Novel Custom Maxillary Disimpaction Splint

PURPOSE: Facial transplantation has emerged as a viable option in treating devastating facial injuries. Despite the high healing rate of Le Fort I-II-III and bilateral sagittal split osteotomies (BSSO) in non-transplant patients (with reported non-union rates of 1.6% and 2.6%, respectively),[1,2] previous studies have reported nonunion between the allograft and the recipient’s bone at the area of maxillary and mandibular osteotomies. [3,4] This suboptimal bone healing remains unexplained and is still yet to be investigated. In this study, we present three patients that received facial transplantation at our institution with a focus on the healing of the mandibular and maxillary osteotomies after osteocutaneous face transplantation. METHOD: A retrospective chart review was conducted of facial allotransplantation patients at the Cleveland Clinic from December 2008 to inception. Demographics such as age, date of birth, and sex were recorded. Additional variables included procedures, revisions, reoperations, medications, and bone stability and healing. Computed tomography (CT) images assessed alignment of skeletal components, bony union quality, and stability of fixation. RESULTS: Three patients receiving facial allotransplantation at our institution were included in our study: two had Le Fort III segment transplantation, and one had transplantation of both a Le Fort III segment and mandibular BSSO. The Le Fort III segment in all three patients exhibited mobility and fibrous union at the Le Fort III osteotomy on CT. In contrast, the BSSO healed uneventfully after transplantation and revision surgery, with bony union confirmed by both CT and histology of the fixation area between the donor and recipient mandible bilaterally. No patients with midfacial fibrous union required revision of the nonunion as they were clinically asymptomatic. CONCLUSION: Le Fort osteotomies demonstrated inferior healing in patients undergoing facial transplantation compared to Le Fort osteotomies in patients treated for malocclusion. Interestingly, the mandible healed uneventfully after facial transplantation, likely due to the amount of rich cancellous bone in the mandible. This similarly reflects bone healing rates in patients undergoing mandibular surgery for correction of malocclusion or hand transplantation at the level of the humerus, radius, and ulna. Nonunion of the midface does not require revision unless the patient is clinically symptomatic. REFERENCES: 1. Imholz B, Richter M, Dojcinovic I, and Hugentobler M, Non-union of the maxilla: a rare complication after Le Fort I osteotomy. Revue de stomatologie et de chirurgie maxillo-faciale. 2010; 111(5-6): p. 270-275. 2. Chin M and Toth BA, Le Fort III advancement with gradual distraction using internal devices. Plast Reconstr Surg. 1997; 100(4): p. 819-30; discussion 831-2. 3. Lantieri L, Grimbert P, Ortonne N, et al., Face transplant: long-term follow-up and results of a prospective open study. Lancet. 2016; 388(10052): p. 1398-1407. 4. Goutard M, Lellouch AG, Dussol B, and Lantieri LA, Facial Trauma 8 years after a Face Transplantation. Plast Reconstr Surg Glob Open. 2021; 9(5): p. e3575.

To investigate the difference in labial and palatal alveolar bone thickness and height during the retention period after incisor retraction treatment with microimplant. A sample of 21 patients (mean age: 17.80 ± 4.38 years) who underwent incisor retraction treatment using microimplants after premolar extraction was investigated. The cone-beam computed tomography images at pretreatment, posttreatment, and retention were used to measure anterior alveolar bone thickness (labial, palatal, and total; at three vertical levels) and height (labial and palatal) and differences in the incisor position during treatment or retention. Repeated-measures analysis of variance with Bonferroni correction was performed to compare the variables at T0, T1, and T2. The maxillary central incisor moved posteriorly by approximately 8.0 mm along with intrusive movement of 1.8 mm after treatment. The alveolar bone thickness significantly decreased on the palatal side and increased on the labial side after treatment. Thereafter, the palatal bone thickness significantly increased and labial bone thickness decreased during the retention period. The palatal interdental bone depressed by incisor retraction showed substantial bone deposition after retention. Radiographic palatal bone dehiscences on the incisor root and palatal bone depression between the incisor roots were apparent after treatment. This palatal bone loss around the incisor roots noticeably recovered with newly formed bone during retention.

