Patient with Pfeiffer’s syndrome treated by midfacial distraction and comprehensive orthodontics
2011; Elsevier BV; Volume: 139; Issue: 2 Linguagem: Inglês
10.1016/j.ajodo.2010.06.020
ISSN1097-6752
AutoresYongJong Park, P. Creighton Hobar, Douglas P. Sinn, Supakit Peanchitlertkajorn,
Tópico(s)Orthodontics and Dentofacial Orthopedics
ResumoTreatment for patients with craniofacial anomalies always presents a great challenge to orthodontists. Treatment usually requires both comprehensive orthodontic treatment and orthognathic surgery. In this article, we report on a patient with Pfeiffer’s syndrome treated by midfacial distraction and comprehensive orthodontics. Treatment for patients with craniofacial anomalies always presents a great challenge to orthodontists. Treatment usually requires both comprehensive orthodontic treatment and orthognathic surgery. In this article, we report on a patient with Pfeiffer’s syndrome treated by midfacial distraction and comprehensive orthodontics. Pfeiffer’s syndrome is a rare autosomal dominantly inherited disorder that is associated with midfacial retrusion, craniosynostosis, broad thumbs and large toes, and partial syndactyly. Hydrocephaly is also found occasionally, along with severe ocular proptosis, ankylosed elbows, abnormal viscera, slow development, significant upper airway compromise, and obstructive sleep apnea.1Moore M.H. Cantrell S.B. Trott J.A. David D.J. Pfeiffer syndrome: a clinical review.Cleft Palate Craniofac J. 1995; 32: 62-70Crossref PubMed Scopus (50) Google Scholar Dental characteristics of the syndrome are similar to those of Apert’s syndrome, Crouzon’s syndrome, and other craniofacial synostoses. General dental characteristics are maxillary hypoplasia, Class III malocclusion, anterior and posterior crossbites, anterior open bite, and severe crowding of the maxillary arch due to hypoplasia. However, Alvarez et al2Alvarez M.P. Crespi P.V. Shanske A.L. Natal molars in Pfeiffer syndrome type 3: a case report.J Clin Pediatr Dent. 1993; 18: 21-24PubMed Google Scholar reported Pfeiffer’s syndrome patients with natal teeth. The incidence of Pfeiffer’s syndrome is 1 in 100,000 persons.3Vogels A. Fryns J.P. Pfeiffer syndrome.Orphanet J Rare Dis. 2006; 1: 19Crossref PubMed Scopus (92) Google ScholarIn addition to these medical and dental problems, patients with craniofacial synostosis are likely to have psychosocial problems because of their appearance. Physical appearance is significantly related to psychosocial well-being in children and young adolescents. Children with craniofacial anomalies are reported to have fewer social activities, problematic peer relationships, and psychological adjustment problems.4Kapp-Simon K.A. Simon D.J. Kristovich S. Self-perception, social skills, adjustment, and inhibition in young adolescents with craniofacial anomalies.Cleft Palate Craniofac J. 1992; 29: 352-356Crossref PubMed Scopus (130) Google Scholar, 5Kapp-Simon K.A. McGuire D.E. Observed social interaction patterns in adolescents with and without craniofacial conditions.Cleft Palate Craniofac J. 1997; 34: 380-384Crossref PubMed Scopus (85) Google Scholar, 6Pope A.W. Ward J. Self-perceived facial appearance and psychosocial adjustment in preadolescents with craniofacial anomalies.Cleft Palate Craniofac J. 1997; 34: 396-401Crossref PubMed Scopus (77) Google Scholar It is also believed that, if correction of the deformities could occur at a younger age, there would be fewer psychosocial problems.7Pertschuk M.J. Whitaker L.A. Social and psychological effects of craniofacial deformity and surgical reconstruction.Clin Plast Surg. 1982; 9: 297-306PubMed Google Scholar Distraction osteogenesis has become a popular treatment of choice to correct severe skeletal discrepancies in the maxillofacial region over the past decade. This technique has been applied to treat severe midfacial hypoplasia related to cleft lip and palate or other syndromes.8Van Sickels J.E. Distraction osteogenesis versus orthognathic surgery.Am J Orthod Dentofacial Orthop. 