impaction 1

IMPACTION

Exodontia

Exodontia is the clinical practice of extracting teeth and tooth fragments.

Surgical exodontias describes the removal of teeth or tooth fragments via the ‘trans - alveolar’ approach, whereby access to, and delivery of the tooth or its fragment(s) is achieved via a surgically created pathway.

Impacted tooth

Impacted tooth is a tooth that fails to erupt in its anatomical arch position, beyond its chronological age of erruption. i.e. even after complete root formation.

Theories of impaction

Genetic theory

Orthodontic theort

Causes of Impaction

Obstruction to the normal path of eruption caused by :

Adjacent tooth; Supernumerary tooth; Pathological lesion (i.e. odontome,

cyst or tumour).

Causes of Impaction

Stunted growth of tooth germ caused by :

severe nutritional deficiency; irradiation; physical trauma.

Rare disorders : cleidocranial dysostosis; hemifacial microsomia; cretinism.

Frequency of impaction

Third molars are by far the most frequently impacted of all teeth in the human jaws.

They are five to six times more likely to be impacted than the maxillary canines, which are the next most frequently impacted teeth after third molars.

Premolars are the third most likely teeth to be impacted, but this is 17 times less likely than with third molars.

Classification

Mandibular third molar impactions These may be classified according to the

degree of impaction. Angulations of the tooth and proximity to the

inferior alveolar canal.

A. Degree of impaction

No impaction – fully erupted tooth which may be in : functional occlusion with tooth in opposing

arch or non – functional.

Soft- tissue impaction : partly erupted tooth; unerupted tooth.

Bony impaction – unerupted tooth with crown that may be; partially surrounded by bone; totally surrounded by bone.

B. Angulation of the tooth

In the sagittal and transverse planes

Vertical: bucco-version linguo- version

Mesio – angular : bucco – version linguo- version

Disto – angular : bucco – version linguo – version

B. Angulation of the tooth Horizontal:

bucco – version linguo-version

Heterotopic

Tooth is found in unusual places along the lower border of the mandible or high up the ascending ramus, usually in an inverted position.

C.Proximity to the inferior alveolar canal

No contact. Root apices in direct contact. Root crossing canal on one side only

– no imprint of canal on root surface.

Roots partially encircling canal – imprint of canal clearly visible on root surface.

Roots completely encircling canal – canal passes between the roots of the tooth.

Winter Classification

Vertical Mesioangular Horizontal Distoangular Buccoangular

Lingoangular Inverted unusual

PELL AND GREGORY’S CLASSIFICATION

Based on the space available distal to the second molar

class I

Sufficient space available between the anterior border of the ascending ramus and the distal side of the second molar for the eruption of the third molar.


Based on the space available distal to the second molar

class II

The space available between the anterior border of the ramus and the distal side of the second molar is less than the mesiodistal width of the crown of the third molar. it denotes that the distal portion of the third molar crown is covered by the bone from the ascending ramus.


class III: the third molar is totally

embedded in the bone from the ascending ramus because of absolute lack of space.

MAXILLARY THIRD MOLAR CLASSIFICATION

Angulation and depth classification is same as mandibular third molars.


Maxillary third molar classification may be divided into three levels of impaction.

First level – the tooth is erupted or partially erupted.


Second level – the tooth is unerupted but the crown margin of the tooth is below the level of the apices of the second molar tooth.


Third level – when the crown of the unerupted maxillary third molar is above the apices of the adjacent second molar tooth then this degree of impaction poses the greatest surgical difficulty of all.


In relation to the maxillary sinus floor:

a. Sinus approximation -

No bone or thin bony partition between maxillary third molar and the floor of the maxillary sinus.

b. No sinus approximation – 2 mm or more bone is present between the

sinus floor and the impacted maxillary third molar.

Indications for third molar surgery

Mandibular third molars

common reasons. • Pericoronitis • Prophylactic – e.g. orthodontic reasons.• Caries.• Periodontal disease – i.e. deep pocketing along distal root of

lower second molar. • Difficult to clean – due to restricted access for toothbrushing. • To improve access for restoration of distal caries in lower

second molar. • Mandibular sagittal split osteotomies.