ObjectivesThis study aimed to assess the correlation of body mass index (BMI) and alveolar bone dimensions in the maxilla using cone-beam computed tomography (CBCT).Materials and methodsThis retrospective, cross-sectional study evaluated 40 patients presenting to the Radiology Department of School of Dentistry, Islamic Azad University of Tehran during 2017–2019 who required CBCT scans of the maxilla for purposes not related to this study. The patients were divided into two groups (n = 20) with BMI ≥ 25 and 18 < BMI < 25. The maxillary alveolar bone height, and the buccal and palatal cortical bone thickness at 4 and 7 mm from the alveolar crest were measured on CBCT scans and compared between the two groups using pairwise correlation coefficient and independent t-test. Datawere analyzed using pairwise correlation coefficient and independent t-test via SPSS version 20.ResultsThe two groups were not significantly different regarding age or gender (P > 0.05). The buccal and palatal cortical bone thickness across all measured sites was significantly greater in patients with higher BMI. BMI had no significant correlation with alveolar bone height (P > 0.05). BMI had a positive correlation with buccal and palatal cortical bone thickness at the site of all teeth except for the palatal bone thickness at the site of first molar at 7 mm distance from the crest.ConclusionPatients with higher BMI showed higher buccal and palatal cortical bone thickness in the maxilla (except for one area) than patients with normal BMI. The buccal and palatal cortical bone thickness at the interdental areas was greater in patients with higher BMI. However, the alveolar bone height was not significantly different between the two groups.

Transverse skeletal and dentoalveolar changes during growth

Maxillary bone characteristics between thick and thin gingival biotypes with dentoalveolar protrusion

To evaluate the related factors for alveolar bone changes surrounding maxillary central incisors in extraction cases with clear aligner therapy, including tooth displacement and movement pattern. A total of 94 patients were included. Pre-treatment (T0) and post treatment (T1) cone beam computed tomography was obtained to calculate tooth displacement and labial bone thickness (LBT), palatal bone thickness (PBT), labial bone height (LBH) and palatal bone height (PBH) at different root levels. Paired-t test and Wilcoxon signed-rank test were performed to compare tooth movement and bone changes between T0 and T1. The two-sided Welch's t-test and Mann-Whitney U test were applied for comparison between movement patterns. Multiple linear regression with backward elimination was used to investigate possible factors related to bone changes. Defect of palatal bone was significant, while labial bone basically maintained. Different bone dimensional changes were found between uncontrolled tipping and controlled tipping. Tooth retraction was associated with the decrease of PBT and the increase of LBT. Crown retraction was a dominant factor related to the reduction of PBH. Incisor intrusion resulted in the increase of PBT, the decrease of LBT and the bone defect of both LBH and PBH. Root distal movement was associated with the resorption of LBT and LBH. Lingual inclination was evidently related to LBT loss. Three-dimensional tooth displacements and movement pattern acted as risk factors for maxillary anterior bone changes after retraction. Treatment planning deign should be aware of predicted tooth movement, preventing alveolar bone defect. Clinical Study Registration Number: HGGC-227.

To assess arch width, palatal surface area, and volume in surgically treated unilateral cleft lip and palate (UCLP) in mixed dentition children in comparison with non-cleft lip and palate (NCLP) children using a 3D laser scanning. 38 subjects (Caucasian origin), 5.63-11.9 years of age (mean, 9.33 ± 1.67 years), were included. 19 in each group (UCLP and NCLP). Digital dental casts were obtained using a 3 Shape R700 laser scanner. Intercanine and intermolar widths (cusp and gingival levels), palatal surface area and volume were measured. An independent sample Student's t-test and an ANOVA were undertaken with significance level set as P < 0.05. Intercanine widths at the cusp (5.60 mm; P < 0.001) and at the gingival level (3.11 mm; P = 0.014), palatal area (141.5 mm2; P = 0.009) and volume (890.7 mm3; P = 0.029) were significantly lower in the UCLP compared to the control group. A smaller part of the subjects was in late mixed dentition phase. To overcome this limitation a matched control group was used. In seven subjects with UCLP, some teeth were missing, which might have had an influence on the dental measurements. However, these subjects could not be excluded because eliminating more severely affected subjects, would have introduced bias. Three-dimensional evaluation of the maxillary arch and palate highlighted significant differences between UCLP and non-UCLP subjects in mixed dentition phase, suggesting that orthopaedic maxillary expansion is advisable in UCLP.

