Biomechanical behavior of three maxillary expanders in cleft lip and palate: a finite element study.

This study evaluated the stress distribution in the dentoalveolar and palatal bone structures during maxillary expansion in a 17-year-old male patient with bilateral cleft lip and palate (BCLP) using expanders with dental (HYRAX) and skeletal anchorage (MARPE). For the generation of the specific finite element models, cone-beam computed tomography was used, and the DICOM files were exported to Mimics 3-Matic (Materialise) and Patran (MSC Software) software. Three specific three-dimensional models were generated: A) HYRAX: conventional four-banded hyrax screw (9 mm); B) MARPE-DS: 3 miniscrews (1.8 mm diameter - 5.4 mm length) and four-banded dental anchorage; and C) MARPE-NoDS: 3 miniscrews without dental anchorage. Maxillary expansion was simulated by activating the expanders transversely 1 mm on the "X" axis. HYRAX resulted in higher levels of deformation predominantly in the dentoalveolar region. MARPE-DS showed stress in the dentoalveolar region and mainly in the center of the palatal region, at approximately 4,000 µÎµ. MARPE-NoDS exhibited evident stress only in the palatal region. High stress levels in the root anchoring teeth were observed for HYRAX and MARPE-DS. In contrast, MARPE-NoDS cause stress on the tooth structure. The stress distribution from the expanders used in the BLCP showed asymmetric expansive behavior. During the initial activation phase of expansion, the HYRAX and MARPE-DS models produced similarly high strain at the dentoalveolar structures and upper posterior teeth displacement. The MARPE-NoDS model showed restricted strain on the palate.

Long-term skeletodental changes with early and late treatment using modified C-palatal plates in hyperdivergent Class II adolescents.

OBJECTIVES: To compare skeletodental changes between early and late treatment groups using modified C-palatal plates (MCPP) and long-term retention outcomes in hyperdivergent Class II adolescents. MATERIALS AND METHODS: Seventy-one hyperdivergent Class II patients were divided into four groups according to treatment modality and treatment timing: group 1, early treatment with MCPP (n = 16; 9.9 ± 0.9 years); group 2, late treatment with MCPP (n = 19; 12.3 ± 0.8 years); group 3, early treatment with headgear (HG; n = 18; 9.6 ± 0.8 years); and group 4, late treatment with HG (n = 18; 12.1 ± 1.2 years). Lateral cephalograms were taken and skeletal and dental variables were measured. For statistical analysis, paired t-tests, independent t-tests, and multiple regression were performed. RESULTS: The early MCPP group showed a more significant decrease in mandibular plane angle than the late MCPP group did, and vertical control was more efficient in the early group than in the late group. In the MCPP groups, both FMA and SN-GoGn were increased with late treatment but decreased with early treatment, and the difference was statistically significant (P < .01). The early-treatment MCPP group had a significant decrease in SN-GoGn of 0.6° compared with an increase of 1.7° in the early treatment HG group (P < .01). Posttreatment stability of both the early and late MCPP groups was maintained in long-term retention. CONCLUSIONS: Early MCPP showed more significant vertical control than late MCPP. However, there was no difference in long-term stability between early and late groups.

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition.

Since the introduction of Invisalign by Align Technology, Inc. in 1999, questions and debates have persisted regarding the precision of Invisalign (clear aligner) therapy, particularly when compared to the use of traditional fixed appliances. This becomes particularly significant in cases involving anteroposterior, vertical, and transverse corrections, where precise comparisons are of paramount importance. To address these inquiries, this study introduces a meticulously devised protocol, placing a primary emphasis on digitally superimposing the movement of maxillary posterior teeth to facilitate accurate analysis. The sample included 25 patients who had completed their first series of Invisalign (clear) aligners. Four maxillary digital models (pre-treatment, post-treatment, ClinCheck-initial, and final models) were digitally superimposed using the palate rugae and dentitions as stable references. A software combination was used for model superimposition and tooth segmentation. Transformation matrices then expressed the differences between the achieved and predicted tooth positions. Thresholds for clinically relevant differences were at ±0.25 mm for linear displacement and ±2° for rotation. Differences were assessed using Hotelling's T-squared tests with Bonferroni correction. The mean differences in rotation (2.036° ± 4.217°) and torque (-2.913° ± 3.263°) were significant statistically and clinically, with p-values of 0.023 and 0.0003 respectively. De-rotation of premolars and torque control for all posterior teeth were less predictable. All mean differences for the linear measurements were statistically and clinically insignificant, except that the first molars seemed slightly (0.256 mm) more intruded than their predicted position. The clear aligner system appears to meet its prediction for most translational tooth movements and mesial-distal tipping in maxillary posterior teeth for non-extraction cases with mild to moderate malocclusions.

