Ass. Prof. of Oral and Maxillofacial Surgery Impacted Teeth By Dr: Waleed A Abdullah Bds, Msc, Phd Ass. Prof. of Oral and Maxillofacial Surgery King Saud University

Definition :- is a tooth that fails to erupt into its normal functioning position in the dental arch within the expected time. The term Unerupted includes both impacted teeth and teeth that are in the process of erupting.

Causes of impaction

Systemic Causes a hereditary syndrom of cliedocranial dysistosis termed primary Retention. endocrinal deficiency (hypothyrodism, hypopituitarism). febrile disease, down syndrom, irradiation (all cause multiple teeth impaction).

Local Factors prolonged deciduous tooth retention malposed tooth germ arch length deficiency odontoginic tumors abnormal eruption path cleft lip and palate

frequency of impaction - The order of frequency of impacted teeth is as follow:-

frequency of impaction mandibular 3rd molar maxillary 3rd molar maxillary cuspid mandibular cuspid Mandibular premolar maxillary premolars maxillary central and lateral incisors

Evaluation

Include clinical inspection to disclose tooth not in position or absent in place and radiographic assessment Showing the unerupted position of the tooth

Standard radiographic techs used to localize the unerupted teeth, these include: The tube shift method Periapical & occlusal films Panoramic view CT

The tube shift method Uses two periapical radiographs, shifting the tube horizontally between exposures. If the unerupted teeth moves in the same direction in which the tube is shifted, its located on the lingual or palatal side A facial or buccally located tooth moves in the opposite direction to the tube shift.

The periapical &occlusal method Uses the periapical radiograph taken with standard technique and an occlusal radiograph to give different views of the impacted tooth. Panoramic film can be used to assess maxillary canine position

Complication of impacted teeth (indication for removal):

the presence of impacted teeth in the jaw can create a variety of problems, so it should be removed as soon as diagnosis is made:

Pericoronitis

when a tooth is partially impacted with a large amount of soft tissue over the axial and occlusal surfaces, the patient frequently has one or more episodes of pericronitis.

Definition of pericoronitis is an infection of the soft tissue around the crown of partially impacted tooth and is caused by the normal oral flora.

Causes If the patient experience a mild transient decrease in host defense, pericoronitis may result. pericronitis may arise secondary to minor trauma from maxillary third molar. The soft tissue that covers the occlusal surface of the partially erupted mandibular third molar known as the operculum can be traumatized and become swollen this can be treated by removal of maxillary third molar.

entrapment of food under operculum, in the pocket under operculum and impacted teeth ,this pocket can not be cleaned ,bacteria invade it and pericoronitis begins. streptococci and anaerobic bacteria (the usual bacteria inhabit the gingival sulcus) cause pericronitis .

Treatment and Management

- Percronitis is present as a localized swelling and soreness. pericronitis can present as a very mild infection or as a sever infection that requires hospitalization of the patient . In its mildest form:- - Percronitis is present as a localized swelling and soreness. - Mild irrigation and curettage by dentist and home irrigation by pt is suffice. In sever infection with local tissue swelling: that is traumatized by maxillary third molar ,the dentist should consider the maxillary third molar and local irrigation .

for the patient who have in addition to local swelling and pain, mild facial swelling ,mild trismus secondary to inflammation extending into muscle of mastication ,and a low grade fever, the dentist should consider administration of antibiotics along with irrigation and extraction, (penicillin is the antibiotic of choice).

the mandibular third molar shouldn't be removed until sign and symptoms of pericronitis have been completely resolved the incidence of post operative complication as dry socket and post operative infection ,increases if tooth is removed during time of active infection.

Dental Caries When third molar is impacted or partially impacted ,the bacteria that cause dental caries can be exposed to the distal aspect of the 2nd molar, as well as to third molar

Periodontal Disease Erupted teeth adjacent to impacted teeth are predisposed to periodontal disease. As it decrease amount of bone on the distal aspect of adjacent 2nd molar, with deep periodontal pocket on the distal aspect of the 2nd molar.

Root Resorption Impacted teeth cause sufficient pressure on the root of an adjacent tooth to cause root resorption.