Mandibular third molars

Uncommon reasons The more uncommon reasons are

• Previous failed attempted extraction elsewhere.

• Associated pathology, e.g. cysts or more rarely tumours.


Exposure under denture or to facilitate the construction of a prosthesis, e.g. lone standing molar in an otherwise edentulous jaw.

Tooth in line of jaw fracture. Prophylactic removal of dubious third molars

for patients with major medical conditions, e.g. patients undergoing radiotherapy or heart valve replacement.

Obscure facial pain. Resorption of adjacent second lower molar.


Maxillary third molars When present, these teeth are often

extracted at the same time as the mandibular third molars since they are seldom of any functional value even when they are fully erupted.


Maxillary third molars The indications for the surgical removal of maxillary

third molars are given below.Erupted teeth might be removed ;

Non – functional – due to impaction of opposing lower third molar.

Super – erupted or buccally displaced – causing direct trauma to operculum surrounding partially erupted lower third molar.

Difficult to clean – due to restricted access for toothbrushing.

Caries. Periodontal disease.


Maxillary third molars Unerupted maxillary third molars are often

asymptomatic. They can be removed for the following reasons:

Lack of space – in the dental arch for eruption into a functional position.

Patient convenience – to have maxillary third molars removed at the same time as removal of mandibular third molars.

Resorption of adjacent maxillary second molars.

Associated pericoronal pathology – e.g. dentigerous cyst, odontogenic tumour.

Contraindications to third molar surgery

Contraindications are usually relative rather than absolute.

In many instances, provided the appropriate precautions are taken, then third molars may be safely extracted in most situations.


Local factors Caution is advised with the following factors :

• Previous radiotherapy to area where tooth is to be removed.

• Teeth in close proximity to tumour – risk of seeding and spread.

• Acute gingival inflammation with gross plaque and calculus deposits – may result in delayed healing and infection of extraction site


Systemic factors Caution is also advised in the following systemic conditions : Uncontrolled diabetic. Pregnancy. Underlying bleeding disorders. Acute blood dyscrasias, e.g. leukaemias. Cardiac conditions with substantial risk of

infective endocarditis. Patients on anticoagulants, steroids, Immunosuppressants or chemotherapy.

Patient Assessement The purpose of this is to outline the essential

steps required to properly assess a patient for third molar surgery.

History

Chief presenting complaint History of presenting complaint Medical history Social history

Patient Assessement

Examination

Extra – oral examination Intra – oral examination Investigations

Decision

Diagnosis Treatment planning

History The first encounter with a patient presenting for

third molar surgery must establish a working diagnosis, which always begins with a verbal history from the patient.

Chief presenting complaint Essentially, the clinician must determine what is

the patient’s main concern. The most common presenting complaint is pain.

Since pain is a subjective phenomenon, a detailed history of the site, nature, duration and extent of pain is essential in order to determine the cause and pathology.

Other presenting problems may include localized swelling, limited mouth opening, discharge or foul taste in the mouth. It is important to realize that the chief presenting complaint is pivotal to the overall management of the patient.

History of the presenting complaint Background information of the presenting

complaint will often provide the clinician with a clearer understanding of the cause and nature of the condition. Questions that may be important in building up a background picture of the patient’s presenting condition may include :

When was the problem first noticed by the patient ?

What are the possible causes or contributing factors ? For example, is the patient unable to insert the toothbrush far enough back to keep clean the erupted or partly erupted third molars ?

What is the natural course of the problem ? For example, is the pain present continuously or does it come and go with a certain frequency?

Has any treatment been sought in the past, and what was the outcome? For example, did a course of antibiotics help to reduce the pain and swelling?

Intra – oral examination A strong light is essential. Gentle use of the

dental mirror and cheek retractors is conducive to good dentist – patient rapport.

Inspection It is always best to inspect the third molars last

as it is often too easy to overlook other pathology within the oral cavity when the teeth are commonly the site of most of the surgical pathology within the mouth.

Tongue – check size, degree of mobility, colour and texture.

