Etiology of Class II

Timothy Shaughnessy, DDS, MS, Workshop Leader Lawrence H. Shire, DDS, Workshop Recorder

In reviewing the literature relative to the develop- sia, and mobius syndrome are a few of the more widely ment of Class II malocclusions, it can be learned that known. "not every Class II is a Class II." Wemust rememberthat Inter-arch problems such as Class II and Class III behind the soft tissue drape of the patient’s face is a malocclusions are genetic in nature, while intra-arch totally dynamic process that can be influenced by our problems also have an environmental component as heritage and altered by our environment. We realize well. when performing an occlusal evaluation of our young Looking at the importance of environmental vs. patients, findings like distal step molar relation or an inherited factors in the etiology of malocclusions, it was unusually large overjet may be presenting a false im- suggested that urbanization (and evolution) influence pression of what appears to be a true skeletal Class II malocclusions, making them more severe. The evolu- . tionary factors involved are: a decrease in the size of the In addition to distal step molar relation, or an unusu- jaws, size and number of the teeth. We have no control ally large overjet, tooth size discrepancy with or without over these evolutionary factors (as well as the hereditary malrelated mandible and maxilla may also give the first factors), whereas the environmental factors can often be impression of a true skeletal Class II malocclusion. eliminated through preventive or interceptive treat- Skeletal Class II malocclusions can be found to have ment at the appropriate time. variants in one or more of the following regions: (1) Mandibular growth deficit following condylar frac- maxillo-mandibular relationship (mandibular tures or major trauma to the joint complex is highly , midface protrusion or both); (2) the cra- likely. Proffit (1980) found between 5 and 10%of all nial base (increased length of the anterior cranial base severe mandibular deficiency or asymmetry problems will contribute to the midface protrusion, while length- were related to previous fracture of the mandibular ening of the posterior cranial base will tend to position condylar process. In this article, Proffit cites Walkerand the temporomandibular articulation more retrusively); also Gilhuus-Moeas noting that the younger the patient (3) vertical dysplasia (anterior upper face height often at the time of the injury, the greater the potential for greater than normal); (4) steep occlusal plane (a reflec- complete regeneration of the condyle, and healing with- tion of vertical skeletal dysplasia). out residual deficit. Proffit (1978) states that Lundfound Whatrole does genetics play in the etiology of Class essentially complete recovery in 75% of the children II malocclusions? According to the study by Lundstrom with early condylar fractures. The treatment goals for (1984), investigations published prior to that article patients with condylar fractures include the restoration have suggested that about 40% of commonanomalies in of joint function, occlusion, and facial symmetry. The tooth position and in the relationship between maxil- current theory on early treatment of condylar fracture in lary and mandibular dental arches are due to genetic the growingchild calls for firm fixation for only I week, differences between individuals. Corruccini and Potter with physical therapy and mouth opening exercises (1980), in studies of different dental and occlusal vari- beginning immediately after release of the rigid fixa- ables, found the heritability of dental overjet was re- tion. duced to zero. Several syndromes have Class II maloc- Condylar fractures often go unnoticed and result in clusions as a major finding. Of these syndromes, Class II malocclusions with asymmetry or severe Treacher Collins, hemifacial microsomia, achondropla- mandibular deficiency. Progressive deformity is associ- ated with mechanical limitations on growth and the resulting condition is referred to as "functional

