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The orthodontist and complex craniofacial anomalies
COMMENTARY
The orthodontist and complex craniofacial anomalies Bruce Ross, DDS, MSc, FRCD(C) Toronto, Ontario
D
espite anatomical abnormalities, there is no need to treat a craniofacial anomaly unless it is, or will become, a real problem for the patient. There must be either an interference with function or an effect on facial esthetics that interferes with psychosocial development. Many craniofacial anomalies do not cause a functional problem. Indeed, in a society less obsessed with facial esthetics, there would be no problem associated with “different” faces. The severe expression of hemifacial microsomia may unilaterally have a condyle and ramus that are severely dysplastic or even absent, no temporal fossa, and severely hypoplastic or virtually absent muscles of mastication. Yet such patients have no associated pain or discomfort, can chew and swallow comfortably, can speak with normal articulation and nasal resonance, and can breathe adequately. Apart from the loss of hearing, there may be no dysfunction except in the narrowest of definitions: the mandible and temporomandibular joint do not function in a “normal” way. Therefore, the primary purpose of treatment is to establish optimum facial esthetics, in the course of which there is usually very favorable jaw(s) repositioning that permits the orthodontist to achieve excellent occlusal function. Thus, planning treatment begins with the identification of (1) the desired facial esthestics, (2) the skeletal and soft tissue alterations necessary to make the desired changes, and (3) the dental changes required. THE TEAM APPROACH
Complex craniofacial anomalies generally require treatment by many different specialists. This seems to work best when a dedicated team is organized and treatment is coordinated. The orthodontist is an essential member of any craniofacial team. The role of the orthodontist on the team is to: • Help determine which craniofacial structures are abnormal in the affected patient. Reprint requests to: Bruce Ross, Department of Dentistry, Division of Orthodontics, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, M5G 1X8, Canada. Am J Orthod Dentofacial Orthop 2001;119:92-4 Copyright © 2001 by the American Association of Orthodontists 0889-5406/2001/$35.00 + 0 8/1/110518 doi:10.1067/mod.2001.110518
92
• Determine the facial growth pattern and predict the future morphology. • Estimate the effect that various treatment modalities, particularly surgery, would have on subsequent growth and advise on the appropriate nature and timing of treatment. • Plan with the surgeon the desired skeletal and soft tissue alterations. • Prepare for the orthognathic component of the surgery by manipulating the teeth and alveolar process, and complete orthodontic corrections after the surgery. • Become involved in clinical research on facial morphology, growth, and response to treatment. HOW WILL THE FACE GROW IF LEFT UNTREATED?
When development goes awry, there will be, over time, 1 of 3 outcomes: the situation will improve, worsen, or remain constant. However, few craniofacial anomalies improve. Infants with Robin sequence may appear to make a remarkable recovery in the first months of life, but they remain decidedly retrognathic into adulthood. On rare occasions a child with hemifacial microsomia will appear to recover. Conditions that become worse with growth include those with direct inhibition of growth areas, such as maxillary and mandibular ankylosis. Developmental bony ankylosis of the mandible is very rare; neonatal or infant trauma or infection is usually the cause of bony ankylosis in young children. Decreased mobility of the mandible is caused by the soft tissue elements of the joint and does not restrict growth. Maxillary ankylosis occurs in Apert and Crouzon syndromes. The posterior displacement and tethering of the condyle in mandibulofacial dysostosis (Treacher Collin syndrome) may be responsible for both the limited mobility and the unusual shape of the lower border that worsens over time. But stability is the rule in the vast majority of cases. Even the facial and bony asymmetries in hemifacial microsomia or unoperated cleft lip and palate are invariably stable during growth of the child; a few worsen slightly and a few improve slightly without treatment. Growth of the affected side parallels that of the nonaffected, regardless of the degree of the initial deformity.
Ross 93
American Journal of Orthodontics and Dentofacial Orthopedics Volume 119, Number 2
When one is confronted with an infant or child with a developmental anomaly, and the parent, pediatrician, and surgeon are asking for the prognosis, a useful rule of thumb is that the face continues to grow in the way it has been growing. It will invariably remain in the same configuration, with the affected areas growing proportionately to the unaffected areas. This does not apply, of course, to an acquired anomaly. WHEN SHOULD TREATMENT BEGIN?