Oral mucosa – begin with the palate, cheeks, labial mucosa and floor of mouth, checking for any changes in colour, texture, ulcers, lumps and so on.

Alveolar ridges and gingivae – assess colur, texture, degree of recession, ulcers and lumps.

Teeth in general – check for number and position of teeth, large restorations, crowns, gross carious lesions, cracked or missing cusps, and exposed dentine, cementum or pulps.

Palpation Palpation is used to check the

following: Soft tissues – check for tenderness,

consistency of lumps and fluctuance of any swelling that may be present.

Third molars – check mobility and use a dental probe to assess defective restoration margins, interproximal carious lesions and periodontal pocketing of the adjacent second molars, or for pus discharge under an inflamed operculum surrounding a partly erupted third molar.

Percussion Using the handle of a dental mirror a

tooth may be tapped to elicit pain due to apical periodontitis, usually in a non – vital tooth, especially a carious fully erupted third molar.

Investigations An adequate and up-to-date radiograph

(preferably less than 6 month old) is the single most important clinical aid in surgical planning. The orthopantomogram is an excellent screening film that is safe and reliable and has now become the standard radio – graph for the preoperative radiological assessment for all third molar surgery.

Investigations are adjunctive measures that serve to provide additional information that cannot be obtained by history and physical examination.

While investigations provide a substantial amount of information, the clinician must be acutely aware of the expense involved, and should balance this with the information being sought that may have a high likelihood of dictating treatment strategies

Periapical X – raysTo summarize : Root tips are often missed; Difficult to position in mouth – especially for gaggers; Difficult to focus central beam; Limited view of surrounding anatomy and pathology; Deeply impacted and heterotopic third molars not seen.

Facial X- rays For those patients who cannot undergo

periapical X-rays or OPG for reasons of intolerance, inability or lack of availability of the appropriate equipment, plain X- ray of the face and jaws may be appropriate.

Lateral oblique views of the mandible are perhaps the most useful of all the available facial projections when it comes third molar assessment

Other imaging techniques Other imaging techniques that are

currently available but are yet to demonstrate any additional benefit in third molar assessment include :

Xeroradiography; Dentascans (tomograms other than

OPG); Intra – oral cameras; Magnetic resonance imaging (MRI) best

for soft tissue.

Factors that indicate a simple extraction

The following factors tend to indicate that extraction will be relatively easy : Clinical factors :

Good access for instrumentation, e.g. patient with good mouth opening;

Periodontally involved teeth; Virtually intact crown; Young patient.

Radiological factors : Simple root configuration, i.e. single,

conical root with broad or open apex with two – thirds root formation;

Well – defined periodontal space.

Factors that indicate a difficult extraction

The likelihood of a difficult extraction is increased in the following circumstances : Clinical factors :

patient with a history of difficult extractions; large, adult male of African or Southern

European descent; grossly carious third molar tooth with

significant likelihood of fracturing upon application of dental elevators;

lone – standing third molar – especially in middle – aged or elderly patients where mandibular or maxillary tuberosity fracture is likely.

Radiological factors :

complex root patterns, e.g. fine curved apical root tips;

bulbous root apex; ankylosis – absence of periodontal space; hypercementosis; dense alveolar bone texture; roots crossing inferior alveolar canal; absence of root formation – crown rolls

around in socket with no stable purchase point for elevators;

maxillary third molars high up behind posterior maxilla;

heterotopic third molars

WHARFE assessment

Winters classification Height of mandible Angulation of 2nd molar Root shape Follicle Path of exit

Position & depth

WHITE LINE:represents occlusal plane joining the enamel caps of errupted molars

AMBER LINE:represents the bone level.It is drawn along the crest of the interdental septum between molars.

RED LINE:indicates depth.It is drawn perpendicular from the amber line to the point of application of the elevator.

Technique for removal of third molars

The basic steps of surgical exodontias

The surgical extraction of teeth and tooth fragments follows six fundamental steps ;

Raising a flap Bone removal Tooth division Removal of the tooth or its fragments Wound toilet Primary closure

Raising a flap A flap is a tongue of tissue comprising a base

and a distal segment that is raised from its surrounding tissue bed. It serves two fundamental purposes :

To gain access to the surgical site. To serve as the primary dressing to cover the surgical defect

that is created.

