also affects functions like speech and hearing. Information on maxillary expansion is provided in depth in the following review article, along with its various effects on the surrounding structure.

Three-Dimensional Analyses of Postoperative Effects of Surgically Assisted Rapid Palatal Expansion (SARPE) on the Soft Tissue of the Midface Region and the Upper Airway Space Using Stereophotogrammetry and Cone Beam Computed Tomography (CBCT).

Surgically assisted rapid palatal expansion (SARPE) is an established method to treat transverse maxillary hypoplasia in skeletally mature adult patients. SARPE affects the surrounding soft tissue. In addition, effects on the airway and breathing have been described. Aim of this study was to assess the effects of SARPE on the nasal soft tissue and the upper airway by means of three-dimensional stereophotogrammetry and cone beam computed tomography (CBCT). This retrospective study used preoperative and postoperative cone beam computed tomography (CBCT) scans and three-dimensional stereophotogrammetry. Ten skeletally adult patients (4 male, 6 female; mean age 27.68 years) with transverse maxillary hypoplasia were included. Patients had undergone SARPE procedure, performed by the same surgical team using the same technique. Nasal soft tissue changes were analyzed, using three-dimensional stereophotogrammetry records taken preoperatively (t0) and at the postoperative checkup appointment (t1). The upper airway was assessed using CBCT scans for surgical planning (t0) and the first scan taken after SARPE (t1). In stereophotogrammetry, it was shown that only a few soft tissue nasal parameters increased significantly and SARPE leads to mainly clinically irrelevant changes in nasal soft tissue. In CBCT, only a significant increase in nasopharyngeal airway volume was found. Results were in alignment with literature. The effects of SARPE on the nasal soft tissue are mostly statistically insignificant and clinically irrelevant. Airway volume significantly increased in the nasopharyngeal area. Further research on SARPE effects should be conducted to reinforce SARPE as a treatment option for sleep apnea patients.

Complications Following One-Stage Versus Two-Stage Surgical Treatment of Transverse Maxillary Hypoplasia

Contemporary literature suggests a similar transverse stability of a surgical-assisted rapid palatal expansion and a segmented Le Fort I osteotomy. The aim of this study was to compare postoperative complications of 1-stage (segmental maxillary osteotomy) and 2-stage (surgical-assisted rapid palatal expansion followed by Le Fort I osteotomy) treated patients to determine the preferred treatment strategy. This retrospective study included 74 consecutive patients (age range: 14 - 57years; 36 males, 38 females) with a moderate transverse maxillary hypoplasia: 32 patients were treated in a 1-stage protocol and 42 in a 2-stage protocol with a postoperative follow-up of at least 1year. Dental complications such as loss of teeth, gingival dehiscence, periodontal bone loss, apical root resorption, and surgical complications such as pain, hemorrhage, altered neurosensitivity, wound infection, aseptic necrosis were analyzed. Univariate analysis consisted of a generalized linear model with logit link or Fisher exact test. No significant difference was found for group characteristics except for longer orthodontic treatment time in the 2-stage group. Incidence and severity of complications were comparable for the 1-stage and 2-stage patients. Only overall pain was significantly greater in the 2-stage patient group (P=.038). Considering a similar complication rate and transversal stability, the choice between 1-stage and 2-stage approach for patients with a moderate transverse maxillary hypoplasia should be patient specific.

Dentofacial dysmorphoses : distant links with musculo-skeletal system and posture

According to several theories, the oro-facial sphere would be interconnected with the rest of the body justifying the requests for care to improve a body zone at a distance. The aim of this literature review was to look for potential distant links of dysmorphoses of the three dimensions of space according to the etiopathogenic theories and the data of science. We carried out a keyword search leading to 58 references. In the transverse dimension, the transverse maxillary hypoplasia and dissymmetry of the molar class of the transverse dimension would not induce a change in the distribution of the weight of the body on a stabilometric platform. In the vertical dimension, hyperdivergent patients have a decreased bite force, cephalic extension with respect to the spine, an extension of the base of the skull, and decreased cervical lordosis. In the anteroposterior dimension, skeletal classesII would be associated with increased cervical lordosis and posterior cephalic extension according to the «true vertical» (inversely for classes III). The prevalence of dental classes II would be increased in scoliosis subjects. Studies with a low level of evidence (grade III, IV or even V) should be interpreted with caution because the simultaneous presence of concomitant anomalies does not allow us to conclude that there is a cause-and-effect relationship.

