Non-syndromic orofacial clefts (NSOCs) are the most common craniofacial malformation. In the complex aetiology and pathogenesis of NSOCs, genetic factors play a crucial role and IRF6, located at chromosome 1q32.2, is the best documented NSOC susceptibility gene. IRF6 is a key factor in oral maxillofacial development and known to contribute the most in NSOCs. It is essential to conduct a complete review of the existing results on IRF6 to further understand its role in the pathogenesis of NSOCs. Thus, the present authors summarised the research progress on the mechanism of IRF6 in NSOCs from both genetic and functional perspectives in this review.
 
Keywords: IRF6, genetics, non-syndromic orofacial cleft (NSOC)

Objective: To compare the sequential healing of maxillary sinuses grafted with two different xenogeneic bone substitutes processed at either a low (300°C) or high (1200ºC) temperature.
Methods: A sinus augmentation procedure was performed bilaterally in 20 rabbits and two different xenogeneic bone grafts were randomly used to fill the elevated spaces. Healing was studied after 2 and 10 weeks, in 10 rabbits during each period.
Results: After 2 weeks of healing, very small amounts of new bone were observed in both groups, and were mainly confined to close to the sinus bone walls and osteotomy edges. After 10 weeks of healing, new bone was found in all regions, with higher percentages in those close to the bone walls and to the osteotomy. In this period of healing, the proportion of new bone in the 300°C group was 20.0% ± 4.3%, and in the 1200ºC group it was 17.2% ± 4.3% (P = 0.162). In the 1200ºC group, translucent, dark fog-like shadows in regions of the grafts were hiding portions of new bone (interpenetrating bone network).
Conclusion: Both biomaterials provided conditions that allowed bone growth within the elevated space, confirming that both biomaterials are suitable to be used as a graft for sinus floor augmentation.
 
Key words: animal study, bone healing, histology, sinus floor augmentation, sinus membrane
 

Objective: To investigate the differences between temporomandibular articular fossa bone surface and the envelope surface of the mandibular condyle movement.
Methods: Thirty-four healthy adults underwent skull base and mandible scans using CBCT and performed mandibular border movement using the mandibular movement recording system. Landmarks of the fossa and tubercle were indicated and distance and angle parameters were measured on the 3D models reconstructed from the CBCT. The condyle movement envelope surfaces were formed according to models reconstructed from CBCT and the mandibular movement trajectory using computer simulation. The highest and lowest points of the envelope surface were indicated to create parameters. The data were analysed using a paired t test in SPSS (version 24.0, IBM, Armonk, NY, USA).
Results: The mandibular fossa bone surface was statistically different to the envelope surface for the height of the first peak of the envelope surface (3.280 ± 1.319 mm) and depth of the mandibular fossa (6.338 ± 2.389 mm) (the ratio was 51.75%), the height of the second peak of the envelope surface (1.463 ± 0.745 mm) and the height of the tubercle (2.000 ± 0.968 mm) (the ratio was 73.15%), and the downwards angle of the envelope surface (25.933 ± 7.539 degrees) and the posterior slope angle of the articular tubercle (35.059 ± 5.224 degrees) (the ratio was 73.97%).
Conclusion: The downwards angle of the envelope surface was statistically significantly smaller than the posterior slope angle of the articular tubercle, suggesting that the condyle movement is flatter than the mandibular fossa bone surface.
 
Key words: artificial fossa component, condyle movement, envelope surface, mandibular fossa bone surface, temporomandibular joint