Dentistry and OMFS

Dalhousie Mini-Medical School 2018

Dr. Trish Brady BSc, DDS

Dr. James Brady BSc, DDS, MD, MSc, FRCDC

Introduction

• Dr. Trish Brady, BSc, DDS

– Grew up in Halifax

– Bachelor of Science degree from St.F.X.U

– Doctor of Dental Surgery degree from Dalhousie

– Owner and practicing dentist at Spring Garden Dentistry

Introduction

• Dr. James Brady BSc, DDS, MD, MSc, FRCDC– Grew up in Tyne Valley, PEI

– Bachelor of Science degree from Acadia

– Doctor of Dental Surgery from Dalhousie

– General Practice Residency from UWO

– Medical Doctor degree from Dalhousie

– Masters of Science in Oral and Maxillofacial Surgery from Dalhousie

– Fellow of the Royal College of Dentists of Canada

– Fellowship training Glasgow, UK

What is Dentistry

• Dentistry is a health science consisting of the study, diagnosis, prevention and treatment of diseases, disorders and conditions of the oral cavity

• Including:

– Dentition (teeth)

– Gingiva (gums) and oral mucosa

– Bone

Applying to Dentistry at Dalhousie

• Up to 40 students accepted

• Academic Requirements– 60 university credit hours with specific

prerequisite courses (biology, chemistry, physics, microbiology, physiology, organic chemistry, writing course)

• Non-academic Requirements– DAT (Dental Aptitude Test)

• Health Requirements– TB testing, immunization, CPR training

Dalhousie Dentistry• 4 year program

– Years 1&2 mostly didactic

– Years 3&4 mostly clinical

• Cost: $179,583.84– Range $40K-$55K per year

• Upon graduation– Practice as a GP dentist

• Own and run a dental practice

• Practice as an associate working for an owner dentist

• GPR (General Practice Residency)

– Specialize in a particular field of dentistry

Specialties of Dentistry

1. Periodontics

2. Endodontics

3. Pediatric Dentistry

4. Orthodontics

5. Oral and Maxillofacial Surgery

6. Prosthodontics

7. Oral Pathology

8. Oral Radiology

1 21.1

1.21.3

2.12.2

2.3

3.1 3.23.3

4.14.24.3

Tooth Numbering System

Tooth Numbering System

Tooth layersEnamel

Dentin

Pulp

TOOTH ANATOMY

Dental Caries

• “Cavities” or “tooth decay”

• Breakdown of tooth structure (enamel and dentin) caused by the acids produced by bacteria

• 2 requirements for cavity formation:

1. Bacteria

2. Plaque – food source for bacteria

Dental Caries

Abscess

Tooth layersEnamel

Dentin

Pulp

Pulpal Diagnosis

• Alive Dead

Pulpitis

Reversible Irreversible

*Spontaneous Pain*Lingering Pain (> 1hour)*Nocturnal

*No response *Face swollen*Fistula

Periodontal Disease

Tooth Loss

• Causes– Tooth decay

– Periodontal disease

– Cracked/fractured tooth

• Consequenses– Decreased chewing function

– Shifting/tilting of adjacent teeth Posterior Bite Collapse

– Excessive or uneven wear of adjacent teeth

Options for tooth replacement

• Dental Implant

• Bridge

• Removable Partial Denture

Implant

Bridge

Removable Partial Denture

www.UniversityOMF.ca

Mini Med School OMFSFacial Trauma

Dr. James Brady

ATLS PRIMARY SURVEY

• Airway and C-spine control

• Breathing and adequate ventilation

• Circulation

• Degree of consciousness

• Exposure

SECONDARY ASSESSMENT

• Need to reeval vital signs throughout. If at any time there is a significant change in status go back to primary survey.

•

• Head to toe IPPA (inpection, palpation, percussion, auscultation)

Mandible fractures

Etiology of Mandibular Fractures

• 43% due to MVC

• 34% due to assaults

• 7% are work related

• 7% due to fall

• 4% due to sporting accidents.

Condylarprocess

Body

Ramus

Coronoid process

ParasymphysealAngle

Location of Mandibular Fractures

Facial fractures associated with mandibular fractures

• Mandible is the only bone fracturedin 70% of patients.

• Number of fractures per mandible:approximately 50% have more thenone fracture.

– 53% one

– 37% two

– 9% three.

Pattern of fracture1. Simple or Closed: no wound open to

external environment.