There are many types of flaps used in surgery, but in surgical exodontias the flap used is a mucoperiosteal flap, which is one comprising oral mucosa and periosteum that covers the alveolar process.

Flaps may also be described in terms of their physical shape or outline, or more foten according to the site from which the flap is raised, for example buccal flap ,palatal flap or lingual flap.

The incision must be made in one continuous stroke through to bone at right angles to the surface of the mucosa.

The base of the flap, where the blood supply is derived, must always be wider than its distal segment in order to maintain the viability of the flap when it is raised from its tissue bed.

Once raised with the aid of a periosteal elevator, the flap must be handled gently to avoid stretching and tearing of its margins, which will compromise its healing potential.

The edges of the flap must always lie on sound bone at the end of the operative procedure in order to prevent wound dehiscence and breakdown.

Removal of boneBone is removed to expose enough tooth in order

to : permit the application of dental elevators;

allow adequate exposure for sectioning of the tooth, and to provide an adequate pathway for delivery of the tooth or tooth fragment(s).

Bone may be removed by the use of sharp chisels or powered handpieces.

The latter are equipped with round or fissured surgical burrs that are water cooled with the exhaust facing away from the surgical site.

High- speed air turbines may create surgical wound emphysema and do not allow enough tactile discrimination between bone and tooth substance.

Tooth division Tooth division is particularly useful in the

following cases: Where the awkward angulation and curvature of the roots of

a multi – rooted tooth do not permit its delivery in one piece.

Where smaller fragments can be easily lifted out of the bony socket therby minimizing the need to remove further bone.

Teeth can be sectioned by using an osteotome or powered handpiece.

An osteotome is quick but the split is often unpredictable.

A powered handpiece, although slow, gives a more predictable split. The split may be completed with a straight elevator after the burr has penetrated the pulp chamber of the tooth.

Wound toilet After the whole tooth or all the tooth fragments

have been completely removed, the remaining surgical defect must be thoroughly debrided and irrigated to remove all loose debris that may cause infections and delay wound healing. Wound toilet may involve.

Excising redundant soft tissue, e.g. remnant of dental follicle.

Curettage of base of socket, especially following the extraction of non – vital teeth, to clear out any periapical pathology such as a periapical granuloma or dental cyst.

Removing any loose fragements of bone or tooth in and around the surgical defect, including under the flap.

Smoothing rough bony edges with a burr or bone files.

Irrigating with sterile isotonic solution and suctioning the area to remove microscopic debris.

On occasions, the surgical defect may be sprinkled with antibiotic power or dressed with antiseptic – soaked ribbon gauze, but this is rarely done these days.

Variations in flap design There are four basic incisions used to raise a flap

when extracting mandibular third molars : a distal relieving incision; an envelope flap, a

buccal extension flap, and a triangular flap

Distal relieving incision A disto – buccal incision is made along the

anterior border of the ascending ramus. The simplest of all flaps can be raised with this incision alone.

It is most often used where the distal part of the crown is covered by soft tissue, such as the operculum.

Envelope flap The anterior incision is extended forwards along the

buccal gingival crevice of the second and first molars as far as the mesial interproximal papilla of the first molar. This has the disadvantages that it

(i) provides limited access for deep impactions; and (ii) if postoperative infection occurs, the gingival

crevice may break down creating periodontal pockets along the first and second molars.

Lingual flaps may be raised by making the anterior incision along the lingual gingival margin fo the adjacent second molar. Access is restricted and there is increased likelihood of injury to the lingual nerve by excessive stretching of the lingual flap.

Buccal extension flap The incision along the gingival crevice is confined to

the second molar with a buccal relieving incision extending inferiorly and anteriorly from the mesial or halfway along the second molar down to the vestibular sulcus in a gentle arc.

