Principles of Surgical Management of Impacted Teeth 2024 Lectures PDF

Lec. Principles of Surgical Management of Dr.Nibras Hamdan Impacted Teeth 1 Lower third molar (LTM) 1.1 Causes of impaction The third molars or the wisdom teeth normally erupt last, between 18 and 25 years of age. Sinc...

Lec. Principles of Surgical Management of Dr.Nibras Hamdan Impacted Teeth 1 Lower third molar (LTM) 1.1 Causes of impaction The third molars or the wisdom teeth normally erupt last, between 18 and 25 years of age. Since they erupt at about the time when the youth goes off into the world to become 'wise' the name 'wisdom teeth' was used to describe them. 1.1.1 Theories of impaction 1. Discrepancy between the arch length and the tooth size. 2. Differential growth of the mesial and distal roots. 3. Evolution theory. 4. Lack of development of jaw bones due to consumption of more refined food which causes lack of functional stimulation to the growth of jawbone. 1.1.2 Local causes of impaction Like Irregularity in the position of adjacent tooth. density of investing bone, presence of inflammation, underdeveloped jaws, retention, or premature loss of primary tooth. 1.1.3 Systemic causes of impaction A. Prenatal causes: Hereditary and miscegenation B. Postnatal causes: Rickets, anaemia, congenital syphilis, tuberculosis, malnutrition. C. Rare conditions: Cleidocranial dysostosis, oxycephaly, achondroplasia, and cleft palate. 1.2 Causes of impacted teeth removal (indications) 1. Pericoronitis and pericoronal abscess: Most common cause for extraction of mandibular third molars (25 to 30%). Its risk increases with vertical orientation and higher the eruption à distoangular and vertical impaction. If improperly treatedà sub masseteric abscess. 2. Dental Caries 3. Periodontal diseases: There is high prevalence of increased periodontal probing depths (PD) in asymptomatic third molar region. 4. Orthodontic reasons: like crowding of incisors or for non-extraction orthodontics, (molar distalization instead of premolars extraction in Class II malocclusion) 5. To facilitate orthognathic surgery: e.g. sagittal split osteotomy 6. Odontogenic cysts and tumours 7. Management of unexplained pain: Possibility of the following must be eliminated. - Temporomandibular joint dysfunction. - Muscle spasm - Clenching habit 8. Resorption of root of adjacent tooth 9. Teeth under dental prosthesis: Teeth that are more superficial. 10. Prevention of jaw fracture: For those engaged in contact games. 11. Deep fascial space infection: In pericoronitis associated with impacted LTM. 12. Impacted teeth as potential source of infection; in partially erupted LTM. Third molar should be removed in following patient to eliminate further complication: a. Prior to administration of radiotherapy b. Cardiac patients with valvular disease or those who have undergone valve replacement. c. Organ transplantation 1  d. Insertion of alloplastic implants 13. For autogenous transplantation to a first molar socket 1.3 Classification of Impacted Mandibular Third Molar It is a tool for predicting the difficulty of removal based on the analysis of the periapical x-ray or OPG. The most widely used: 1. Angulation (Winter, 1926) of the impacted tooth: Vertical, Mesioangular, Horizontal, Distoangular, Buccoangular, Linguoangular, Inverted, Unusual. 2. Relationship of the impacted tooth to the anterior border of the ramus (Pell and Gregory, 1942) à space available between ramus and the distal side of the second à space available for tooth eruption: Class I: Sufficient space available to erupt. Class II: Space is less than the mesio-distal width of the crown of LTM. Class III: All or most of LTM located within the ramus (difficult to remove). 3. Depth of impaction and the type of tissue overlying the tooth (Pell and Gregory Classification based on relationship to occlusal plane): i.e. soft tissue, partial bony, or complete bony impaction: Position A: Highest portion of LTM is on a level with or above occlusal line. Position B: The highest portion of LTM is below the occlusal line but above the cervical line of second molar. Position C: Highest portion of LTM is below the cervical line of second molar. A mesioangular impaction with a CLASS I ramus relationship and POSITION A depth would be the easiest type à distoangular impaction with a class III ramus relationship and position C depth would involve a difficult surgical procedure. 4. Type of tissue overlying the tooth: i.e. soft tissue, partial bony, or complete bony impaction. 5. State of Eruption; 1. Erupted 2. Partially erupted 3. Unerupted. 6. Number of roots 1. Fused roots (Single) 2. Two roots 3. Multiple roots Notes: Disadvantage of classification: no accepted classification for impacted tooth In edentulous jaw Associated with infection (bony/soft tissue) or pathological lesions. Associated with local complicating factors or systemic condition. 1.4 Clinical Examination 1.4.1 History Taking: 1.4.1.1 Complaints of the patient. 1.4.1.2 Medical and dental history. 1.4.2 Extraoral Examination The face and neck are examined for signs of swelling or redness of the cheek suggestive of infection. The lower lip is tested for anaesthesia or paraesthesia. The regional lymph nodes are palpated for enlargement and tenderness. 1.4.3 Intraoral Examination 1. Mouth opening. 2  2. General examination of oral cavity: Oral mucosa, teeth, oral hygiene. 3. LTM area: State of eruption of tooth, tissue overlying the tooth (bone/soft tissue only), signs of pericoronitis. 4. Condition of impacted LTM: Carious or with fillings, internal resorption, angulation of tooth, locking of crown of third molar beneath second molar. 5. Condition of second molar and first molar: Crown condition, periodontal condition 6. Amount of space available between the distal surface of second molar and the ascending ramus: If the distance is small, the tooth is less accessible. 7. Pathological complications due to skeletal diseases should be noted. 1.5 Radiographic examination Should provide additional information to those found during clinical examination about: Ø LTMs Ø Related teeth Ø Related anatomical features Ø Surrounding bone. The one or combination of the following intra oral and extra oral radiographs usually used: 1. Periapical radiograph: are more discriminating than OPG and may be more helpful in detecting caries, bone height at the level of second molar and root contour. 