Influence of alveolar bone thickness and bucco-palatal inclination on root resorption of lateral incisors in unilateral maxillary impacted canines: a retrospective observational study.

BACKGROUND: This study aimed to investigate the potential associations between alveolar bone thickness, bucco-palatal inclination of maxillary lateral incisors, and lateral incisor root resorption in patients with unilateral maxillary impacted canines (UMICs). METHODS: A total of three hundred and five subjects (120 males, 185 females; mean age, 16.39 years; standard deviation, 4.04) with UMICs were included. Canine position and root resorption were assessed using CBCT. UMICs were divided into palatal, buccal and mid-alveolus groups (PICs, BICs and MAICs), with 117, 137 and 51 subjects, respectively. Alveolar bone thickness and bucco-palatal inclination of lateral incisors were measured using the Dolphin software. RESULTS: The prevalence of lateral incisor root resorption was significantly lower in the BICs (13.9%) than MAICs (29.4%) and PICs (29.1%). Alveolar bone thickness of the apical area was smaller in UMICs with lateral incisor root resorption than no resorption in both PICs (8.33 ± 1.64 vs 10.53 ± 2.55 mm) and BICs (8.94 ± 1.85 vs 10.76 ± 2.28 mm). Furthermore, lateral incisors on the impacted side were more buccally inclined in PICs with lateral incisor root resorption than no resorption, while in both BICs and MAICs, there was no statistical difference between lateral incisor root resorption than no resorption. Moreover, alveolar bone thickness of the apical area, rather than bucco-palatal inclination of lateral incisors, was significantly correlated with lateral incisor root resorption both in PICs and BICs. CONCLUSIONS: Lateral incisor root resorption is less common in BICs. Thinner alveolar bone thickness at the apical area of lateral incisors can be considered as a potential risk factor for lateral incisor root resorption in UMICs.

Unconventional use of Invisalign® in the treatment of ectopic palatal maxillary canines.

BACKGROUND: The proper development of the dental arches, including the eruption and correct positioning of the canines in the arch, is essential for the oral health of growing patients. Impacted canines not only give rise to functional challenges but also pose esthetic issues for patients. The aim of this article is to show if it is possible to benefit from the exclusive use of transparent aligners to guide the eruption of ectopic upper canines into the arch in the correct position. CASE REPORT: The subject of the study is the clinical case of a 13-year-old female growing patient who presented displaced upper permanent canines located in the palatal ectopic site. Following the surgical extraction of the retained deciduous elements, treatment with aligners for repositioning the ectopic canines in the arch was performed in two phases. At the end of the treatment, a Class I canine was achieved with satisfactory repositioning of the upper canines in the arch. CONCLUSION: The use of transparent aligners makes it possible, with some procedural precautions and in carefully selected cases, to reposition the ectopic palatal canines in the dental arch using a treatment that is both esthetic and effective.

Clinical behavior of recurrent pleomorphic adenoma in the palate: a systematic review.

PURPOSE: This systematic review analyzed the clinical behavior and odds of malignancy of the palatal recurrent pleomorphic adenomas. METHODS: Systematic review of patients with recurrent pleomorphic adenoma arising in the palate. Database search: MEDLINE, Scopus, Web of Science, Cochrane, EMBASE, Virtual Health Library, Google Scholar, and OpenGrey. A binomial logistic regression was performed to assess the odds of detecting recurrence five, 10 and 20 years after the treatment of primary tumor. RESULTS: Thirteen studies (n = 18 patients) out of 336 were included. The recurrent pleomorphic adenoma in palate was more common in females (61.6%), average age was 49 years old (range 9-73 years old). Four patients progressed to malignant transformation. The odds ratio (OR) of detecting a recurrence at 10 (OR = 5.57; 95% confidence interval - 95%CI 1.13-27.52), and 20 years (OR = 18.78; 95%CI 3.18-110.84) after treatment of primary pleomorphic adenoma was significantly higher than at one-year follow-up. CONCLUSIONS: The recurrence of pleomorphic adenoma in palate remains a rare event of late occurrence. It mainly affects middle-aged female and carries a risk of malignant transformation. Although uncommon, patients with palatal pleomorphic adenoma should be warned about the possibility of recurrence or malignant transformation of tumor at advanced ages.

