j-hooks) is fitted with a metal arch onto headgear tubes attached to the rear upper and lower molars. this facebow then extends out of the mouth and around the patient's face. j-hooks are different in that they hook into the patient's mouth and attach directly to the brace (see photo for an example of j-hooks). head cap: the head cap typically consists of one or a number of straps fitting around the patient's head. this is attached with elastic bands or springs to the facebow. additional straps and attachments are used to ensure comfort and safety (see photo). attachment: typically consisting of rubber bands, elastics, or springs—joins the facebow or j-hooks and the head cap together, providing the force to move the upper teeth, jaw backwards. the headgear application is one of the most useful appliances available to the orthodontist when looking to correct a class ii malocclusion. see more details in the section orthodontic headgear. pre-finisher the pre-finisher is moulded to the patient's teeth by use of extreme pressure on the appliance by the person's jaw. the product is then worn a certain amount of time with the user applying force to the appliance in their mouth for 10 to 15 seconds at a time. the goal of the process is to increase the exercise time in applying the force to the appliance. if a person's teeth are not ready for a proper retainer the orthodontist may prescribe the use of a preformed finishing appliance such as the pre-finisher. this appliance fixes gaps between the teeth, small spaces between the upper and lower jaw, and other minor problems. complications and risks a group of dental researchers, fatma boke, cagri gazioglu, selvi akkaya, and murat akkaya, conducted a study titled: “relationship between orthodontic treatment and gingival health.” the results indicated that some orthodontist treatments result in gingivitis, also known as gum disease. the researchers concluded that functional appliances used to harness natural forces (such as improving the alignment of bites) do not usually have major effects on the gum after treatment. however, fixed appliances such as braces, which most people get, can result in visible plaque, visible inflammation, and gum recession in a majority of the patients. the formation of plaques around the teeth of patients with braces is almost inevitable regardless of plaque control and can result in mild gingivitis. but if someone with braces does not clean their teeth carefully, plaques will form, leading to more severe gingivitis and gum recession. experiencing some pain following fitting and activation of fixed orthodontic braces is very common and several methods have been suggested to tackle this. pain associated with orthodontic treatment increases in proportion to the amount of force that is applied to the teeth. when a force is applied to a tooth via a brace, there is a reduction in the blood supply to the fibres that attach the tooth to the surrounding bone. this reduction in blood supply results in inflammation and the release of several chemical factors, which stimulate the pain response. orthodontic pain can be managed using pharmacological interventions, which involve the use of analgesics applied locally or systemically. these analgesics are divided into four main categories, including opioids, non-steroidal anti-inflammatory drugs (nsaids), paracetamol and local anesthesia. the first three of these analgesics are commonly taken systemically to reduce orthodontic pain. a cochrane review in 2017 evaluated the pharmacological interventions for pain relief during orthodontic treatment. the study concluded that there was moderate-quality evidence that analgesics reduce the pain associated with orthodontic treatment. however, due to a lack of evidence, it was unclear whether systemic nsaids were more effective than paracetamol, and whether topical nsaids were more effective than local anaesthesia in the reduction of pain associated with orthodontic treatment. more high-quality research is required to investigate these particular comparisons. the dental displacement obtained with the orthodontic appliance determines in most cases some degree of root resorption. only in a few cases is this side effect large enough to be considered real clinical damage to the tooth. in rare cases, the teeth may fall out or have to be extracted due to root resorption. history ancient old braces at a museum in jbeil, lebanon according to scholars and historians, braces date back to ancient times. around 400-300 bc, hippocrates and aristotle contemplated ways to straighten teeth and fix various dental conditions. archaeologists have discovered numerous mummified ancient individuals with what appear to be metal bands wrapped around their teeth. catgut, a type of cord made from the natural fibres of an animal's intestines, performed a similar role to today's orthodontic wire in closing gaps in the teeth and mouth. the etruscans buried their dead with dental appliances in place to maintain space and prevent the collapse of the teeth during the afterlife. a roman tomb was found with a number of teeth bound with gold wire documented as a ligature wire, a small elastic wire that is used to affix the arch wire to the bracket. even cleopatra wore a pair. roman philosopher and physician aulus cornelius celsus first recorded the treatment of teeth by finger pressure. unfortunately, due to a lack of evidence, poor preservation of bodies, and primitive technology, little research was carried out on dental braces until around the 17th century, although dentistry was making great advancements as a profession by then. 18th century portrait of fauchard from his 1728 edition of "the surgical dentist". orthodontics truly began developing in the 18th and 19th centuries. in 1669, french dentist pierre fauchard, who is often credited with inventing modern orthodontics, published a book entitled "the surgeon dentist" on methods of straightening teeth. fauchard, in his practice, used a device called a "bandeau", a horseshoe-shaped piece of iron that helped expand the palate. in 1754, another french dentist, louis bourdet, dentist to the king of france, followed fauchard's book with the dentist's art, which also dedicated a chapter to tooth alignment and application. he perfected the "bandeau" and was the first dentist on record to recommend extraction of the premolar teeth to alleviate crowding and improve jaw growth. 19th century although teeth and palate straightening and/or pulling were used to improve the alignment of remaining teeth and had been practised since early times, orthodontics, as a science of its own, did not really exist until the mid-19th century. several important dentists helped to advance dental braces with specific instruments and tools that allowed braces to be improved. in 1819, christophe françois delabarre introduced the wire crib, which marked the birth of contemporary orthodontics, and gum elastics were first employed by maynard in 1843. tucker was the first to cut rubber bands from rubber tubing in 1850. dentist, writer, artist, and sculptor norman william kingsley in 1858 wrote the first article on orthodontics and in 1880, his book, treatise on oral deformities, was published. a dentist named john nutting farrar is credited for writing two volumes entitled, a treatise on the irregularities of the teeth and their corrections and was the first to suggest the use of mild force at timed intervals to move teeth. 20th century in the early 20th century, edward angle devised the first simple classification system for malocclusions, such as class i, class ii, and so on. his classification system is still used today as a way for dentists to describe how crooked teeth are, what way teeth are pointing, and how teeth fit together. angle contributed greatly to the design of orthodontic and dental appliances, making many simplifications. he founded the first school and college of orthodontics, organized the american society of orthodontia in 1901 which became the american association of orthodontists (aao) in the 1930s, and founded the first orthodontic journal in 1907. other innovations in orthodontics in the late 19th and early 20th centuries included the first textbook on orthodontics for children, published by j.j. guilford in 1889, and the use of rubber elastics, pioneered by calvin s. case, along with henry albert baker. today, space age wires (also known as dental arch wires) are used to tighten braces. in 1959, the united states national aeronautics and space administration (nasa) made an alloy of nickel and titanium called nitinol to be utilized for solar panels and antennas on their satellites. in 1979, dr. george andreasen developed a new method of fixing braces with the use of the nitinol wires because they had super-elasticity. andreasen used the wire on some patients and later found out that he could use it for the entire treatment. andreasen then began using the nitinol wires for all his treatments and as a result, dental doctor visits were reduced, the cost of dental treatment was reduced, and patients reported less discomfort.