2. Compound or Open: open to externalenvironment.

3. Comminuted: bone splintered orcrushed.

4. Greenstick: one cortex of the bone isbroken, the other bent.

5. Pathologic: from mild injury because ofpreexisting bone disease.

Indications for Closed Reduction

1. Nondisplaced favorable fractures

2. Grossly Comminuted Fractures

3. Coronoid process fractures

NOT ALL THAT COMMON

Length of Fixation

• In general for uncomplicated fractures:

– Children: IMF 2 to 3 weeks

– Adults: IMF 3 to 4 weeks

– Older patients: IMF 6 to 8 weeks.

Indications for Open Reduction

1. Displaced unfavorable angle fractures2. Displaced unfavorable body or parasymphyseal fractures3. Multiple fractures of the facial bones4. Midface fractures and displaced bilateral condylar fractures5. Fractures of an edentulous mandible with severe displacement of the

fractured fragments6. Edentulous maxilla opposing a mandibular fracture7. Delay of treatment and interposition of soft tissue between

noncontacting displaced fracture fragments8. Malunion9. Special systemic conditions contraindicating IMF

– Seizure psychiatric or neurologic disorder– Compromised pulmonary functions– Gastrointestinal disorder

MOST COMMON

Fixation

Rigid Non Rigid

Load Bearing Load Sharing

Fixation

Rigid Non Rigid

Load Bearing Load Sharing

NonRigid Internal Fixation Examples

• Functionally stable fixation

– Single miniplate technique of treating mandibularangle or body fractures = The Champy Method

The Champy Method:

•Single, noncompression miniplateattached with 2.0 mm monocorticalscrews.•Because this plate is placed in themost biomechanically advantageousarea for this region (superiorborder), a small plate can neutralizethe functional forces and permitactive use of the mandible duringthe healing.

Fixation

Rigid Non Rigid

Load Bearing Load Sharing

RIGID FIXATIONLoad-Bearing

• Load-Bearing Fixation

– Sufficient strength and rigidity that it can bear theentire load applied to the mandible duringfunctional activities.

RIGIDLoad-Bearing Fixation

• Mandibular reconstruction bone plate

• Required in:

– Comminuted fractures of the mandible

– Fractures where there is very little bony interfacebecause of atrophy

– Injuries that have resulted in a loss of a portion ofthe mandible (defect fractures)

Atrophic mandibular fracture

• In the atrophic mandible a stronger bone plate should be applied below the inferior alveolar canal.

Fixation

Rigid Non Rigid

Load Bearing Load Sharing

RIGID Fixation

• Load-Sharing Fixation– Internal fixation that is of insufficient stability to

bear all of the functional loads applied across thefracture by the masticatory system.

Case #1

Left Subcondylar

Case #2

Right angle

Case #3

Trans buccal approach to angle

Left angle # Right Body #

Case #4

Right Subcondylar

Case #5(Review of Surgical Approach)

Fell off the back of a truck

while car surfing the night before

CT Nov 14,2015

– Procedures:

• ORIF – Left parasymphyseal # (intraoral)

– Right Subcondylar # (transparotid)

– Left Subcondylar # (transparotid)

• Chin laceration repair

Down to Masseter (Different

Case)

Case #6

Left body #Right Scubcondylar #

Right Ramus #

Study Design

• A retrospective study was carried out on all patients who underwent open treatment (ORIF) of their condylar fractures at our center – Atlantic Centre for Oral and Maxillofacial Surgery in

Halifax, Nova Scotia– Study Period: September 2015 and February 2018

• Type of fracture, surgical approach used, facial nerve weakness and the number of plates used for fixation were all recorded.

• All fractures were grouped based on the AO classification of condylar fractures.

Results

TPA SMA

Fractures (patients) 18 (14) 27 (24)

Type 11 Subcondylar7 Neck

25 Subcondylar2 Neck

Facial Nerve Injury 0/18 (0%) 6/27 (22%)

2-Plate Fixation 18/18 (100%) 25/27* (93%)

*= 2 Neck Fractures

Case #78 yo girl

• Running outside at school and ran into another boy’s shoulder.

Left Body #Right Parasymphysis #

Case #8 8 yo boy

• Was lying on ground during recess when he was clobbered by a girls foot as she was completing a cartwheel!

Post Op

Left ParasymphysisRight Body

THE END

Questions???