Dentoskeletal effects of mini-screw assisted, non-surgical palatal expansion in adults using a modified force-controlled polycyclic protocol: a single-centre retrospective study.

OBJECTIVES: This study assessed the dental and skeletal effects of pure bone-borne, non-surgical maxillary expansion, using a modified force-controlled polycyclic protocol. METHODS: Records of 17 adult patients, mean age 24.1 years; range 18-39 years, who had undergone maxillary expansion using a bone-borne Quad-expander (with 4 mini-screws), were analysed. In all patients, 0.17 mm/day of expansion was completed for 1 week, followed by a cyclic protocol of expansion of forward and backward turns until the force needed to turn the expander was below 400 cN, assessed weekly. After this, expansion continued at a rate of 0.17 mm/day until the desired amount of expansion was achieved. Cone beam computer tomography scans were taken pre- and post-expansion. RESULTS: The mid-palatal suture was successfully opened in 100% of patients included in this study. Axially, the amount of skeletal opening at the posterior nasal spine was 61% of the anterior nasal spine. Expansion was pyramidal in the coronal plane. Significant increases at the dental and skeletal levels were achieved, with changes at the skeletal level reaching 73%. The alveolar bone angle increased more than the angular changes at the molars and premolars. LIMITATIONS: This is a retrospective study with short-term results. CONCLUSION: The Quad-expander, with a force-controlled polycyclic expansion protocol, effectively produced a significant increase in maxillary width in skeletally mature subjects in the short term.

Assessing the fate and contribution of Foxd1-expressing embryonic precursors and their progeny in palatal development, homeostasis and excisional repair.

Oral mucosal tissues heal rapidly with minimal scarring, although palatal mucosa can be associated with excessive fibrosis in response to injury. Investigations on the balance between neovascularization and tissue repair suggests regulation of angiogenesis is an important determinant of repair versus scarring. Associated with pericyte mediated fibrosis in kidney injury, FoxD1 is implicated in growth centres during cranio-facial development, although which cell lineages are derived from these embryonic populations in development and in adult animals is unknown. Using a lineage tracing approach, we assessed the fate of embryonic Foxd1-expressing progenitor cells and their progeny in palatal development and during wound healing in adult mice. During palatal development as well as in post-natal tissues, Foxd1-lineage progeny were associated with the vasculature and the epineurium. Post-injury, de novo expression of FoxD1 was not detectable, although Foxd1-lineage progeny expanded while exhibiting low association with the fibroblast/myofibroblast markers PDGFα, PDGFß, vimentin, α-smooth muscle actin, as well as the neuronal associated markers S100ß and p75NTR. Foxd1-lineage progeny were primarily associated with CD146, CD31, and to a lesser extent CD105, remaining in close proximity to developing neovascular structures. Our findings demonstrate that FoxD1 derived cells are predominantly associated with the palatal vasculature and provide strong evidence that FoxD1 derived cells do not give rise to populations involved directly in the scarring of the palate.

Clinical comparative study on the accuracy of palatal rugae in models obtained by different impression materials and intraoral scanning.

OBJECTIVE: Palatal rugae are frequently used in the evaluation of tooth movement after treatment in orthodontics and as a stable region in superimposition. It is important to note that the impression method and material used to record the rugae region affect the accuracy of the impression. The aim of this study is to compare the accuracy of palatal rugae, in three-dimensional (3D) by employing both conventional and digital impression methods. MATERIALS AND METHODS: In this study, 22 patients (12 females, 10 males) mean age of 13.5 ± 1.7 years old were selected with complete permanent dentition. Three different impressions were taken from the maxillae of the patients: conventional impression using silicone rubber impression material, conventional impression using alginate impression material, and optical impression using an intraoral scanner. The impressions' digital data were analyzed by the GOM Inspect (Version 2018, Braunschweig, Germany), a 3D analysis software. The Root Mean Square (RMS) values of the total ruga region were evaluated in this software. The data were statistically analyzed using the Jamovi program. The Kruskal-Wallis test and Mann-Whitney U test were performed due to the non-normal distribution of the data. RESULTS: There is no statistically significant difference between the comparison points of the right and left rugae's medial and lateral points and total rugae regions' RMS values. Although there was no statistically significant difference, the total RMS values of alginate and digital scan measurements showed closer results than the RMS values of silicone and digital scan measurements. CONCLUSION: The study found that there was no statistically significant difference in the total RMS values of the ruga region between traditional and digital impression methods. CLINICAL RELEVANCE: The treatment period in orthodontics is long. Different impression materials and methods can be used for diagnostic, mid-treatment, and final impressions. For superimpositions and treatment and post-treatment palatal ruga evaluations, traditional and digital impression methods are clinically acceptable and can be used as alternatives to each other.

