Mohamed G Hassan

• PhD. MSc. BDS.
• Assiut University

Craniofacial abnormalities are among the most common features of human genetic syndromes and disorders. The etiology of these conditions is often complex, influenced by both genetic context and the environment. Frequently, craniofacial abnormalities present as part of a syndrome with clear comorbid phenotypes, providing additional insight into mech...

Manitoba-oculo-tricho-anal (MOTA) syndrome is a rare condition defined by eyelid colobomas, cryptophthalmos and anophthalmia/microphthalmia, an aberrant hairline, a bifid or broad nasal tip, and gastrointestinal anomalies such as omphalocele and anal stenosis. Autosomal recessive inheritance had been assumed because of consanguinity in the Oji-Cre...

Mechanical loading is required for bone health and results in skeletal adaptation to optimize strength. Local nerve axons, particularly within the periosteum, may respond to load-induced biomechanical and biochemical cues. However, their role in the bone anabolic response remains controversial. We hypothesized that spatial alignment of periosteal n...

Mechanical loading is required for bone health and results in skeletal adaptation to optimize strength. Local nerve axons, particularly within the periosteum, may respond to load-induced biomechanical and biochemical cues. However, their role in the bone anabolic response remains controversial. We hypothesized that spatial alignment of periosteal n...

This protocol details the quantification of basic bone parameters including bone area, bone area fraction, periosteal perimeter, etc., dynamic indices of bone formation using calcein double labels, and the length, density, and branching of nerve endings present in long bone cross-sections imaged by confocal microscopy.

Background The maternal diet is essential to offspring development, but the specific effects on tooth morphology are still unknown. The aim of this study was to evaluate the effects of altering maternal calcium (Ca) and phosphorus (P) supplementation during gestation and lactation on offspring dentition. Methods Pregnant mice were fed an experimen...

Introduction Competitive swimmers spend considerable time practicing their sport. Prolonged exposure to chlorinated water can alter salivary parameters and might compromise oral health. This study aimed to determine erosive tooth wear status and its related risk factors among competitive swimmers as compared to non-swimmers. Materials and methods...

Purpose of Review This review examines the diverse functional relationships that exist between the peripheral nervous system (PNS) and bone, including key advances over the past century that inform our efforts to translate these discoveries for skeletal repair. Recent Findings The innervation of the bone during development, homeostasis, and regene...

Clefts of the lip or palate (CLPs) are the most common craniofacial birth defect, with a worldwide incidence of ~1 in 700 live births. The objective of this study is to assess the characteristics of the nasopharyngeal airway in growing vs. non-growing cleft lip/palate subjects and compare them with normal subjects. This retrospective study analyzed...

Background: To study the relation between social media mentions and academic citations for articles published in peer-reviewed orthodontic journals. Methods: Articles published in early 2018 in seven peer-reviewed orthodontic journals were retrospectively analyzed in September 2022. Citation counts of the articles were evaluated using two databases...

Objective: Despite the clear drive from both research and clinical dentistry toward digital transformation, there are limitations to implementing intra-oral scanning (IOS) into daily dental practice. This study aimed to compare the precision of digital models obtained from two alternative indirect workflows to direct IOS. Material and methods: Two...

Spontaneous bleeds are a leading cause of death in the pediatric JAG1-related liver disease Alagille syndrome (ALGS). We asked whether there are sex differences in bleeding events in patients, whether Jag1Ndr/Ndr mice display bleeds or vascular defects, and whether discovered vascular pathology can be confirmed in patients non-invasively. We perfor...

Background: Bone remodeling during development and growth is important for craniofacial integrity of offspring. The aim of this study was to investigate the changes in offspring adult skull morphology when the osteoclasts number was altered in utero, using three-dimensional (3D) geometric morphometric analysis (GMA). Material and methods: We alt...

The adaptive response of the mandible and temporomandibular joint (TMJ) to altered occlusion in juvenile patients is presently unclear. To address this question, we established a mouse model in which all molars were extracted from the maxillary right quadrant in pre‐pubertal, 3‐week‐old mice and analyzed morphological, tissue, cellular, and molecul...

Introduction The effects on offspring craniofacial bone morphology and accretion because of altered maternal exposure to dietary components such as calcium (Ca) and phosphorus (P) are unclear. The objective of this study was to investigate the changes in offspring skull morphology and tissue mineral density (TMD), including sex-specific changes, wi...

Objectives: To evaluate the perceptions of clinical dental students on the role of online education in providing dental education during the COVID-19 crisis. Materials and Methods: A cross-sectional online survey was sent to four Egyptian dental schools from the 20th of January 2021 to the 3rd of February 2021. Survey questions included the demogra...