336 SPECIALREPORT -- ETIOLOGY OFCLASS II MALOCCLUSIONS:Shaughnessy and Shire ankylosis." Ankylosis of the mandible can be thought of tal components. Changes in head, jaw, and tongue as fusion across the TMJ. This fusion restricts motion position could be seen in the experimental group. Some and inhibits growth. "In order to grow properly, the traits commonamong the sample were increased face mandible must be able to translate" (Proffit 1980). height, steeper mandibular plane angle, and larger Sometheories to explain the growth of the craniofa- gonial angle. It should be noted that someof the animals cial complexinclude: (1) Sicher’s role of sutural growth; in the experimental group developed other than Class II (2) Scott’s role of the cartilage and the knowledgethat malocclusions. Class III malocclusions as well as Class I bone growth is secondary to cartilage growth; or (3) malocclusions were also seen. It is not the change in Moss’s functional matrix hypothesis that cartilage and breathing pattern that caused the malocclusions, but bone respond secondarily to soft tissue growth. Still rather it is the change in related functional demandson another theory is that of the influence of mouth breath- the craniofacial musculature and their obligatory re- ing vs. nasal breathing to which Harvold (1980) eluded. sponse. Proffit (1978) states that the postural positioning Experiments on transplantation and obvious reac- of the head, mandible, and tongue are all at the subcon- tions to manipulation of the sutures have, to some scious level. Dentoalveolar morphology can be shown degree, ruled out the sutural growth theory. Cartilage to be related to head posture. The more the head is held studies have shown both positive and negative influ- forward, the more likely that the upper dentoalveolar ences on growth whentransplantation of cartilage is the height will be increased. Also, there will be an increase variable factor of the studies. This depends upon in the steepness of the occlusal plane related to forward whether the cartilage is primary (from the primordial posturing of the head. skeleton) or secondary cartilage. Primary cartilage is McNamara(1981) reviewed Linder-Aronson’ s work growth center where.as secondary cartilage, like that of from 1975 where it was shown, on a small sample size, the condyle, is a growthsite. It has been shownthat there that removal of nasal obstruction (adenoidectomy) in is a positive correlation betweenthe soft tissue influence children, followed for 5 years postoperatively, had an and the growth of the craniofacial complex. For ex- average°. reduction in the mandibular plane angle of 4 ample, excessive intracranial pressure will cause hydro- This was twice the reduction found in the control group cephaly, with a markedincrease in the size of the calvar- (those without nasal airway obstruction and without ium, whereas diminished growth of the brain causes adenoidectomy). microcephaly. Whenan eye is removed from a child for . Are there other environmental factors that cause treatment of a tumor, the orbit does not continue to grow Class II malocclusions? Early loss of maxillary primary in the normal fashion. molars can influence the development of Class II maloc- Normally, teeth are balanced between the tongue clusions by allowing the maxillary molar, that maybe in and the lips. Resting pressure must be considered more an end-on relation with the mandibular molar, to slip important than the pressure created during chewing, forward thus establishing a dental Class II situation. It swallowing, or speaking, since the time we are at rest far would appear that local environmental factors influ- outweighs the time we are performing these other func- ence a dental Class II morethan they influence a skeletal tions. Whencomparing forces necessary to moveteeth, Class II. Understanding the etiology of the malocclu- heavy intermittent pressure has less effect than light sion, should play a role in developing a treatment plan. continuous forces. Howdo habits relate to Class II malocclusions? As The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the was previously stated, the light continuous forces are views of the Department of the Armyor the Department of Defense. much more detrimental to the oral complex than are heavy intermittent forces. Habits such as thumb suck- Dr. Shaughnessyis in the private practice of in Marietta, ing, when performed for fewer than 6 hr per day, have Georgia, and Dr. Shire is deputy director, U.S. ArmyPediatric Den- not been shownto be responsible for anterior open bites tistry Residency Program, Ft. Lewis, Washington. Reprint requests should be sent to: Dr. Lawrence H. Shire, QTRS2338 S. 3rd St., Ft. or Class II malocclusions. Forward positioning of the Lewis, WA98433. tongue (seen during swallowing in patients with ante- rior open bite) is morelikely to be an effect than a cause. Corruccini RS, Potter RH: Genetic analysis of occlusal variation in What is the mechanism by which nasal impairment twins. AmI Orthod 78:140-54. 1980. could alter dentofacial form? Harvoldet al. (1981), using Harvold EP etal: Primate experiments on oral respiration. AmJ rhesus monkeys, forced them to become mouth breath- Orthod 79:359-72, 1981. ers by mechanical obstruction of their nasal airway. He Lundstrom A: Nature versus nurture in dentofacial variation. Eur J was able to show that previously obligate nose breath- Orthod 6:77-91, 1984. ers forced to breathe 100%of the time through their mouth, exhibited changes in their soft tissue and skele-

Pediatric Dentistry: December,1988 - Volume10, Number4 337 McNamaraJA: Influence of respiratory pattern on craniofacial bances.Am J Orthod78:1-24, 1980. growth.Angle Orthod 51:269-300, 1981. Proffit WR:Equilibrium theory revisited: factors influencingposi- MossML, Salentijn L: Theprimary role of the functionalmatricies in tion of the teeth. AngleOrthod 48:175-86, 1978. facial growth.Am J Orthod55:566-77, 1969. SolowB, Tallgren A: Headposture and craniofacial morphology. Proffit WR,Vig KW,Turvey TA: Early fracture of the mandibular AmJ PhysAnthropol 44:417-35, 1976. condyles:frequently an unsuspectedcause of growthdistur-