2. Occlusal X-ray: This will help to show: Ø Bucco-lingual relationship indicated by a periapical X-ray. Ø Exact position of the crown of the tooth Ø Shape of laterally deviated roots. 3. Lateral oblique view of mandible: useful in the following situations: Ø Periapical film could not be taken due to retching, trismus, etc. Ø To provide additional information like vertical height of mandible, amount of bone beneath deeply buried impacted tooth in a thin mandible, existence of pathology in the area. Its use should be considered in the absence of OPG. 4. Orthopantomogram (OPG): All the information available from a lateral oblique view can be had from OPG with less distortion (considered the gold standard for surveying the maxilla and mandible for pathological conditions in the lateral plane). 5. Cone beam computed tomography (CBCT): Advised when the OPG suggests a close relationship between the roots of the LTM and IAN. 1.5.1 Interpretation of Periapical X-ray a. Access: By noting the inclination of the radiopaque line cast by the external oblique ridgeà If this line is vertical the access is poor and if horizontal, access is good b. Position and depth of impacted tooth: This is determined by a method described by George Winter; three imaginary lines are drawn described as 'white', 'amber' and 'red' lines. Ø White line: drawn along the occlusal surface of the erupted mandibular molars and extended to LTM region. This gives the axial inclination (vertical. mesioangular, distoangular) of LTM. Ø Amber' line; drawn from the surface of the bone lying distal to LTM to the crest of the interdental septum between the first and second molar; indicates the margin of alveolar bone covering LTM. 3  Ø Red line; measures the depth of impaction in bone. It is a perpendicular line dropped from the 'amber' line to an imaginary 'point of application' of an elevator (cementoenamel junction on the mesial surface of LTM). Ø Every 1 mm increase in the length of 'red' line, extraction difficulty increases about three times. Ø Any tooth with a 'red' line 5 mm or more is better removed under general anaesthesia. Ø When assessing the depth of disto-angular impactions, the 'red' line should be dropped to the cemento-enamel junction on the distal side of LTM. c. Root pattern of impacted tooth: Ø The number, shape, and curvature of roots Ø The presence of hypercementosis or ankylosis Ø Root appears blunt and short when the apical portion of root takes a sharp bend in the direction of X-ray beam. Ø Root morphology influences the degree of difficulty: i- Limited root development leads to a "rolling" tooth à difficult to remove à sectioned in multiple planes. ii- A tooth with 1/3 to 2/3 root development is easier to remove. iii- LTM with conical and fused roots are easier to remove than those with widely separated roots. iv- Roots with severe curvature are more difficult to remove. v- Roots that curve in the same direction as the pathway of removal break less often. vi- Roots with a mesiodistal diameter that is greater than the tooth diameter at the cervical line must be sectioned longitudinally before removal. vii- The presence of multiple roots may not be visible in radiographs (overlapping) à change angulation of central ray. d. Shape of crown: Teeth with large crowns and prominent cusps à difficult to remove. e. Texture of the investing bone: If cancellous spaces are large and the bone structure is fine, the bone is generally elastic. The denser the boneà more time required for its removal with a bur. f. Inferior alveolar canal: It can be seen to be crossing the roots of LTM due to either superimposition or grooving/ perforation of the root. This can be distinguished through: 1. A band of reduced radio-opacity crossing the roots and coinciding with the outline of the inferior alveolar canal indicates that the tooth root is grooved by the inferior alveolar canal. 2. The compact bone forming the roof and floor of the canal is represented on the radiograph by parallel lines of radio-opacity. Break in the continuity of one or both lines can be seen when the root is grooved by the inferior alveolar canal. 3. In cases where the radiolucent band crosses the apex of the root and if only the upper white line is broken, a notching of the root is present. 4. Characteristic narrowing of the radiolucent band with loss of white lines is suggestive of perforation of the root by the inferior alveolar canal. The following signs suggests increased risk of nerve injury during LTM surgery: Diversion of the inferior dental canal (IDC) Darkening of the root when crossed by the canal. Interruption of the white lines of the canal. Notes Ø If the grooving is on the lingual side of the tooth, generous amount of bone is removed on the buccal side and the tooth delivered through the resultant defect. 4  Ø If apical notching present; tooth division is done to avoid nerve damage. Ø If root is perforated by the neurovascular bundle àremoval of buccal plate of bone àroot is then carefully sectioned using a bur at the level of the neurovascular bundle à root fragments removed. g. Position, root pattern and nature of crown of second molar: Ø The closer LTM is to the second molar à more difficult the surgery. Ø Distal tilt of the long axis of the second molar à more difficult the surgery. Ø If the second molar has a single conical root it can be easily displaced by an elevator applied to the mesial surface of LTM. Ø Large restorations, crown, and root canal therapy in second molar teeth à risk to damage to it. 1.6 Armamentarium 1. Local anaesthesia: Local anaesthetic containing vasoconstrictor (e.g. lignocaine 2% with adrenalin) ensures adequate analgesia as well as reduces bleeding. 2. Instruments to incise mucoperiosteum: Usually No.15 scalpel blade on a No.3 Bard Parker handle. 3. Instruments to reflect mucoperiosteum: Mucoperiosteum is reflected using periosteal elevator. Howarth periosteal elevator is an ideal instrument for reflecting the mucoperiosteum. This instrument can also be used as a retractor of the mucoperiosteum. 