A Proposed New Classification of Craniofacial Anomalies LINTON A. WHITAKER, M.D. HERMINE PASHAYAN, M.D. JOSEPH REICHMAN, M.D. for The American Cleft Palate Association Committee on Nomenclature and Classification of Craniofacial Anomalies Introduction In the fall of 1976, Kenneth R. Bzoch, President of the American Cleft Palate Association, requested the formation of an Ad Hoc Committee for Reclassification of Craniofacial Anomalies. The impetus for this was the rapid growth of new knowledge and understanding about the malformations that had occurred as a result of the development of craniofacial surgery during the previous few years. The original committee consisted of the following people: Linton A. Whitaker, M.D., Chairman; Howard Aduss, D.D.S.; Asa Berlin, Ph.D.; Mutaz Habal, M.D.; and Joseph Reichman, M.D. Each of these people helped in the early formulation of ideas about the new classification. Subsequently, Malcolm Johnson, D.D.S., and Hermine Pashayan, M.D. were added to the committee. The paper, as finally developed and edited, was written by Drs. Whitaker, Reichman, and Pashayan and was completed in the spring of 1980. Since it was thought to be desirable to present the information at the International Cleft Palate Meeting in Acapulco in May, 1981, publication has been withheld until following that meeting. KEY WORDS: craniofacial anomalies, classification of anomalies, malformations Malformations of the craniofacial complex cian requires simplicity with clinical applica- abound with great variation. Previously, fa- bility. Such a system should be broadly based cial malformations were usually categorized both etiologically and anatomically and by two means: 1) pathogenic mechanisms and should, ideally, combine treatment goals and 2) anatomic conditions. These two areas were principles. , often mutually exclusive. The confusion in A review of some of the more widely used nomenclature arises because the names of syn- classification systems is given below. Anoma- dromes (Le., Crouzon's, Treacher-Collins, lies of the face have most often been classified etc.) do not fulfill the criteria necessary for according to a major structure involved, i.e. either the basic scientists or the clinician. lip and palate, eye, nose, mandibular, and They arose serendipitously or by isolated ob- maxillary abnormalities. servations with no effort to fit them into a system as a whole. Because of such occur- Pathogenetic Classification rences, there is now the need for a compre- hensive system that will allow the classifica- I. Lie aAnp PaAuratE tion of new syndrome entities without the use Of all facial deformities, classification of of eponyms. In formulating a new system, it cleft lip and palate has received the most is desirable to satisfy both the basic scientist attention. Superb reviews of classification sys- and the clinician. tems have been done by Millard (1976) and The basic scientist desires an embryologic Berlin (1971). While the earlier classification or biochemical classification, while the clini- systems of Davis and Ritchie (1922) and Veau 161 162 Cleft Palate Journal, July 1981, Vol. 18 No. 3 (1931) were based upon "operative" (ana- In the International Classification, several tomic) findings, recent advances in under- problems are apparent: standing the embryology of cleft lip and pal- 1. Numbering of groups may cause confu- ate laid the foundations of a more complete sion with the classifications of Veau and classification. These advances evolved into the Davis and Ritchie. (1972) present systems: 2. The term "anterior palate" is used A. International Classification: rather than "primary palate" (Kerna- Classification of the lip, alveolus, and pal- han and Stark, 1955) or prepalate ate (based on embryological principles) (Ber- (ACPA) (1968) lin, 1971): 3. Median clefts are listed under facial Group 1: Clefts of the anterior (primary) clefts rather than clefts of the lip. palate 4. The lip is not truly an embryologic part a. Lip: right and/or left of the "primary" palate. b. Alveolus: right and/or left It seems that the classifications of Kernahan Group 2: Clefts of the anterior and posterior and Stark (1955) and of the American Cleft (primary and secondary) palates: Palate Association (Haskins et al., 1962) are a. Lip: right and/or left the best. Both are relatively simple and incor- b. Alveolus: right and/or left porate three major areas: c. Hard palate: right and/or left 1. Clefts anterior to the incisive foramen Group 3: Clefts of the posterior (secondary) 2. Clefts posterior to the incisive foramen palate 3. Combinations of both types of clefts a. Hard palate: right and/or left While there is no agreement as to which b. Soft palate: median system is best, a more visual mode of catego- (For further