Oral Conditions: MCCQE1 Preparation Guide

Introduction

Oral conditions encompass a wide range of pathologies affecting the lips, tongue, floor of the mouth, hard and soft palate, and salivary glands. For the MCCQE1, candidates must distinguish between benign self-limiting conditions and those requiring urgent intervention or malignancy workup.

This guide focuses on high-yield topics such as oral ulcers, leukoplakia, oral cancer, and salivary gland disorders, strictly aligned with Canadian clinical practice guidelines.

Anatomy and Physical Examination

A systematic examination is crucial. In Canada, opportunistic screening for oral cancer is recommended during periodic health examinations, especially for patients with risk factors.

Key Anatomical Areas to Inspect

1. Vermilion border of lips (Actinic cheilitis, SCC)
2. Buccal mucosa (Linea alba, Lichen planus)
3. Hard and Soft Palate (Torus palatinus, Kaposi sarcoma)
4. Dorsal and Ventral Tongue
5. Floor of Mouth (High-risk area for SCC)
6. Retromolar Trigone

Benign vs. Malignant Lesions

Differentiating between benign and potentially malignant lesions is a core objective.

1. Oral Ulcerations

2. White and Red Patches

Oral Cancer (Squamous Cell Carcinoma)

Squamous Cell Carcinoma (SCC) accounts for >90% of oral malignancies. Early detection significantly improves survival rates.

Risk Factors (Canadian Context)

• Tobacco: Cigarettes, cigars, pipes, smokeless tobacco.
• Alcohol: Synergistic effect with tobacco.
• HPV: Human Papillomavirus (specifically HPV-16) is increasingly responsible for oropharyngeal cancers in younger, non-smoking Canadians.
• Sun Exposure: Lip cancer.
• Betel Quid: Relevant in certain immigrant populations in Canada.

Clinical Presentation

• Non-healing ulcer (> 3 weeks).
• Induration (firmness) on palpation.
• Fixation to underlying structures.
• Associated cervical lymphadenopathy.
• Dysphagia or odynophagia.

Management Strategy

Salivary Gland Disorders

1. Sialolithiasis (Salivary Stones)

• Location: Submandibular gland (80%) > Parotid. Wharton’s duct is long and flows against gravity.
• Presentation: Post-prandial pain and swelling.
• Management: Hydration, sialogogues (lemon drops), massage, NSAIDs. Antibiotics only if secondary infection (sialadenitis) is present.

2. Sialadenitis

• Etiology: Staphylococcus aureus is the most common pathogen. Often occurs in dehydrated/elderly patients.
• Treatment: IV Antibiotics (Cloxacillin or Clindamycin), hydration, warm compresses.

3. Salivary Tumors

• Rule of Thumb: The smaller the gland, the higher the likelihood of malignancy.
  • Parotid: 80% of tumors, 80% are benign (Pleomorphic Adenoma is #1).
  • Sublingual/Minor Glands: Higher rate of malignancy (Adenoid Cystic Carcinoma, Mucoepidermoid Carcinoma).
• Investigation: FNA biopsy. Open biopsy is contraindicated in parotid tumors due to risk of seeding and facial nerve injury.

Dental Infections & Emergencies

Ludwig’s Angina

A life-threatening cellulitis of the floor of the mouth (submandibular, sublingual, and submental spaces), usually dental in origin.

• Signs: “Bull neck” appearance, woody induration of the floor of the mouth, elevated tongue, trismus, drooling.
• Management:
  1. Airway Management: Priority #1 (Fiberoptic intubation or Tracheostomy).
  2. IV Antibiotics: Broad-spectrum (e.g., Penicillin G + Metronidazole or Clindamycin).
  3. Surgical Decompression.

Canadian Guidelines & Public Health

1. HPV Vaccination

Health Canada recommends HPV vaccination (Gardasil 9) for:

• Females aged 9-45.
• Males aged 9-26.
• This is a primary prevention strategy for HPV-related oropharyngeal cancers.