A narrowed maxillary dental arch can be treated by laterally expanding either the maxillary arch or maxillary bone with a RME appliance. But, the effects of RME on maxillary and mandibular dental arches, palatal morphology, and oral function have not been sufficiently clarified. Therefore, to investigate if differences in palatal morphology affect changes brought about by maxillary expansion, we examined post-expansion changes in maxillary and mandibular dental arches and palatal morphology. We also examined the direction of the width of mastication pathway and tongue elevation pressure. The study was composed of 12 pediatric patients; they were treated using a rapid maxillary expansion appliance. Maxillary and mandibular dental models, width of mastication pathway, and tongue elevation pressure were taken at T1, T2, and T3 ; lateral cephalograms were also taken at T1. Dental model measurement results indicated greater palatal width and lower palatal height in G1 than those in G2. Lateral cephalograms indicated significant differences between G1 and G2 for the gonial angle, Frankfort mandibular plane angle, lower facial height, and occlusal plane. The above findings revealed that the rapid expansion stage for RME varies according to palatal morphology: in patients with rectangular dental arches, expansion occurred mainly in the palatal base area,whereas in patients with high palates, expansion occurred mainly in the shallow palatal areas. In addition, we found that width of mastication pathway, tongue elevation pressure,lower molar dental arch width, and lower tooth bucco-lingual inclination increased in patients with rectangular dental arches.

Maxillary anterior gingiva and dentoalveolar changes after en-masse retraction between thick and thin gingival biotypes

The purpose of this communication is to explore in detail the developmental anatomy of the soft palate, its pathologies, and strategies for management. Despite the voluminous literature regarding complete cleft palate in its usual presentation, little attention has been paid to the biology of the isolated soft palate cleft. It exists as a spectrum, ranging in severity from the submucous variant, with nothing notable save a groove and a palpable defect of the posterior spine, all the way to a complete disruption of the soft tissue envelope and the horizontal palatine shelves. All these presentations are but variations of common pathology. Much can be gained from a disciplined examination of these. Our discussion includes two parts. The first part is on the embryologic events that generate the mesenchymal building blocks from which the posterior palate is constructed: palatine bone, oral and nasal mucosa, palatine aponeurosis, and muscle slings. Palate structures develop from neural crest and mesoderm; these tissues originate at specific sites along the axis of the embryo and they can be mapped according to the developmental units of the central nervous system (CNS) from which they are innervated. These units, called neuromeres, are specific zones within the neural tube, the boundaries of which are established by the expression pattern of homeotic genes. The forebrain (prosencephalon) has telencephalon and 3 prosomeres, the midbrain (mesencephalon) has 1-2 mesomeres, and the hindbrain (rhombencephalon) has 12 rhombomeres. Each neuromere has a specific neuroanatomic content and is hardwired to specific tissues outside the brain. We next consider a model of the palate which is analogous to a pinball machine that consists of a platform (bone) and mobile “flippers” or lever arms (the velum). In this study, the osseous platform is discussed in detail with neural crest bones being coded by the sensory innervation of their surrounding soft-tissue envelope. Maxilla, palatine bone, and vomers are all derivatives of hindbrain neural crest arising from rhombomere 2 but distributed according to various neurovascular pedicles of the V2 stapedial system, the anatomy of which will be explained in detail. Next, the evolution of palate will be presented as a series of innovations favoring increased metabolic capacity. A final appendix presents a functional classification of cranial nerves which I have endeavored to make straightforward. This will prove useful when reading the second part of this manuscript having to do with the neuromuscular apparatus of the soft palate.

