CHAPTER 2 - ODONTECTOMY (DENTOALVEOLAR SURGERY, IMPACTED CANINES, IMPACTED THIRD MOLARS)

DENTOALVEOLAR SURGERY

surgical procedures that oral & maxillofacial surgeons perform most often and pertains to those procedures that are associated with the dentate segment of the maxilla or mandible (which is collectively called the alveolar ridge)

1. tooth extractions

2. alveloplasty (recontouring of the alveolar bone)

3. removal of tori (benign bony growths in the maxilla or mandible)

4. placement of dental implants

5. exposure of impacted teeth for orthodontic treatment

6. extraction of impacted teeth

The following are a few of dentoalveolar surgery procedures:

1. alveolar osteitis (dry socket) socket

2. Nerve injury

3. Displacement of a tooth fragment during surgery

Common complications of dentoalveolar surgery:

ALVEOLAR OSTEITIS (dry socket)

• described by patients as postoperative pain that is felt inside and around the extraction site → which increases in severity at any time between 1st & 3rd day after extraction

• Accompanied by a partial or total disintegration of the blood clot within the alveolar socket (with or without halitosis)

ODONTECTOMY

Surgical removal of a tooth by the reflection of a mucoperiosteal flap, excision of bone surrounding the tooth, and followed by the adequate application of force that is necessary to effectively remove the tooth from the socket

IDEAL TIME FOR REMOVAL OF IMPACTED THIRD MOLARS

The time when the roots of the tooth are 1/3 formed, but just before 2/3 of the roots are formed

TIMING OF REMOVAL OF IMPACTED THIRD MOLARS

• usually occurs between the middle & late teenage years of an individual (i.e., 17-20 years old)

• early removal of an impacted tooth reduces postoperative morbidity and also allows for better healing after the procedure

• best done before the presence of any symptoms especially pain

ADVANTAGES FOR REMOVING AN IMPACTED TOOTH IN YOUNGER PATIENTS

1. young patients can better tolerate the procedure

2. faster recovery for young patients

3. periodontal healing is better in younger patients

4. more complete regeneration of the periodontal tissues located in the distal surface of a second molar (or the tooth that is adjacent to the impacted tooth)

5. better chance of recovery if a nerve was injured during the procedure

FACTORS THAT MAY COMPLICATE EXTRACTION ON IMPACTED CANINES

1. difficulty in ocalization (most important factor)

2. close proximity to the roots of the neighboring teeth

3. Maxillary sinus approximation

4. abnormal root curvature & morphology

5) hypercementosis

6) patients inability to open the mouth widely

HYPERCEMENTOSIS

Excessive development of secondary cementum on the tooth surface which mainly occurs on the apex of a tooth

FACTORS THAT MAY COMPLICATE EXTRACTION ON IMPACTED MAXILLARY 3RD MOLARS

1. Maxillary sinus approximation

2. Third molar is within or above the roots of the maxillary second molar

3. Fusion and/or concrescence of roots with the maxillary second molar

4. Abnormal root curvature & morphology

5. Hypercementosis

6. Extreme bone density (especially with elderly patients)

7. Dental follicular space is filled with bone

8. Patient’s inability to open the mouth widely

FUSION

• complete or incomplete union of 2 adjacent normal tooth germs during tooth development, usually resulting in 1 large tooth, & 1 less tooth in the dental arch

• Two teeth are fused → but have two separate root canals

• Can occur anywhere along the tooth surface and may involve the fusion of the entire tooth (i.e., enamel, dentin, & cementum)

CONCRESCENCE

• type of fusion where there is union of greater than or equal to 2 adjoining teeth from cementum deposition

• It only occurs only in the root portion of a tooth, or it is the fusion of the cementum only

GEMINATION

Unsuccessful division of 2 teeth that result in 2 teeth that share only 1 root canal

TWINNING

Wherein 2 separate teeth from 1 tooth bud will produce 1 extra tooth in the dental arch