PEDIATRICDENTISTRY/Copyright © 1988 by The AmericanAcademy of Pediatric Dentistry Volume 10, Number4

Supervision of Class II discrepancies Gerald S. Samson, DDS, Workshop Leader Michael J. Hechtkopf, DDS, MSD, Workshop Recorder

Literature Review rience for both children and adults. He revealed data Early orthodontic treatment continues to be contro- that suggested that children as young as 3 and 4 years of versial and the subject of arguments amongdentists, age are potentially influenced by physical attractive- especially pediatric dentists and orthodontists. ness. He also noted that appearance creates certain Clearly, there are psychological and sociological stereotypes, which stimulates expectations of specific reasons for accepting the concept of early treatment. attributes, and that this process may actually emerge Attractiveness does have an effect on one’s life. In 1978, shortly after birth and continue throughout life. Others Kalick noted that cosmetic facial alterations improve a have suggested that as early as infancy, physical attrac- patient’s appearance and thereby directly enhance his tiveness may have profound influences upon parental or her social value. The way in which others perceive the attitudes, expectations, and behavior with their infants individual is also based on attractiveness; physically (Hildebrant 1976; Boukydis 1977). Adams (1981) attractive persons are preferred to the unattractive and made a most profound observation in noting that teach- thus receive preferential treatment (Bersheid and ers, like parents, are influenced by attractiveness; teach- Walster 1974; Adams and Crossman 1978; Bersheid ers were more attentive and positive to attractive chil- 1981). dren. Bersheid (1981) noted that physical appearance Graber (1981) relates a surge in orthodontic care for makes a difference in one’s life -- in education and younger children under early orthodontic guidance for careers. Allen (1978) showed that social choices were dentofacial esthetic purposes. Graber further notes that based on appearance, which one would expect, but also most children present for care due to parental motiva- noted that attractive persons were perceived to be more tion, seeking dental and facial form alteration for per- honest and independent. Of special importance is an- sonal and social gain rather than biologic or physiologic other of Bersheid’s commentsdescribing how behavior improvement. is affected by our physical attractiveness, and howthat There are, of course, other reasons for early ortho- behavior in turn affects another person’s behavior. Self- dontic treatment, especially for the Class II patient. Bass esteem also is impacted by attractiveness, and has psy- (1983) raises the possibility of the risk of trauma chological importance associated with a variety of be- unprotected incisors in active children. Approximately haviors (Aronson and Mettee 1968). 10% of children with severe overjet will fracture or Adams (1981) reported evidence exists to suggest avulse one or more maxillary incisors before attaining that attractiveness has an impact upon the social expe- age 12 (Eichenbaum 1963; McEwenet al. 1967). Another consideration is whether changes can be

