Mouse Models of Orofacial Clefts: SHH and TGF-ß Pathways.

Birth defects have always been one of the most important diseases in medical research as they affect the quality of the birth population. Orofacial clefts (OFCs) are common birth defects that place a huge burden on families and society. Early screening and prevention of OFCs can promote better natal and prenatal care and help to solve the problem of birth defects. OFCs are the result of genetic and environmental interactions; many genes are involved, but the current research has not clarified the specific pathogenesis. The mouse animal model is commonly used for research into OFCs; common methods of constructing OFC mouse models include transgenic, chemical induction, gene knockout, gene knock-in and conditional gene knockout models. Several main signal pathways are involved in the pathogenesis of OFCs, including the Sonic hedgehog (SHH) and transforming growth factor (TGF)-ß pathways. The genes and proteins in each molecular pathway form a complex network to jointly regulate the formation and development of the lip and palate. When one or more genes, proteins or interactions is abnormal, OFCs will form. This paper summarises the mouse models of OFCs formed by different modelling methods, as well as the key pathogenic genes from the SHH and TGF-ß pathways, to help to clarify the pathogenesis of OFCs and develop targets for early screening and prevention.

Implications of Virtual CBCT-Based Immediate Implant Planning for Maxillary and Mandibular First Molars.

The purpose of his study was to investigate the projected ridge-implant dimensions derived from virtual superimposition of implants on intact first molars mimicking immediate implantation in the mandible (Md1) and maxilla (Mx1) using cone-beam computed tomography (CBCT). The CBCT records of 41 patients (19 males and 22 females) with Md1 or Mx1 were collected. Ten-millimeter-long cylindrical implants with different diameters were virtually positioned at prosthetically ideal angles into interradicular septum using CBCT software. Radiographic alveolar ridge height (ARH), alveolar ridge width (ARW), gap distance, and vertical distance from the implant platform to the alveolar crest were measured. Twenty Mx1s (48.8%) and 21 Md1s (51.2%) were included. The mean ARH values were 7.13 ± 4.32 and 15.64 ± 1.80 mm for Mx1 and Md1, respectively; 87.8% of mesiobuccal sites had gap distance of >2 mm when 6-mm-diameter implants were used. Increasing implant diameter from 6 to 9 mm decreased the percentage of sites with ARW > 2 mm from 80.5% to 41.5% buccally and from 86.4% to 26.8% lingually. The mean vertical distance from the implant platform to the alveolar crest was 1.41 ± 1.09 mm buccally and 1.11 ± 1.10 mm lingually. Immediate implant placement of first molars, especially in the maxilla, requires stringent presurgical evaluation. Implants no wider than 6 mm placed into the interradicular septum may meet acceptable running room and alveolar plate thickness criteria if the jumping distance is grafted. Further clinical trials are needed to confirm these findings in this virtual study.

Morphologic analysis of alveolar bone in maxillary and mandibular incisors on sagittal views.

PURPOSE: The aim of this study was to analyze the morphologic features of alveolus in relatively healthy maxillary and mandibular incisors using cone-beam-computed tomography (CBCT). METHODS: CBCT images of 318 patients were retrospectively acquired. Alveolar bone in incisive area was divided into: type 1 (thick), type 2 (relatively thick with mono-plate concavity), type 3 (thin with double-plate concavities), and type 4 (vulnerably thin). Alveolus prevalence and widths were analyzed statistically relative to age, gender, and molar relationship. RESULTS: Prevalence of type 1 alveolus was 78.9% in maxillary central incisors, 15.1% in maxillary lateral incisors, 24.1% in mandibular central incisors, and 5.0% in mandibular lateral incisors. Type 2 alveolus was commonly observed in the maxillary lateral incisors (82.2%), mandibular central incisors (66.2%), and mandibular lateral incisors (87.9%). Prevalence of type 3 and 4 alveoli ranged from 0.0 to 9.4%. As for maxillary central incisors, type 1 was the widest both at the alveolar crest (7.77 ± 0.58 mm) and apical area (9.05 ± 1.86 mm), while type 3 had the lowest width at the apical region (4.08 ± 0.51 mm). Among maxillary central incisors, prevalence of type 1 tended to decrease with age. At all maxillary and mandibular incisor sites, alveolus widths were significantly thicker in males than in females. At maxillary lateral incisor and mandibular incisor sites, prevalence of alveolus type was significantly different among three molar relationships. CONCLUSION: A 4-type classification system was suggested for alveolus morphology in incisive region. Identification of alveolus type might aid in the corresponding treatment.

Allergy-Related Sialodochitis: A Preliminary Cohort Study.