Variations in bone removal Bone surrounding the tooth may be removed in

one of a number of ways. Lingual split technique Despite the advantages of speed, rapid healing

and the requirement for only simple instrumentation, the lingual split technique is now rarely used in Western countries outside Great Britain.

The major disadvantages are the requirement for large flaps, the removal of large segments of lingual bone plate, and the increased potential risk of injury to the lingual nerve.

Buccal approach This uses a high – powered handpiece with a

round surgical burr. Bone removal is confined to the buccal aspect,

where a bone gutter is created around the tooth to expose the maximum convexity of the crown so as to create a point of application for the dental elevators.

Sectioning Teeth The most difficult part of mandibular third molar

surgery is understanding the most mechanically advantageous way of dividing a tooth according to its impaction.

Vertical impactions – The incision is carried along the alveolar crest to the distal aspect of the second molar .

If there is a gingival perforation made by an erupting cusp, the incision is interrupted by the opening but the design is not altered.

The incision should penetrate the entire mucoperiosteum. The flap is reflected from the bone with a periosteal elevator, starting anteriorly in the gingival crevice and working posteriorly.

After buccal and occlusal bone has been removed, a careful inspection is made as to the amount of bone impinging on the distal surface of the tooth

If the tooth has straight roots, it can be elevated in a vertical direction and therefore it is only necessary to create space a little larger than the perimeter of the crown.

If the roots are curved distally, remove a considerable are of bone in the ramus behind the tooth to be able to tilt the crown.

The interdental leverage method for luxation

can be used if the tooth tapers toward the root, if there is a space between the neck of the tooth and the second molar, or if the tooth is slightly inclined mesially.

Luxation by buccal leverage .

Horizontal impactions – The incision is made in the usual manner except for deeply embedded teeth. In such situations an oblique extension of the anterior end of the incision into the vestibule provides better access and prevents tearing of the gingival.

The tooth then is divided horizontally, as previously described, from a superior or a buccal approach. After the tooth has been sectioned, the crown is removed with an elevator.

but if the roots are firm or extremely curved, it may be necessary to divide them with a bur and remove each separately.

The crown is separated from its roots and removed first. The roots are themselves divided and removed individually into the space vacated by the crown.

Mesio – angular impactions – The incision is the same as for other partly erupted or unerupted molars and consists of an envelope flap for high – positioned teeth and an angulated flap for low – positioned teeth.

After a flap has been reflected on the buccal side, bone is removed until the distal, cuccal, and occlusal surfaces of the tooth are exposed.

From this point the procedure depends on whether there is sufficient room to elevate the tooth without disturbing the second molar.

Disto-angular impactions – the tooth may be divided in half along its

longitudinal axis or the crown may be sectioned from its roots with the roots being elevated into the space vacated by the crown.

Maxillary third molars Planning the surgical approach When maxillary third molars are considered

in isolation, the degree of surgical difficulty may be considered on three levels:

First level – the tooth is erupted or partially erupted. These teeth are easily removed under local anaesthesia alone with relatively little morbidity.

Second level – the tooth is unerupted but the crown margin of the tooth is below the level of the apices of the second molar tooth.

Third level – When the crown of the unerupted maxillary third molar is above the apices of the adjacent second molar tooth then this degree of impaction poses the greatest surgical difficulty of all. In some cases, a general anaesthetic may be required to gain wider and greater access to the tooth, which harbours an increased likelihood of being accidentally displaced into the maxillary antrum or infratemporal fossa.

Removal of erupted or partly erupted teeth

The technique used to extract maxillary third molars depends on the position of the tooth.

With erupted teeth, the initial step is buccal and palatal infiltration of local anaesthetic solution.

A straight or curved elevator is then placed with the interproximal area, between the second and third molar.

Twisting the elevator in the bucco – distal direction will luxate the tooth sufficiently for the tooth to be removed with the fingers, which should be straddling the socket.

An upper curved forceps may also be used to extract erupted maxillary third molars, with the force concentrated mainly in the buccal direction.