FACTORS THAT MAY COMPLICATE EXTRACTION ON IMPACTED MANDIBULAR 3RD MOLARS

1. mandibular canal approximation

2. Third molar is within or below the roots of the mandibular second molar

3. Fusion and/or concrescence of roots with the mandibular second molar

4. Abnormal root curvature & morphology (such as long thin roots or divergent roots)

5. complete bony impaction

6. dense inelastic bone

7. thin dental follicle

8. narrow periodontal ligament space

9. patient's inability to open the mouth widely

10. increased size or width of the patient's tongue (macroglossia)

NORMAL RANGE OF MOUTH OPENING

• varies from patient to patient: males exhibit a greater degree of mouth opening than females

• Maximum range of motion (ROM) of the jaws & maximum mouth opening (MMO) are correlated to body height & size

NORMAL RANGE (width; based on gender)

MEN (50 - 60 mm)

WOMEN (45 - 55 mm)

NORMAL RANGE (width; regardless of gender)

40 - 60 mm (with other authors placing the lower limit at 35 mm) or 2 - 4 fingerbreadths

Width of an index finger (at the nail bed)

17 - 19 mm

Width of an index finger (at the nail bed)

17 - 19 mm

3 fingerbreadths

54 - 57 mm

BASIC DIAGNOSTIC TEST/TOOL FOR INTERINCISAL DISTANCE

3 finger test or using a Boley gauge

NORMAL LATERAL MOVEMENT OF THE JAWS

8 - 12 mm

CAUSES OF INABILITY TO OPEN THE MOUTH

1. Trismus/Jaw Hypomobility

2. Pseudo-ankylosis

3. False ankylosis

4. True ankylosis

TRISMUS / JAW HYPOMOBILITY

• pertains to the jaw's limited, restricted range of motion, or progressive reduction in mouth opening

PSEUDO-ANKYLOSIS

• pertains to the mechanical interference in the temporomandibular joint (TMJ)

FALSE ANKYLOSIS

• refers to the extracapsular condition which results from pathological conditions outside of the temporomandibular joint (TMJ)

TRUE ANKYLOSIS

• pertains to an intracapsular condition where there is a fusion of the bony surfaces (condyle & glenoid fossa) of the temporomandibular joint (TMJ)

TYPES OF IMPACTION (based on the nature of the overlying tissues)

• SOFT TISSUE IMPACTION

• HARD TISSUE IMPACTION / BONY IMPACTION

  • Partial bony

  • Complete bony

SOFT TISSUE IMPACTION

• there is insufficient space to enable the gums to pull back for thorough cleaning and cleansing of the tooth

INDICATIONS FOR EXTRACTION (Impacted Canines)

1. Ankylosed impacted canines

2. Canines that cannot be transplanted

3. Severely dilacerated roots

4. Canine is undergoing external or internal root resorption

5. Impaction is severe (canine is lodged between the roots of the central & lateral incisors)

6. Occlusion is acceptable with the first premolar located in the position of the canine

7. Presence of pathologic changes (e.g., infections or cysts)

8. Patient is not planning to undergo orthodontic treatment

PARTIAL BONY IMPACTION

• enough space is available to allow the crown to partially erupt, but the tooth is unable to function optimally in the dental arch

• Radiographic appearance: height of the crown is below the level of the surrounding bone

COMPLETE BONY IMPACTION

• absence of space for the tooth to erupt from the jaw bone

• Radiographic appearance: tooth is completely embedded or encased in bone which requires adequate surgical technique & skill for adequate removal

CONTRAINDICATIONS FOR EXTRACTION (Impacted Canines)

1. Canine can be brought into position through surgery

2. Canine can be brought into position through orthodontic treatment

CLASSIFICATION OF IMPACTION (Maxillary Canines)

I. According to Archer (1975)

• Class I, Class II, Class III, Class IV, Class V, Class IV (newly added into the classification)