4. Instruments to retract mucoperiosteal flap: Numerous instruments are available for this purpose. Austin's retractor for retracting the flap, Kilner retractor for holding the lip, Lack's tongue depressor for retracting the tongue and Rowe's lingual retractor. Other retractors now available are Minnesota retractor, Cawood-Minnesota. A flat bladed retractor to hold the mucoperiosteal flap when bur is used to remove bone. 5. Bone cutting/tooth division instruments: Chisel and bur are used for the removal of bone. Chisel has the advantage of rapidity, no production of heat and no generation of bone dust. However, use of chisel and mallet is an unpleasant experience for the patient à under L.A. avoided à use bur. Other situations for bur usage over chisel are: Ø Mandible is thin and atrophic or when the bone is brittle or sclerosed. Ø Access is limited for the use of chisel (e.g. deeply impacted tooth) Use of chisel and mallet: Give short, sharp, light taps with the mallet by wrist movement. A chisel has a bevelled and a flat surface à with the bevel superiorly, a deeper cut will result when used with mallet. The chisel should be held at right angles to bone surface with good support to the mandible by the assistant àavoid damage to the temporomandibular joint. Use of micromotor and bur: micromotor, straight hand piece and bur. Note Air driven handpiece can cause surgical emphysema and drive tooth and bone particles into soft tissues à postoperative infection. Tungsten carbide fissure bur now commonly used for 1bone cutting ('guttering') and 2 sectioning of tooth compared to the round bur (rose head bur). It is preferable to use a straight handpiece since, it is easier to control during use as well as effortless to clean. 6. Instruments for irrigation and suction: continuous irrigation used to avoid overheating of bone (can result in necrosis of viable bone cells à osteomyelitis). For that purpose, saline filled syringe with its needle directed towards the revolving bur is used. An alternative method is to use a system with inbuilt saline pump connected to the handpiece. It is mandatory to use a suction apparatus for effective drainage of the irrigant and blood as well as to clear the surgical site off the debris. 5  7. Instruments for removal of tooth and debridement of surgical site: Once, adequate amount of bone has been removed, only slight force with an elevator is usually sufficient to deliver it: Dental extraction forceps in general are not advisable à can result in fracture of mandible. Cross bar elevators like Winter's cross bar elevator also generate tremendous force à should be avoided. Moreover, their beaks can cause perforation of thin lingual plate pushing the fractured root piece into the lingual pouch. Instruments that can be safely used are elevators with small mechanical advantage like Warwick James elevator. After the tooth has been removed à debridement of the wound à uneventful healing: Curved mosquito à remove follicular remnants and bone pieces. Angulated curette à clean the socket off the debris. Bone file à Smoothening rough edges of bone The socket and the soft tissue flap are once again thoroughly irrigated with saline taken in a syringe to wash off the debris. 8. Instruments for closure of mucoperiosteal flap: Medium sized triangular cutting needle with ½ or 3/4 circle. Needle holder. Toothed dissecting forceps Suture material (3-0 size) à black silk, linen, catgut or vicryl. 9. Other equipment: like Operating loupe à better visualization of the surgical site. Mouth prop àreduces the fatigue of the jaw. 1.7 Surgical procedure 1.7.1 Patient positioning Generally, for procedures in mandible the occlusal plane of lower teeth should be parallel to the floor and for the maxillary teeth the occlusal plane of the upper teeth at 45° angles to the floor. 1.7.2 Incision and Designing the Flap The deeper LTM à more extensive the bone removal required and the necessity for tooth sectioning. The most used flap is the envelope flap, which extends from just posterior to the position of the impacted tooth anteriorly to the level of the first molar. The posterior end of the incision is directed buccally along the external oblique ridge. If greater access is required, a release incision is given on the anterior aspect of the incision, creating a triangular flap (started from a point approximately 6 mm down in the buccal sulcus and then extended obliquely upwards to the gingival margin to a point at the junction of the posterior and middle thirds of the second molar). The blunt end of the periosteal elevator is passed beneath the mucoperiosteum to reflect the soft tissue. Reflection of lingual mucoperiosteum is kept to the minimum to avoid injury to lingual nerve. 6 1.7.3 Bone Removal The amount of bone removal varies with the depth of impactionà remove enough bone to free the tooth from obstruction and to provide a point of application for the elevator. A. A common technique 'lingual split bone technique' introduced by Ward (1956) à a section of bone lingual to the wisdom tooth is fractured off to facilitate the removal of the impacted tooth. B. Buccal approach; should be kept to minimum to avoid weakening of the mandible. 1. The bone on the buccal and the distal aspect of the impacted tooth is removed down to the level of the cervical line (Further bone removal if required is done minimally to maintain strength of mandible) à achieved by drilling a deep vertical gutter alongside the buccal and/or distal aspect of the tooth. 2. Guttering will ensure that the 1height of the buccal plate is maintained and 2 adequate space is created for tooth delivery. 3. As the bur reaches the apex of the tooth, the inferior alveolar canal may be opened à brisk haemorrhage from inferior alveolar vessels à controlled with pressure pack or bone wax. 4. Drilling in the region mesial to impacted tooth is kept to the minimum to avoid damage to second molar. 5. If the tooth requires more than moderate force to be removed à further bone removal or tooth sectioning. 6. Index finger of left hand should rest on the occlusal surface of the wisdom tooth to judge its movement and the other fingers support the mandible. 