Anterolateral advancement pharyngoplasty versus barbed reposition pharyngoplasty in patients with obstructive sleep apnea.

OBJECTIVES: To compare functional outcomes and complication rates of anterolateral advancement pharyngoplasty (ALA) versus barbed reposition pharyngoplasty (BRP) in the treatment of obstructive sleep apnea patients with palatal and lateral pharyngeal wall collapse. STUDY DESIGN: Prospective study. SETTING: University hospitals. SUBJECTS AND METHODS: Forty-six patients were included in this study. Patients were divided into two groups randomly, group 1 (23 cases) underwent anterolateral advancement pharyngoplasty and group 2 (23 cases) underwent barbed relocation pharyngoplasty. According to the following criteria: both sex, age between 18 and 65 years, body mass index ≤ 32 kg/m2, Friedman stage II or III, type I Fujita, nocturnal polysomnography study diagnostic for OSA, retropalatal and lateral pharyngeal wall collapse, diagnosis with flexible nasoendoscopy during a Muller's maneuver based on a 5-point scale and drug-induced sleep endoscopy. Patients who suffered from retroglossal airway collapse were rolled out. RESULTS: Apnea-hypopnea index decreased from 27.50 ± 11.56 to 11.22 ± 7.63 (P ≤ .001) in group 1 and from 33.18 ± 10.94 to 12.38 ± 6.77 (P ≤ .001) in group 2. Retropalatal posterior airway space increased from 9.84 ± 1.29 mm to 21.48 ± 2.8 mm (P ≤ .001) in group 1 and increased from 10.26 ± 1.2 mm to 22.86 ± 2.62 mm (P ≤ .001) in group 2. Retropalatal space volume increased from 1.9 ± 0.68 cm3 to 2.75 ± 0.7 cm3 (P ≤ .001) in group 1 and increased from 1.96 ± 0.88 cm3 to 2.82 ± 0.83 cm3 (P ≤ .001) in group 2. Surgical success was 86.95% in group 1 compared to 82.6% in group 2. CONCLUSIONS: Both techniques appear to be effective with a high surgical success rate in the treatment of OSA patients with retropalatal and lateral pharyngeal wall collapse.

Involvement of microRNA-4680-3p against phenytoin-induced cell proliferation inhibition in human palate cells.

Cleft palate (CP) is one of the most common birth defects and is caused by a combination of genetic and/or environmental factors. Environmental factors such as pharmaceutical exposure in pregnant women are known to induce CP. Recently, microRNA (miRNA) was found to be affected by environmental factors. The aim of the present study was to investigate the involvement of miRNA against phenytoin (PHE)-induced inhibition of proliferation in human embryonic palatal mesenchymal (HEPM) cells. We demonstrated that PHE inhibited HEPM cell proliferation in a dose-dependent manner. We found that treatment with PHE downregulated cyclin-D1 and cyclin-E expressions in HEPM cells. Furthermore, PHE increased miR-4680-3p expression and decreased two downstream genes (ERBB2 and JADE1). Importantly, an miR-4680-3p-specific inhibitor restored HEPM cell proliferation and altered expression of ERBB2 and JADE1 in cells treated with PHE. These results suggest that PHE suppresses cell proliferation via modulation of miR-4680-3p expression.

The relationship between third molar agenesis and craniofacial morphology: a systematic review and meta-analysis.