Make sure the airway is protected otherwise the luxated tooth may accidentally be lost in the pharynx with the possible danger of it being aspirated

Removal of unerupted teeth

Flap variations A full mucoperiosteal flap is raised with a

periosteal elevator. The flap outline consists of a distal and mesial incision, which may vary as follows :

Distal incision – made behind the distal aspect of the second molar ; Sagittally along the maxillary tuberosity; Diagonally across the maxillary tuberosity.

Mesial incision – made across the buccal attached gingival of the adjacent second molar: Along the gingival crevice, which has restricted

access to low impactions; Diagonally upward relieving incision, which

may be extended according to the height of the impaction to provide very good access.

Tooth delivery Once the toothis adequately exposed, a fine

curved elevator, such as a curved Warwick –James, is placed across the mesial surface of the third molar in the interproximal space between it and the distal surface of the second molar.

Rotation of the elevator will effectively luxate the tooth in the bucco – distal direction so a protective posteriorly placed retractor will help direct the delivery of the tooth in a buccal direction.

Closure Closure is preceded by thorough wound toilet,

ensuring there is no oro – antral communication. Primary closure is achieved with sutures across the distal and mesial incisions.

However, some clinicians do not place any sutures since the cheek itself holds the flap in place.

Factors that predispose to root fractures during third molar surgery

Several factors increase the likelihood or root fractures during third molar surgery ;

Extensively restored teeth History of difficult extractions. Complex root pattern with multiple

and in particular, fine roots. Dense bone, hypercementosis and

ankylosis. Clumsy use of excessive force to

extract tooth.

Types of third molar infections In third molar surgery, the clinician may encounter the

following conditions that will require surgical attention. Common infections : Caries ; Periodontal disease ; Periocoronitis; Postoperative infection Dry socket; Buccal space abscess; Infected haematoma; Wound dehiscence and breakdown.

Uncommon infections; Cervicofacial actinomycosis; Osteomyelitis; Osteomyelitis; Ludwig’s angina; Cavernous sinus thrombosis; Mediastinitis.

Oedema facial swelling or oedema is a normal reaction of the body to surgical

extraction of third molars, and the severity of the swelling will depend on the difficulty and length of time taken for the surgery.

Measures used to minimize the degree of postoperative facial swelling may include:

Careful extraction technique – delicate handling of tissues with minimal tissue damage.

Increased operator experience – which results in reduced operating time.

Steroids – such as methylprednisolone or dexamethasone are best reserved for the surgical removal of difficult impacted teeth.

NSAIDs (non – steroidal anti – inflammatory drugs) – the anti inflammatory properties of this class of drugs have failed to demonstrate any proven ability to reduce postoperative swelling.

Ice packs – applied to the face immediately after surgery theoretically helps to reduce facial swelling by reducing blood flow and hence the inflammatory response in the vicinity of the surgical site.

Complications of third molar surgery

Sources of complications Complications from third molar surgery may

surgery may arise from either one or a combination of the following factors.

The patient – particularly those with poor compliance to post operative instructions or those who are medically compromised.

The clinician – which is directly dependent on their level of training, their skills and experience, and their attitudes towards total patient care.

The surgical procedure - which is dependent on the complexity of the procedure and the local anatomy of the surgical site, i.e. access and proximity of important structures such as nerves and blood vessels.

Intra – operative complications In the practice of third molar surgery the

most common complications may be subdivided into the following major headings:

Dental complications. Soft – tissue complications. bone complications Nerve complications Sinus complications Instrument breakage.

Dental complications Fractures Fractures can affect the crown, due to gross

caries or excessive force, or the root, due to abnormal morphology such as fine curved apical root tips.

Furthermore, the clumsy use of instruments can cause fractures of adjacent teeth or restorations in adjacent teeth that were not intended for extraction.

Management Radiographs are taken to check the root

pattern and position of remaining fragments. Analgesics and possible antibiotics are

prescribed, and the patient should be promptly referred to a specialist for extraction.

Soft – tissue complications Trauma Trauma to surrounding soft tissues may be caused by : Excessive retraction forces. Slippage of powered handpieces, e.g. surgical burr. Use of hot instruments straight out of the autoclave. Leaning an instrument against a numb lip.