OBJECTIVES/HYPOTHESIS: To explore the clinically feasible diagnosis criteria and treatment outcomes of allergy-related sialodochitis (ARS). STUDY DESIGN: Prospective Cohort Study. METHODS: Ninety-six consecutive patients were enrolled by the following criteria: 1) recurrent swelling of ≥2 large salivary glands that lasted for ≥3 months; 2) with mucus plug exudations; 3) with atopic diseases; 4) ductal stenosis and/or ectasia. Sixty-four patients with elevation of peripheral blood eosinophil (PBE) and/or serum IgE level comprised group A (highly-suspected ARS group), while the remaining 32 comprised group B (patients without confirmed evidence of ARS). These patients were treated with interventional endoscopy. A chronic obstructive sialadenitis symptom (COSS) questionnaire was used to quantify the treatment outcomes. RESULTS: In group A, Serum IgE was elevated in 84.4% of patients and PBE was elevated in 34.4% of patients. Percentage of submandibular gland involvement was higher in group A than group B (48.4% vs. 18.8%). On sialograms, the snowflake changes of branch ducts were seen in higher percentage of group A compared with group B (59% vs. 35% for parotid glands, 27% vs. 8% for submandibular glands, respectively). Mucus plug smears showed abundant eosinophils in 14 group A patients. Biopsy of five group A patients revealed significant eosinophil infiltration around the main and interlobular ducts. During follow-up, the COSS scores were significantly decreased in both groups, and group B was improved better than group A. CONCLUSION: PBE and serum IgE are important diagnostic indexes of ARS. Mucus plug smear or histopathology verifies the diagnosis. Interventional endoscopy is helpful for ARS cases. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:2030-2035, 2021.

Treatment strategy of hilar and intraglandular stones in wharton's duct: A 12-year experience.

OBJECTIVES/HYPOTHESIS: To suggest a strategy for transoral removal of hilar and intraparenchymal submandibular stones. STUDY DESIGN: Retrospective case series. METHODS: Retrospective evaluation was performed for 514 consecutive patients with hilar and intraparenchymal submandibular stones treated via endoscopy-assisted surgery from January 2006 to June 2018. Three patients had bilateral stones. The stones were classified as: hilar (type I), posthilar (type II), intraparenchymal (type III), and multiple stones (type IV). RESULTS: The affected glands included 311 with type I, 84 with type II, 65 with type III, and 57 with type IV stones. Stones were successfully removed in 478 glands (92.5%, 478/517). Main treatment techniques included hilum ductotomy in 311 glands, intraparenchymal ductotomy in 68, submandibulotomy in 14, intraductal retrieval in 74, and hilum ductotomy accompanied by intraductal retrieval in 11. At a mean 40-months follow-up of 478 successful cases, clinical outcomes were good in 425, fair in 27, and poor in 26 glands. Postoperative sialograms in 75 stone-free patients were categorized as: type I, normal (n = 6); type II, ectasia or stenosis in the main duct and no persistent contrast on functional films (n = 44); type III, ectasia or stenosis in the main duct and mild contrast retention (n = 15); and type IV, poor shape of the main duct and evident contrast retention (n = 10). Postoperative sialometry of 32 patients revealed no significant differences of the gland function between the two sides. CONCLUSIONS: Appropriate use of various endoscopy-assisted approaches helps preserve the gland and facilitates recovery of gland function in patients with different depths of hilo-parenchymal submandibular stones. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:2360-2365, 2020.

Prevalence and Morphology of Mandibular Incisive Canal: Comparison among Healthy, Periodontitis and Edentulous Mandibles in a Population of the Beijing Area Using Cone-beam Computed Tomography.

OBJECTIVE: To evaluate and quantify the prevalence and morphology of the mandibular incisive canal (MIC) comparatively among healthy, periodontitis and edentulous mandibles using cone-beam computed tomography (CBCT). METHODS: CBCT images of 1,070 hemimandibles from 535 consecutive patients, including 448 with healthy dentition, 42 with severe periodontitis mandibles and 45 with edentulous mandibles, were retrospectively analysed. MICs were identified, and linear measurements were performed. Statistical analyses were conducted to investigate differences in the prevalence and morphology of MICs relative to gender, laterality, age group and dental status. RESULTS: The MIC was observed in 92.8% of 1,070 hemimandibles. No significant differences of MIC prevalence were found between left and right sides, or between healthy and periodontitis mandibles. However, males had a higher prevalence of MIC than females, and patients with dentate mandibles had a higher prevalence of MIC than those with edentulous mandibles. For dentate mandibles, MICs started most commonly below the first premolar (51.9%) and ended around the canine (58.5%). The mean diameter of MIC was 2.5 ± 0.5 mm at origin, and 20.6% of MICs began with a diameter of ≥ 3 mm. The mean length of MIC was 13.4 ± 3.3 mm. The mean distances from the MIC to the labial cortex, lingual cortex, alveolar ridge and inferior border of mandible were 3.7 ± 0.9, 5.1 ± 1.6, 19.5 ± 3.8 and 8.9 ± 1.7 mm, respectively. Moreover, significant differences of measurements were found relative to gender, age group, and dental status. CONCLUSION: Due to the large variations in size and course of MICs, special caution should be exercised in any individual surgery affecting the anterior mandible.