Impaction of teeth Dr. Rafik Al Kowafi BDS, MSc, German board of - PDF document

Impaction of teeth Dr. Rafik Al Kowafi BDS, MSc, German board of Oral and Maxillofacial Surgery ( Berlin- Germany), Doctoral degree by LBMS Definition • The impacted tooth 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 eruption. 12 April 2014 LIMU Dr. Rafik Al Kowafi 2 1

Causes of impaction 1. Hereditary factors that result in a disproportion in size between teeth and jaws. 2. Local causes include: a) Retention or premature loss of a deciduous predecessor. b) The presence of supernumerary teeth. c) Abnormal position of or injury to the tooth germ. 3. Tumours and cysts (e.g. dentigerous cyst, OKC, ameloblastoma). 4. Certain conditions such as: a) Cleft palate. b) Cleidocranial dysostosis. c) Hypopituitarism. d) Cretinism. e) Rickets f) Facial hemiatrophy predispose to delay or failure of eruption. 12 April 2014 LIMU Dr. Rafik Al Kowafi 3 Frequency of impaction 1. Mandibular 3rd molars. 2. Maxillary 3rd molars. 3. Maxillary canines. 4. Mandibular premolars. 5. Maxillary premolars. 6. Mandibular canines. 7. Maxillary central and lateral incisors. 12 April 2014 LIMU Dr. Rafik Al Kowafi 4 2

Indications for removal of impacted teeth 1. Prevention of Dental Caries. 2. Prevention of Pericoronitis. 3. Prevention of Periodontal Disease. 4. Prevention of Root Resorption. 5. Impacted Teeth Under a Dental Prosthesis. 6. Prevention of Odontogenic Cysts and Tumors. 7. Treatment of Pain of Unexplained Origin. 8. Prevention of Jaw Fractures. 9. Facilitation of Orthodontic Treatment. 10. Optimal Periodontal Healing. 11. Facilitation of Orthognathic / Reconstruction Surgery 12. Autogenous Transplantation to First Molar Socket 13. Prophylactic removal - Patients with Medical or Surgical Conditions Requiring Removal of Third Molar (e.g. chemotherapy, radiotherapy). 12 April 2014 LIMU Dr. Rafik Al Kowafi 5 1.Prevention of Dental Caries • When a third molar is impacted or partially impacted, the bacteria that cause dental caries can be exposed to the distal aspect of the second molar, as well as to the third molar. 12 April 2014 LIMU Dr. Rafik Al Kowafi 6 3

2. Prevention of 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 pericoronitis. • Pericoronitis is an infection of the soft tissue around the crown of a partially impacted tooth. 12 April 2014 LIMU Dr. Rafik Al Kowafi 7 3. Prevention of Periodontal Disease • Erupted teeth adjacent to impacted teeth are predisposed to periodontal disease. • The presence of an impacted mandibular third molar decreases the amount of bone on the distal aspect of an adjacent second molar and causes food impaction and deep pockets. 12 April 2014 LIMU Dr. Rafik Al Kowafi 8 4

4. Prevention of Root Resorption. • Occasionally, an impacted tooth causes sufficient pressure on the root of an adjacent tooth to cause root resorption. • Although the process by which root resorption occurs is not well defined, it appears to be similar to the resorption process primary teeth undergo during the eruptive process of the succedaneous teeth. 12 April 2014 LIMU Dr. Rafik Al Kowafi 9 5. Impacted Teeth Under a Dental Prosthesis • After teeth are extracted, the alveolar process slowly undergoes resorption. Thus the impacted tooth becomes closer to the surface of the bone. • The denture may compress the soft tissue onto the impacted tooth, the result is ulceration of the overlying soft tissue and initiation of an odontogenic infection. 12 April 2014 LIMU Dr. Rafik Al Kowafi 10 5

6. Prevention of Odontogenic Cysts and Tumors. • When impacted teeth are retained completely within the alveolar process, the associated follicular sac is also frequently retained and it may undergo cystic degeneration and become a dentigerous cyst or keratocyst. • Odontogenic tumors can arise also from the epithelium contained within the dental follicle. The most common odontogenic tumor to occur in this region is the ameloblastoma. 12 April 2014 LIMU Dr. Rafik Al Kowafi 11 7. Treatment of Pain of Unexplained Origin. • Occasionally, patients come to the dentist complaining of pain in the retromolar region of the mandible for no obvious reasons. • If conditions such as myofascial pain dysfunction syndrome and other facial pain disorders are excluded and if the patient has an impacted tooth, removal of the tooth sometimes results in resolution of the pain. 12 April 2014 LIMU Dr. Rafik Al Kowafi 12 6