Most craniofacial anomalies are recognized at birth, and the various specialists involved in their management plan the best and safest time to begin treatment, particularly with regard to surgical intervention. The parents would like treatment completed in the neonatal period. The speech pathologist would like the speech mechanism corrected in the first year. The psychologist would like the facial appearance treated at least before the child reaches school age. The orthodontist would like a corrected jaw relationship stabilized in the primary dentition. The surgeon might like to wait as long as possible to avoid interfering with facial growth. If a condition threatens the life or health of the patient, treatment must be instituted at once. If an anomaly poses no serious problem and is stable, as it is in the vast majority of cases, we have the luxury of treating when it is most convenient for all concerned: the patient, the parents, and the health care professionals. One advantage of an early approach is that the child has a more attractive face throughout childhood. Surgery for a preschooler will alleviate the impact of a severe facial deformity on the child during the early school years when self-esteem is fragile and patterns of social interactions are developing. In moderate cases with some esthetic problems, the timing of treatment depends on the attitude of the patient and parents. If the facial difference is not of great concern to the patient and parents, if it does not appear to be causing a psychosocial problem, and if no significant functional advantage is to be gained by early correction, then it is probably preferable to wait until facial growth has neared completion. Treatment can begin as the patient enters adolescence and social activities begin to cause more concern about facial differences. OVERTREATMENT
With a serious anomaly, there is an urgent desire to do something. Many orthodontists and surgeons micromanage their cases in an attempt to control the condition and please the parents. Early orthodontic treatment is often wasted, and early and frequent surgery may produce a poor result. Almost every craniofacial anomaly requires some form of surgical treatment to achieve a safisfactory result; orthodontic treatment alone can
do little more than tip the teeth and alveolar process. Yet some clinicians mistakenly believe in the “worsening” theory, and conclude, for example, that growth of the dysmorphic condyle in hemifacial microsomia while a functional appliance is being worn proves the effectiveness of the appliance. In fact, the same profuse growth would occur without appliance intervention. In treating patients with cleft lip and palate, orthodontists place appliances at birth and needlessly keep the child under treatment almost continuously until young adulthood. Presurgical infant orthopedics, for example, have been in use for more than 50 years without a single confirmed benefit. For any protocol or procedure, the onus is on the advocates to prove it is worthwhile and safe, not on the opponents to prove it is not. There are times to intervene and times to simply observe as the child participates in other therapeutic activities or is permitted to have a rest and just grow. CAN ORTHODONTIC OR ORTHOPEDIC TREATMENT INFLUENCE CRANIOFACIAL GROWTH?
Alas, it would seem that orthodontists have very little effect on the growth of the basal bones of the face, including the mandible and maxilla. The permanent response to treatment can be measured in millimeters or fractions thereof. This is a small accomplishment in a face that is severely deficient or deformed. THE EFFECTS OF SURGERY ON FACIAL GROWTH
Most anomalies have functional or esthetic problems that require reconstructive surgery to the hard and soft tissues. There are usually compelling reasons to attempt treatment of these conditions as early as possible, and surgery to the growing child is often proposed. Surgery to an area generally affects the subsequent growth of that area, usually in a detrimental way. Surgery to the mandible or maxilla can attenuate or arrest subsequent growth. In most cases, elective surgery should be delayed until facial growth is close to completion unless one has reasonable certainty that surgical treatment will not inhibit further growth. CONGENITAL OR ACQUIRED?
It is useful and often essential to determine whether a facial malformation is developmental or acquired. There are many indicators: • Pain indicates an acquired anomaly. There is no pain or discomfort with developmental anomalies, and no history of pain. • A change over time in the condition, either the appearance of new symptoms or a change in morphology, indicates an acquired anomaly.
94 Ross
American Journal of Orthodontics and Dentofacial Orthopedics February 2001
• A temporary change in symptoms associated with function (eg, heavy chewing) indicates an acquired anomaly. Developmental anomalies are not affected by function. • The presence of developmental anomalies of contiguous structures (eg, ear, eye, palate, macrostomia, muscle deficiency) suggests a developmental etiology. • Crepitis or clicking in the joint suggests an acquired anomaly. • Ankylosis is almost always acquired. Limitation of mandibular forward translation may be developmental, but rotation is not usually limited to any great extent. • Marked dental compensations for an asymmetrical mandible indicate that there was very early devel-
opment of the asymmetry, possibly congenital or in infancy. The corollary is that if there are severe crossbites, then the condition was probably acquired at a later time. • The condyle in a developmental condition may be deficient or excessive, but it is round and smooth. If the condylar head is flat or an irregular shape, it is an acquired anomaly. Orthodontists tend to have an admirably idealistic approach to the occlusion, but in dealing with craniofacial anomalies, we must always be prepared to accept some functional and esthetic compromises. Modern techniques have made these compromises much more tolerable.
ESTATE PLANNING & PLANNED GIVING Estate Planning: The AAO Foundation offers information on estate planning to AAO members and their advisors on a complimentary basis and at no obligation. Planned Giving: Those individuals who are contemplating a gift to the AAO Foundation through their estates are asked to contact the AAOF prior to proceeding. Please call (800) 424-2481, extension 246. Please remember the AAO Foundation in your estate planning.