7. To apply the elevator, a point of application (purchase point) is required àeither in the bone or a bur cut is made on the tooth. 8. Factors That Make Impaction Surgery Notes: Factors That Make Impaction Surgery Less Difficult 1. Mesioangular position 7. Large follicle 2. Pell and Gregory class 1 ramus 8. Elastic bone 3. Pell and Gregory position A depth 9. Separated from second molar. 4. Roots 1/3 to 2/3 formed. 10. Separated from inferior alveolar nerve. 5. Fused conical roots. 11. Soft tissue impaction 6. Wide periodontal ligament Factors That Make Impaction Surgery More Difficult 1. Distoangular position 7. Thin follicle 2. Pell and Gregory class 2 or 3 ramus 8. Dense, inelastic bone 3. Pell and Gregory position B or C depth 9. Contact with second molar. 4. Long, thin roots 10. Close to inferior alveolar canal 5. Divergent, curved roots 11. Complete bony impaction 6. Narrow periodontal ligament 7 Lec. Principles of Surgical Management of Dr.Nibras Hamdan Impacted Teeth 1.7.4 Sectioning and Tooth Delivery Tooth sectioning is performed either with a bur or a chisel and it helps to: Reduce operating time. Avoid the need to remove additional amount of bone. When sectioning is required, could be made at the neck of the tooth using bur to facilitate crown removal followed by the root(s). Divergent roots usually divided and removed separately. Notes: If sectioning tooth in a buccal to the lingual direction à only three quarters the way is cut. The reminder is then split with a straight elevator à prevents injury to the lingual cortical plates and lingual nerve. If sectioning in the superior to inferior direction à Entry of bur is limited to three fourth of the width of the tooth and the rest is separated with elevator à to prevent possibility of damaging the contents of the canal The line of sectioning of crown/tooth should be perpendicular. If NOT à sectioned segment will be wider at the bottom à elevation will be difficult 1.7.5 Other Methods for Removal of Impacted LTM Sagittal split ramus osteotomy: In this technique a longitudinal split of ramus is done to remove LTM in patients with: Ø history of recurrent infection with/ or without trismus associated with a deeply impacted LTM, and/or Ø impacted LTM intimately involved with the inferior alveolar nerve. Lingual Split technique: Involves the use of a chisel and mallet to remove or displace the lingual plate (adjacent to LTM). A small amount of buccal bone is often removed to facilitate exposure of the crown and provide a point of application for an elevator. Partial Odontectomy: (coronectomy, deliberate root retention) procedure devised to protect the IAN. Radiographic features suggesting an intimate relationship: o Darkening of the root and interruption of the white line of the canal o Narrowing of the canal o Deflection of the roots Adequate amount of root must be removed below the crest of the lingual and buccal plates of bone à bone forms over the retained roots. Contraindications to Partial Odontectomy o Active infection around the tooth o Mobile teeth - any retained mobile root à nidus for infection. o Horizontally impacted tooth along the course of the nerveà sectioning the tooth will damage the IAN. 1  Orthodontic extraction: used when there is proximity to mandibular canal; involves surgical exposure of LTM crown and attaching orthodontic appliance to extrude the tooth moving it away from IAN, facilitating its removal. 1.7.6 Complications of LTM Impaction Surgery 1.7.6.1 Complications during the Surgical procedure 1. Complications during incision; Excessive bleeding may occur in the following situations: Pre-existing local inflammation. a. Bleeding from retromolar vessels b. Bleeding from facial vessels c. Damage to lingual nerve. 2. Complications during bone removal a. Use of bur Accidental burns Laceration of soft tissues Injury to inferior alveolar bundle Injury to adjacent tooth Injury to lingual nerve Necrosis of bone Emphysema b. Use of chisel: Splintering of bone Fracture of mandible Displacement of tooth into lingual pouch Injury to lingual nerve Injury to second molar tooth and soft tissues 3. Complications during sectioning of tooth Incorrect line of sectioning of crown Injury to mandibular canal 4. Complications during elevation of tooth Fracture of impacted tooth/ root Breakage of bur Injury to second molar Fracture of mandible (applying excessive force) Dislodgement of tooth/crown into the lingual pouch or lateral pharyngeal space; if the displaced tooth can be palpated it can be directed back to the socket using finger pressure or it can be retrieved using a long tissue forceps, no blind attempt should be made, if retrieval fails another operation is needed. Injury to mandibular canal 1.7.6.2 Post-Surgical Sequelae and Complications 1. Oedema 2. Trismus 3. Pain These three complications are considered as acute reversible inflammatory response to surgical trauma. They can be minimized by gentle surgical technique, the use of 2  NSAIDs or steroids. These complications peak after 48 hours and resolve within a week. 4. Haemorrhage 5. Infection 6. Alveolar osteitis (Dry socket); it occurs 3-4 days postoperatively due to blood clot disintegration, the predisposing factors include: a. Smoking history. b. Women taking oral contraceptives. c. Pre-existing infection. d. Excessive surgical trauma. 7. Nerve Injury: Temporal or permanent nerve dysfunction of the inferior dental nerve and lingual nerve, this is manifested as anaesthesia, paraesthesia, or dysesthesia. Recovery of normal sensation may take few days to several months. 8. Surgical Emphysema 9. Hematoma 10. Pain during swallowing 11. Pyrexia 12. Osteomyelitis 13. Temporomandibular joint (TMJ) complications 14. Fracture of instruments: Especially that of sharp Ones 15. Periodontal pocket formation distal to second molar 16. Aspiration /Swallowing of tooth 1.8 Other lines of treatment (other than removal) 1. Observation: when impacted teeth do not meet the indications of removal. 2. Operculectomy; which is the excision of the soft tissue overlying the impacted tooth, it is indicated only in selected cases, subsequent excision may be needed. 