Objective: To investigate the sagittal root position and apical bone height of the maxillary anterior teeth in order to provide anatomical information for immediate implant placement in the esthetic region. Methods: Cone-beam CT (CBCT) data from 300 randomly selected patients who met the inclusion criteria were included in this study. After three-dimensional reconstruction, the sagittal plane (the sagittal plane through the long axis of the tooth) was determined. The positions and angulations of the tooth roots were classified with reference to the alveolar process. By comparing the buccal and palatal bone thickness at the mid-root level, the toot positions with reference to the mid-alveolar line were defined and classified as follows, type B (closer to the buccal alveolar surface), type M (midway between the buccal and palatal alveolar surface) and type P (closer to the palatal alveolar surface). By comparing the angulations of the alveolar process with the long axis of the roots, the angulations were classified as follows, type 1 (root apex angulated toward the palatal side or parallel to the alveolus), type 2 (root apex angulated toward the buccal side with the long axis passing posterior to point A) and type 3 (root apex angulated toward the buccal side with the long axis passing anterior to point A). The frequency of each category was counted and the apical bone height was measured. The subjects were divided into three age groups, 19-30 years, 31-50 years and 51-75 years. Results: The overall mean apical bone height of the healthy maxillary central incisors was (9.2±3.0) mm, the lateral incisors was (10.0±2.9) mm and the canine was (8.1±3.1) mm. There was no significant difference in the height of apical bone between central incisors and lateral incisors (P>0.05). There was no significant difference in the height of apical bone between male and female (P>0.05). The height of apical bone in group 31-50 years and 51-75 years were greater than that in group 19-30 years (P<0.05), respectively. The proportion of the maxillary anterior teeth type B, M, P was 98.5% (1 774/1 800), 0.3% (5/1 800) and 1.2% (21/1 800) respectively. The proportion of type 1, 2, 3 was 2.6% (46/1 800), 58.6% (1 055/1 800) and 38.8% (699/1 800) respectively. Conclusions: There was enough apical bone height in the area of maxillary anterior teeth, but the majority of roots positioned more buccally.

Palatal displacement of maxillary anterior teeth is common in clinical practice. Previous studies have reported that the labial bone around palatally-displaced incisors is thinner than that around normally-placed teeth. Therefore, it is necessary to elucidate alveolar bone changes after alignment to guide orthodontic treatment. In this study, we investigated the alveolar bone changes around palatally-displaced maxillary lateral incisors before and after treatment, and the effects of extraction and age using cone-beam computed tomography. In this retrospective study, 55 patients with unilateral palatally-displaced maxillary lateral incisors were included. Three-dimensional alveolar bone changes were measured at three levels (25%, 50% and 75% of the root length) using cone-beam computed tomography. Group comparisons were made between displaced and control teeth, extraction and non-extraction groups, and adult and minor groups. After orthodontic treatment, labiopalatal and palatal alveolar bone widths decreased at all measured levels. Labial alveolar bone width increased significantly at P25, but decreased at P75. Concavity decreased, while tooth-axis angle, tooth length, B-CEJ and P-CEJ increased. Changes in LB and LP at P75, B-CEJ and P-CEJ were statistically significant. After treatment, the tooth-axis angle on the PD side increased by 9.46°. The change in tooth-axis angle on the PD side was significantly smaller, and LB and LP decreased more at P75, in the extraction group. Compared to the control teeth, alveolar bone thickness and height for the displaced teeth decreased more significantly after treatment. Tooth extraction and age also influenced alveolar bone changes.