338 SPECIALREPORT -- SUPERVISION OFCLASS II DISCREPANCIES:Samson and Hechtkopf effective in early treatment of Class II malocclusions. Samsoninto four major categories: (1) treatment timing; Enlow (1982) relates that the face grows and develops (2) records and analysis; (3) treatment objectives; and rapidly throughout the childhood period, as it "catches selection of clinician. Each of these were presented with up" with the earlier maturing brain and brain case. Bass one or more subheadings in question form to stimulate (1983) describes a first phase of orthodontics as discussion. The workshop then focused on each cate- orthopedic phase to establish normal relationships of gory and discussed it. the skeletal componentssupporting the dentition. This, in turn, improves adverse soft tissue patterns. Treatment Timing As discussed by Krieg (1987), there are growth spurts Age for Evaluation between the ages of 5 and 12, which he describes as The workshop participants were interested in the periods of growth in the craniofacial dimensions in age that a practitioner, regardless of specialty, should which one period exceeds the growth velocity of a evaluate the developing dental and facial structures and previous period by twice. He notes that spurts are found advise the parents regarding the need for detailed throughout this age range, with highest peaks of growth orthodontic records and analysis. There is presently no velocities in the younger age groups. He relates that due definitive literature available on the recommendedage to the active growth that characterizes the childhood for a first orthodontic exam, so the workshoptried to and juvenile growth periods, early treatment can be establish someguidelines. quite advantageous for certain orthodontic problems. There was little disagreement among the workshop Krieg adds that these younger patients are significantly participants that for any craniofacial anomalyincluding more cooperative than older groups. There is then a cleft palate, an orthodontic evaluation should occur at good possibility that the dentist’s efforts maybe helped birth, although this does not always mean a need for by these growth spurts. immediate treatment. Such evaluation should by done As early as 1960, Ricketts treated a sample of 8-year- by a team, and the dentist on the team, although usually old Class II patients, and showed that the maxilla was a pediatric dentist, can be any dental practitioner (pedi- not an immutable structure. He showed that forces atric dentist, orthodontist, or general dentist) whocan transmitted to the sutures of the maxilla did affect the makea critical evaluation of the pati,ent. growth of the maxilla, changed teeth dramatically, and Other patients whopresent to the dentist at birth or relieved lip strain. Also, incisors were intruded and shortly thereafter do not need a team evaluation. Such molars distalized. The distal movementof the maxillary patients are those whopresent due to parental concerns first molar was most evident during the transition be- or physician referral, or where there is potential of tween the primary and mixed dentitions. For this rea- malocclusion due to a family history or hereditary prob- son, Ricketts concluded, early treatment seemed advis- lem. Also included in this category are asymmetries of able for maximumorthodontic orthopedic correction the skull or face. Again, the workshop participants even at the primary dentition level. Even earlier, Hahn agreed that usually a pediatric dentist was the practitio- (1954) reported that treatment of extreme Class II, Divi- ner whoshould evaluate this patient, but that the evalu- sion 1 malocclusions and maxillary protrusions in the ation could be performed by an orthodontist or general primary dentition is valuable in that it retards the prog- practitioner qualified to do a critical examof the patient. ress of the malocclusions and gives a better opportunity The practitioner should be familiar with normal vs. for success in the second period of treatment. Kloehn abnormal skeletal and facial structures, growth and (1954) agreed that treatment should be directed and development, and the temporomandibular joint com- correlated with growth and not against it. He concluded plex. The College of Diplomates made the recommen- that this philosophy demandsthat treatment be started dation that some type of documentation is needed for as early as any factors and forces are recognized which these patients, including photographs. will inhibit growth and development. Terry (1954) also One of four dual-trained pediatric dentist/ortho- advocated early treatment of Class II malocclusionso In dontists attending the workshopnoted howlittle ortho- 1962, Hahn, Cheney, and Tweedall supported the the- dontic residency programs teach students concerning ory of early treatment of Class II, Division 1 malocclu- normal pediatric developmental changes. It was agreed sions, in the mixed dentition stage. that more information needs to be taught and shared in It is clear from this brief review that there are socio- both pediatric dental and orthodontic residency pro- psychological reasons for early treatment of Class II grams concerning early growth of the skull, face, and malocclusions, and at least moderate psychological and dentition. It also was stated that orthodontists and other mechanical evidence to support the effectiveness of this practitioners mustrealize that it is in the best interests of treatment. children to allow more dissemination of information on The workshop concerning Supervision of Class II discrepancies was divided by moderator Dr. Gerald