Skeletal and dental effects of surgically assisted rapid palatal expansion: a systematic review of randomized controlled trials.

Surgically assisted rapid maxillary expansion (SARME) is a surgical technique developed to correct transverse discrepancies in skeletally mature patients. However, there is limited evidence concerning the immediate skeletal and dental changes obtained only due to SARME. The aim of the present systematic review is to investigate the immediate skeletal and dental effects of SARME in adult patients with transverse maxillary hypoplasia. An electronic search of the literature in MEDLINE, The Cochrane Library, Lilacs and Scopus databases was performed. Only randomized controlled trials (RCTs) studies investigating the skeletal and dental effects of SARME procedures in adult patients were included. The included studies received a methodological quality scoring according to the revised Cochrane risk-of-bias tool for randomized trials. The quality of evidence was assessed by means of the Grading Recommendation Assessment, Development and Evaluation (GRADE) system. For each included study and for each analysed parameter, the difference in means and 95 per cent confidence interval was calculated between baseline and immediate post-expansion. A meta-analysis of original outcome data, if possible, was conducted. Nine articles were selected. The methodological quality ratings indicated that one study was at low risk of bias, seven presented some concerns and only one was at high risk of bias. In all the included studies, the SARME procedure resulted in a significant expansion of the maxillary transverse dimension. The meta-analysis compared skeletal and dental inter-molar width before and after treatment: the mean difference was of 3.3 mm (2.8-3.9) and 7.0 mm (6.1-7.8), respectively (P-value less than 0.001). The quality of evidence was low-moderate. SARME is effective in obtaining a significant expansion of the maxillary transverse dimension. However, the immediate SARME effect is mainly a molar expansion rather than a pure bone transverse widening of the maxilla. The review protocol was registered at PROSPERO database with the registration number CRD42018117967.

Transversal Maxillary Distraction in Patients with Cleft Lip and Palate.

The aim of this study is to describe the importance of osteodistraction with transpalatal distractors for treating transversal maxillary hypoplasia in patients with cleft and lip palate. The participants were 17 patients (9 females and 8 males) with cleft lip and palate. Among these, 10 presented unilateral cleft lip and palate, 4 bilateral cleft lip and palate, and 3 cleft palate only. All patients experienced a satisfactory palatal expansion and crossbite correction. The mean lengthening was 12.7 mm. The average increase of intercanine distance, intermolar distance, maxillary transverse dimension (MTD), facial transverse dimension (FTD) was 12.16, 8.45, 1.77, and 1.67 mm, respectively. The clinical follow-up was 29.7 months (range: 6-61 months). Palatal distraction is a safe and successful alternative for treating maxillary transversal alterations in patients with cleft lip and palate. This technique facilitates the establishment of an adequate transverse dimension of maxillary, and consequently a proper dental occlusion.

Nasal soft- and hard-tissue changes following tooth-borne and hybrid surgically assisted rapid maxillary expansion: A randomized clinical cone-beam computed tomography study

PurposeThe aim of this study was to assess the effects of tooth/bone-borne (hybrid) and tooth-borne (TB) surgically assisted rapid maxillary expansion (SARME) on the width of the nasal soft and hard tissue. Patients and methodsTwenty skeletally mature patients (nine males and 11 females; mean age 19.4 years) with transverse maxillary hypoplasia were randomly assigned to hybrid or TB devices. The patients had undergone SARME operations, performed by the same surgical team using the same procedure (Le Fort I osteotomy with pterygomaxillary dysjunction, midline osteotomy, and no down-fracture). Nasal soft- and hard-tissue changes were analyzed using CBCT preoperatively (T0), at the end of the active expansion phase (T1), and after 6 months of retention (T2). The study was approved by the relevant ethics committee. ResultsThe skeletal and soft-tissue nasal parameters increased significantly in the T0–T1 and T0–T2 periods in both groups (P < 0.05). No statistically significant differences between the groups were observed. The mean piriform aperture width increased from 1.26 mm in T0–T1 to 0.97 mm in T1–T2 and 2.17 mm in T0–T2 (P < 0.008). In the soft tissue, the alar base width increased to 2.78 mm and the alar width to 2.95 mm in T0–T2 (P = 0.001). There was a positive correlation (63.6%) between the changes in skeletal and soft-tissue values. ConclusionThe hybrid and TB devices led to similarly significant widening effects in nasal soft and hard tissues in both the short term and 6 months after SARME.

