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Ortho Tribune Middle East & Africa No. 2, 2018

Dental Tribune Middle East & Africa Edition | 2/2018 ORTHO TRIBUNE E5 ◊Page E4 tooth surface. Once firmly seated, maintain pressure on the jigs with finger force, applied 45-degrees to the enamel surface. This procedure ensures uniform contact between each pad and the respective tooth.4 (8) Assuming the correct amount of adhesive was applied to the pad, there will be no excess when the pad is pressed onto the tooth surface. If adhesive extrudes from between the tooth and pad, use a microbrush dipped in the bonding agent to re- move the excess. (9) Maintaining firm finger pressure as previously described, use the cur- ing light for half the time specified, then release the finger pressure and complete the second half of the cur- ing process in a passive manner. (10) Lightly spray the bonded bracket and attached jig with water for sev- eral seconds to dissolve the adhesive holding them together. (11) Use a Weingart utility plier to gently remove the jigs from the brackets. Begin by loosening the at- tachment in a mesiodistal direction. Then remove the jig by rolling it to the lingual, in a reversal of the path used to seat the pad on the surface of each tooth. Make sure the bond is broken on all surfaces of the bracket before completely removing the jig. (12) Insert the first prescribed arch- wire, usually a stock 0.014-in CuNiTi, to begin alignment (Fig. 6).5 Conclusion The recommended bonding pro- cedure is extremely important for Insignia® custom brackets. Properly installing the precise, digital device is readily accomplished in a relatively brief appointment by adhering to the standardized bonding protocol. Acknowledgment Thanks to Mr. Paul Head for proof- reading this article. References 1. Lee A, Chang CH, Roberts WE. Skel- etal Class III crowded malocclusion treated with the Insignia custom bracket system. Int J Orthod Implan- tol 2017;47:52-69. 2. Chang C, Lee A, Chang CH, Roberts WE. Bimaxillary protrusion treated Fig. 6: For the premolar extraction case shown, teeth with red Xs will be extracted. Place segmental 0.014-in CuNiTi archwires that terminate distal to the canines and mesial to the extraction sites. At the terminal ends of the segments, leave about 4mm of wire to curve lingually to ensure patient comfort. with Insignia system customized brackets and archwires. Int J Orthod Implantol 2017;48:50- 70. 3. Lee A, Chang CH, Roberts WE. Tru- Root: Increasing simulation accu- racy of Insignia by CBCT. Int J Orthod Implantol 2017;48:98-99. 4. Chang C, Lee A, Chang CH, Roberts WE. Rebonding tips for the custom bracket system: Insignia, Int J Orthod Implantol 2017;47:110-113. 5. Lee A, Chang CH, Roberts WE. Arch- wire sequence for Insignia: a custom bracket system with a bright future. Int J Orthod Implantol 2017;46:60- 69. Avoiding common problems in tooth extractions By Dr Kamis Gaballah, UAE The last two decades have seen sig- nificant advances in restorative tech- niques and materials for dentistry. The latter, along with community- based preventive measures that aim to reduce the incidence of car- ies, have resulted in many patients living with functional teeth for a longer period. Yet, extraction of teeth forms the considerable bulk of the workload in oral surgeries owing to several factors, including the late presentation of patients with ad- vanced dental disease, the presence of symptomatic impacted teeth, such as third molars, and the need to extract teeth for orthodontic or orthognathic treatment. The extraction of teeth varies greatly based on the type of patient who is undergoing the procedure. For ex- ample, elderly patients with signifi- cant co-morbidities and on a com- plex combination of medications as compared with young healthy individuals render the procedure complicated and require much more preparation with modifications dur- ing and after patient management. Additionally, extractions can range from a single, fully erupted tooth with favourable morphology to mul- tiple misaligned, impacted teeth or teeth with challenging morphology. Local anatomy, such as tooth prox- imity to the nerve, maxillary sinus and tuberosity, also plays a signifi- cant role. These variations usually dictate who is to perform the extrac- tion, as many general practitioners deal with less complicated cases of dental extraction in individuals re- garded as healthy patients and may not feel comfortable operating on medically complex patients. Complex extraction cases have been linked to a higher rate of postop- erative complications; therefore, a cautious and systematic approach should be adopted that includes a detailed preoperative assessment to predict the potential difficulties that might arise during extraction. The documentation of all complicat- Photograph: Komsan Loonprom /Shutterstock ing risk factors along with their po- tential postoperative morbidities is crucial and should be included in the informed consent. In the following article, other useful tips will be pro- vided that are not usually included in traditional textbooks or lecture notes to help general practitioners to perform safer extractions. During clinical examination, it