Pediatric Dentistry: December,1988 - Volume10, Number4 339 this subject, so that dentists evaluating children do so radiograph for determination of skeletal age. In addi- with expertise, or refers to another dentists as indicated. tion, a panoramic radiograph should be repeated once a The participants further suggested that the American year while treatment continues to check for any possible Academy of Pediatric Dentistry provide more knowl- indication of root resorption or ectopic eruption of teeth. edge for its members regarding the anatomy of the Attention should be given to condylar position, infant face and skull, and that neonatologists and other contour, and space on panoramic radiographs. This physicians, as well as dentists, be called upon for this radiograph gives a screening of normality to the anat- information. Only in this manner can criteria be set for omyof the condyles. If suspicious areas are noted, then a functional history and dentofacial exam, which should more detailed tomogram-type radiographs should be be a part of every routine exam. ordered. Although the above criteria were agreed upon for In recommending a , certain any child’s evaluation, there was far less agreement on key factors should be required. Most Diplomates felt the age that a child with a routine Class II malocclusion that any analysis used for treatment on children should should be evaluated. It was decided that these patients be able to be related to age, race, facial type, facial soft should certainly be seen not later than the eruption of tissue and profile, possibly sex, and aimed at the grow- the full complementof primary teeth and possibly ear- ing patient and aging of the face. lier. Someof these patients maybe too young for actual Discussion then centered on which methods avail- treatment, but appropriate information should be re- able could provide the desired information. It was noted lated to parents; habits that contribute to the problem that the Steiner analysis was not age or race related and could be eliminated and nasal airways evaluated. It also was based on the sample analysis of one white female was pointed out that there is a need for age-appropriate patient, and that Tweed’s analysis did not have a known exam forms relating to patient development instead of sample of patients, although the University of Michigan the standard universal form for all ages of children used had age related Tweed’s analysis. in most offices. It was generally accepted that the Rickett’s cepha- lometric analysis provided most of the relating informa- Age of Diagnosis tion needed for diagnosis, although a few persons pres- The next discussion centered on the appropriate age ent felt it might be less accurate for very young children for diagnosis, that is, actual orthodontic records. Most than it is for those aged eight years and older. agreed that for very young children, the severity of the case, the eruption of the second primary molars, and Treatment Objectives patient managementhad to be taken into account. In Although there was not complete agreement con- order to observe whether the malocclusion is naturally cerning objectives of early treatment, the following improving or worsening, it was noted that some records statement was adopted: "The objective of early Class II had to be taken, for comparison of later findings. This treatment should be to obtain maximally achievable would be appropriate for those cases where treatment is results toward a Class I skeletal and dental relationship, not immediately indicated for any reason. These rec- and as closely as possible functional and esthetic nor- ords might be what are termed "mini-records," which mality." would consist of a detailed clinical description and It was agreed that the overall objective was to attain photographs. Optional data for these abbreviated rec- optimal facial and dental development, including facial ords might include study models and cephalometric harmonyand balance, TMJfunction, Class I skeletal and analysis. The workshopparticipants all agreed that the dental relationships, periodontal health, and enough detailed clinical description should include a functional space for eruption of the remaining permanent teeth. temporomandibular joint exam and test for hypermo- In determining whether early treatment for Class II bility of the mandible. cases can avoid extractions or orthognathic surgery later; ~here was less discussion by the Diplomates. Most Records and Analysis felt that preventing extractions in any subsequent treat- Records would include a detailed clinical exam, a ment by early intervention was highly variable, but functional exam, and description of discrepancy, photo- certainly more likely. The workshop participants also graphs, a lateral cephalometric radiograph, traced and were in agreement that early treatment would most analyzed, a panoramic radiograph, and trimmed study likely prevent the need for surgery at a later date. There models. Optional data to be included should be frontal was concensus that early treatment did not necessarily radiograph, traced and analyzed, and a hand/wrist preclude the need for orthodontics at a later age, but surely makes a case less difficult and complicated, and as stated, with less need for extractions or surgery. In

340 SPECIAL REPORT-- SUPERVISION OF CLASS II DISCREPANCIES: Samson and Hechtkopf essence, phase I treatment is not complete until phase II Boukydis ZC: Infant attractiveness and the infant-caretaker relation- treatment begins. ship, paper presented to the International Conference on Love and Attraction. Wales, United Kingdom; University of Swansea, September 1977. Selection of Clinician The final discussion by the College of Diplomates Cheney EA: Treatment planning and therapy in the mixed dentition, concerned who is best qualified to care and treat the presented at the 1962 annual meeting of the American Associa- tion of Orthodontists as part of a panel discussion by Hahn G, Class II pediatric dental patient. The workshop con- Cheney E, Tweed C, Terry H, Murray R. AmJ Orthod 49:568-80, cluded that any dental practitioner, whether a pediatric 1963. dentist, orthodontist, or general dentist, should treat Eichenbaum IW: A correlation of traumatized anterior teeth to these patients provided the clinician meets the follow- occlusion. ASDCJ Dent Child 30:229-36, 1963. ing criteria: (1) understands howto modify growth and developmentof the face; (2) is adequately trained; (3) Enlow DH: Handbook of Facial Growth, 2nd ed. Philadelphia; WB able to enlist the complianceof the child patient; (4) Saunders Co, 1982. "experienced" in providing the services; (5) has stayed Graber LW: Psychological considerations of orthodontic treatment, abreast of the current literature; (6) has adequate knowl- in Psychological Aspects of Facial Form, Lucker GWet al., eds, edge on adjusting and manipulating the appliances monograph 11, Craniofacial Growth Series. Ann Arbor, Michi- used; and (7) has provided the appropriate information gan; Center for Human Growth and Development 1980. to the parent, including proper informed consent and Hahn GW:Treatment in the deciduous dentition, read as part of a deposition of the case to completion or maturity, noting panel discussion before the American Association of Orthodon- the likelihood of a second phase of treatment. tists, May20, 1954. AmJ Orthod 41:255-61, 1955.