8. Prevention of Jaw Fractures • An impacted third molar in the mandible occupies space that is usually filled with bone. This weakens the mandible and renders the jaw more susceptible to fracture at that site. • If the jaw fractures through the area of an impacted third molar, the impacted third molar is frequently removed before the fracture is reduced. 12 April 2014 LIMU Dr. Rafik Al Kowafi 13 9. Facilitation of Orthodontic Treatment • When patients require retraction of first and second molars by orthodontic techniques, the presence of impacted third molars may interfere with the treatment. It is therefore recommended that impacted third molars be removed before orthodontic therapy is begun. • Some orthodontic approaches to a malocclusion might benefit from the placement of retromolar implants to provide distal anchorage. When this is planned, removal of impacted lower third molars is necessary. 12 April 2014 LIMU Dr. Rafik Al Kowafi 14 7

10. Optimal Periodontal Healing • Patients whose third molars are removed before age 25 are more likely to have better bone healing and the infra bony pockets distal to the second molar can be decreased than those whose impacted teeth are removed after age 25. • In the younger patient, not only is the initial periodontal healing better, but the long-term continued regeneration of the periodontium is clearly better. 12 April 2014 LIMU Dr. Rafik Al Kowafi 15 11. Facilitation of Orthognathic Surgery 12 April 2014 LIMU Dr. Rafik Al Kowafi 16 8

Contraindications 1. Extremes of age. 2. Patients with compromised medical status. 3. Probable excessive damage to adjacent structures. 4. When there is a question about the future status of the second molar. 5. Acute pericoronal infection. 12 April 2014 LIMU Dr. Rafik Al Kowafi 17 Classification Of Impacted teeth • Maxillary and mandibular third molar molars are classified radiographically by: A. Degree of impaction. B. Angulation of the tooth. C. Proximity to the inferior alveolar canal. • The most common classification systems used are: – Pell And Gregory Classification. – George B. Winter’s Classification. 12 April 2014 LIMU Dr. Rafik Al Kowafi 18 9

A. Degree of impaction 1. No impaction – fully erupted tooth which may be in : – Functional occlusion with tooth in opposing arch or – Non – functional. 2. Soft- tissue impaction : – Partly erupted tooth. – Unerupted tooth. 3. Bony impaction – unerupted tooth with crown that may be; – Partially surrounded by bone. – Totally surrounded by bone. 12 April 2014 LIMU Dr. Rafik Al Kowafi 19 B. Angulation of the tooth In the sagittal and transverse planes 1. Vertical: – bucco-version – linguo- version 2. Mesio – angular : – bucco – version – linguo- version 3. Disto – angular : – bucco – version – linguo – version 12 April 2014 LIMU Dr. Rafik Al Kowafi 20 10

B. Angulation of the tooth 4. Horizontal: – bucco – version – linguo-version 5. 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. 12 April 2014 LIMU Dr. Rafik Al Kowafi 21 B. Angulation of the tooth • Classification of impaction of mandibular third molars, according to the angulations of the tooth. 1. Mesioangular. 2. Distoangular. 3. Vertical. 4. Horizontal. 5. Bucco-version. 6. Linguo-version. 7. Inverted. 12 April 2014 LIMU Dr. Rafik Al Kowafi 22 11

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. 12 April 2014 LIMU Dr. Rafik Al Kowafi 23 C. Proximity to the inferior alveolar canal 12 April 2014 LIMU Dr. Rafik Al Kowafi 24 12

Pell And Gregory Classification • In Relation Of The Tooth To The Ramus Of The Mandible And The Second Molar: – Class I. – Class II. – Class III. • Relative Depth Of The Third Molar In Bone: – PositionA. – PositionB. – PositionC. 12 April 2014 LIMU Dr. Rafik Al Kowafi 25 Class I • The available Space, at the level of the retromolar triangleIs sufficient to accommodate the mesiodistal diameter of the crown of the third molar. 12 April 2014 LIMU Dr. Rafik Al Kowafi 26 13