The aim of this paper is to ascertain the quantitative measurements of alveolar bone thickness at all maxillary anterior teeth and qualitatively demonstrate the relationship between tooth angulation (TA) and alveolar bone thickness. Cone-beam computed tomography (CBCT) images of 189 maxillary anterior teeth were collected. Sagittal view was selected to perform the measurement on alveolar bone wall at crestal, midlevel, and palatal. TA was measured along to the tooth long axis (TLA) related to the alveolar bone housing. Spearman's correlation coefficients were conducted to test the correlation between the variables. The facial alveolar bone (FAB) is predominantly thin (<1 mm) at the crestal and midroot region. A significant difference was recorded in the median thickness of FAB at the midroot and apical area (p = 0.001, p = 0.021). The FAB thickness was not gradual with midroot being thinner than crestal. For the palatal alveolar bone (PAB), the thickness was increased continuously toward the apex. At all apical levels of inspected teeth, a significant negative correlation existed between TA and FAB. A positive correlation of TA was only significant at the facial crest of lateral incisor (r = 0.308). However, the canines did not correlate with the FAB, but correlated with the PAB at the apical level (r = 0.478). The FAB wall crest of maxillary anterior teeth was generally thin and not gradual with the lateral incisor being the thinnest. A significant correlation of TA existed based on different types of maxillary anterior teeth and alveolar bone level. The maxillary anterior teeth with increased buccolingual angulation were correlated with thicker bone at the apical level. The quantitative assessment of FAB and TA in degree may serve as an anatomical index for ideal implant position.

To investigate three-dimensional (3D) morphologic changes in the alveolar bone around the maxillary central incisors of patients who underwent premolar extraction and subsequent anterior tooth retraction using temporary anchorage devices (TADs). The subjects consisted of 16 patients with bimaxillary protrusion. The maxillary anterior teeth were retracted using sliding or loop mechanics and TADs for anchorage reinforcement. Cephalograms and computed tomography scans taken pretreatment and posttreatment were registered with respect to the palatal structures. The movement of the maxillary central incisors and morphologic changes in the anterior alveolar bone were evaluated quantitatively. Displacement in the palatal direction was observed in the alveolar bone around the incisors and the interdental septum. The displacement and bone remodeling/tooth movement ratio were larger on the labial side than the palatal side, and decreased progressively from the crest to apex level. The bone thickness was significantly increased on the labial side and decreased on the palatal side. Regional differences exist in morphologic changes of the alveolar bone during anterior tooth retraction using TADs. Attention should be paid to the crest region of the palatal alveolar bone because of its small original thickness and low remodeling activity.

Aim of the study Maxillary transverse deficiency (MTD) significantly impacts oral function, facial aesthetics, and respiratory health. Treatment modalities range from non-invasive skeletal expansion techniques to complex orthognathic surgery. This study aimed to compare the clinical effectiveness of three distinct approaches—Maxillary Skeletal Expander (MSE), Surgically Assisted Rapid Palatal Expansion (SARPE), and segmented Le Fort I osteotomy (LFT)—in adult patients diagnosed with MTD. The null hypothesis was that no significant difference exists between these treatment strategies. Materials and methods A total of 30 adult patients diagnosed with MTD were allocated into three treatment groups (MSE, SRP, and LFT). Pre- and post-treatment evaluations included clinical examination, cone-beam computed tomography (CBCT), and psychological assessment. Primary outcome measures were interpremolar distance, distance between palatal root apices of molars, and nasal airway volume. Data were analyzed using one-way ANOVA and Tukey post-hoc tests at a significance level of p 0.05. Results Statistically significant increases in interpremolar width, root apex distance, and nasal airway volume were observed in all groups post-treatment (p 0.001). The LFT group showed the highest skeletal and airway improvements, followed closely by the SRP group. The MSE technique yielded more limited changes, primarily within the alveolar process. Patient-reported discomfort was lowest in the MSE group and highest in the LFT group. Conclusions All three techniques improved transverse maxillary dimensions, but their effectiveness varied with case severity. LFT remains the most effective for severe cases, while SRP and MSE are appropriate for moderate and mild forms, respectively. Individualized treatment planning, combined with long-term retention strategies, is critical for sustained outcomes.