Pain of unexplained origin: Pain in the retro molar region with no obvious reason.

Odontogenic cyst and Tumors The dental follicle may undergo cystic degeneration and become a dentigerios cyst or keratocyst. A meloblastoma may developed from epithelium within the dental follicle

Fracture of the jaw impacted third molar occupies space that is usually filled with bone, this weaken the mandible and render the mandible to fracture.

Facilitation of orthodontic treatment impacted teeth under dental prosthesis: Facilitation of orthodontic treatment to relief crowding of mandibular anterior teeth.

Contraindication for removal of impacted teeth:

compromised medical status: extreme of age: - as the bone become highly calcified, less flexible, less likely to bend under force of tooth extraction the result ,bone more surgically removed to displace tooth from its socket and less post operative sequla compromised medical status: probable excessive damage to adjacent structure:

Classification system of impacted teeth - this is done to help dentist in evaluation of the extent of the surgical procedure and in the planning of this procedure.

1-Classification of impacted mandibular third molar:

A - Relation of the tooth to the ascending ramus of the mandible and to the distal surface of the 2nd molar: (Pell &Gregory) this show the anterioposterior relationship of the tooth to the arch and the amount of resistance offered by the bone of the ascending ramus that may influence the tooth removal

Class1 the space between the anterior part of the ascending ramus and the distal surface of the 2nd molar is sufficient to accommodate the mesiodistal diameter of the crown of the third molar.

Class2 the space between the anterior part of the ascending ramus and distal surface of the 2nd molar is less than the mesiodistal diameter of the crown of the third molar (part of the tooth located within the ramus)

Class3 all the third molar is located within the ascending ramus of the mandible.

B - Relative depth of the third molar in bone: - this show the superior inferior relationship of the tooth in relation to the occlusal plan. (Pell & Gregory) Position A: the highest portion of the tooth is on level with or above the occlusal plane. Position B: the highest portion is below the occlusal plane but above the cervical margin of the 2nd molar Position C: the highest point of the tooth is below the cervical margins of the 2nd molar (deep impaction)

3-mesioangular impaction. 4-destoangular impaction: C - the position of the long axis of the impacted tooth in relation to the long axis of the 2nd molar (winter's classification): 1-vertical: the long axis of the third molar is parallel to that of the 2nd molar. 2-horizontal:the long axis of the third molar is at right angle to that of the 2nd molar . 3-mesioangular impaction. 4-destoangular impaction: all the previous four classes can come in: a - lingual deflection. b - buccal deflection. 5-inverted impaction

2 -Classification of impacted maxillary third molar:

The relationship of the tooth to occlusal plane of the 2nd molar (as before) The relationship of tooth to maxillary sinus : a-sinus approximation : (s.a) where no bone or very thin bone exist between the impacted teeth and floor of sinus. b-no sinus approximation : (n.s.a) where 2 mm or more of bone exist between the floor of sinus and impacted teeth.

3-Classification of impacted maxillary cuspids:

Class1: palatally impacted cuspids ,these could be in vertical, horizontal, semivertical position. Class2: labialy impacted cuspide which could be in vertical, horizontal, semivertical. Class3: impacted cuspid located both in the palatal and labial surfaces. Class4: impacted cuspid that are present in an edentulous maxilla and may assume any of the previous three classes.

Surgical removal of impacted teeth:

1- Proper radiographic and clinical evaluation of the condition: A- periapical radiograph B- occlusal radiograph C- panoramic radiograph 2- Classification of impaction to help in planning the surgical procedure: 3- Selection of the time for surgical procedure: surgical removal of impacted third molar is not as a surgical emergency, it is an elective procedure which shouldn't be postponed for along period of time until several complication arises.