subdivisions, the terms "total" rization was presented by Kernahan (1973) in and "partial" should be used.) the form of a "Y." This was modified by Rare Facial Clefts Based Upon Topograph- Elsahy (1973) and Millard (1976): . ical Findings a) Cleft: area stippled a. Median clefts of the upper lip with or b) Submucosal muscle and bony cleft: hor- without hypoplasia or aplasia of pre- izontal lines maxilla c) Nasal deformity marked with horizontal b. Oblique clefts (oro-orbital) lines proportionate to severity c. Transverse clefts (oro-auricular) d. Clefts of the lower lip, nose, and other II. Face anp SKULL very rare clefts. B. Kernahan and Stark (1955): Classification ~The most extensive overall compilation of using the incisive foramen as a boundary facial malformation with regard to patho- marker: , physiology is that proposed by Pruzansky 1. Clefts of the primary palate: lip and (1975): Sociogenic and iatrogenic factors premaxilla - Intrauterine mechanical factors 2. Clefts of the secondary palate: hard and h Focal necrosis soft palate posterior to incisive foramen. C0 Morphokinetic arrest Further description as to left, right, com- iB Primary malformations of the skull plete, and incomplete are added. i C. American Cleft Palate Association (Harkins, with secondary effects on the brain Primary malformations of the CNS et al. 1962): O 1. Prepalate: unilateral, bilateral, and me- with secondary deformities of the skull dian lip clefts; also alveolar clefts 7. Chromosomal abnormalities 2. Palate: all palatal clefts to incisive fora- 8. Environmental factors men 9. Inborn errors of metabolism 3. Prepalate and palate: unilateral and bi- 10. Syndromes of unknown etiology lateral complete clefts; incomplete clefts Sociogenic and iatrogenic factors are not of lip and palate relevant to the present classification. The 4. Rare clefts other than prepalatal or pal- ramifications of intrauterine mechanical fac- atal types. tors are uncertain. There is experimental data Whitaker et al., Crassrication or Cr Anomalies 163 (Trasler, et al., 1956) demonstrating that am- e. vomer and cartilagenous nasal sep- niotic sac puncture constricts the embryo and tum may cause cleft palate by mechanical inter- f. premaxillary bone ference. Furthermore, amniotic strands have g. anterior primary palantine triangle been found to be attached to the head and 2. Lateral brachial arch segments (2) mouth of human fetuses (Torpin, 1968). Am- Skeletal elements of the face derived from the niotic strands have also accounted for ampu- brachial arches: tations of digits. a. temporal bone, in part, and ossicles The role of focal necrosis as a causal mech- b. zygomatic arch anism has been pursued in recent years. Pos- c. maxillary bone willo (1973, 1975b) has demonstrated an ex- d. mandible perimental model for hemifacial microsomia e. hard palate by the induction of hemorrhage of the prim- The face can then be divided into three itive stem of the stapedial artery. The extra- horizontal planes. Malformations may affect vascular blood clot results in the sequential one horizontal segment solely or predomi- processes of focal tissue death, repair, and nantly. The upper (frontal) horizontal seg- redifferentiation. It is felt that the primitive ment derives solely from the frontal (fronto- pattern of morphodifferentiation observed in nasal) process. The middle (maxillary) seg- the affected neonate is a result of varying ment is derived from the maxillary process of degrees of primary damage followed by a the first brachial arch and the prolabium greater or lesser degree of "catch-up" remod- (from the frontonasal process). The third hor- eling. A similar model (Poswillo, 1975a) is izontal segment, the lower (mandibular) seg- postulated for mandibulofacial dysostosis but ment is derived from the mandibular process with a different pathogenic mechanism. of the first brachial arch. There is early destruction of neural crest cells In studying median facial anomalies, the au- of the facial and auditory primordia which thor classifies five types of tissue defic1ency migrate to the first and second brachial disorders which he terms holoprosencephaly arches. (DeMeyer, 1964): An example of morphokinetic arrest is that . i- Cyclopia Ethmocephaly of hypertelorism. It is conceivable that the Nn Cebocephaly angulation between the orbits might remain So in the fetal state because of a midline aber- ~ With median cleft lip (premaxillary age- ration. nesis) Craniostenosis is an example of a primary 5. With median philtrum-premaxilla an- malformation of the skull which may affect * lage the brain. Premature closure of sutures is When there is a normal or an excess amount associated with increased intracranial pres- of tissue in the midline structure, DeMeyer sure or facial deformity.