An original approach of maxillary transversal deficiency with lingual orthodontics

The difficulty of management of a transverse maxillary hypoplasia is to choose the right treatment and the appropriate tools. When transverse maxillary insufficient is associated to sagittal and/or vertical discrepancies in adults, the gold standard treatment is a surgical procedure combined with orthodontic treatment. The surgical procedure can be done in 1 or 2 stages. If the patient chooses a lingual orthodontic technique, the tools for expansion and the stabilization of expansion are not simple to use. The aim of this article is to report the case of a 25-year-old male patient, referred to our cabinet for skeletal Class-III malocclusion associated with laterognathism and transverse maxillary deficiency. The patient underwent one-stage surgery. He choose to be treated by a lingual orthodontic technique, we used the FKS® disjunction device.

Assessment of the upper respiratory tract in patients eligible for treatment with transverse maxillary expansion

Transverse maxillary hypoplasia may negatively affect respiration. Maxillary narrowing has to be treated early. An appliance for Rapid Maxillary Expansion (RME) is the most common method, and it aims to expand the skeletal base and maintain this width until a new bone has been formed to fill in the fissure. Aim. Comparison of the results of measurements of bone structures and of the upper airways on lateral teleroentgenograms of the head in patients with transverse maxillary hypoplasia and in patients with normal dimensions of the maxilla. Material and methods. The study was carried out in a group of 20 people with maxillary narrowing (10 girls and 10 boys) aged 7 to 10 years. The control group consisted of 20 lateral teleroentgenograms of patients (9 girls and 11 boys) of similar age treated for other malocclusions. The structures of the facial skeleton and the upper respiratory tract were assessed in teleroentgenograms after earlier determination of measurement points and planes according to selected parameters of the McNamara and Preston et al. methodology. The obtained results were analysed statistically using the Mann-Whitney's test. Results. Angular measurements showed statistically significantly smaller SNA and SNB angles in the study group compared to the control group. The analysis of linear measurements indicated a statistically significant larger dimension of the actual length of the midfacial segment (Co-A) and distance between the Sella point and the posterior nasal spine (PNS-S), and a smaller dimension of the posterior facial height (PFH) in the study group compared to the control group. The highest differences in upper respiratory tract measurements were noted in the Ba-ho-PNS angle, which was lower in the study group. The result was not statistically significant. Conclusions. No significant differences in cephalometric measurements of the upper airways were observed. There is a need to extend studies to include groups of patients with features of night apnoea and maxillary narrowing. &lt;b&gt;(Dargiewicz E, Szarmach IJ, Sawczuk M. Assessment of the upper respiratory tract in patients eligible for treatment with transverse maxillary expansion. Orthod Forum 2018; 14: 97-105)&lt;/b&gt;

Bone-borne surgically assisted rapid maxillary expansion: A retrospective three-dimensional evaluation of the asymmetry in expansion

PurposeAsymmetrical expansion occurs in patients treated with Surgically Assisted Rapid Maxillary Expansion (SARME). In the clinical setting, this asymmetrical expansion is seen in multiple directions. However, the frequency, actual directions and amount of asymmetry are unclear. Hence, the aim of this study was to analyze the directions and amount of asymmetrical lateral expansion in non-syndromic patients with transversal maxillary hypoplasia on employing bone-borne transpalatal distraction by means of SARME. Treatment involved corticotomies of all four bony supports, including pterygomaxillary disjunction. Materials and methodsA retrospective case series was formed from patients treated with SARME. Pre- and postdistraction Cone Beam Computed Tomography scans were superimposed. A reference frame was created to analyze lateral expansion asymmetries in five directions. ResultsClinical relevant asymmetries (>3.0 mm) in at least one of the investigated directions occurred in 55% of the patients. Lateral expansion asymmetries occurred mostly in the inferior-anterior part between the left and right segment and asymmetry in total expansion was noted between the anterior and posterior part of the maxilla. ConclusionThis study confirms the clinical suspicion that using SARME with a bone-borne distractor and pterygomaxillary disjunction to treat non-syndromic patients with transversal maxillary hypoplasia, results in regular asymmetrical lateral expansion.

