PRESENTER- Dr. HEENA AGARWALMODERATOR -Dr. MAHENDRA P.

• Definition• Etiology of impaction• Indications & contraindications• Imaging modalities of an impacted tooth• Localization of impacted tooth• Impacted maxillary third molar• Impacted maxillary cuspids• Impacted mandibular cuspids• Reference

The word “ The word “ IMPACTIONIMPACTION’ is from Latin origin – ’ is from Latin origin – IMPACTSIMPACTS

Impacted tooth is one that fails to erupt and will not Impacted tooth is one that fails to erupt and will not eventually assume its anatomical arch relationship beyond eventually assume its anatomical arch relationship beyond the chronological age of eruption and its further eruption is the chronological age of eruption and its further eruption is

prevented by the surrounding soft tissue or bone ” prevented by the surrounding soft tissue or bone ” ARCHERARCHER

An An UNERUPTEDUNERUPTED tooth – is a tooth that is in the process tooth – is a tooth that is in the process of eruption and is likely to erupt based on clinical and of eruption and is likely to erupt based on clinical and radiographic findings.radiographic findings.

MALPOSEDMALPOSED tooth - A tooth unerupted or erupted tooth - A tooth unerupted or erupted which is in an abnormal position in the maxilla or in the which is in an abnormal position in the maxilla or in the mandible.mandible.

An An EMBEDDED EMBEDDED tooth – is the tooth that has failed to tooth – is the tooth that has failed to erupt completely or partially to its correct position in the erupt completely or partially to its correct position in the dental arch and its eruption potential has been lost.dental arch and its eruption potential has been lost.

Impacted teeth can be defined as those teeth that are prevented from eruption due to a physical barrier within the path of eruption (Farman, 2004).

The term impaction was defined by Peterson as tooth that fails to erupt into the dental arch within the expected time (Peterson, 1998).

ETIOLOGY of ETIOLOGY of IMPACTED IMPACTED

TEETHTEETH

PHYLOGENIC PHYLOGENIC THEORYTHEORY

DECREASE IN JAW DECREASE IN JAW FUNCTIONFUNCTION

DECREASE IN JAW DECREASE IN JAW SIZESIZE

IMPACTIONIMPACTION

DISUSE THEORYDISUSE THEORY

MENDILIAN MENDILIAN THEORYTHEORY

LARGE TEETHLARGE TEETHSMALL JAWSMALL JAW

LACK OF SPACE FOR LACK OF SPACE FOR TOOTH ERUPTIONTOOTH ERUPTION

IMPACTIONIMPACTION

FATHERFATHERMOTHERMOTHER

HERIDETARY HERIDETARY THEORYTHEORY

ENDOCRINE THEORYENDOCRINE THEORYENDOCRINE DISTURBANCE

DECREASED GROWTH OF JAWSDECREASED GROWTH OF JAWS

LACK OF SPACE FOR TOOTH LACK OF SPACE FOR TOOTH ERUPTIONERUPTION

IMPACTIONIMPACTION

ORTHODONTIC ORTHODONTIC THEORYTHEORY

HINDERENCE TO HINDERENCE TO TOOTH MOVEMENT TOOTH MOVEMENT AND JAW GROWTHAND JAW GROWTH

FORWARD FORWARD DIRECTIONDIRECTION

TRAUMA ,TRAUMA ,DENSE BONE ,DENSE BONE ,

MALOCCLUSIONMALOCCLUSION

IMPACTIOIMPACTIO

NN

Systemic cause

Order of frequency of Impaction

Indication

Contraindication Health consideration

Prosthetic consideration

Socioeconomic reasons

Radiographic evaluation of impacted teeth

The diagnostic radiograph must demonstrate the following:

Entire outline of the impacted teeth

Outline of the follicle sac

Occlusal radiography

Occlusal radiography represents an excellent imaging method when the image field extends more apically then the coverage of the standard IOPA radiograph.

Also helpful on patients with a limited mouth opening

Anterior Maxillary topographical projection

Lateral Maxillary topographical projection

Anterior Max. occlusal Cross-sectional

Lateral

Panaromic radiography

OPG that display the entire dentoalveolar complex and adjacent anatomy are excellent for imaging many impacted teeth.

Skull radiography

Special techniqueCT scansCT scans are useful and indicated if an impacted tooth is

positioned in an ectopic positioned in an ectopic position distant from the oral cavity or associated with neoplastic or inflammatory process with morbidity in the contiguous tissues.

Based on anatomic position

A) Relative depth of the impacted third molar in bone:

Class A: The lowest portion of the crown of the impacted

maxillary 3rd molar is on a line with the second

molar.

Class B: The lowest portion of the crown of the impacted

maxillary 3rd molar is between the occlusal plane

of the second molar and cervical line.