Hahn GW:Treatment planning and therapy in the mixed dentition, Dr. Samsonis in the full-time private practice of orthodontics and presented at the 1962 annual meeting of the American Associa- dentofacial orthopedics in Marietta, Georgia, and Dr. Hechtkopf is in the private practice of pediatric dentistry in Virginia Beach, Virginia. tion of Orthodontists as part of a panel discussion by Hahn G, Cheney E, Tweed C, Terry H, Murray R. AmJ Orthod 49:563-67, Reprint requests should be sent to: Dr. Michael J. Hechtkopf, Rose 1963. Hall Professional Centre, 3145 Virginia Beach Blvd., Virginia Beach, VA 23452. Hildebrant KA: Adult responses to infant cuteness (unpublished master’s thesis). East Lansing, Michigan; Michigan State Univer- Adams GR, Crossman, SM: Physical Attractiveness: A Cultural Imperative. Roslyn Heights, NewYork; Libra Publishing, 1978. sity, 1976. Kalick SM: Toward an interdisciplinary psychology of appearances. AdamsGR: The effects of physical attractiveness on the socialization Psychiatry 41:243-53, 1978. process, in Psychological Aspects of Facial Form, Lucker GWet al., eds, monograph11, Craniofacial Growth Series. Ann Arbor, Kloehn SJ: At what age should treatment be started?, read as part of Michigan; Center for Human Growth and Development 1980. a panel discussion before the American Association of Orthodon- tists, May20, 1954. AmJ Orthod 41:262-78, 1955. Allen BP: Social Behavior: Fact and Falsehood. Chicago; Nelson Hall, 1978. Krieg WL:Early facial growth accelerations -- a longitudinal study. Aronson E, Mettee DR: Dishonest behavior as a function of differen- Angle Orthod 57:50-62, 1987. tial levels of induced self-esteem. J Personal Doc Psych 9:121-27, 1968. McEwenJD, McHughWD, Hitchin AD: Fractured maxillary central incisors and incisal relationships. J Dent Res 46:1290, 1967. Bass NM:Dentofacial orthopedics in the correction of the skeletal Class II malocclusion, in Clinical Alterations of the GrowingFace, Ricketts RM:The influence of orthodontic treatment on facial growth and development. Angle Orthod 30:103-31, 1960. McNamaraJA Jr et al., eds, monograph14, Craniofacial Growth Series. Ann Arbor, Michigan; Center for Human Growth and Terry HK: Cases indicating early treatment, read as part of a panel Development 1983. discussion before the American Association of Orthodontists, May 20, 1954. AmJ Orthod 41:279-90, 1955. Bersheid E, Walster E: Physical attractiveness, in Advancesin Experi- mental Social Psychology, vol 7, Berkowitz L, ed. New York; Tweed CH: Treatment planning and therapy in the mixed dentition, Academic Press, 1974. presented at the 1962 annual meeting of the American Associa- tion of Orthodontists as part of a panel discussion by Hahn G, Bersheid E: An overview of the psychological effects of physical Cheney E, Tweed C, Terry H, Murray R. AmJ Orthod 49:881-906, attractiveness, in Psychological Aspects of Facial Form, Lucker 1963. GWet al., eds, monograph 11, Craniofacial Growth Series. Ann Arbor, Michigan; Center for Human Growth and Development 1980.