Primary haemorrhage Primary haemorrhage from surrounding gingival tissues may be

persistent where there is excessive surgical trauma, inflamed tissue or an underlying bleeding diathesis of the patient.

Management Management requires an adequate record of any bleeding

disorders that the patient may have. Local haemostatic measures include; Direct pressure by biting on gauze for 20 min. Suturing. Surgicel, Gelfoam, topical thrombin, etc. Diathermy where available.

Bone complications Haemorrhage Bleeding vessels within bone may be controlled with: Bone wax. Compression or crushing of bone with blunt instrument. Packing the socket or bone defect with ribbon gauze

soalked in adrenaline – containing local anaesthetic solution.

Plugging the area with mouldable dental compound or stent.

Replacing the extracted vital tooth, especially in cases of significant haemorrhage caused by the disruption of a vascular lesion in close proximity to the extracted tooth.

Fracture of maxillary tuberosity Predisposing factors for a fracture of the maxillary

tuberosity include long – standing maxillary third molar in elderly patients, or

ankylosed maxillary third molars. Large and complex root patterns of the maxillary third

molars may also be a factor.

Management Replace the fragment and splint with

sutures or dental wires for 3 – 4 weeks then plan for surgical removal of the tooth once the tuberosity is fully healed.

Alternatively, remove the fragment and close the wound primarily with sutures.

Instruct the patient to avoid nose blowing.

Temporomandibular joint dislocation

There is an increased risk of temporomandibular joint dislocation if excessive forces are used to extract mandibular third molars without proper mandibular support.

A further predisposing factor is medication with drugs that have extrapyramidal side – effects, such as the phenothiazine major tranquillizes.

Management Perform digital manipulation of the mandible back

into place making user the thumbs are placed in the vestibule clear of the occlusal surfaces of the teeth.

The use of narcotic analgesia, diazepam or local anaesthesia into the joints may be helpful in relieving the muscle spasm and discomfort of reducing the dislocated mandible.

Fracture of mandible This can be caused either by excessive

extraction forces on mandibular third molars in an unsupported mandible, or by poor surgical technique.

The risk is greater if the tooth is in an otherwise edentulous atrophic mandible, or if there is osteolytic pathology, or if the patient has brittle bones.

Management The fracture can be managed either by

closed reduction with intermaxillary dental wire fixation, or by open reduction and internal fixation; in the latter case the patient must be referred to a specialist !

Nerve complications The inferior alveolar and mental nerves are at most risk

of damage from third molar surgery.Local anaesthetic blocks Direct trauma involves penetration of the needle into

the in ferior alveolar nerve trunk, which results in a sudden electric shock – like pain followed by deep anaesthesia. Nerve injury can also follow indirect trauma, in which a haematoma forms by direct penetration of nearby blood vessels by the needle.

Management consist of explanation and ressurance to the patient. The nerve will normally recover naturally in a few days.

Lingual nerve damage This can be caused by excessive retraction of lingual

tissues or by pressure from a tongue retractor leaning against the lingual alveolus.

Alternatively, the damage may be due to inadvertent severance of the nerve with a burr or scalpel.

Inferior alveolar nerve This can be affected particularly in the

region of the apices of the lower third molars. The roots may directly breach the inferor alveolar canal resulting in direct injury to the nerve upon removal of the tooth.

Alternatively, upon attempted extraction the root tip can be displaced directly into the canal causing a pressure injury of the nerve.

A third possibility is inadvertent severance of the nerve with a burr.

Maxillary sinus complications

Breach of sinus floor An oro – antral communication may be created by the

extraction of maxillary third molars where : The roots extend will beyond the sinus floor. The extraction is difficult and traumatic, e.g. curly root

pattern. The maxillary sinus is abnormally large. The tooth is ankylosed.

Management The immediate treatment options are Replace a vital non – carious tooth and splint into position

and plan to extract surgically at a later date. OR Cover defect with antiseptic – soaked ribbon gauze and

remove in 2-3 weeks to allow healing by secondary intention. OR

Reduce bony socket edge and suture margins together. Refer to specialist, who may do an immediate closure with

a buccal advancement flap provided the sinus is clear of infection.

