Management of Impacted TeethPart II

Dr. Rahaf Al-Habbab BDS. MsD. DABOMSDiplomat of the American Boards of OMFSConsultant of Oral and Maxillofacial SurgeryHead of Orthognathic UnitSaudi Boards Residents DirectorHospital Education and Residency Director2013

Management of Impacted TeethPart I

• Impacted Teeth vs. Unerupted Teeth

• Indications of Impacted Teeth Removal

• Management of Pericoronitis

• Contraindications for Removal of Impacted Teeth

Management of Impacted TeethPart II

• Classification System of Impacted Teeth

• Modification of Classification Systems for Maxillary Impacted Teeth

• Surgical Procedure

• Perioperative Patient Management

Classification System of Impacted Teeth

• The difficulty of extraction should be determined prior to the surgery

• The primary factor determining the difficulty of the removal is ACCESSIBILITY

• ACCESSIBILITY is determined by adjacent teeth, or other structures impairing access or delivery pathway

• Panoramic radiograph shows the most accurate picture and is the radiograph of choice

Classification System of Impacted Teeth

• Angulation • Relationship to Anterior Border of Ramus

• Relationship to Occlusal Plane

Angulation

• Most commonly used classification system

• Determined by the angulation of the impacted tooth with respect to the long access of the adjacent second molar.

• Angulation of the third molar determines the pathway for removal

• Provides initial evaluation of the difficulty of extractions, but not sufficient by itself to define difficulty for molar removal fully

Angulation

Mesioangular:

Generally acknowledged as the least difficult impaction,particularly when only partially impacted.

Most common type of impaction, making up approximately 43% of all impactions

Angulation

Horizontal:

Long access of the third molar is perpendicular to the second molar

More difficult to remove than mesioangular

Less frequently seen, count for 3% of all mandibular impactions

Occlusal films to determine bucco-lingual position

Angulation

Vertical:

Long axis of the impacted tooth is parallel to the long axis of the second molar

Second most common impaction to occur, count for 38% of all impaction

Third in difficulty of removal

Angulation

Distoangular:

Most difficult tooth to remove

Long axis of the third molar is distally or posteriorly angled away from the second molar

Uncommon, counting for 6% of all impacted third molars

Relationship to Anterior Border of Ramus

• Based on the amount of third molar covered by the mandibular ramus bone

• Known as the Pell and Gregory Classification 1, 2, and 3

• Surgeon have to examine the relationship between the tooth and the anterior part of the ramus.

Pell and Gregory Classification

Class 1 Relationship:

The mesiodistal diameter of the crown is completely anterior to the anterior border of the ramus

If the tooth is vertical and the root is incompletely formed, it has a great chance to erupt.

Pell and Gregory Classification

Class 2:

The tooth is positioned posteriorly so that one half is covered by the ramus

The tooth can not erupt completely free because of bone distally overlying the crown

Pell and Gregory Classification

Class 3:

Tooth is located completely within the mandibular ramus

Provides the least accessibility and therefore presents the greatest difficulty

Relationship to Occlusal Plane

• The Depth of the impacted tooth compared with the height of the adjacent second molar

• Determines the difficulty of impaction removal

• Known as the Pell and Gregory A, B, and C classification

Pell and Gregory Classification

Class A:

The occlusal surface of the impacted tooth is at the same or nearly the same level as the occlusal plane of the second molar.

Pell and Gregory Classification

Class B:

Impacted tooth occlusal surface between the occlusal plane and the cervical line of the second molar

Pell and Gregory Classification

Class C:

The occlusal surface of the impacted tooth is below the cervical line of the second molar

Summery • All these three classifications are used to determine the

difficulty of extraction.

Example;• Mesioangular impaction with a class 1 ramus and class A

depth is usually straight forward to remove

Root Morphology

• As it is an important factor in determining the degree of difficulty in the extraction of an erupted tooth, it is as important in Impacted teeth

ConsiderationsRoot length

• 1/3-2/3 root formed, with blunt roots• Longer might have some abnormal morphology• Shorter will rotate

Considerations

Root fusion:• Fused, conical roots vs. • widely separated roots

Root Curvature:• Severely curved or dilacerated roots vs.• Straight or slightly curved

Considerations

• Careful examination of the apical area of impacted teeth on the radiographs (small, abnormal, sharply hooked roots)

• The direction of the root curvature (distally curved tip vs. straight or mesially curved)

• Total width of the roots mesiodistally should be compared with the width of the tooth at the cervical line (more difficult, more bone removal, or sectioning)

• Periodontal ligament space (wider vs. narrow) especially in patients over 40.