3. Surgical reimplantation/ transplantation; in selected cases, when the first molar is badly carious or unrestorable, the impacted tooth is carefully extracted and reimplanted in the socket of the first molar and splinted. 2 Upper third molars (UTM) 2.1 Classification of impacted UTM: State of Eruption; 1. Fully erupted 2. Partially erupted 3. Unerupted Angulation of the Tooth; 1. Vertical, 2. Mesioangular, 3. Distoangular, 4. Laterally displaced with the crown facing the cheek, horizontal, inverted, and transverse positions, 5. Aberrant position. Pell and Gregory Classification: Ø Position A: UTM occlusal surface is at the same level of that of 2nd molar. Ø Position B: UTM occlusal surface is between occlusal plane and cervical line 2nd molar. Ø Position C: UTM occlusal surface is at or above cervical line of 2nd molar. Relationship of Impacted UTM to the Maxillary Sinus Ø Sinus approximation (SA): No bone or a thin partition of bone between UTM and maxillary sinus. 3  Ø No sinus approximation (NSA): 2 mm or more bone between UTM and maxillary sinus. Nature of Roots; 1. Fused (conical) 2. Multiple—Favourable/Unfavourable 2.2 Indications for the Removal of UTM 1. Extensive dental caries which is beyond restoration 2. Recurrent pericoronitis 3. Buccally or distally erupting tooth à cheek biting 4. Tooth involved in pathological process. 5. Over erupted and non-functional UTM 6. Buccally erupting upper 3rd molar impinging on the coronoid process à pain during movement. 7. Interference with placement of prosthesis 2.3 Local Contraindications for Removal 1. Symptom-less UTM completely embedded in bone. 2. UTM high in alveolus à displacing into antrum or infratemporal fossa. 3. Deeply impacted tooth àremoval can damage the adjacent second molar. 2.4 Radiographic Examination 1. Periapical X-ray 2. OPG 3. Occlusal X-ray 4. True lateral view 5. PNS (paranasal sinus) view of maxilla à if associated pathology 6. CT scan—especially if associated pathology 2.5 Determining the Degree of Difficulty of Removal 1. Angulation: same angulations in mandibular LTM cause opposite degree of difficulty for UTM extraction. 2. Position in buccoangular direction: directed towards the buccal aspect à easy. Positioned towards the palatal aspect à difficult to remove. 3. Type of overlying tissues; only soft tissue covering is easier to remove. 4. Proximity to maxillary sinus 5. Proximity to maxillary tuberosity; tuberosity can be fractured. Factors contributing to this hazard are: Dense and non-elastic bone as in old age Multirooted tooth with large bulbous roots Large maxillary sinus (that include roots of UTM) Use of excessive force to elevate UTM. Mesioangular impactions 6. Other factors influencing the degree of surgical difficulty: Tooth with roots which are thin àdifficulty increased. Hypercementosis àdifficulty increased. Wide periodontal space àdifficulty decreased. Tooth with a wide follicular space àdifficulty decreased. Bone is more elastic as in young patients àdifficulty decreased. Close relationship to second molar àdifficulty increased. 4  Fusion of UTM with roots of second molaràdifficulty increased. Presence of large restoration on second molar àdifficulty increased. Difficult access due to small oral aperture or trismusàdifficulty increased. 2.6 Steps in the operative procedure for removal One of the difficulties that will be encountered during its surgical removal is the limited access due to the presence of the coronoid process. This can be overcome by opening the mouth only partially. 1. Incision: It starts from the mesial aspect of first molar and extends posteriorly beyond the distobuccal aspect of second molar and then continued into the tuberosity. If greater access is required (deep impaction) à release incision in the mesial aspect of second molar to raise a triangular flap. 2. Using a Howarth's periosteal elevator, the mucoperiosteum is reflected. 3. Bone removal is restricted to the occlusal and the buccal aspect of the tooth down to the cervical line (using chisel or bur). Additional bone is removed on the mesial aspect of the tooth above the height of contour of the crown à for the insertion of an elevator and to act as a purchase point. 4. UTM rarely need sectioning (overlying bone usually thin and elastic). If bone is thick, sclerotic, and less elasticàbone removal rather than tooth sectioning. 5. Delivery of the tooth: using small straight elevators. The following point should be borne in mind while elevating UTM: Due to the proximity of the maxillary sinus and infratemporal fossa à no upward pressure should ne exerted This can be avoided by i- Creating sufficient room between crown and surrounding bone ii- Placing Minnesota retractor or periosteal elevator distal to UTM. 6. Debridement and Closure: A single suture is all that is needed to secure the wound. The suture is passed from the palatal side of the interdental papilla between the first and second molars into the anterior end of the buccal flap. 2.7 Complications During Surgery of Impacted UTM 1. Displacement of tooth into maxillary sinus: Partially erupted and has conical roots. Excessive force is exerted for elevating a buried wisdom tooth. Retrieval can be accomplished via a Caldwell-Luc approach. 2. Dislodgement into soft tissues and into the infratemporal fossa may occur: Buccal flap is not adequate. Decreased visibility during surgical extraction. Incorrect extraction technique Distolingual angulation of tooth UTM crown above the level of the adjacent molar root apices. Such displaced tooth should be removed as early as possible to avoid development of infection. Tooth retrieval can be done with haemostat or Allis’ forceps. Surgical access is gained through an incision along the crest of the alveolus. If the tooth could not be removed after a single effort à patient informed à antibiotic is administered to prevent infectionà tooth removed four to six weeks later by an oral and maxillofacial surgeon. 5 3 Maxillary canines Those are impacted in about 1%-3.5% of the population; the rate among female patients is twice as high as that in males. 