Displacement of tooth or root into sinus If the tooth or root fragment cannot be retrieved via the

socket then stop the procedure immediately to prevent further displacement.

Take X- rays to confirm the position of the tooth or fragment, and inform the patient. Immediate management consists of analgesics, antibiotics and nasal decongestants.

Refer the patient to a specialist, who may elect to remove the tooth fragement in one of two ways:

directly, by surgically enlarging the socket and either suctioning or flushing out the fragment with saline, or

indirectly by the Caldwell – Luc approach via a surgical window through the anterior maxilla giving the greatest access to the whole sinus interior.

Special precautions Do not attempt to close a suspected oro – antral

communction when : A tooth or root is displaced into the sinus. Pus or purulent material is liberated upon extraction of a

tooth. Clear fluid flows from the sinus upon extraction of a tooth,

which may indicate the presence of a cyst or mucocoele. Unusual soft tissue prolepses through the extraction site.

Postoperative complicationsAlveolar osteitis Alveolar osteitis is the most common cause of delayed

postoperative pain. Alveolar osteitis is a condition in which there is loss of the blood clot from the socket.

Initially the clot has a dirty gray appearance, and then in disintegrates, ultimately leaving a gray or grayish yellow bony socket bare of granulation tissue.Bare bone is encountered, which is extremely sensitive.

Suppuration is generally absent, but a foul odor is present, and there is severe radiating pain.

The pain is usually described as a throbbing ache and is caused by the chemical and thermal irritation of the exposed nerve endings in the periodontal ligament and alveolar bone.

The symptoms generally start on the third to fifth day after extraction of the tooth and, if untreated, will last for about 7 to 14 days.

The cause of alveolar osteitis is variably ascribed to preexisting infection, trauma , ISCHEMIA because of the hemostatic effect of the epinephrine or , , the presence of dense bone, general debilitation, and loss of the clot .

Curettage should never be employed in the treatment of alveolar osteitis. This procedure not only predisposes the patient to the spread of infection, but also destroys any previous attempt at normal healing.

Moreover, since the socket is already infected, any new blood clot formed also will subsequently undergo lysis.

The routine use of antibiotics in the treatment of alveolar osteitis is not recommended because the major problem is one of pain control rather than of unlimited infection

Infection Postoperative infection can be caused by: Excessive trauma. Surgery on inflamed tissues. General lack of resistance Haematoma formation – collection of blood in a potential tissue space

which serves as a good culture medium for bacteria. Poor patient compliance.

Clinical presentation Local involvement presents with pain, erythema, swelling, pus and

fistula formation. Systemic involvement is characterized by increased temperature, pulse rate and respiration rate, lymphadenopathy, malaise and increased white cell count.

Management of infections Local measures are to incise and drain a fluctuant swelling and maintain

drainage by using drain tubes or strips. The site is kept clean by warm saltwater or other mouth rinses. Debride any necrotic tissue and irrigation the area.

Systemic measures, in conjunction with local treatment, consist of rest, fluids and warmth, along with analgesics and antimicrobial chemotherapy. Culture and sensitivity tests are the ideal but are not always clinically practical.

Haemorrhage Delayed haemorrhage Delayed haemorrhage occurs within 24- 48 hours after surgery

and may be due to increased blood flow to the surgical site as a hypertensive response to postoperative pain. On rare occasions it may be due to an undiagnosed bleeding diathesis such as von Willebrand’s disease.

Secondary haemorrhage This classically occurs about 10 days after surgery and is often

caused by a breakdown of the blood clot due to infection.

Management

First, use a strong light and good suction to determine the site of bleeding. Clean out the surgical site with saline then get the patient to bit on gauze for 20 – 30 min. If bleeding persists, consider further local measures such as sutures, or haemostatic agents such as Gelfoam or Surgicel to pack into the bleeding site.

If bleeding persists depite local measures, refer the ap0tient to hospital for full haematological screening and management for a possible underlying systemic bleeding disorder. In hospital the following measures may be used.

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