Pediatric Dentistry: December, 1988 ~ Volume 10, Number 4 341 PEDIATRICDENTISTRY/Copyright © 1988 by The AmericanAcademy of Pediatric Dentistry Volume 10~ Number4

Corrective methods for Class II patients ]ames R. Long, DMD,Workshop Leader Paul S. Casarnassimo, DDS, MS, Workshop Recorder

The Class II malocclusions represent a treatment others -- emphasizes that particular aspect of the neu- challenge for which various appliances can be used, romuscular physiology of the stomatognathic system based on patient characteristics. This workshop ad- which its originator considered important. These vari- dressed the following questions. ations are reflected in differences in the construction 1. Can the mandible be "grown?" and use of the appliance. 2. What is a functional appliance? Any appliance which alters growth is a functional 3. Whatcriteria should be considered in Class II correc- appliance. Headgear, for example, might be considered tion? a functional appliance. A functional appliance ad- 4. What types of appliances are appropriate for Class II dresses; (1) mandibular position; (2) mandibular tooth correction? position; and (3) the neuromuscular component of oro- 5. Does each treatment affect the growing face in the facial complex. same way? 6. Whichcharacteristics of a Class II malocclusion favor What Criteria Should be Considered in Class II Correction? the selection of a functional appliance?’ 7. What are the treatment effects of various appliances The following elements should be considered in the according to the resource readings provided? use of any appliance in Class II correction: Cephalometric appraisal -- Chin position/relation- Discussion ships; maxillary position/relationships; mandibular Can the Mandible be Grown? position/relationships; tooth position/relationships It appears that with timely treatment and using an Clinical appraisal -- Habits; breathing; posture; intelli- appropriate appliance, the mandible can be stimulated gence; age of patient; temporomandibular joint status to grow and improve the malocclusion to some degree. Complianceappraisal -- Goal-orientedi persistence; The many variables affecting growth and its inherent adaptability to alternative appliance types to help pa- unpredictability makeit difficult to use growth stimula- tient comply. tion reliably. What types of appliances are appropriate for Class II correction? What is a Functional Appliance? The variety of functional appliances complicates a In a general sense, the following types of appliances seem appropriate for Class II correction: (1) those aimed definition. Each appliance reflects the philosophy, ob- at orthodontic change; (2) those aimed at orthopedic jectives, and experience of its originator. An encompass- ing definition of the functional appliance is: change; and (3) those aimed at alleviating parafunc- tional habits. A functional appliance works on the malocclusion by Ideally, an appliance should combineall 3 aspects of employingthe activation of neuromuscularreflexes to guide treatment so as to address the individual patient’s the developing jaws and erupting teeth of children into more needs. In most cases, the functional appliance is ortho- acceptablerelationships. dontic, orthopedic, and corrects parafunctional prob- Each appliance design -- the Frankel, Bionator, and lems.

342 SPECIAL REPORT -- CORRECTIVE METHODS FOR CI_ASS II PATIENTS; Longand Casamassimo Does Each Treatment Affect the Growing short corpus length; less-than-normal lower face height. Face in the Same Way? The workshop consensus was that all patients do not Whatare the Treatment Effects of Various respond in the same fashion, nor do all appliances work Appliances According to the Resource in the same way. Treatment outcomes may be similar, Readings Provided? but the mechanisms and pathways may differ. The The Table depicts the anticipated treatment effects Table shows the varying treatment effects of functional for the following structures: maxillary first permanent appliances. molar; mandibular first permanent molar; upper lip; chin; mandible; maxilla; maxillary incisor; and mandi- WhichFactors of a Class II Malocclusion Favor the bular incisor. Selection of a Functional Appliance? The appliances described in the resource readings The following characteristics were identified as fa- and compared in discussion include the following fixed vorable to the choice of a functional appliance: deep and removable appliances: Bionator; activator; head- ; lower arch crowding; greater than normal gear (cervical, occipital, and hook-on); combinedhead- overjet; Class II permanent molar relationship; protru- gear-activator; edgewise appliance; edgewise with sive maxillary incisors; retruded mandibular incisors; Class II elastics; and Frankel II.

TA.LE.Class II TreatmentEffect

Upper Lower UpperLip Chin Mandible Maxilla Max. Mand. Molar Molar Incisor Incisor Bionator Same as Same as . No No No No Tipped Intruded growth growth change change change change lingual with growth Activator Same as Upward No No Slight Held Tipped No growth change change change back lingual change from from growth growth Headgear Distal Distal Flatter Down- No Held No Slight 1. Cervical direc- intruded ward change back change lingual tional from from move- growth growth/ ment distal- ized 2. Occipital Distal Sameas Sameas No Auto- Distal- No No direc- growth growth change rotation ized change change tional from growth 3. Hook-on Direc- Sameas Flatter/ No Auto- Distal- Tipped No tional growth fuller change rotation ized lingual change directional from growth Combined HG- Distal Vertical Sameas Forward Auto- Distal- Direc- Tipped Activator growth rotation ized tional labial Edgewise No No No No Slight No Direc- Direc- change change change change change change tional tional Edgewise with No Upward Flatter Forward Slight Distal- Direc- Tipped Class II change vertical change ized tional labial from growth FrankelII Vertical Vertical More No No No Tipped Tipped full change change change lingual labial from from growth growth