2000; 118: 482-484Abstract Full Text Full Text PDF PubMed Scopus (14) Google ScholarDiagnosis and etiologyThe patient was referred to Children’s Medical Center of Dallas, Texas, at the age of 2 with a chief complaint of facial abnormalities. She had marked midfacial hypoplasia, mild hypertelorism, broad thumbs, and large toes (Fig 1). After a thorough examination, she was diagnosed with Pfeiffer’s syndrome. The physical examination showed no signs of neurologic problems or increased intracranial pressure. Neither were there signs or symptoms of upper airway constriction or obstructive sleep apnea. Therefore, no treatment was deemed necessary at that time. At the age of 4, orbital hypertelorism was corrected by a craniofacial surgeon (Fig 2). The patient recovered well from the surgery and continued to be followed by the craniofacial team annually.Fig 2Facial change after hypertelorism correction.View Large Image Figure ViewerDownload Hi-res image Download (PPT)At the age of 11 years, the patient began complaining of both masticatory and psychosocial problems because of severe midfacial retrusion. Therefore, a surgical- orthodontic plan was developed to address these problems. The facial examination showed a severely concave profile, decreased lower facial height, and deficient incisal display on full smile. Dentally, she was in the late mixed dentition. She exhibited Class III molar and canine relationships, a negative overjet of –10 mm, an overbite of 50%, and severe maxillary and mandibular anterior crowding. Cephalometrically, she had a retrusive maxilla with an ANB angle of –1°, a flat mandibular plane angle, a relatively normal anteroposterior position of the mandible, and proclined mandibular incisors (Fig 3, Fig 4, Table).Fig 3Pretreatment photographs and x-rays.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 4Pretreatment dental casts.View Large Image Figure ViewerDownload Hi-res image Download (PPT)TableCephalometric analysisPretreatementPostdistractionFinalNormValueSDValueSDValueSDSkeletal measurements N-A-Pg5.5−22.64.5−0.94.5−74.5 A-B ‖ OP (mm)−0.5−2.124.22−3.42 SNA8269.1379.5379.73 SNB8079.9478.2481.54 ANB2−10.81.51.31.5−1.81.5 OP-HP9−8.12.502.53.92.5 PP-HP0.53.736.537.13 MP-HP2520.5520.5518.75 Y-axis (SGn-FH)6057.2355.5355.93 UFH (N-ANS/[N-ANS+ANS-Me]) (%)4343.510045.610045.5100 LFH (ANS-Me/[N-ANS+ANS-Me]) (%)5756.510054.410054.5100 Ba-S-N130122.4100120.8100116.6100Dental measurements 1/ (HP)110112.56.5116.36.5118.36.5 /1 (HP)6068.44.5694.570.94.5 1/-(UL) (mm)2.50.41−0.61−0.51 1/1130135.98132.78132.68 /1 (MP)9091.1590.5590.45 /1 (A-Pg) (mm)2.58.720.623.12 /1 (N-Pg) (mm)3.51.62.50.32.50.82.5Soft-tissue measurements Facial convexity (G’-Sn-Po’)13.5−8.25.516.25.58.55.5 UL protrusion (UL-SnPg’) (mm)3.52.51.84.81.85.31.8 LL protrusion (LL-SnPg’) (mm)2.84.61.71.51.72.11.7 Upper lip to E-plane (mm)−3−6.42−2.32−5.22 Lower lip to E-plane (mm)−2.5−1.12.5−3.22.5−4.32.5 Open table in a new tab Pfeiffer’s syndrome is caused by a mutation of a fibroblast growth factor receptor gene, FGFR1 or FGFR2. A mutation of either FGFR1 or FGFR2 causes prolonged signaling, which can promote early maturation of bone cells and premature fusion of bones.3Vogels A. Fryns J.P. Pfeiffer syndrome.Orphanet J Rare Dis. 2006; 1: 19Crossref PubMed Scopus (92) Google Scholar Maxillary hypoplasia causes severe maxillary arch crowding and crossbite. A flat mandibular plane angle and decreased lower facial height also are caused by overclosure of the mandible due to a hypoplastic maxilla. There are 3 types of Pfeiffer’s syndrome.3Vogels A. Fryns J.P. Pfeiffer syndrome.Orphanet J Rare Dis. 2006; 1: 19Crossref PubMed Scopus (92) Google Scholar Type I, or classic Pfeiffer’s syndrome, involves mild manifestations including brachycephaly, midface hypoplasia, finger and toe abnormalities, and normal intelligence. Patients with type I generally have a good prognosis. Patients with type II have a cloverleaf skull, extreme proptosis, finger and toe abnormalities, elbow ankylosis or synostosis, developmental delays, and neurologic complications. Patients with type III are similar to type II except for the cloverleaf skull.Treatment objectivesThe general treatment objectives for patients with craniofacial synostosis are to achieve favorable facial balance and dental occlusion. It was also reported that patients with a severe craniofacial anomaly can often experience airway problems.9Lo L.J. Chen Y.R. Airway obstruction in severe syndromic craniosynostosis.Ann Plast Surg. 1999; 43: 258-264Crossref PubMed Scopus (66) Google Scholar, 10Perkins J.A. Sie K.C. Milczuk H. Richardson M.A. Airway management in children with craniofacial anomalies.Cleft Palate Craniofac J. 1997; 34: 135-140Crossref PubMed Scopus (142) Google Scholar Therefore, the airway must be considered when planning treatment if the patient suffers from breathing problems or sleep apnea. Since this patient had no airway problems, the treatment objectives for her were to (1) create a