The effects of surgically assisted rapid maxillary expansion (SARME) on the dental show and chin projection

ObjectiveTo quantify the postoperative changes of the dental show and chin projection following SARME using 3D CBCT imaging. Material and methods78 patients with transversal maxillary hypoplasia and mandibular hypoplasia who underwent SARME were enrolled into the study. A cone beam computed tomography (CBCT) scan was acquired preoperatively and at least 1 year postoperatively. 3D postoperative changes in the dental show and pogonion position were measured based on soft tissue and hard tissue landmarks. Results68 patients (87%) exhibited a postoperative increase in the dental show. The dental show was increased by a mean of 2.2 ± 2.0 mm (p < 0.01). The mean horizontal and vertical displacement of the chin (pogonion) following SARME was 1.6 ± 2.5 mm posteriorly and 1.6 ± 2.0 mm inferiorly (p < 0.01). An inferior displacement of the maxilla and maxillary tooth as well as a consequent clockwise pitch of the mandible seemed to play a role in inducing these postoperative changes. ConclusionAn increase in dental show and a posterior and inferior displacement of the chin should be considered prior to SARME to prevent undesirable postoperative changes of the facial esthetics.

Soft, hard-tissues and pharyngeal airway volume changes following maxillomandibular transverse osteodistraction: Computed tomography and three-dimensional laser scanner evaluation.

Maxillomandibular transverse osteodistraction (MMTOD) is an alternative approach to the traditional treatment for transverse maxillary and mandibular deficiencies and crowding. The aim was to report soft and hard-tissues changes and airway volume variation. In this study, skeletally mature, non-syndromic patients with transverse maxillary and mandibular hypoplasia, who underwent a MMTOD between 2010 and 2012, were included. Surgical changes were analysed using clinical evaluation, three-dimensional facial surface data and computed tomography analysis before (T0) and after the completion of post-op orthodontic treatment (T1). Nineteen patients (eight males and eleven females; average age: 26.3 years) were enrolled. MMTOD produces facial changes in the cheek, paranasal areas, nasal base and chin. Facial changes are mostly explained by the underlying skeletal movements, which are essentially represented by the transverse enlargement of both the maxilla and the mandible. Following MMTOD, the airway volume and the lateral dimension of the cross-sectional airway increased significantly. MMTOD is a technique that allows an increase in airway volume and in both maxillary and mandibular arch perimeters simultaneously by increasing skeletal width. Facial appearance is improved and a stable occlusion is obtained.

Espansione rapida palatale chirurgicamente assistita versus osteotomia di Le Fort I multisegmentata

ObjectivesThe aim of this work is to present, by means of an international literature review, a complete overview of the main methods of surgical treatment in adult patients with contraction of the maxillary transverse diameters, in order to assess risks and benefits of each. Materials and methodsA systematic review of the international literature was conducted on MedLine database (www.ncbi.nlm.nih.gov/pubmed). The chosen keywords were: “surgical palatal expansion”; “rapid palatal expansion”; “Le Fort I osteotomy”; “crossbite”; “transverse maxillary hypoplasia”. ResultsIn adult patients, the definitive therapy consists of a surgical treatment for restoring a correct relationship between the maxillary and mandibular bones. The two main options are Surgically Assisted Rapid Palatal Expansion (SARPE) and multisegmental Le Fort I osteotomy. ConclusionsThe SARPE technique seems to be the ideal treatment for the correction of isolated transverse maxillary deficiencies, including severe cases, whereas the multisegmental Le Fort I osteotomy is useful to correct transverse deficiencies ≤ 7-8mm, if associated with alterations on sagittal and vertical planes, thus solving the whole malocclusion in a single surgical step.

