. Author manuscript; available in PMC: 2011 Jun 9.

Published in final edited form as: Am J Med Genet A. 2009 Jun;149A(6):1149–1158. doi: 10.1002/ajmg.a.32854

TABLE I. Classification of Orofacial Clefts by Defect Status and Laterality, National Birth Defects Prevention Study, 1997-2004.

Clinical Presentation	CL (N = 751) N (%)	CLP (N = 1,399) N (%)	CP (all) (N = 1,194) N (%)	CP with Pierre Robin sequence^e (N = 279) N (%)	CP without Pierre Robin sequence^e (N = 915) N (%)
Isolated	691 (92) ^a,^b	1,185 (85) ^a,^c	942 (79)^b,^c	216 (77)	726 (79)
Multiple	60 (8) ^a,^b	214 (15) ^a,^c	252 (21)^b,^c	63 (23)	189 (21)
Bilateral	56 (7)^d	423 (30)^d	n/a	n/a	n/a
Unilateral	599 (80)^d	844 (60)^d	n/a	n/a	n/a
Unilateral, Right	209 (35)	291 (34)	n/a	n/a	n/a
Unilateral, Left	372 (62)	502 (59)	n/a	n/a	n/a
Unilateral, NOS	18 (3)	51 (6)	n/a	n/a	n/a
Midline	10 (1)	9 (1)	n/a	n/a	n/a
NOS	86 (11)	123 (9)	n/a	n/a	n/a

Chi-square analysis comparing proportion of isolated and multiple defects between CL and CLP (p <0.01).

Chi-square analysis comparing proportion of isolated and multiple defects between CL and CP (p <0.01).

Chi-square analysis comparing proportion of isolated and multiple defects between CLP and CP (p <0.01).

Chi-square analysis comparing proportion of unilateral and bilateral defects between CL and CLP (p <0.01).

Pierre Robin sequence is determined by diagnosis and notation in the medical record by the clinician providing care to the infant/child.