Oral Examination Under General Anaesthesia

Introduction

The endotracheal tube does not allow full closure of the mouth to examine the relationship between the teeth. In the anaesthetised patient prior to intubation, the muscles are relaxed and the tongue often gets in the way, so a complete evaluation of occlusion is not always possible.

The oropharynx should be examined prior to endotracheal intubation. Normal anatomical features of the oral cavity need to be identified and inspected. A check list is given below:

Oropharynx: Soft palate Palatoglossal arch Tonsillary Crypts Tonsils Hamular process of the pterygoid Fauces

Lips and Cheeks: Mucocutaneous junction Vestibules Philtrum Frenula (maxillary and mandibular) Salivary papilla (parotid and zygomatic)

Oral Mucous Membranes: Alveolar mucosa Mucogingival line Attached gingiva Free gingiva Mucosa of the hard and soft palate

Hard Palate: Incisive papilla Incisive duct openings Palatine rugae and raphe (always check the rugae for hair impaction in dogs presenting with halitosis especially brachycephalic breeds)

Floor of Mouth: Sublingual caruncle Tongue Lingual frenulum – it is important to check the ventral aspect of the tongue as pathology in this area is often missed. This is a common location for squamous cell carcinomas in cats. Linear foreign bodies can often become trapped here and are not always noticed. Lingual salivary gland Tongue papillae

Filling in a dental chart during examination under general anaesthesia© Lisa Milella 2013

Any abnormalities need to be noted – look for swellings, inflammation, ulcerations. Check if the lesion is localised to one area or more generalised. Always biopsy abnormal tissue if a cause cannot be identified.

Under general anaesthesia, it is also useful to recheck the temporomandibular joints for crepitus or clicks if a problem is suspected. The mandibular symphysis should also be checked for mobility – a small degree of movement is normal in cats.

Indices and Criteria

The following indices and criteria should be evaluated for each tooth:

1. Gingivitis and gingival index
2. Periodontal probing depth
3. Gingival recession
4. Furcation involvement
5. Mobility