BACKGROUND: Agenesis of third molar agenesis has a higher incidence than other tooth development anomalies. Previous research identified a potential correlation between third molar agenesis and specific craniofacial morphology; however, no systematic review and meta-analysis on this topic currently exists. OBJECTIVE: The objective of this systematic review and meta-analysis was to evaluate the association between third molar agenesis and craniofacial sagittal and vertical morphology. SEARCH METHODS: An electronic search was conducted on PubMed, Embase, Web of Science, and the Cochrane Library without restrictions on publication year or language; this was supplemented by the manual retrieval of relevant literature. SELECTION CRITERIA: Cross-sectional studies that compared craniofacial morphology using angular and linear measurements obtained from lateral cephalography between patients with third molar agenesis and those without were included. DATA COLLECTION AND ANALYSIS: The quality assessment of the enrolled articles was evaluated by the Joanna Briggs Institute critical appraisal tool. Meta-analysis and sensitivity analysis were performed by Review Manager software (The Cochrane Collaborative, version 5.4, Cochrane IMS). RESULTS: A total of seven studies were included. Meta-analysis demonstrated that the ANB (mean differences (MD) = -0.75, 95% CI: -1.31 to -0.19, P < 0.01), palate length (ANS-PNS, MD = -1.68, 95% CI: -2.24 to -1.11, P < 0.01), and mandibular length (Go-Pog, MD = -0.36, 95% CI: -0.59 to -0.13, P < 0.01) were smaller in patients with third molar agenesis. With regard to vertical craniofacial morphology, the mandibular plane angle (MP-FH; MD = -1.88, 95% CI: -3.45 to -0.31, P = 0.02), gonial angle (gonial angle; MD = -1.73, 95% CI: -2.69 to -0.77, P < 0.01) and lower face height (lower face heigh angle; MD = -1.36, 95% CI: -1.94 to -0.77, P < 0.01) were smaller in patients with third molar agenesis, indicating a flatter or brachyfacial skeletal pattern. CONCLUSIONS: The results of this study suggest that third molar agenesis maybe associated with a reduced maxillary length and a flatter mandible. However, these findings need to be interpreted with caution due to inconsistencies in the certainty of evidence. CLINICAL TRIAL REGISTRATION: PROSPERO (CRD42023448226).

Palatal shield technique: a novel approach for improved donor site healing in mucogingival procedures - report of two cases.

OBJECTIVE: Mucogingival surgery involving tissue grafts is commonly employed for cosmetic procedures like root coverage, and is increasingly applied in implant therapy to modulate peri-implant soft tissues and enhance implant survival. These procedures involve harvesting autologous connective or epithelial connective tissue, often from the palate or tuber maxillae. However, this can cause patient morbidity due to postoperative pain. Substitute materials, including animal-derived and xenografts, have been developed but lack qualities of autologous grafts. METHOD AND MATERIALS: To address postoperative discomfort, a novel technique, named "palatal shield," using composite resin stabilized on adjacent teeth's palatal surface is proposed as an aid to donor site healing after mucogingival procedures. Two cases are reported where this technique was successfully applied. The first case involves a 53-year-old woman undergoing free gingival graft surgery for peri-implant treatment. The second case features a 58-year-old man receiving subepithelial connective tissue graft surgery for root sensitivity. RESULTS: Ten days post surgery, both patients reported excellent postoperative comfort. The technique's effectiveness is highlighted in these cases, demonstrating its applicability in various surgical cases involving free gingival graft or connective tissue graft harvesting. CONCLUSION: The proposed "palatal shield" technique offers several advantages, including enhanced patient comfort, ease of application, and cost-effectiveness, making it a promising addition to mucogingival surgical procedures.

Variability associated with maxillary infrazygomatic crest and palatal bone width, height, and angulation in subjects with different vertical facial growth types: a retrospective cone-beam computed tomography study.

OBJECTIVES: To assess the infrazygomatic crest (IZC) and palatal bone width, height, and angulation in patients with different vertical facial growth types as potential miniscrew insertion sites. MATERIALS AND METHODS: In this retrospective cone-beam computed tomography study, 162 subjects (81 males and 81 females, mean age 16.05 ± 0.65 years) were included. They were divided into three groups (hypodivergent, normodivergent, and hyperdivergent) based on the Frankfort mandibular plane angle. Ten buccal bone measurements were made at two different coronal sections: maxillary first molar mesiobuccal and distobuccal roots (bilaterally). Six palatal bone measurements were made on a sagittal section at the maxillary central incisors (bilaterally). A total of 32 measurements per subject were considered in the study. RESULTS: No significant difference was observed for the IZC (width and angle) at the maxillary first molar mesiobuccal root. A comparison of normodivergent and hyperdivergent groups for buccal width at the distobuccal root of the first molar showed significant differences. Palatal bone thickness at the level of 2 mm distal to the apex of the central incisor was significantly higher for the hyperdivergent group (10.43 mm) compared with the normodivergent (7.58 mm) and hypodivergent groups (7.83 mm). CONCLUSIONS: Hyperdivergent subjects tend to present a longer and deeper IZC and increased palatal bone thickness compared with other groups. The recommended insertion angle for the IZC mini-implant at 3 mm from the alveolar crest should be between 75.5° and 77°.