2. Dental Care Access

• Under the Canada Health Act, routine dental care is not an insured service for most Canadians.
• Indigenous Health: Non-Insured Health Benefits (NIHB) covers dental care for First Nations and Inuit.
• Canadian Dental Care Plan (CDCP): A new federal initiative (rolling out 2024) to help lower-income families.
• MCCQE1 Relevance: Recognize that cost is a major barrier to care, leading to delayed presentations of oral pathology in lower socioeconomic groups.

3. Antibiotic Stewardship

• The Canadian Dental Association advises against routine antibiotics for dental pain without systemic signs of infection (fever, swelling, lymphadenopathy).

Key Points to Remember for MCCQE1

• Leukoplakia vs. Candidiasis: Candidiasis scrapes off; Leukoplakia does not.
• Biopsy Rule: Any oral lesion persisting > 2-3 weeks without an obvious cause requires a biopsy.
• Airway: Ludwig’s angina is an airway emergency. Secure the airway before sending for imaging.
• Referral: Unexplained otalgia (ear pain) with a normal ear exam in a smoker demands an ENT referral to rule out base of tongue/hypopharynx cancer.
• Medications: Phenytoin, Cyclosporine, and Calcium Channel Blockers (Nifedipine) cause gingival hyperplasia.

Sample Question

Clinical Scenario

A 62-year-old male presents to his family physician complaining of a “sore spot” on the left side of his tongue for the past 4 weeks. He has a 40-pack-year smoking history and consumes 2-3 alcoholic beverages daily. On examination, there is a 1.5 cm indurated, ulcerated lesion with rolled borders on the left lateral tongue. It is non-tender to palpation. There are no palpable cervical lymph nodes. The remainder of the oral exam is unremarkable.

Which one of the following is the most appropriate next step in management?

Options

• A. Prescribe a 7-day course of oral penicillin
• B. Prescribe a topical corticosteroid paste and follow up in 2 weeks
• C. Perform an incisional biopsy
• D. Reassure the patient and advise smoking cessation
• E. Order a CT scan of the neck

Explanation

The correct answer is:

• C. Perform an incisional biopsy

Detailed Explanation: This patient presents with a classic clinical picture concerning for Squamous Cell Carcinoma (SCC): an older male with significant risk factors (tobacco and alcohol) presenting with a persistent (> 3 weeks), indurated ulcer on a high-risk site (lateral tongue).

• Option C is correct: The definitive diagnosis for a suspicious oral lesion is histological confirmation. An incisional biopsy (or immediate referral to an oral surgeon/ENT for biopsy) is the standard of care. Delaying diagnosis worsens the prognosis.
• Option A is incorrect: Antibiotics are indicated for infectious etiologies. The lesion is non-tender and chronic, making a bacterial infection unlikely.
• Option B is incorrect: Topical steroids are used for inflammatory conditions like aphthous ulcers or lichen planus. Treating a potential malignancy with steroids can delay diagnosis and may temporarily mask symptoms without treating the underlying pathology.
• Option D is incorrect: While smoking cessation is crucial for long-term health, reassurance is inappropriate for a persistent, high-risk lesion.
• Option E is incorrect: While imaging (CT/MRI) is part of the staging process after a diagnosis of cancer is confirmed or highly suspected to assess depth and nodal involvement, the immediate next step to establish the diagnosis is a biopsy. Tissue is the issue.

References

1. Medical Council of Canada. (n.d.). Objectives for the Qualifying Examination Part I. Retrieved from mcc.ca 
2. Canadian Cancer Society. (2023). Oral Cavity Cancer Statistics and Risk Factors.
3. Canadian Dental Association. (2023). Position Statement on Oropharyngeal Cancer.
4. Lalwani, A. K. (2020). Current Diagnosis & Treatment Otolaryngology—Head and Neck Surgery (4th ed.). McGraw-Hill Education.
5. Compendium of Pharmaceuticals and Specialties (CPS). (2024). Therapeutic Choices: Dental Infections. Canadian Pharmacists Association.