Spatial Position Analysis Of Maxilla Relative To Cranial Base In Normal Population Group

In recent years, the incidence of maxillofacial fractures caused by trauma increased. Among all of the cases, the treatment of panfacial fractures is the most difficult. Due to involving many important anatomic structures, panfacial fractures often cause serious damage such as facial distortion, occlusal disorder, dysfunction and combined with serious systemic organs damage, etc. Therefore, active therapy for panfacial fractures, restoring anatomical configuration and correcting dysfunction became the treatment emphases of maxillofacial trauma surgery.The development of radiological technology provides great convenience for the diagnosis and treatment of maxillofacial fractures. At present, the radiological techniques which are commonly used in clinic mainly include X-ray and tomography technology, three-dimensional CT rebuilt, CT image reconstructed 3-d entity model and so on.At present, the clinical therapies for maxillofacial fractures mainly includes: conservative therapy, surgery and repairing of defected tissue.For common clinical simple fracture cases, conventional treatments often can get good therapeutic effect, because we can use many relatively intact anatomical structures as the restoration symbols to restore face configuration and fracture sections. For example, we can restore the facial height by means of the three maxillofacial buttresses; we can restore the contralateral jaw by means of occlusion, etc. However, for many complex cases, such as serious comminuted fracture, oldfracture, and combined with most hard & soft tissue coloboma, etc, such conventional treatments often can not achieve favorable restoration effect. Especially, for the cases, whose nasomaxillary buttress, zygomaticomaxillary buttress and pterygomaxillary buttress are completely damaged, the right spatial position becomes more uncertain. How to fix the position of maxilla accurately often makes many clinicians bewildered. Facing"positioning problem", this great difficulty, current home and abroad treatments still lack of effective and practical ways to deal with.In numerous of maxillofacial fractures cases, we have found that, the incidence of cranial base fractures and shift position is very low. The spatial position of cranial base is relatively stable, and it can guide the restoration for maxilla in clinical surgery. Therefore, this experiment was designed to seek the anchor points in maxilla and cranial base; measure the quantity relationship between the anchor points. So as to determine the spatial position of maxilla relative to cranial base, and takes it as a position standard to guide the restoration for maxilla in panfacial fractures patients. The core part of this experiment is the facial height determining and palatal plane positioning.This experiment randomly extracted 816 people from normal people group, regardless of gender, the sample must be healthy, developed normally, born in Jilin province, with Han nationality and over 20 years old. According to gender, put the samples into male and female 2 gender groups; then, according to age, put each gender samples into 20-34 years old, 35-49 years old and 50 years old and above 3 age groups. Using Planmeca panoramic X-ray machine to photograph the digital radiographic cephalometric projection for subjects. Positioning sella (S), nasion (N), porion (P), anterior nasal spine (ANS), posterior nasal spine (PNS) and subspinale (A) six anchor points with Winceph 8.0 software. Measuring