The orthodontist and complex craniofacial anomalies Bruce Ross, DDS, MSc, FRCD(C) Toronto, Ontario
D
espite anatomical abnormalities, there is no need to treat a craniofacial anomaly unless it is, or will become, a real problem for the patient. There must be either an interference with function or an effect on facial esthetics that interferes with psychosocial development. Many craniofacial anomalies do not cause a functional problem. Indeed, in a society less obsessed with facial esthetics, there would be no problem associated with “different” faces. The severe expression of hemifacial microsomia may unilaterally have a condyle and ramus that are severely dysplastic or even absent, no temporal fossa, and severely hypoplastic or virtually absent muscles of mastication. Yet such patients have no associated pain or discomfort, can chew and swallow comfortably, can speak with normal articulation and nasal resonance, and can breathe adequately. Apart from the loss of hearing, there may be no dysfunction except in the narrowest of definitions: the mandible and temporomandibular joint do not function in a “normal” way. Therefore, the primary purpose of treatment is to establish optimum facial esthetics, in the course of which there is usually very favorable jaw(s) repositioning that permits the orthodontist to achieve excellent occlusal function. Thus, planning treatment begins with the identification of (1) the desired facial esthestics, (2) the skeletal and soft tissue alterations necessary to make the desired changes, and (3) the dental changes required. THE TEAM APPROACH
Complex craniofacial anomalies generally require treatment by many different specialists. This seems to work best when a dedicated team is organized and treatment is coordinated. The orthodontist is an essential member of any craniofacial team. The role of the orthodontist on the team is to: • Help determine which craniofacial structures are abnormal in the affected patient. Reprint requests to: Bruce Ross, Department of Dentistry, Division of Orthodontics, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, M5G 1X8, Canada. Am J Orthod Dentofacial Orthop 2001;119:92-4 Copyright © 2001 by the American Association of Orthodontists 0889-5406/2001/$35.00 + 0 8/1/110518 doi:10.1067/mod.2001.110518
92
• Determine the facial growth pattern and predict the future morphology. • Estimate the effect that various treatment modalities, particularly surgery, would have on subsequent growth and advise on the appropriate nature and timing of treatment. • Plan with the surgeon the desired skeletal and soft tissue alterations. • Prepare for the orthognathic component of the surgery by manipulating the teeth and alveolar process, and complete orthodontic corrections after the surgery. • Become involved in clinical research on facial morphology, growth, and response to treatment. HOW WILL THE FACE GROW IF LEFT UNTREATED?
When development goes awry, there will be, over time, 1 of 3 outcomes: the situation will improve, worsen, or remain constant. However, few craniofacial anomalies improve. Infants with Robin sequence may appear to make a remarkable recovery in the first months of life, but they remain decidedly retrognathic into adulthood. On rare occasions a child with hemifacial microsomia will appear to recover. Conditions that become worse with growth include those with direct inhibition of growth areas, such as maxillary and mandibular ankylosis. Developmental bony ankylosis of the mandible is very rare; neonatal or infant trauma or infection is usually the cause of bony ankylosis in young children. Decreased mobility of the mandible is caused by the soft tissue elements of the joint and does not restrict growth. Maxillary ankylosis occurs in Apert and Crouzon syndromes. The posterior displacement and tethering of the condyle in mandibulofacial dysostosis (Treacher Collin syndrome) may be responsible for both the limited mobility and the unusual shape of the lower border that worsens over time. But stability is the rule in the vast majority of cases. Even the facial and bony asymmetries in hemifacial microsomia or unoperated cleft lip and palate are invariably stable during growth of the child; a few worsen slightly and a few improve slightly without treatment. Growth of the affected side parallels that of the nonaffected, regardless of the degree of the initial deformity.
Ross 93
American Journal of Orthodontics and Dentofacial Orthopedics Volume 119, Number 2
When one is confronted with an infant or child with a developmental anomaly, and the parent, pediatrician, and surgeon are asking for the prognosis, a useful rule of thumb is that the face continues to grow in the way it has been growing. It will invariably remain in the same configuration, with the affected areas growing proportionately to the unaffected areas. This does not apply, of course, to an acquired anomaly. WHEN SHOULD TREATMENT BEGIN?