Size of Follicular Sac

• Young patients tend to have larger follicles• In narrow or non-existent space, the surgeon must create

space around the crown

Density of Surrounding Bone

• Radiographs are not reliable• Best determined by the age of the patient (less than 18, older than 35)

Contact with Mandibular Second Molar

• If space exist, easier extraction will take place

• Distoangular or Horizontal impaction, usually in a direct contact with the second molar, carefull extraction should take place.

Relationship to IAN

• Third molar roots are usually superimposed on the IAC on radiographs

• The canal is usually on the buccal aspect of the tooth

• If in close relationship, injury to the nerve can occur resulting in paresthesia or anesthesia

• Usually lasts few days, weeks, or months, and rarely permanent depending on the degree of injury

• Cone-beam computerized tomographic scans for preoperative assessment of the root and canal relationship

Nature of Overlying Tissue

Classification system used to determine the morestraightforward extraction from the more difficult one:

1) Soft tissue2) Partial bony3) Full bony

Soft Tissue Impaction

The height of the contour of the tooth is above the level of the alveolar bone

The superficial portion of the tooth is covered only by soft tissue

To remove it, the surgeon should reflect a soft tissue flap to obtain access to the tooth

The easiest of the three types

Partial Bony Impaction

The superficial portion of the tooth is covered by soft tissue At least a portion of the height of the contour of the tooth is below the level of the surrounding alveolar bone

To remove it, the surgeon must reflect a soft tissue flap, and remove the bone above the height of the contour

Tooth sectioning might also be needed

More difficult that the first type

Complete Bony Impaction

Tooth is completely encased in bone

When reflecting the soft tissue flap, the tooth will not be visible

To remove the tooth, extensive amount of bone should be removed

The tooth almost always requires sectioning

The most difficult type of extraction

Modification of Classification Systems for Maxillary Impacted Teeth

• The same as the mandibular classification, with several distinctions and additions

• The same angulation in mandibular third molar extraction cause opposite degree of difficulty for maxillary third molar extraction

Modification of Classification Systems for Maxillary Impacted Teeth

Angulations:

• Vertical Impaction (63%)

• Distoangular Impaction (25%)

• Mesioangular Impaction (12%)

Rarely, other positions areencountered (transverse, inverted,horizontal), accounting for lessthan 1%

Maxillary Impacted Teeth

• Mesioangular impaction is the most difficult impaction, because the bone that requires removal or expansion is on the posterior aspect of the tooth, which is much thicker than in vertical or distoangular

• Buccopalatal direction is also important

• Palatal impaction requires more bone removal with possible injury to the nerves and vessels of the palatine foramina.

• Radiographic and clinical examination by digital palpation of the tuberusity area

Maxillary Impacted Teeth

•Most common factor that causes difficulty is a thin, nonfused roots with erratic curvature

•PDL space•Follicular space•Bone density (age)•Relationship to the adjacent tooth•Adjacent large restorations•Type of impaction

Maxillary Impacted Teeth

Additional factors doesn’t exist for the mandibular third molar:• Maxillary sinus proximity (sinusitis, oroantral fistula)• Maxillary tuberosity

Factors increasing the risk of tuberosiy fracture:• Nonelastic bone (older patients)• Multirooted tooth with large bulbous roots (older patients)• Large and greatly pneumatized maxillary sinuses• Use of excessive force

Other Impacted Teeth

Impacted maxillary CanineIf decided to be removed or exposedDetermine tooth position (labial, palatal, or midway)

Exposure:• Flap is created• Tooth exposure• Luxation and Debridement• Gold chain placement • Flap repositioning allowing maximum coverage

Other Impacted Teeth

• Impacted mandibular premolars

• Supernumerary teeth

Position is still needed to be determined

Mesiodens:• Midline supernumerary tooth, most commonly in the palate• Approached from the palatal direction to be removed

Surgical Procedure

Five basic steps are followed in almost any impaction:1. Adequate Exposure2. Sufficient bone removal3. Tooth sectioning4. Tooth delivery by appropriate elevators5. Bone filing, wound irrigation, flap reapproximation and

suturing

Surgical Procedure

• Bone removal should be enough to expose the impacted tooth, but not too much prolonging the healing time

• Tooth sectioning should be done to avoid excessive bone removal, not prolonging the procedure so much

Surgical Procedure1- Adequate Exposure

Reflecting adequate flaps for accessibility:• Adequate mucoperiosteal flap• Adequate dimension to allow the placement and stabilization of

retractors and instruments for bone removal

Envelope Flap:• Preferred technique• Quicker to close• better to heal

Three-cornered Flap:• Envelop flap with releasing incision• Allows greater access to apical region

Envelope Flap

• Extends from the mesial papilla of the mandibular first molar around the neck of the teeth

• To the distobuccal line angle of the second molar, and then

• Posteriorly and laterally up the anterior border of the mandibular ramus.