3.1 The proposed causes for maxillary canine impaction include: 1. Maxillary canines start their development at a higher level than the adjacent teeth and erupt after them. The long distance that this tooth needs to travel into its normal position there is an increased chance of deflection. 2. The space for its eruption may be taken up by the first premolar. 3. Disturbance of the axis of the tooth germ, scar tissue in the path of eruption. 4. Failure of resorption or ankylosis of the root of the deciduous predecessors, or their early loss. 5. Missing lateral incisor which acts as a guide for the canine. 6. Genetic theory: This theory is based on the observation that palatally impacted maxillary canines are often associated with other dental abnormalities, such as tooth size, shape, number, and structure. If the maxillary canine fails to erupt by the age of 13 years, its position should be investigated, the orthodontist should be consulted to determine if the tooth can be brought to normal occlusion. 3.2 Classification of impacted maxillary canine. Classification helps much in the diagnosis and treatment planning. The following classification suggested by Archer (1975): Class I: Impacted canines in the palate 1: Horizontal 2: Vertical 3: Semi vertical Class II: Impacted canines located on the labial surface. 1: Horizontal 2: Vertical 3: Semi vertical Class III: Impacted canine located labially and palatally; crown on one side and the root on the other side. Class IV: Impacted canine located within the alveolar process, usually vertically between the incisor and first premolar. Class V: Impacted canine in edentulous maxilla 3.3 Clinical examination The position of the tooth may be obvious by the presence of a bulge either palatally or buccally. The palatal impaction is more common than the buccal one. Palpation of the maxilla through the labiobuccal sulcus may reveal the presence of the bulge buccally. The lateral incisor may be proclined due to the presence of the canine labial to the root or may be retroclined if the canine is palatal. 6 Lec. Principles of Surgical Management of Dr.Nibras Hamdan Impacted Teeth 3.4 Radiographic examination and assessment The radiographic views that can be used include periapical, occlusal, OPG, lateral skull view cone beam CT (CBCT) can also be used. 1. The periapical radiograph provides a detailed view of the tooth, surrounding bone, root formation, the presence of root resorption of the adjacent lateral incisor or the presence of any pathology. Localization of the canine is important especially when it cannot be determined clinically. Methods of localization include: o Buccal object rule (parallax method, tube shift technique- Clark 1909); Two periapical films are taken, shifting the tube horizontally distally between exposures, if the tooth moves in the same direction in which the tube is shifted it is localized palatally, if it moves in opposite direction, it is buccally located, in a rule called SLOB (Same Lingual Opposite Buccal). o Vertex occlusal projection: which produces an axial view of the incisors, will demonstrate the buccopalatal localization of the canine. o Periapical-occlusal method; uses a standard periapical view and an occlusal view to give two different views of the impacted tooth. 2. OPG; can be used to localize impacted canine on the basis that palatally impacted canine appear magnified. It can also demonstrate the vertical angulation and its height. 3. Lateral skull view or cephalometric. 4. CBCT. 3.5 Options of treatment 3.5.1 Retention or leave in situ; indicated when: i. The canine is asymptomatic, and its extraction may lead to damage to the adjacent teeth. ii. Aesthetically acceptable. 3.5.2 Surgical exposure and orthodontic traction. A procedure that allows natural or orthodontically guided eruption of the impacted teeth, an active collaboration with an orthodontist is essential for planning this procedure. Certain criteria must be fulfilled: A. There should be adequate space in the arch to accommodate the tooth. B. There should be an unobstructed path of eruption. C. After eruption the tooth should be in near to normal position in all planes. D. The timing of the procedure should be as close as possible to the normal eruption time. The approach is through a palatal envelope flap, extending from the first molar to the first molar on the other side in bilateral impaction cases, or from the first molar to the first premolar on the other side in unilateral impaction cases. Buccally impacted teeth are approached through a 3-sided buccal flap, depending on its location. 1 After reflection of a full mucoperiosteal flap, the crown is exposed using bur and a low-speed handpiece or a sharp curette in cases of thin overlying bone. The exposure should be conservative taking care not to expose the cementoenamel junction (increased incidence of external root resorption). The orthodontist can attach a bracket to the crown, after conducting proper haemostasis, at the same session. In palatally positioned canine, a window is excised in the soft tissue before replacing the flap, if the bracket is not attached at the same operation the window is packed with a suitable pack until it epithelializes for 2-3 weeks. In buccal approaches it is more appropriate to suture the flap above the crown (apically repositioned flap) and the area below covered with a pack to ensure that the tooth will erupt into an area of keratinized mucosa. 3.5.3 Transplantation. In this procedure the canine is carefully extracted and transferred to a surgically prepared socket in the dental arch with minimum delay. The transplanted tooth should be splinted in its new position for about a month with an orthodontic appliance. It is essential to have sufficient space to accommodate the crown of the canine. Success rate is increased when the unerupted teeth still have open apex and when the handling of the root is kept to minimum to ensure the viability of the cementum and periodontal membrane. Endodontic treatment should be performed as soon as possible after surgery (about 6-8 weeks), periodic follow up is required to allow early detection of root resorption which is common. 3.5.4 Removal. Surgical extraction maybe performed when the other options are unavailable. The main indications include: 1- Before construction of a dental prosthesis. 