well-balanced facial profile by advancing her midface, (2) eliminate her ocular proptosis, (3) slightly increase her nasal bone projection, (4) increase her maxillary incisal display, (5) create proper overjet and overbite, (6) align her dentition, and (7) establish maximal interdigitation of her teeth.Treatment alternativesTreatment options for patients with craniosynostosis vary depending on the severity of the skeletal and dental problems and the patient’s psychosocial condition. If the midfacial hypoplasia is mild, the treatment usually involves conventional LeFort III or monobloc advancement along with comprehensive orthodontic treatment in the permanent dentition.11Fearon J.A. Halo distraction of the Le Fort III in syndromic craniosynostosis: a long-term assessment.Plast Reconstr Surg. 2005; 115: 1524-1536Crossref PubMed Scopus (130) Google Scholar For patients with more severe dental and skeletal conditions, LeFort III midfacial distraction is usually required for a more stable outcome in addition to comprehensive orthodontic treatment. Unlike orthognathic surgery, distraction osteogenesis can be performed on younger patients whose growth has not been completed.11Fearon J.A. Halo distraction of the Le Fort III in syndromic craniosynostosis: a long-term assessment.Plast Reconstr Surg. 2005; 115: 1524-1536Crossref PubMed Scopus (130) Google Scholar, 12Figueroa A.A. Polley J.W. Management of severe cleft maxillary deficiency with distraction osteogenesis: procedure and results.Am J Orthod Dentofacial Orthop. 1999; 115: 1-12Abstract Full Text Full Text PDF PubMed Scopus (140) Google ScholarTwo treatment plans were presented to the patient and her parents. Both involved distraction osteogenesis because of the severity and the patient’s age. The first plan would begin with preoperative orthodontic preparation, followed by LeFort III distraction, and would finish with postoperative orthodontic treatment. The second plan would start with LeFort III distraction and be followed by comprehensive orthodontic treatment. The second plan was chosen based on the patient’s complaint of psychosocial problems related to her midfacial hypoplasia. The plan aimed to resolve her severe midfacial retrusion as early as possible to improve her psychosocial well-being. The comprehensive orthodontic treatment would then correct any residual malocclusion and maximize her dental esthetics. The orthodontic plan included extraction of the maxillary and mandibular first premolars because of severe crowding.Treatment progressOrthodontic and surgical records were obtained to plan for anterior movement of the midface and the maxillary dentition. The dental casts showed that the maxillary and mandibular arches were coordinated. It was also determined that the maxillary teeth, when brought forward, would fit the mandibular teeth in a stable position. A surgical stent for a halo-type distraction device (rigid external distraction device) was fabricated. It was then banded to the maxillary first molars and bonded to the lingual surfaces of the maxillary teeth before surgery. During the surgery, the LeFort III osteotomy was made to mobilize the midfacial complex, and then the distraction device was placed and attached to the surgical splint and the nasal bone (Fig 5). After a 7-day latency period, the activation began. The rate of distraction was 1 mm of advancement per day. The patient’s midface was distracted anteriorly until a favorable facial profile was obtained and the ocular proptosis was eliminated.Fig 5Placement of the halo distractor.View Large Image Figure ViewerDownload Hi-res image Download (PPT)After distraction, a Class II molar relationship and 4 mm of overjet were achieved for overcorrection to compensate for future mandibular growth (Fig 6, Fig 7). The maxilla was advanced 15 mm. No anterior open bite was observed. The patient continued to wear the distractor for another 3 months to allow for consolidation. Orthodontic treatment began after the distractor was removed. The maxillary and mandibular first premolars were extracted because of the severe anterior crowding. Fixed appliances consisting of 0.018-in slot brackets were placed on the maxillary and mandibular anterior teeth, and 0.022-in slot brackets were bonded to the posterior teeth. After initial leveling and aligning, the maxillary and mandibular extraction spaces were closed with sliding mechanics by using elastomeric chains. A gingivectomy was performed on all second molars to increase crown length for banding. Once all the orthodontic treatment objectives were achieved, the orthodontic appliances were removed, and maxillary and mandibular removable Hawley retainers were delivered.Fig 6Postdistraction photographs and cephalogram.