The upper jaw bone located in the center of the human face skull.In pairs, i.e. left and rightMaxillaThe maxilla is composed of 1 bone body and 4 protrusions connected in the midline.
The upper part of the bone forms the eye socketInferior wall, connected inside and outsideNasal meatusThere is a Hi ghmori sinus opening in the inner side（Maxillary sinusmaxillar sinus）。
mandibleIt is divided into body part and ascending branch, and both sides of the body part are united in the middle.There are two above the mandibular ramusBonyThe process at the rear is called the condyle, and the process at the front is called the coracoid process（Myoid process）The concave edge between the two is called sigmoid notch.
The intersection of the posterior edge of the ascending branch and the lower edge of the mandible is calledMandibular angle, there is a hole in the middle of the inner side of the lifting branchMandibular foramenThis hole is a pipe extending downward and forward in the mandible, which is called mandibular canal.Mandibular canalFirst, secondPremolarA hole is punched out between the roots of teeth, calledMental foramen。Inferior alveolar nerve. The blood vessels enter the mandibular canal from the mandibular foramen and go forward, and exit at the mental foramenMental nerveAnd blood vessels.
becausemandibleThe structures at the neck of the condyle, mandibular angle, mental foramen, and median symphysis are relatively weak, so trauma often occursfracture。
diagnosisJaw fractureFirst of all, we should know the cause of the injury, the location of direct injury and the course of the injury, then we should check the local and systemic signs, refer to the above clinical characteristics, and determine whether there isfractureThe location and type of fracture.If conditions permit, furtherX-rayInspection andCT examinationUnderstand the position, number, direction and displacement of fracture line in detail.
Jaw fractureAfter that, it is mainly reset and fixation.The important sign of jaw fracture reduction is to restore the normal occlusion relationship of the upper and lower teeth, that is, the extensive contact relationship of the teeth.Otherwise, it will affectFracture healingRecovery of masticatory function.There are three common reset methods:
1．Manual reposition: In the early stage of jaw fracture, the fracture segment is relatively active, and the displaced fracture segment can be restored toNormal position。
Maxillary fractureIf the fracture segment moves backward, it can be placed on the maxillary dentitionDental archThe splint is made on the head withMetal supportThe elastic traction was made between the dental arch splint and the metal bracket to make the fracture of the maxilla reposition forward.Need moreTractive forceIt can also be used for horizontal gravity traction.
3. Open reduction:IndicationsWide.The fracture segment has been displaced for a long timeFibrous propertyHealing orBonyIf the dislocation is healed and cannot be restored by manipulation or traction, open reduction should be performed.Difficult in manual reduction or unstable after reductionFresh fractureorOpen fractureGenerally, surgical open reduction is adopted.The fibrous tissue formed in the dislocation healing between fracture ends is removed orChiselCallus, reDisconnectionTo restore the jaw to its normal position.
Jaw fractureThe fixation after reduction is an important link in treatment.frequently-usedFixing methodHaving single jaw dental archSplint fixation, intermaxillary fixation, intermaxillary ligation fixation, miniplate or microplate fixation, craniomandibular fixation, and other methods include perimandibular fixation, compression plate fixation, etc.
1. Fixation method of single jaw dental arch splint: aluminum wire with a diameter of 2mm or finished hooked dental arch splint is used to form the dental arch according to the shape of the dental arch, and then fine metal is usedLigature wirego throughInterdental spaceThe dental arch splint is tied to part or all of the teeth on both sides of the fracture line to fix the fracture segment.This method is applicable to fractures without obvious displacement, such asmandibleMedian chinLinear fractureLimitationsAlveolar fracture。
2．Intermaxillary fixationThe commonly used method is to place the splint with hook on the upper and lower teeth, and then use a small rubber band for intermaxillary fixation to keep the jaw in the position of normal occlusion.This method is reliable and suitable for various mandibular fractures.
Advantages: It can make the jaw bone heal in a good position, which is conducive to recovery of function.
Disadvantages: The wounded cannot eat with his mouth open, and it is difficult to keep his mouth clean, so he should strengthen nursing.
