Table 2.

Classifications of Transbasal Approaches Reported in the Literature

Transbasal Approach	Level I Transbasal Approach	Level II Transbasal Approach	Level III Transbasal Approach
Derome13	Raimondi and Gutierrez62	Raveh et al20	Tessier et al5
Honeybul et al31		Lang et al17	Fujitsu et al30
Maroon and Kennerdell50
Spetzler and Pappas27	Jane et al35	Honeybul et al31	Beals and Joganic1
Jakumeit63	Cophignon et al32	Fliss et al37	Kellman and Marentette38
Blacklock et al64	Osguthorpe and Patel29	Beals and Joganic1	Feiz-Erfan et al33
George et al26	Honeybul et al31	Fujitsu et al30	Converse et al14
McCutcheon et al65	Sekhar et al42	Alvarez-Garijo et al40
Pompili et al34	Tzortzidis et al44
Arita et al28	Ross et al66	Kellman and Marentette38
Morioka et al36		Moore et al46
Ohnishi et al67	Shen et al52	Pinsolle et al68
Ketcham et al8	Zhou et al49	Tessier et al6
Samii and Draf39	Kawakami et al51	Saito et al18
Unterberger4	Beals and Joganic1	Fukuta et al69
Liu et al41	George et al26
Malecki70	DeMonte54
Kurtsoy et al43	Chandler and Silva61
Raso and Gusmao2	Delfini et al53,*
Obeid and Al-Mefty47,†	Sekhar and Wright45
Fahlbusch et al48	Shah et al55
Housepian71	Hallacq et al56
Love and Bryar72	Persing et al57
	Kaplan et al58
	Lesoin et al59
	Terasaka et al23
	Moore et al46
	Kurtsoy et al43
	Chandler et al60
	Raso and Gusmao2
	Kawauchi et al19
	Johns and Kaplan73
	Obeid and Al-Mefty47,†

^*Based on technical description by Delfini et al,⁵³ the status of the medial canthal ligaments cannot be defined, preventing a clear categorization to level I or II. However, based on personal communications (Spetzler, Delfini, unpublished data) status of medial canthal ligaments was elucidated.

^†Based on the technique described by Obeid and Al-Mefty,⁴⁷ it is unclear whether an orbital bar osteotomy is applied preventing a clear categorization to transbasal or level I.