Evaluation of three-dimensional reconstructed palatal morphology in skeletal class III subjects with different vertical patterns using cone beam computed tomography.

BACKGROUND: This study aims to evaluate the difference of three-dimensional (3D) reconstructed palatal morphology between subjects with skeletal Class III and skeletal Class I in different vertical patterns using cone beam computed tomography (CBCT). METHODS: In this study, 89 subjects with skeletal Class III (49 females, 40 males; 25.45 ± 3.81 years) and 85 subjects with skeletal Class I (45 females, 40 males; 23.95 ± 4.45 years) were collected retrospectively and divided into hyperdivergent, normodivergent and hypodivergent groups. Dolphin software was used to reorient the CBCT images of these subjects. After segmenting 3D object of maxilla from the 3D skull by ProPlan software, Geomagic Studio was used to reconstruct 3D palatal morphology and establish an average 3D palatal morphology for each group. The differences of 3D palatal morphology between different groups were compared by deviation patterns on 3D colored map analysis. RESULTS: 3D colored map analysis showed the posterior part of male's palate was higher and wider than that of female's palate in skeletal Class III subjects. In skeletal Class III subjects, males with hyperdivergent pattern had a higher and narrower palate compared with hypodivergent subjects, while females with hyperdivergent had a higher but not obviously narrower palate compared with hypodivergent subjects. In the similar vertical patterns, skeletal Class III subjects had a flatter but not narrower palate compared with skeletal Class I subjects, along with a smaller palate volume. CONCLUSIONS: This method allows more intuitive between-group comparisons of the differences of 3D palatal morphology. In skeletal Class III subjects, as the vertical dimension increased, the palate tends to be higher and narrower. Therefore, the influence of vertical patterns on the palatal morphology should be fully considered in the orthodontic and orthognathic treatment of skeletal Class III subjects.

CAD/CAM design and 3D printing of a personalised rapid palatal expander for maxillary transverse deficiency.

Bone -borne ra pid ma xilla ry expansion appliances can achieve skeletal expansion while avoiding the undesirable dental side effec ts caused by a conventional rapid palatal expansion appliance. Typically, t hese (bone-bo rne appliances) included prefabricated devices, which can have limitations such as inadequate palatal adaptation leading to anch orage los s. In addit ion, a s bone thickness is not accounted for, prefabricated expanders cannot ensure the primary stability of the mini-implants. These disadvantages can be overcom e by customisation. This repor t aims to describe the digital design and three-dimensional printing workflow for constructing a personali sed M iniscrewassisted rapid palatal expansion (pMARPE) and present a case depicting its application in a 27-year-old female with 5.0 mm t ransverse discrepancy b etween the maxilla and the mandible. The result demonstrated that the pMARPE could be manufactured without the need for conventional impre s sion or laborator y p rocedures and effec tively e xpanded the palate of an ad ult pat ient with maxillar y transverse deficiency.

[Research progress in molecular mechanism of palatal development].

Cleft palate is one of the most common maxillofacial birth defects, which can occur alone or accompany with many known deformities. Palatal selves need to complete the process of vertical growth, elevation, adhesion and fusion in a specific time window of embryo development. Any abnormality in this process will lead to cleft palate. Although previous studies have identified many molecular networks that regulate the growth, location and fusion of palatal selves, there are still many unknown mechanisms for palatal development. The pathogenesis of cleft palate has not been clarified so far. In recent years, the molecular research on palate development has been deepened continuously. Here we summarize major recent advances and integrate the genes and molecular pathways with the cellular and morphogenetic processes of palatal shelf growth, patterning, elevation, adhesion, and fusion, in order to comprehensively understand the genotype-phenotype functional relationship and provide assistance in formulating effective prevention strategies for cleft palate disease.