Class C: The lowest portion of the crown of the impacted

maxillary 3rd molar is at or above the cervical line

of second molar.

B)The position of the long axis of the impacted maxillary third molar in relation to the long axis of the second molar:

1. Vertical2. Horizontal 3. Mesioangular 4. Distoangular 5. Inverted 6. Buccoangular7. Linguoangular

C) Relationship of impacted maxillary third molar with maxillary sinus

1. Sinus approximation (S.A.): no bone or a thin portion of bone between the impacted maxillary 3rd molar and the maxillary sinus, known as maxillary sinus approximation.

2. No sinus approximation (N.S.A.): 2 mm or more of bone between the impacted maxillary 3rd molar and the maxillary sinus, known as no maxillary sinus approximation.

Class AClass A

Class BClass B

Class CClass C

Factor complicating surgical removal

Envelop flap

Palatal flap

Removal of overlying bone

Complications

Reasons for canine impaction1. BECKER CONCEPT (1984) Hypothesized 2 processes in palatal

impaction

2. MC BRIDGE CONCEPT Canine formed high in anterior wall – below the

floor of orbit – long tortous path of eruption.

Absence of Absence of initial early initial early guidance guidance

Failure of Failure of buccal buccal

movement of movement of canine canine

MOYERS CONCEPT : summarised by BISHORA

BERGER CONCEPT ( systemic cause of impaction)

Malnutrition, Syphilis, Rickets, Progeria etc Syndromes – Cliedocranial dysplasia,

Achondroplasia,

VONDER HEYDT CONCEPT Total arch length of permanent teeth -established

very early in life Canine is larger and later erupting -it may get

impacted.

GUIDANCE THEORY – MILLER Canine usually have more mesial development path,

which is guided downwards apparently along the distal aspect of the lateral incisor roots.

PECKS AND PECKS CONCEPT Palatal impacted canine is an inherited trait occurs

in combination with tooth size reduction, supernumery tooth and other ectopicaly tooth

Palatally impacted canine as dental anomaly as genetic origin

FIELD AND ACKERMAN CLASSIFICATION (1935)MAXILLARY CANINESa LABIAL POSITION

Crown in intimate relationship with incisors.Crown well above the apices of incisors.

b PALATAL POSITIONCrown near the surface in close relationship to roots of incisors.Crown deeply embedded in close relationship to apices of incisors.

c. INTERMEDIATE POSITIONCrown between lateral incisor and 1st premolar roots.Crown above these teeth with crown labially placed and root palatally placed or vice versa.

d. UNUSUAL POSITIONIn nasal or antral wall.In infra orbital region.

Class I: Impacted cuspids located in the palate a. Horizontal b. Vertical c. Semivertical Class II: Impacted cuspids located in the labial or buccal surface of the maxilla a. Horizontal b. Vertical c. Semivertical

Class III: Impacted cuspids located in both the palatal process and labial or buccal maxillary bone.Class IV: Impacted cuspid located in the alveolar process, usually between the incisor and first bicuspid.Class V: Impacted cuspids located in an edentulous maxilla

Indication Changed position of adjacent teeth

Resorption of roots of adjacent teeth

Cyst formation

Cleft palate

Before the fitting of full or partial denture

Neurologic symptom

Contraindication When the cuspid can be brought into normal

position either by surgical positioning or combination of surgery and orthodontia at an early age .

Factor complicating the removal of impacted maxillary cuspid

Proximity of impacted cuspid to adjacent teeth and vital structure.

Possibility of forcing cuspid into maxillary sinus.

Most impacted cuspid roots have a pronounced curvature at the apical third

Impacted mandibular cuspids - usually vertically impacted - found close to the labial surface.

Occasionally - located beneath the apices of the mandibular incisors lying transversely at a 45 degree angle to the lower border of the mandible.

Rarely - found in a horizontal position or on the lingual side of the dental arch.

FIELD AND ACKERMAN CLASSIFICATION (1935)MANDIBULAR CANINESLABIALVerticalObliqueHorizontal

ABERRANTAt inferior borderOn the opposite side

Complication of max. & mand. canine Infection Paresthesia Damage to adjacent structures Noneruption Loss of soft tissue flap Lack of attached gingiva. Devitalization of the pulp pain

Conclusion…. Acc to Chandler and Laskin, the best way to

determine the complexity of any operation is at the time of surgery.

Opinions based on comparison of radiograph with operative report are more accurate than those based purely on radiographs.

References Minor oral surgery – G HowePrinciple of oral & maxillofacial Surgery –

PetersonContemporary oral & maxillofacial Surgery –

PetersonImpacted teeth – Alling & AllingTextbook of oral & maxillofacial Surgery –

KrugerOral Surgery – ArcherPrinciple of oral & maxillofacial surgery –

Moore & GillbeTextbook of oral & maxillofacial Surgery – SM

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