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 7Postdistraction dental casts.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Treatment resultsA well-balanced facial profile was obtained. The patient’s ocular proptosis was eliminated. Class I canine and molar relationships were obtained. The dentition was well aligned. Appropriate overjet and overbite were achieved (Table). The final panoramic radiograph shows good root parallelism with no root resorption. Superimposition of the predistraction and postdistraction cephalograms demonstrated that the patient’s midface was moved forward without tipping of the maxillary incisors. No clockwise rotation of the mandible was observed (Fig 8, Fig 9, Fig 10). Her mandible continued to grow in a normal range after distraction and during orthodontic treatment. A favorable profile was achieved despite a negative posttreatment ANB angle. The negative ANB could have been due to the forward displacement of the nasal bone (nasion point) during the distraction osteogenesis. The superimposition of the predistraction and postorthodontic cephalograms showed the following changes as a result of treatment (Fig 11): (1) correction of the midfacial hypoplasia by midfacial advancement, (2) correction of the negative overjet by maxillary advancement, (3) maintenance of the mandibular plane angle after distraction, (4) normal mandibular growth after distraction, and (5) good stability of the maxilla after distraction.Fig 8Superimposed tracings (black, initial; blue, postdistraction).View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 9Posttreatment photographs and x-rays.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 10Posttreatment dental casts.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 11Superimposed tracings (black, initial; red, posttreatment).View Large Image Figure ViewerDownload Hi-res image Download (PPT)The patient was satisfied with both the facial and dental treatment outcomes. Her parents also reported that she became more confident and socially outgoing. The treatment took 49 months for both distraction osteogenesis and orthodontics. After 2 years of retention, the occlusion is stable, and good facial esthetics have been maintained. Cephalometric superimpositions showed no noticeable change in skeletal pattern with a slight increase in the proclination of the maxillary and mandibular incisors (Fig 12, Fig 13).Fig 12Retention photographs.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 13Superimposed tracings (red, final; blue, 2-year postretention).View Large Image Figure ViewerDownload Hi-res image Download (PPT)DiscussionTreating patients with craniosynostosis such as Crouzon’s disease, Apert’s syndrome, and Pfeiffer’s syndrome requires an interdisciplinary approach from both medical and dental specialties. These specialists participated in interdisciplinary care to optimize the treatment. The team, referred to as a craniofacial team, usually consists of an orthodontist, a pediatric dentist, a prosthodontist, a plastic surgeon, a maxillofacial surgeon, a neurosurgeon, an ophthalmologist, a geneticist, a pediatrician, a psychologist, and a speech pathologist. This patient was evaluated and treated by the craniofacial team at the Dallas Children’s Medical Center. Distraction osteogenesis is usually indicated for severe skeletal hypoplasia, and conventional orthognathic surgery is indicated for mild or moderate conditions. Distraction can also be performed in younger patients, whereas conventional orthognathic surgery is usually performed when facial growth is complete.13Iannetti G. Fadda T. Agrillo A. Poladas G. Filiaci F. LeFort III advancement with and without osteogenesis distraction.J Craniofac Surg. 2006; 17: 536-543Crossref PubMed Scopus (31) Google Scholar In this patient, the midface could be distracted without orthodontic preparation; this allowed us to address the patient’s psychosocial problems earlier than with conventional orthognathic surgery.When midfacial distraction is planned, clinicians should consider the final positions of other midfacial structures, such as inferior orbital rim, malar bone, and nasal bone. As the midface is distracted forward, an anterior open bite could occur by counterclockwise rotation of the midface. To