Single-cell Transcriptomics Reveals Activation of Macrophages in All-trans Retinoic Acid (atRA)-induced Cleft Palate.

Cleft palate is among the most common birth defects with an impact on swallowing and speaking and is difficult to diagnose with ultrasound during pregnancy. In this study, we systematically capture the cellular composition of all-trans retinoic acid (atRA)-exposed and normal embryonic gestation 16.5 days mouse palate by the single-cell RNA sequencing technique. The authors identified 14 major cell types with the largest proportion of fibroblasts. The proportion of myeloid cells in atRA-exposed palate was markedly higher than those in the normal palate tissue, especially M1-like macrophages and monocytes. The upregulated genes of the different expression genes between atRA-exposed palate and normal palate tissue were linked to the biological processes of leukocyte chemotaxis and migration. Protein TLR2, CXCR4, THBS1, MRC1, transcription factor encoding genes Cebpb, Fos, Jun, Rela, and signaling pathway IL-17 and phagosome were found to be significantly involved in these processes. Subsequently, cellular communication network analysis suggested that myeloid-centered cell interactions SELL, SELPLG, MIF, CXCL, ANNEXIN, THBS, and NECTIN were significantly more activated in atRA-exposed palate. Overall, we delineate the single-cell landscape of atRA-induced cleft palate, revealing the effects of overexposure to atRA during palate tissue development and providing insights for the diagnosis of cleft palate.

Age-related changes in the midpalatal suture: Comparison between CBCT staging and bone micromorphology.

The age-related maturation of the human midpalatal suture is challenging to predict, but critical for successful non-surgical rapid maxillary expansion (RME). While cone-beam computed tomography (CBCT) can be used to categorize the suture into stages, it remains unclear how well the stages predict the actual micromorphology of the palate. To address this clinically relevant question, we used CBCT together with three-dimensional micro-computed tomography (µCT) analysis on 24 human palate specimens from individuals aged 14-34 years. We first classified the specimens into stages (A-E) using CBCT images and then correlated the results with our comprehensive µCT analysis. Our analysis focused on several factors, including bone volume fraction (BV/TV), sutural width, volume, interdigitation, ossification, and their associations with age, CBCT stage, and sex. Our µCT analysis revealed a decrease in sutural width and volume after the age of 20 years, accompanied by sutural closure beginning in the palatal segment. The overall rate of ossification remained low but increased after the age of 20 years. No significant differences were found between males and females. Importantly, we also found no correlation between individual age and CBCT stages. Furthermore, there was no association between CBCT stages and patalal suture volume, ossification and interdigitation. Taken together, our findings cast doubt on the reliability of CBCT stage as a means of predicting skeletal maturity of the palatal suture, as it appears to lack the precision required to accurately assess the true micromorphology of the palatal suture. Future investigations should explore whether alternative CBCT parameters may be more useful in addressing the challenging question of whether RME requires surgical bone weakening.

Clinical and histological wound healing patterns of collagen-based substitutes: An experimental randomized controlled trial in standardized palatal defects in humans.

AIM: To evaluate the progression of wound healing of standardized palatal defects in groups using three different collagen-based wound dressings and a control group, in terms of wound closure, pain perception and descriptive histology. MATERIALS AND METHODS: Twenty participants were enrolled in this experimental study, in whom four palatal defects were created. The defects (6 mm diameter, 3 mm depth) were randomly assigned to one of four treatment modalities: C (control), MG (Mucograft®), MD (mucoderm®) and FG (Fibro-Gide®). Photographs were taken, and pain assessment was performed before and after treatment and at 5, 7, 9, 12, 14 and 16 days after surgery. All participants wore a palatal splint for a duration of 16 days. RESULTS: All groups achieved complete wound closure at 14 days. The percentage of the remaining open wound on day 7 amounted to 49.3% (C; interquartile range [IQR]: 22.6), 70.1% (FG; IQR: 20.7), 56.8% (MD; IQR: 26.3) and 62.2% (MG; IQR: 34.4). Statistically significant differences were found between FG and C (p =.01) and between MD and FG (p =.04). None of the participants rated pain higher than 4 out of 10 during the entire study period. CONCLUSIONS: Collagen-based wound dressings provide coverage of open defects, albeit without acceleration of wound closure or reduction of pain. FG (which is not intended for open oral wounds) showed slower wound closure compared to C and MD.