Changes in transverse tooth and bone dimensions during transversal maxillary hypoplasia treatment by maxillary distraction osteogenesis using a device installed on a bone

Abstract Introduction A transverse maxillary hypoplasia is a deformation often observed in orthodontic patients. Various techniques are used to treat this problem. Aim The aim is to present results of transversal maxillary hypoplasia treatment with a bone-borne device. Material and methods A retrospective analysis included 27 patients, age 17–26 years (17 ± 2.6). Dental casts and X-ray were made before operation period (T1), and post distraction (T2). On the casts were determined points: on cusps of maxillary canines (3-3), first maxillary premolars (4-4) and first maxillary molars (6-6). Angles and distances were measured on standard posterior-anterior (PA) images. Results and discussion At the 3-3 level, the average expansion was 5.8 mm, at the 4-4 level the average expansion was 7.3 mm, at the level of 6-6 palatial cusps the average expansion was 6.11 mm. Measurements in the PA X-ray were performed at the nasal cavity, with the average dimensions being 29.03 mm before treatment, and 31.95 mm post-treatment. The angle was measured between first molars (6-6_ang) and the anterior nasal spine before and after treatment, with a significant change in that angle from 98.93° on average to 102.89° after distraction. Conclusions Use of maxillary distraction osteogenesis with bone-borne device in maxillary expansion is an effective treatment method. Maxillary expansion results in increase of the nasal cavity. Used distractor is easy to operate for the patient.

Rapid maxillary expansion on the permanent teeth versus the deciduous teeth: Comparison of skeletal and dentoalveolar effects by volumetric tomography

BackgroundThe aim of this study was to evaluate skeletal and dentoalveolar effects of rapid maxillary expansion (RME) on the permanent and deciduous teeth by means of volumetric tomography. MethodsThe sample included 12 patients with transverse maxillary hypoplasia (6 treated with RME on the permanent first molars, 6 treated with RME on the deciduous second molars) in the mixed-dentition phase. Beginning and postexpansion cone beam computed tomography images were compared for analysis of the skeletal and dentoalveolar effects of the two devices. ResultsRME treatment significantly increased the palatal volume in both groups (by 10.78% with RME on the permanent teeth vs. by 9.89% with RME on the deciduous teeth). Intermolar width increased for both skeletal and dental measurements. First upper molar tipping was greater on the first permanent molars when RME was anchored on the deciduous teeth than when anchored on the permanent teeth (4.02° vs 2.13°). Decompensation of the lower molars was greater in patients treated with RME on the permanent teeth than on the deciduous teeth (4.58° vs. 1.71°). ConclusionsRME treatment significantly increased palatal volume. RME anchored on the permanent teeth determined greater dental intermolar width variation and a significant difference in decompensation of the lower molars. RME anchored on the deciduous teeth was more effective in increasing skeletal intermolar width and inclination of the first molars.

Dental and Skeletal Effects of Two-Piece and Three-Piece Surgically Assisted Rapid Maxillary Expansion With Complete Mobilization: A Retrospective Cohort Study

The aim of this study was to examine the dental and skeletal widening effects of 2 surgically assisted rapid maxillary expansion (SARME) techniques after complete mobilization of the maxilla in patients with transverse maxillary hypoplasia and bilateral crossbite. A retrospective cohort study design was implemented evaluating 2 treatment groups with complete Le Fort I osteotomy and segmentation of the maxilla followed by distraction using a tooth-borne expansion device: patients without crowding of the incisor roots underwent 2-piece SARME and patients with crowding underwent 3-piece SARME. Linear transverse measurements were performed on dental casts (intercanine and inter-second molar distance) and posteroanterior cephalograms (skeletal jugulum distance) before surgery (T1) and at 6 weeks (T2), 6 months (T3), and 12 months (T4) postoperatively. The study included 24 patients (13 women and 11 men; mean age, 27 yr; standard deviation, 18.5 yr). Significant maxillary expansion was achieved by the 2 surgical techniques (P < .05), especially in the posterior portion. From T1 to T2, widening values (+3.8 mm) at the intercanine level in the 2-piece SARME group were significantly higher (P = .004) than those in the 3-piece SARME group. Distraction effects were mainly skeletal, whereas dental relapse tendencies predominated at T3 and T4. The 2 SARME methods ensured sufficient widening with satisfactory results after a 12-month period. To decrease surgical risks to the incisor roots and esthetic impairments, 3-piece SARME with complete mobilization is recommended in cases of transverse posterior maxillary hypoplasia and crowding of the incisor roots.