While Twitter has substantial benefits in real-time sharing and dissemination of information and facilitating discussions, currently there is a noticeable absence of its use in the orthodontic profession and peer-reviewed journals. This review aims to introduce the basics of using social media; provide a perspective and prospective vision on effect...

Moving within the second wave of the coronavirus (COVID-19) pandemic, dental education delivery has been profoundly affected by this crisis, so has the structure, evaluation, and future of dental education. Both pre-clinical and clinical dental education have experienced challenges ranging from fully online educational content to limited dental tra...

Recent advances in developmental, molecular and cellular biology as well as biomedical technologies show a promising future for crossing the gap between biomedical basic sciences and clinical orthodontics. Orthodontic research shall utilise the advances and technologies in biomedical fields including genomics, molecular biology, bioinformatics and...

Alagille syndrome (ALGS) is generally thought of as a pediatric cholestatic liver disease, but spontaneous bleeds are a major cause of death. Here, we investigated bleeding in patients and a mouse model for ALGS (Jag1Ndr/Ndr mice) and asked whether phenotypes identified in mice could be detected in patients non-invasively. Jag1Ndr/Ndr mice spontane...

Background and Objectives: The aim of this systematic review was to review the effect of different activation protocols of miniscrew-assisted palatal expanders used in the treatment of maxillary skeletal transverse deficiency. Material and methods: A search was conducted in MEDLINE via PubMed, Web of Science, Scopus, Cochrane Library till May 2020....

The aim of this review was to evaluate the current evidence regarding post-treatment effects of tooth-bone-borne vs. bone-borne expanders. A search was conducted in MEDLINE via PubMed, Web of Science, Scopus, Cochrane Library, Google Scholar, and Open Gray; in addition to a hand search in reference lists of selected articles and creating a search a...

Bone marrow adipose tissue (BMAT) is an important cellular component of the skeleton. Understanding how it is regulated by the nervous system is crucial to the study of bone and bone marrow related diseases. BMAT is innervated by sympathetic and sensory axons in bone and fluctuations in local nerve density and function may contribute to its distinc...

Variations in craniofacial morphology may arise as a result of adaptation to different environmental factors such as soft diet (SD), which lessens functional masticatory load. Prior studies have shown that changes in the masticatory muscle function associated with a switch to short-term SD led to changes in craniofacial morphology and alveolar bone...

Background and objective: The roles of, and crosstalk between genes and environment during craniofacial development and morphogenesis has been a subject of discussion for many years. The role of osteoclasts as a determinant of avian beak length was previously reported after significantly higher tartrate-resistant acid phosphatase (TRAP) activity, a...

Objectives The purpose of our study was to determine morphological changes and bone mineral density (BMD) differences in the adult mandible of offspring exposed to high calcium, low phosphorus diets in utero until weaning age. Materials and Methods Time‐mated FVB wild‐type mice were fed normal or experimental diet during gestation and until weanin...

- Clefts of the lip and/or palate (CLP) is the most common craniofacial birth defect, occurring with a worldwide incidence of ~1 in 700 live births. (Dixon et al,. 2011). - In CLP patients, the associated craniofacial features include midface deficiency, retrognathic mandible, and increased vertical dimensions, resulting in the reduction of the pha...

Sclerostin modulation is a novel therapeutic bone regulation strategy. The anti-sclerostin drugs, proposed in medicine for skeletal bone loss may be developed for jaw bone indications in dentistry. Alveolar bone responsible for housing dentition share common bone remodeling mechanisms with skeletal bone. Manipulating alveolar bone turnover can be u...

Background: P63 gene is vital to palatogenesis and amelogenesis. CLP caused by p63 mutation is accompanied by extensive dental defects not fully characterized. Aim: To investigate the effect of losing one p63 allele on enamel structure and salivary gland formation using morphological and histological data. Methods: Enamel structure, density and vol...

Many factors that regulate development of the cranioskeleton also may contribute to the development of Class III malocclusion. MicroCT imaging offers a means to both qualitative and quantitative assess cranioskeletal phenotypes in three dimensions (3D). 3D imaging allows recording of craniofacial landmark coordinates that can subsequently be employ...

Objective: Midfacial hypoplasia (MFH) is a common condition that typically presents as class III malocclusion. However, little is know about the pathogenetic mechanisms. MFH is also a common co-morbidity of craniosynostosis, which results from the premature fusion of the cranial bones. Normally, a zone of undifferentiated mesenchyme (or suture) sep...