2- To permit orthodontic alignment of other anterior teeth. 3- When there is resorption of the roots of adjacent teeth. 4- When a follicular cyst has developed. 5- Infection although uncommon. Extraction can be performed with retention of the primary canine with restorative procedures to improve aesthetic contour, extraction can also be accompanied with extraction of the primary canine and orthodontic closure of the space by the first premolar. Implant supported crown can also be used to close the space created by extraction of the impacted canine and the primary canine. Impacted canine is approached from the surface of the maxilla with which they are most closely associated, palatally positioned teeth are approached through palatal envelope flap, while buccal teeth are approached through buccal flap. Occasionally tooth sectioning is required after bone removal and the tooth is extracted in segments. Possible complications of upper canine removal include: o Palatal hematoma formation, this can be prevented by an acrylic splint to support the soft tissue. o Perforation into the floor of the nose, but it rarely causes a problem. 2 4 Impacted mandibular canine. These are less frequently impacted than maxillary canines (about 0.3% of population) and are mostly buccally located, partially erupted teeth can be removed easily using elevators or forceps. Localization of the unerupted teeth is by periapical film, OPG or occlusal view that is taken with the X-ray directed along the long axis of the teeth. Removal is by raising a 2-sided or 3-sided buccal mucoperiosteal flap with care to avoid damaging the mental nerve, bone removal and the tooth is extracted wholly or after sectioning. Deeply impacted teeth or those located lingually can be left in situ if they do not cause any damage to the adjacent roots or not associated with other pathologies. Surgical exposure and orthodontic traction are also indicated after consultation with the orthodontist, the exposure is either through a flap or sometimes through excision of the overlying soft tissue when the tooth is only covered by soft tissue. It is noteworthy to say that orthodontic traction is difficult since impacted mandibular canines are frequently in horizontal position near the roots of the adjacent teeth, also due to the dense bone in the region as well as the buccal position of the impacted teeth It is always essential to consult an orthodontist before extraction of impacted canine. 5 Impacted lower premolars. It occurs mostly due to loss of space by drifting forward of the first permanent molar after early extraction of the second deciduous molar, other causes are gross malformation and retention of the deciduous predecessor. Localization is by periapical film or OPG with occlusal view to demonstrate the buccolingual position. Removal is by raising a 2-sided or 3-sided buccal flap, with preservation of the mental nerve, bone removal, sectioning of the tooth if needed and extraction of the tooth. In young patients it is essential to consult an orthodontist before extraction. 6 Impacted maxillary premolars. It is usually impacted with its crown palatally, or it may be within the arch between adjacent roots. It can be partially erupted, completely buried or the crown may be wholly exposed, in the latter case extraction is easy with an elevator or forceps. Completely impacted teeth require a palatal envelope flap extending from the second molar to the lateral incisor on the same side, bone removal and extraction of the tooth. Buccal approach is needed in cases where the tooth is within the arch between the standing teeth, sectioning of the tooth is needed when the root is curved. Care is taken not to damage the adjacent teeth. 3 7 Impacted first and second molars. These are uncommonly impacted, their management consist of surgical extraction through a buccal flap, bone removal avoiding damage to the inferior dental nerve that may cross buccal to the neck of the teeth, sectioning of the tooth may be necessary. The indications of surgical treatment include symptomatic teeth, those that have caused infections, or have evidence of radiographic changes such as cyst or resorption of adjacent teeth roots. Rarely all the three mandibular molars or the second and the third molars are impacted, in this case we start with the mesial of the two and the middle of the three. Another line of treatment is the surgical uprighting, especially of the impacted second molar. This is done through buccal approach, the tooth is exposed carefully without exposing the CEJ, if the third molar is present it needs to be removed, if not, bone posterior to the second molar is removed, followed by tipping the tooth slightly posteriorly and superiorly, and the tooth can be allowed to erupt spontaneously. This procedure is better carried out when 2/3 of the roots of the impacted second molar are developed. Teeth with fully developed roots have poor prognosis for this procedure. Usually there is no need for fixation, but RCT may be needed 6- 8 weeks after surgery, also there should be no occlusal forces on the tooth in the postoperative period. Follow up for about 2 years is necessary. 8 Buried deciduous molars. These are usually ankylosed and should be removed surgically through buccal approach, bone removal and tooth sectioning if necessary. 