• The incision should not extend posteriorly in a straight line.. Why?

• Flap reflected laterally exposing the external oblique ridge, using periosteal elevator (minimally)

• Stabilize retractor on bone

Releasing Incision

• If the tooth is deeply embedded in bone and requires more bone removal

• Releasing incision extending from the mesial aspect of the second molar

• Flap must have a broad base with a smooth edge

• Incision should be closed on bone and not on a defect

• Should avoid vital structures

• Only a single releasing incision should be used

2- Removal of Overlying Bone

• Amount of bone varies according to the depth of the tooth, morphology of the roots, and the angulation of the tooth

• Avoid lingual bone removal

• Large round bur (No.8) is desirable (end-cutting bur)

• Fissure burs (lateral cutting)

Removal of Overlying Bone

• The bone of the occlusal aspect is first removed

• Followed by the buccal and distal aspect down to the cervical line of the impacted tooth

• Remove bone between tooth and cortical bone (ditching)

• Create purchase points and pathway for delivery

Removal of Overlying Bone

For maxillary teeth:• If bone removal is needed, it is removed primarily on the

buccal aspect of the tooth , down to the cervical line to expose the entire clinical crown.

• Usually accomplished using a periosteal elevator, rather than a bur.

• Additional bone removal from the mesial aspect of the tooth should be done to allow purchase point

3 -Sectioning The Tooth

• Allow portion of the tooth to be removed through the opening created

• The direction of dividing the tooth, depends primarily on the angulation of the tooth

• Sectioning is performed using a bur, ¾ of the way toward the lingual aspect

• Straight elevator is then used to split the tooth through the slot created.

Mesioangular Mandibular Impaction

The least difficult impaction to remove After sufficient bone removal, the distal half of the crown is sectioned off

Starting at the buccal groove to just below the cervical line at the distal aspect

The portion is removed, and the reminder of the tooth is then removed using a dental elevator

Purchase point can be created in the tooth using a bur

Horizontal Impaction

The next least difficult impaction to remove

Sufficient bone is removed down to the cervical line to expose the superior aspect of the distal root and the majority of the buccal surface of the crown

Tooth is sectioned by dividing the crown of the tooth at the cervical line

Crown is removed, and the roots are displaced into the space, using a cryer elevator.

If the roots are divergent, further sectioning might be required.

Vertical Impaction

One of the most difficult impactions to remove

Bone removal and sectioning procedure is similar to the mesioangular tooth

Occlusal, buccal, and distal bone is removedThe distal half of the crown is sectioned and removed

The tooth is then elevated from a mesial approach

Because it is difficult to obtain access around the second molar, requires substantial

amount of bone removal buccally and distally

Distoangular Impaction

The most difficult tooth to remove

Sufficient bone should be removed from the occlusal, buccal, and distal aspect of the crownThe crown is sectioned from the roots just above the cervical line

If the roots are fused, elevate the tooth into the space using a cryer or a straight elevator

If the roots are divergent, they will be sectioned into two pieces and individually delivered

Difficulty of this impaction is related to the substantial amount of bone removal needed distally, and because of the distal direction of

the tooth elevation

4 -Delivery of the Sectioned Tooth with Elevator

Following adequate bone removal, and tooth exposure, the tooth is delivered from the alveolar process with dental

elevator

The most commonly used elevators are the • Straight elevator• Cayer elevator (paired)• Crane elevator

4 -Delivery of the Sectioned Tooth with Elevator

The difference between the removalof impacted mandibular third molar andother teeth in the mouth:

• No luxation of the tooth• Bone removal instead of expansion• Tooth is sectioned and pathway is

created

• Excessive forces should be avoided• Tuberosity should be supported

during maxillary third molar extraction

5 -Preparing For Wound Closure

• Smooth bone margins using a bone file

• Vigorous irrigation allowing proper debridement of the wound (normal Saline)

• Remove any remnant of the dental follicle

• Final irrigation and inspection

• Control bleeding points if exist

• Application of antibiotics to the socket

• Primary closure starting with the Initial suture (on the posterior aspect of the second molar)

• Releasing incision and passive maxillary flap

Perioperative Patient Management

• Anxiety control

• Long acting local anesthetics

• Analgesics

• Parenteral (IV) steroids administration (Dexamethasone)

• Ice pack use

• Antibiotics (pericoronitis, abscess)