Most craniofacial anomalies are recognized at birth, and the various specialists involved in their management plan the best and safest time to begin treatment, particularly with regard to surgical intervention. The parents would like treatment completed in the neonatal period. The speech pathologist would like the speech mechanism corrected in the first year. The psychologist would like the facial appearance treated at least before the child reaches school age. The orthodontist would like a corrected jaw relationship stabilized in the primary dentition. The surgeon might like to wait as long as possible to avoid interfering with facial growth. If a condition threatens the life or health of the patient, treatment must be instituted at once. If an anomaly poses no serious problem and is stable, as it is in the vast majority of cases, we have the luxury of treating when it is most convenient for all concerned: the patient, the parents, and the health care professionals. One advantage of an early approach is that the child has a more attractive face throughout childhood. Surgery for a preschooler will alleviate the impact of a severe facial deformity on the child during the early school years when self-esteem is fragile and patterns of social interactions are developing. In moderate cases with some esthetic problems, the timing of treatment depends on the attitude of the patient and parents. If the facial difference is not of great concern to the patient and parents, if it does not appear to be causing a psychosocial problem, and if no significant functional advantage is to be gained by early correction, then it is probably preferable to wait until facial growth has neared completion. Treatment can begin as the patient enters adolescence and social activities begin to cause more concern about facial differences. OVERTREATMENT
With a serious anomaly, there is an urgent desire to do something. Many orthodontists and surgeons micromanage their cases in an attempt to control the condition and please the parents. Early orthodontic treatment is often wasted, and early and frequent surgery may produce a poor result. Almost every craniofacial anomaly requires some form of surgical treatment to achieve a safisfactory result; orthodontic treatment alone can
do little more than tip the teeth and alveolar process. Yet some clinicians mistakenly believe in the “worsening” theory, and conclude, for example, that growth of the dysmorphic condyle in hemifacial microsomia while a functional appliance is being worn proves the effectiveness of the appliance. In fact, the same profuse growth would occur without appliance intervention. In treating patients with cleft lip and palate, orthodontists place appliances at birth and needlessly keep the child under treatment almost continuously until young adulthood. Presurgical infant orthopedics, for example, have been in use for more than 50 years without a single confirmed benefit. For any protocol or procedure, the onus is on the advocates to prove it is worthwhile and safe, not on the opponents to prove it is not. There are times to intervene and times to simply observe as the child participates in other therapeutic activities or is permitted to have a rest and just grow. CAN ORTHODONTIC OR ORTHOPEDIC TREATMENT INFLUENCE CRANIOFACIAL GROWTH?
Alas, it would seem that orthodontists have very little effect on the growth of the basal bones of the face, including the mandible and maxilla. The permanent response to treatment can be measured in millimeters or fractions thereof. This is a small accomplishment in a face that is severely deficient or deformed. THE EFFECTS OF SURGERY ON FACIAL GROWTH
Most anomalies have functional or esthetic problems that require reconstructive surgery to the hard and soft tissues. There are usually compelling reasons to attempt treatment of these conditions as early as possible, and surgery to the growing child is often proposed. Surgery to an area generally affects the subsequent growth of that area, usually in a detrimental way. Surgery to the mandible or maxilla can attenuate or arrest subsequent growth. In most cases, elective surgery should be delayed until facial growth is close to completion unless one has reasonable certainty that surgical treatment will not inhibit further growth. CONGENITAL OR ACQUIRED?
It is useful and often essential to determine whether a facial malformation is developmental or acquired. There are many indicators: • Pain indicates an acquired anomaly. There is no pain or discomfort with developmental anomalies, and no history of pain. • A change over time in the condition, either the appearance of new symptoms or a change in morphology, indicates an acquired anomaly.
94 Ross
American Journal of Orthodontics and Dentofacial Orthopedics February 2001
• A temporary change in symptoms associated with function (eg, heavy chewing) indicates an acquired anomaly. Developmental anomalies are not affected by function. • The presence of developmental anomalies of contiguous structures (eg, ear, eye, palate, macrostomia, muscle deficiency) suggests a developmental etiology. • Crepitis or clicking in the joint suggests an acquired anomaly. • Ankylosis is almost always acquired. Limitation of mandibular forward translation may be developmental, but rotation is not usually limited to any great extent. • Marked dental compensations for an asymmetrical mandible indicate that there was very early devel-
opment of the asymmetry, possibly congenital or in infancy. The corollary is that if there are severe crossbites, then the condition was probably acquired at a later time. • The condyle in a developmental condition may be deficient or excessive, but it is round and smooth. If the condylar head is flat or an irregular shape, it is an acquired anomaly. Orthodontists tend to have an admirably idealistic approach to the occlusion, but in dealing with craniofacial anomalies, we must always be prepared to accept some functional and esthetic compromises. Modern techniques have made these compromises much more tolerable.
ESTATE PLANNING & PLANNED GIVING Estate Planning: The AAO Foundation offers information on estate planning to AAO members and their advisors on a complimentary basis and at no obligation. Planned Giving: Those individuals who are contemplating a gift to the AAO Foundation through their estates are asked to contact the AAOF prior to proceeding. Please call (800) 424-2481, extension 246. Please remember the AAO Foundation in your estate planning.