9 Supernumerary teeth These are more in the males than in the females, they can be present in the primary dentition as well as in the permanent dentition, 50% of the cases in primary dentition will have supernumerary teeth in the permanent dentition. They are associated with cleidocranial dysostosis and cleft lip and palate. Supernumerary teeth can be classified according to their position into Mesiodens, Paramolar and Distomolar. According to the shape they can be conical (peg-shaped), supplementary, which have the shape and size of a normal tooth, or they can have conventional shape with smaller or larger size. Mesiodens; is situated in the premaxilla in the midline and it is commonly conical, it can have a horizontal or inverted position. Supplemental teeth may also occur in the anterior maxillary region. Supernumerary teeth can be single or multiple, unilateral, or bilateral. Paramolar; appear in the premolar or molar region and is situated buccally or lingually to the teeth, they can be conical or supplemental. Distomolar; appear as a fourth molar usually distal to the standing molars and they are either normal or smaller in size. 4 Supernumerary teeth can have no effect on other standing teeth, or they can cause failure of eruption of the other teeth, crowding, malposition or misalignment, resorption of the roots of the adjacent teeth or they can be associated with other pathologies (e.g. cysts). Erupted supernumerary teeth are extracted easily especially if they are conical in shape. Unerupted teeth can be left in situ if they have no effect on the adjacent teeth, but they should be monitored regularly. If they need removal, they should be localized using periapical films (buccal object rule) or vertex occlusal view. OPG is needed to determine the vertical position of the tooth and its position in relation with the floor of the nasal cavity or maxillary sinus. They are approached palatally through palatal flap or buccally through buccal flap. Bone removal and tooth sectioning may be needed. Sometimes combined palatal and buccal approach is necessary. It is essential to avoid damaging the roots of the adjacent teeth. 10 Dilacerated incisors Trauma to the deciduous incisors especially in the 2-3 years of age can cause damage to the underlying permanent incisor tooth germ causing root development to take place at an angle. Exposure and orthodontic traction can be performed, if possible, but if not, these teeth should be removed, and the lateral incisors allowed filling their space. It is essential to seek the opinion of an orthodontist. 11 Summary of Instructions to Patient Following Surgical Removal of Impacted Tooth 1. Remove the gauze pack after 30 minutes to one hour. 2. Apply ice (ice cubes taken in a polythene bag) on the face for the first 24 hours. 3. For the first day take cold liquids or semisolids. 4. Avoid warm saline gargle in the first 24 hours. 5. There may be mild to moderate swelling on the side of the face for three to four days. 6. Mild bleeding/oozing of blood can be there from the surgical site for one to two days. In the event of excessive bleeding: bite on a fresh sterile gauze piece and inform the doctor. 7. In the first few days, difficulty may be experienced in opening the mouth. To avoid this, from the next day of surgery onwards try to open the mouth forcefully. 8. From the next day onwards after surgery or once the oozing of blood has completely stopped, warm saline mouth-baths can be used at fourth hourly intervals. Avoid application of dry heat on the face. 9. Tooth brushing must be done from the next day on wards. 10. Take the drugs prescribed by the doctor at regular intervals. 11. Avoid alcohol, smoking, physical exercise, and long journey for the next few days. 12. Report for review to the doctor as suggested for suture removal. 12 Drug therapy. 12.1 Use of antibiotic Postoperative oral prophylactic antibiotics have not shown to contribute to a better wound healing, less pain, or increased mouth opening and could not prevent inflammatory problems 5 after surgery. And therefore, is not recommended for routine use. The following principles should be considered before prescribing antibiotics: 1. The surgical procedure should harbour a significant risk for infection, for example: Long procedure (> 30 minutes) or difficult surgery involving significant tissue trauma. Where there is existing infection in and around the surgical site. 2. Administration of the antibiotic must be immediately prior to or within 3 hours after the start of surgery: The ability of systemic antibiotics to prevent the development of a primary bacterial lesion is confined to the first 3 hours after inoculation of the wound. Commencing prophylactic antibiotic cover the day before surgery may lead to the development of resistant organisms. Continuing antibiotics for days after surgery has not been shown to decrease the incidence of wound infection. 3. Prophylactic antibiotics should be given at twice the usual dose over the shortest effective time to minimize the potential side-effects of long-term use (e.g. diarrhoea) and to prevent the growth of resistant strains of bacteria. 4. Examples of antibiotic prophylactic regimens: Amoxicillin 3 gm orally, 45 minutes before surgery under local anaesthesia. Clindamycin 600 mg orally, 30 minutes before surgery under local anaesthesia. Benzyl Penicillin 600 mg IV/IM on induction for procedures under general anaesthesia. Erythromycin lactobionate 500 mg IV on induction for surgery under general anaesthesia for patients allergic to penicillin. The above dose may be followed with an additional oral dose 6 hours after the initial dose. 12.2 Use of Anti-inflammatory Drugs and Steroids Perioperative corticosteroids have been used to minimize swelling, trismus, and pain in oral and maxillofacial surgery patients. The most widely used steroids are dexamethasone and methylprednisolone. Common dosages of dexamethasone are 4 to 12 mg given IV at the time of surgery. Additional oral dosages of 4 to 8 mg. twice a day for the day of surgery and 2 days afterwards leads to the maximum relief of swelling, trismus, and pain. Methylprednisolone is commonly given IV 125 mg at the time of surgery followed by significantly lower doses, usually 40 mg 3 or 4 times daily taken orally for the day of surgery and for 2 days after surgery. 12.3 Use of Non-steroidal Anti-inflammatory Drugs (NSAIDs) They are frequently used after surgical procedures to reduce the soft tissue oedema and pain by suppressing inflammation. 12.4 Use of Analgesics It has been reported that soluble aspirin 900 mg provides significant and more rapid analgesia than paracetamol 1,000 mg in the early postoperative period. Patients should be encouraged to take analgesics either before the onset or at the time of onset of pain or discomfort rather than waiting till the pain becomes unbearable. Long-acting local anaesthetic solutions may be of value in some situations where extreme pain is likely to be a feature in the immediate post-operative period. 6