has been proven useful to observe the patient’s build. Tall and muscular in- dividuals tend to have a long ramus with a higher mandibular foramen, and this increases the possibility of failure of the inferior dental nerve block procedure if the former is not taken into account when determin- ing the height of the injection site. This can be aided by tracing the in- ferior dental canal (IDC) to the man- dibular foramen in the preoperative panoramic radiograph. The teeth of such individuals may also have longer and more curved roots and be embedded in highly dense, compact alveolar bone, and thus sectioning of the teeth may be required to ease the resistance. Racial differences should also be taken into account, as extrac- tions of teeth from individuals of Afro-Caribbean descent tend to be more challenging owing to the hard- ness of their bone and divergence of roots in their molars. The resistance of hard tissue should be expected, particularly if maxil- lary second and third molars are being extracted, as the potential for fracture of both the buccal plate and the tuberosity is relatively com- mon when excessive force is applied with dental forceps. Fracture of the tuberosity may produce irregular sharp bony boundaries, significant soft-tissue laceration and potentially an oroantral fistula. If such risk fac- tors are identified, tooth sectioning should be followed by elevation of roots with dental luxatomes instead of traditional elevators or forceps, which are known to deliver much higher force to the alveolar bone. The indications for the extraction of impacted lower third molars (LM3) have been the subject of long- standing debate. Surgical procedures for the extraction of unerupted LM3 are associated with significant mor- bidity. This includes pain, swelling and the possibility of temporary or permanent nerve damage, result- ing in altered sensation of the lip, chin, gingiva or tongue. Damage to the inferior dental nerve (IDN) is a well-known complication of surgical extraction of deeply impacted LM3. It should be acknowledged that this is not simply a loss of sensation; the damaged nerve can be responsible for a number of abnormal sensa- tions, including sharp pain and ab- normal response to stimuli, such as the perception of a light touch as a sharp stab. This can have a sig- nificant impact on quality of life for many patients. Injury to the IDN may occur from compression of the nerve, either indirectly by forces transmitted by the root and surrounding bone dur- ing elevation or directly by surgical instruments, such as elevators. The nerve may also become transected by rotary instruments or during ex- traction of a tooth whose roots are notched or perforated by the IDN. The risk factors for IDN injury dur- ing extraction of LM3 are shown in Table I. Preoperative radiographic investiga- tions may include intra-oral images, such as occlusal radiographs; pano- ramic views of the jaws; and conven- tional CT or CBCT scans. It should be noted that risk-predicting signs in radiographs only indicate that there is an increased risk of nerve damage associated with the extraction of the corresponding third molar. How- ever, they cannot actually prevent the nerve injury if the tooth is to be extracted. The effective strategies that may avoid or minimise the risk of injury to the IDN can be collec- tively categorised into two main sets. The first is the preoperative workup, which should include critical assess- ment of the need to extract the third molar, clinical examination and radiographic investigation, and the second is intra-operative measures, including proper selection of local anaesthetic agent, the injection tech- nique, modification of the surgical procedure and measures to reduce the degree of potential injury to the nerve. Most literature published in the last decade has given us sufficient evi- dence to suggest a significant risk of damage to both the inferior dental and the lingual nerve owing to the nerve block procedure. This injury may be related to the pharmacological properties of the agent itself or the injection tech- nique. Studies have shown that the lingual nerve is affected approxi- mately twice as often as the IDN, and one reason for this may be the fascic- ular pattern in the region where the injection is given. It also appears that about half of patients feel an electric shock sensation during injection. There is a higher incidence of reports of nerve injury after the use of artic- aine and prilocaine. Although the reason for this remains unknown, it has been suggested that this may be because they are 4 % solutions, whereas the other commonly used local anaesthetics have lower con- centrations. Others associate the damage with the neurotoxicity po- tential of 4 % articaine and 3–4 % pri- locaine. Hence, it is recommended that the use of such anaesthetics be limited to local infiltration. It has been claimed that needle contact with a nerve felt by the patient as an electric shock is related to injection injury. An obvious explanation is that the possibility of mechanical in- jury to the nerve is more likely in the case of multiple repeated attempts ÿPage E6

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