Table I. Causes of 110 reported cases of non-traumatic atlanto-axial subluxation (1830-2004).

Causes		No. cases
Infection		77
	Upper respiratory infection	34
	Tosillitis	12
	Mastoiditis or otitis media	6
	Acute rheumatic fever	5
	Retropharyngeal abscess	5
	Cervical adenitis	3
	Parotitis	3
	Tonsillar abscess	2
	Cervical abscess	2
	Fever of unknown origin	2
	Alveolar infection	1
	Posterior pharyngeal ulcer	1
	Influenza	1
Post-operative		25
	Tonsillectomy and/or adenoidectomy	11
	Mastoidectomy	9
	Pharyngoplasty	3
	Choanal atresia repair	1
	Resection para-pharyngeal mass	1
Inflammatory		4
	Arthritis	4
Neurological dysfunction		1
Primitive neuro-ectodermal tumour		1
No cause stated		2