II. According to Field-Ackerman (1935)

• Labial Position, Palatal Position, Intermediate Position, Unusual Position

III. According to Ericson & Karol (1987)

• Sector 1

• Sector 2

• Sector 3

• Sector 4

• Sector 5

CLASS I - According to Archer (1975)

• palatally impacted canine

  • Horizontal

  • Vertical

  • Semi-vertical

CLASS II - According to Archer (1975)

• labial or buccal located impacted canine

  • Horizontal

  • Vertical

  • Semi-vertical

CLASS IV - According to Archer (1975)

• located in the alveolar surface

• Usually in a vertical position between the incisors & the first premolar

CLASS IV - According to Archer (1975)

• located in the alveolar surface

• Usually in a vertical position between the incisors & the first premolar

CLASS V - According to Archer (1975)

Situated in an edentulous maxilla

CLASS VI - According to Archer (1975)

Located in an aberrant or unusual position

LABIAL POSITION - According to Field-Ackerman (1935)

A) I - crown is closely positioned with the incisors

B) II - crown is well above the apices of the incisors

PALATAL POSITION - According to Field-Ackerman (1935)

A) I - crown is near the surface with close proximity to the roots of incisors

B) II - deeply embedded crown with close proximity to the apices of the incisors

INTERMEDIATE POSITION - According to Field-Ackerman (1935)

A) I - crown is between the lateral incisors & the roots of the first premolar

B) II - crown is above the teeth with the crown labially placed & the roots are palatally located

C) III - crown is above the teeth with the crown palatally placed & the roots are labially located

UNUSUAL POSITION - According to Field-Ackerman (1935)

A) I - located in the nasal or antral wall

B) II - located in the infraorbital region

SECTOR 1 - According to Ericson & Karol (1987)

• cusp tip of the canine is located distal to the root of the lateral incisor

• Cusp tip of the canine is between the inter-incisor median line & the long axis of the central incisor

SECTOR 2 - According to Ericson & Karol (1987)

• cusp tip of the canine is located mesial to sector 1, but distal to the midline of the lateral incisor root

• Cusp tip of the canine is between the major axis of the central & lateral incisors

• Cusp tip of he canine is overlapped on the distal half of the root of the lateral incisor

SECTOR 3 - According to Ericson & Karol (1987)

• cusp tip of the canine is located mesial to sector 2, but distal to the mesial outline of the lateral incisor root

• Cusp tip of the canine is between the major axis of the lateral & the first premolar

• Cusp tip of the canine is overlapped on the mesial half of the root of the lateral incisor

SECTOR 4 - According to Ericson & Karol (1987)

• cusp tip of the canine is located mesial to the mesial outline of the root of the lateral incisor

• Includes all areas mesial to sector 3

• Cusp tip of the canine is overlapped on the distal half of the root of the central incisor

SECTOR 5 - According to Ericson & Karol (1987)

• cusp tip of the canine is overlapped on the mesial half of the root of the central incisor

CLASSIFICATION OF IMPACTION (MANDIBULAR CANINES)

I. Based on Angulation (mesioangular, distoangular, vertical, horizontal)

II. Based on Depth (level a, level b, level c)

III. According to Field-Ackerman (1935) (labial position, unusual position)

MESIOANGULAR

Tooth is tilted or angled forward, towards the midline or front of the mouth

DISTOANGULAR

• tooth is tilted or angled backward, away from the midline & facing the rear of the mouth

VERTICAL

Tooth forms upright at a right angle in which the long axis of the tooth is parallel (or almost parallel) to the long axis of the adjacent tooth

HORIZONTAL

Tooth forms sideways at a right angle in which the long axis of the tooth is perpendicular (or almost perpendicular) to the long axis of the adjacent tooth

LEVEL A

Cusp tip of the crown is at the cervical line of the adjacent tooth

LEVEL B

Cusp tip of the crown is between the cervical line & root apices of the adjacent teeth

LEVEL C

Cusp tip of the crown is beneath the root apices of the adjacent teeth