4- The condition should be explained to patient in a simple easy way directing his attention to possible complication that may arise from leaving tooth in position 5- Surgical removal can be made under local anesthesia as well as general anesthesia the choice of the anesthetic technique depends on: a- general condition of the patient and his ability psychologically and physically take the procedure. in very apprehensive patient, general anesthesia is preferred. b- position of impaction and extent of surgical procedure c- patient co-operation d- number of impaction that will be removed in the setting

the surgical procedure is divided into following stages:

1- gaining access to impacted tooth: A- elevation of an adequate mucoperosteal flap to expose the field of surgery: Pyramidal flap used in all third molar impaction, the anterior incision of the flap could extend from the distal aspect to 2nd molar running at 45 degree angel and extend to the mucobucal fold. In deep impaction ,a bigger flap is advisable. the anterior incision could start from the mesial aspect of 2nd molar

Surgical Extraction of Impacted Molars Envelope Incision and reflection When more accessibility is needed , a releasing incision is made.

Envelope Flap Incision and Reflection Triangular Flap Incision and Reflection

extraction of impacted maxillary 3rd molar

with palatally impacted maxillary cuspid - exposure of the field of surgery can be done by gingival incision extending from the palatal side of premolar in one side to other side all around the palatal gingiva of the present teeth. with labially placed impaction - a labial pyramidal flap is adequate

2- bone removal This is done for :- A- exposure of impaction B- reduction of resistance C- making a point for application of the elevator

Bone Removal With a Fissure Surgical Bur

3- tooth delivery 1- total delivery by application of force using elevators: a- mesial application of force :straight elevators and pot's elevators. b- buccal application of force :winter elevator 2-delivery of the tooth after tooth division : - division is indicated to reduce resistance ,create a space or remove interlocked cusps of the tooth a- decapitation:- division of the crown of the tooth at cervical margin level . - indicated in horizontal mandibular and maxillary third molar impaction and pallataly impacted maxillary cuspid b- longitudinal tooth division: - indicated when the impacted tooth has a widely divergent straight roots, or when one root is straight and the other is curved c- division of the interlocking cusp: - this is done with mesioangular impaction ,removal of the inter locking segment of the tooth usually located under the distal surface of 2nd molar

Bone is removed with the surgical bur to expose the whole crown Decapitation is then performed A purchase point is prepared in the root, which is then removed with an elevator The second root is removed in the same way

Preparation for wound closure: - after removal of the tooth from it's socket the wound is gently irrigated with sterile normal saline solution and inspected for: a- any remnant of the residual tooth sac is removed b- remnant of tooth structure or fragments of bone debris is gently removed c- small fragments of the detached bone d- sharp edges of interseptal or alveolar bone is trimmed and smoothed - then final irrigation and wound now is ready for closure.

closure of the wound: post operative care: well designed and properly reflected flap fall back easily into place. using have circle a traumatic needle and 000 black silk suture to hold flap into place post operative care: a pressure pack is held in place for 1hour post operative instruction given to pt: cold packs on outside of face 20 min/h 5 time daily proper antibiotic therapy mouth wash soft diet patient return back for check up after two days suture removal after 5 days

Complication associated with surgical removal pf impacted tooth:

1- laceration of the soft tissue flap: a-improper incision b-improper elevation of the flap and improper retraction this leads to delayed healing and sever discomfort 2- affection of the alveolar bone: 3- fracture of the jaw: - in angle of mandible ,improper use of elevator with uncontrolled force 4- fracture of tuberosity: this occurs with erupted rather than unerupted tooth due to improper use of force

a-injury to inferior alveolar canal: 5-comlication related to injury of adjacent structure: a-injury to inferior alveolar canal: - occurs in deeply seated vertical impaction, the nerve pass between roots of impacted tooth .permanent numbness and heamorraghe b-damage to nasal floor: - during surgical removal of impacted maxillary cuspid, profuse bleeding from nasal mucosa c- involvement of maxillary sinus: - during removal of impacted maxillary third molar. oro anntral fistula results d- pushing of impacted tooth into maxillary sinus: e- pushing of impacted maxillary molar into pterigopalatine fossa: - uncontrolled mesial application of force in deep impaction f- pushing impacted mandibular third molar into sub-mandibular space: - uncontrolled buccal application pf force and fracture of the lingual plate g-aspiration or swallowing of impacted tooth: - with general anesthesia ,

post operative complication: pain. infection heamoraghe anesthesia or parenthesis of the lingual or inferior alveolar nerve trismus,limitation of jaw movement osteomylitis pain at tmj pain on swallowing due to edema of pharynx and hematoma formation.

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