3. InterosseousligationFixation: in the case of surgical open reduction, drill holes at both fracture ends, and then pass throughStainless steel wireMake ligation and fixation.This is also a reliable fixation method.childrenJaw fractureAnd edentulous jaw fractures can also be fixed by this method.
4. Small steel plate or mini steel plate fixation: On the basis of manual open reduction, small steel plate or mini steel plate with appropriate length and shape shall be placed across the bone surface of both fracture ends and threaded with special screwsBone cortexFix the plate to fix the fracture.Small steel plate is generally used formandible, micro steel plate forMaxilla。
5. Craniomandibular fixation method: The transverse fracture of the maxilla cannot be fixed solely by the mandible, but can be fixed by the skull, otherwise the middle of the face is prone to elongation and deformation.The fixation method is to place dental arch splints on the upper teeth first, and then useStainless steel wireOne end is tied atPosterior teethOn the dental arch splint, the other end penetrates the zygomatic and buccal soft tissue through the oral cavity and is suspended on the bracket of the plaster cap.At the same time, intermaxillary fixation was added.
Jaw fractureThe fixed time can be determined according to the patient's injury, age, general condition, etc.It is generally 3-4 weeks for maxilla and 4-8 weeks for mandible.
The combination of dynamic and static methods can be used to shorten the time of intermaxillary fixation.After 2-3 weeks of fixation, remove the rubber when eatingLeather ring, allowing appropriate activities.Use small steel plate or micro steel plate to strengthenInternal fixationCan be carried out in advanceFunctional trainingTo promote fracture healing.
clinical manifestation
According to the anatomical structureweak link There are three classic types of maxillary fractures.Type I fracture (Lefort type I fracture): the bone fracture line passes through the lower edge of the piriform holeMaxillary sinusLower, horizontal to both sidesMaxillary tubercle；The fracture line of the second type fracture (LeFort II fracture) passes through the nasal boneLacrimal bone, orbital floor, below cheekbone, reachingMaxillaPosterior wall;The fracture line of the third type fracture (LeFort type III fracture) also passes through the nasal bone and lacrimal bone, but crosses the orbital fossa and above the zygoma, and reaches back to the posterior wall of the maxilla, making the maxilla, zygoma and skull completely separated, so it is also called craniofacial separation.
mandibleIt is the only bone of the head that can move. It also has its weak parts in anatomical structure, such as the central chin, the mental apertureMandibular angleAnd condylar neck, these areMandibular fractureThe predilection site of.Due to its prominent position and anatomical morphology, the mandible is found inincidence ratehighest.
Jaw fractureCompared with other fractures, it has some common clinical symptoms, such asLocal pain, swelling, abnormal movement or displacement of bone fracture end, dysfunction, etc., also have their clinical characteristics, which is determined by the anatomical and physiological structure of the jaw.
1. Fracture segment displacement: The fracture segment displacement after jaw fracture mainly depends on the fracture type, impact direction, muscle traction and the weight of the fracture segment itself.
MaxillaIn case of transverse fracture, the fracture segment is often sagging and displaced due to gravity.If the impact direction is from front to back, the fracture segment can be displaced backward to make the middle of the facesunken；The impact from bottom to top often results in incarcerated fracture.
Mandibular fractureThe displacement of segment is mainly caused by muscle traction.Mental foramenIn case of partial fracture, the anterior fracture segment is often displaced downward due to the traction of the jaw depressor muscles, and the posterior fracture segment is often displaced upward due to the traction of the jaw elevator muscles.GenialComminuted fractureThe middle fracture section is due to genioglossus muscleGeniohyoid musclePull and move backward.Both fracture segmentsMandibular hyoid muscle、Hyoglossal muscleThe traction ofmandibleThe front bow narrows.This fracture can causeRetroglossumOccurreddyspnea, even suffocation, special attention should be paid.The condyle fracture is mostly caused by the intermodal force, which can occur at the same time as the chin fracture. Attention should be paid to check to avoid missed diagnosis.After condylar fractureLateral pterygoid muscleAnd the lower jawAscending branchUpward displacement due to the pulling of the maxillary musclesAnterior teethThe state that cannot be closed.If bilateral condylar fractures occur, the anterior teethOpen occlusionMore obvious.