Pediatric Dentistry: December,1988 - Volume10, Number4 343 Conclusions Harvold EP, Vargervik K: Morphogenetic response to activator treatment. Am J Orthod 60:478-90,1971. The treatment of Class II malocclusions can involve a variety of appliance designs, many of which act to Klein PL: An evaluation of cervical traction on the maxilla and the stimulate mandibular growth. The functional appliance upper first permanent molar. Angle Orthod 27:61-68, 1957. affects neuromuscular reflexes to help correct the mal- McNamara JA et al: Skeletal and dental changes following functional occlusion. Selection of appropriate appliances is based regulator therapy on Class II patients. Am J Orthod 88:91-110, on patient characteristics as well as diagnosis. Certain 1985. Class II malocclusion characteristics seem more suited Odom WO: Mixed dentition treatment with cervical traction and to the functional appliance. The correction of the maloc- lower lingual arch. Angle Orthod 53:329-42, 1983. clusion by different appliances can be linked to differing effects on various parts of the stomatognathic system. Owen AH: Mandibular incisolabial responses in Class II, division 1 treatment with Frankel and edgewise. Angle Orthod 56:56-87, 1986. Dr. Long is in the full-time private practice of orthodontics in Atlanta, Georgia, and Dr. Casamassimo is chief of dentistry and director, Ricketts RM: The influence of orthodontic treatment on facial growth Pediatric Dentistry Residency Program, Children's Hospital, Colum- and development. Angle Orthod 30:103-31, 1960. bus, Ohio. Reprint requests should be sent to: Dr. Paul S. Casamas- simo, Columbus Children's Hospital, Dept, of Pediatric Dentistry, Schmuth GPF: Milestones in the development and practical applica- 700 Children's Dr., Columbus, OH 43205. tion of functional appliances. Am J Orthod 84:48-53, 1983.

Armstrong MM: Controlling the magnitude, direction, and duration Schulhof R], Engle GA: Results of Class II functional appliance of extraoral force. Am J Orthod 59:217-43, 1971. treatment. J Clin Orthod 16:587-99, 1982. Gianelly A et al: A comparison of Class II treatment changes noted with the light wire, edgewise, and Frankel appliances. Am J Orthod 86:269-76,1984.

PEDIATRIC DENTISTRY/Copyright 6 1988 by The American Academy of Pediatric Dentistry Volume 10, Number 4

Pioneer in Pediatric Dentistry: James J. Leib

Dr. James J. Leib was born on Decem- Dental Society and the Southern Cali- ber 21,1945, in Los Angeles, California. fornia Society of Pediatric Dentistry. Dr. He attended the local elementary Leib served the American Academy of schools, and was graduated from Bev- Pediatric Dentistry as president in 1972, erly Hills High School in 1942. and as a member of the Board of Trus- After attending the University of tees. Southern California from 1942 to 1944, He was a member of the Dental Care he enlisted in the U.S. Navy and served Committee of the California Dental from 1943 to 1946, and again from 1948 to Association (1960-65), the Legislation 1949 and 1952 to 1954. In 1948 Dr. Leib Council (1961 -71), and the University of received the DDS degree from the Col- the Pacific Dental Alumni Board of Di- lege of Physicians and Surgeons, Univer- rectors (1948). Dr. Leib is a Fellow of the sity of the Pacific School of Dentistry. American and International College of Dr. Leib was clinical instructor in Dentists and the American Academy of pediatric dentistry at the University of Pediatric Dentistry. Southern California from 1957 to 1958 and from 1970 to Dr. Leib, his wife Marian, and their two children, 1972. His hospital affiliations included Children's Hos- Geoffrey and Denise, reside in Pasadena, California. pital of Los Angeles, Tarzana Hospital, and Encino Hospital where he is chairman of the dental and oral Ralph L. Ireland, DDS surgery staff. Historian Emeritis He is a past-president of the San Fernando Valley

344 SPECIAL REPORT — CORRECTIVE METHODS FOR CLASS II PATIENTS: Long and Casamassimo