Minimally invasive surgically assisted rapid palatal expansion with limited approach under sedation: a report of 329 consecutive cases

Surgically assisted rapid palatal expansion consists of a surgical liberation of the sites of resistance combined using orthopaedic forces. Most technical descriptions advocate the use of general anaesthesia with hospital admission. We report a new technique sought to attain a balance between maximum mobilization of the maxilla and minimum morbidity that allows to carry out the surgery under sedation. Between March 2000 and December 2012, surgery was performed on 329 consecutive cases with transverse skeletal maxillary hypoplasia with local anesthesia plus sedation. The incision ran horizontally to reach the level of the laterals. Osteotomies of lateral walls and pterygoid disjunction were performed in all cases. A V–Y closure was performed in 2 layers. Patients were discharged after recovery from sedation. Mean age was 18.3 years. Mean surgical time from incision to last suture was 19 min. At the 1-year follow-up visit, mean expansion was 8.0 at the canines and 8.9 at the mesiovestibular cuspid of the first molar. The new technique that we report seeks to combine both aspects and allows for rapid intervention with local anesthesia plus sedation and a minimal approach with a total liberation of the maxillar. The minimal approach guarantee vascular support to the maxilla.

Volumetric changes of the nose and nasal airway 2 years after tooth‐borne and bone‐borne surgically assisted rapid maxillary expansion

This study aimed to assess the effects of bone-borne and tooth-borne surgically assisted rapid maxillary expansion on the volumes of the nose and nasal airway 2 yr after maxillary expansion. This prospective cohort study included 32 patients with transverse maxillary hypoplasia. Expansion was performed with a tooth-borne distractor (Hyrax) in 19 patients and with a bone-borne distractor [transpalatal distractor (TPD)] in the remaining 13. Cone beam computed tomography scans and three-dimensional (3D) photographs of the face were acquired before treatment and 22 ± 7 months later, and were used to evaluate the volumes of the nose and nasal airway. Nasal volume increased by 1.01 ± 1.6% in the Hyrax group and by 2.39 ± 2.4% in the TPD group. Nasal airway volume increased by 9.7 ± 5.6% in the Hyrax group and by 12.9 ± 12.7% in the TPD group. Changes in the nasal volume and in the nasal airway volume between the pre- and post-treatment measurements were statistically significant, whereas differences between the treatment groups were not; 22 months after surgically assisted rapid maxillary expansion, the increases in the nasal volume and in the nasal airway volume were comparable between tooth-borne and bone-borne devices.

Three-dimensional evaluation of soft tissue changes in the orofacial region after tooth-borne and bone-borne surgically assisted rapid maxillary expansion

This study seeks to three-dimensionally assess soft tissue changes in the orofacial region following tooth-borne and bone-borne surgically assisted rapid maxillary expansion (SARME). This prospective cohort study included 40 skeletally mature patients with transverse maxillary hypoplasia. A tooth-borne distractor (Hyrax) was used for expansion in 25 patients. In the remaining 15, a bone-borne distractor (transpalatal distractor, TPD) was used. Cone beam computed tomography (CBCT) scans were acquired before treatment (T0) and 22 months later (T1). 3D models were constructed from CBCT data and superimposed using voxel-based matching. Distance maps between the superimposed 3D models were computed to evaluate the degree of skeletal and soft tissue changes in the maxillary region. Distance maps showed negative distances (mean -1.25 (±1.5) mm) in the middle of the upper lip, indicating posterior repositioning of this area. The cheek region showed positive changes (mean 1.66 (±1.1) mm), reflecting the underlying increase in maxillary width. There was no significant difference between the two groups in all measured distances (p > 0.05). Retro-positioning of the upper lip accompanied skeletal remodeling in the anterior alveolar region at a mean ratio of 88 %, while the cheek region followed 32 % of the alveolar expansion. Soft tissue changes following SARME include posterior repositioning of the upper lip and increased projection of the cheek area. These changes were comparable between bone-borne and tooth-borne appliances. This study provides clinicians with more information over the expected orofacial soft tissue changes following SARME.