2. TeethocclusionDisorder: the common cause of the occlusal relationship between the upper and lower teethJaw fractureDisturbance caused by segment displacement is the most obvious symptom of jaw fracture, which is of great significance for the diagnosis of jaw fracture.
Transverse fracture of the maxilla, with the fracture segment displaced downwardPosterior teethAndmandiblePosterior odontogenesisEarly exposureTo make the front teeth open and closed.Mandibular fractureAfter the fracture, the teeth often appear due to displacement of the fracture segmentDisordered occlusion。If there is no displacement of fracture segment, there is no obvious dislocation of teeth occlusion.
3. Abnormal activity of fracture segment:MaxillaIt is a bone that cannot move. If it moves, it is fracturedsign。
mandibleUnder normal circumstances, the whole movement is performed through the joint. Segmental abnormal movement indicates that there is a fracture.
4. Abnormal feeling:Maxillary fractureWhen, if anyInfraorbital nerveInjured, numbness may appear in the lower part of the orbit, upper lip and nose.In case of mandibular fracture, such as accompanied by lower alveolar boneNerve injury, numbness may appear on the lower lip of the same side.
5. Restricted mouth opening:Jaw fractureLater, due to pain, fracture segment displacementMasticatory muscleDyskinesia and reflex spasmTemporomandibular jointThe mouth opening is limited due to damage and other reasons.especiallyMandibular fracture, which has great influence on mouth opening movement.
6. Impact on respiration and swallowing: jaw fracture may affect the function of respiration and swallowing due to displacement of fracture segment.
PathogenesisToothache, swelling of corresponding parts of the face,Purulent fluid, numbness of the lower lip, obvious redness and swelling of the lower part of the orbit, nasal cavity perforation and pyorrhea, fibrous tissue hyperplasiaTissue swelling, fibrous tissue is hard,fistula, pyorrhea, gingival effusion.
The disease is acute and systemic symptoms are obvious.The local first felt the pain of the source tooth, which quickly extended to the adjacent tooth, leading to the pain of the entire affected side and spread to the temporal part.Swelling of corresponding parts of the face, redness and swelling of gums and vestibular sulcus, multiple affected areasLoose teeth。The pus often overflows from the periodontium.Mandibular osteomyelitis due toMasticatory muscleInvaded, often with varying degrees of mouth opening limitation.Inferior alveolar nerveThe affected lower lip may be numb.Osteomyelitis of maxillaIt is often found in newborns and infants, and the source of infection is often blood borne.Its local manifestation is obvious redness and swelling in the lower part of the orbit, which often extends to the periphery of the eye, causing the eyes to be unable to open.LaterMedial canthus, nasal cavity and oral cavity perforation and pus discharge.
If the acute osteomyelitis of jaw is not thoroughly treated, it can become chronic.The common reason is simply taking drugsConservative treatmentThe pus is self piercing and the drainage is not smooth.chronicOsteomyelitis of jawperiod,Acute symptomsMost of them subsided, and the systemic symptoms were not obvious, and the pain was significantly reduced.Local fibrous tissue hyperplasia, swelling and hardening.Fistula often overflows with pus and even discharges small dead bones.Multiple lesion areasTooth loosening, gingival effusion.When the bodyResistanceAcute attack may occur when it is reduced or the drainage is not smooth.If you delay for a long time, you will lose weightanemia. The body is weak.
Pathology
Osteomyelitis of jawThere are three main sources of infection, namely, odontogenic, traumatic and blood borne.
Hematogenous osteomyelitis of jaw is rare and mainly occurs in children.Odontogenic osteomyelitis of jaw is the most common, accounting for 90% of all jaw osteomyelitis.In China, due to the improvement of medical conditions, the incidence has dropped significantly.Odontogenic osteomyelitis of jaw is common, which is related tomandibleThe cortical bone is dense, surrounded by hypertrophic muscles and dense fascia,Medullary cavityThe accumulation of pus is not easy to puncture and drain.
chronicOsteomyelitis of jawAt the same time, efforts should be made to improve the patient's body condition, keep the drainage unobstructed, pull out the source tooth in time, thoroughly remove the focus, curette or removeDead bone。