prevent such a rotation, additional wires attaching from the nasal bone or the zygomatic arch to the distractor are often used to control the midface as it comes forward. However, these wires can cause some changes to the structures to which they are attached. In this patient, wires were attached to the distractor from the nasal bone and the intraoral stent. Superimposition of pretreatment and postdistraction cephalograms shows no counterclockwise rotation of the maxilla. An increased nasal projection was also achieved by forward movement of the nasal bone.LeFort III advancement is usually indicated for hypoplasia of the upper midfacial structures (malar, orbital, and nasal bones). When performed alone, it is sometimes inadequate to correct the discrepancy at the dentoalveolar level. Therefore, patients and parents should be advised of possible LeFort I orthognathic surgery after facial growth to maximize the occlusal relationships.14Fearon J.A. The Le Fort III osteotomy: to distract or not to distract?.Plast Reconstr Surg. 2001; 107: 1091-1103Crossref PubMed Scopus (58) Google ScholarSome clinicians reported the use of internal distractors. Internal devices are less conspicuous and more accepted by patients than external devices. However, the distraction vector cannot be adjusted during activation, unlike the external type. They are also harder to place because of the anatomy and poor bone quality of the maxilla. As a result, external devices are used more frequently because of their easier placement and removal. However, scarring of the scalp, created by transcutaneous pins, sometimes causes an unpleasant appearance and can be a disadvantage.15William H. Bell C.A.G. Distraction osteogenesis of the facial skeleton. BC Decker, Hamilton, Ontario, Canada2007Google ScholarFearon11Fearon J.A. Halo distraction of the Le Fort III in syndromic craniosynostosis: a long-term assessment.Plast Reconstr Surg. 2005; 115: 1524-1536Crossref PubMed Scopus (130) Google Scholar reported that the maxilla remained stable after LeFort III halo distraction without relapse, and no anterior growth was observed up to 5 years postoperatively. Therefore, most patients will probably avoid another LeFort III advancement. Bu et al16Bu B.H. Kaban L.B. Vargervik K. Effect of Le Fort III osteotomy on mandibular growth in patients with Crouzon and Apert syndromes.J Oral Maxillofac Surg. 1989; 47: 666-671Abstract Full Text PDF PubMed Scopus (16) Google Scholar reported that the mandible was not affected by the LeFort III osteotomy and continued to grow after distraction. Superimposition of the patient’s cephalograms shows good stability of the maxilla after distraction. The mandible also continued to grow throughout orthodontic treatment. There was no clockwise rotation of the mandible after distraction. The correction of overjet was achieved mostly by skeletal movement of the midface, since the inclination of the maxillary incisors did not change throughout the distraction osteogenesis.ConclusionsThis case report demonstrates that a patient with severe midfacial hypoplasia, caused by Pfeiffer’s syndrome, can be successfully treated with midfacial distraction osteogenesis and comprehensive orthodontics. Pfeiffer’s syndrome is a rare autosomal dominantly inherited disorder that is associated with midfacial retrusion, craniosynostosis, broad thumbs and large toes, and partial syndactyly. Hydrocephaly is also found occasionally, along with severe ocular proptosis, ankylosed elbows, abnormal viscera, slow development, significant upper airway compromise, and obstructive sleep apnea.1Moore M.H. Cantrell S.B. Trott J.A. David D.J. Pfeiffer syndrome: a clinical review.Cleft Palate Craniofac J. 1995; 32: 62-70Crossref PubMed Scopus (50) Google Scholar Dental characteristics of the syndrome are similar to those of Apert’s syndrome, Crouzon’s syndrome, and other craniofacial synostoses. General dental characteristics are maxillary hypoplasia, Class III malocclusion, anterior and posterior crossbites, anterior open bite, and severe crowding of the maxillary arch due to hypoplasia. However, Alvarez et al2Alvarez M.P. Crespi P.V. Shanske A.L. Natal molars in Pfeiffer syndrome type 3: a case report.J Clin Pediatr Dent. 1993; 18: 21-24PubMed Google Scholar reported Pfeiffer’s syndrome patients with natal teeth. The incidence of Pfeiffer’s syndrome is 1 in 100,000 persons.3Vogels A. Fryns J.P. Pfeiffer syndrome.Orphanet J Rare Dis. 2006; 1: 19Crossref PubMed Scopus (92) Google Scholar In addition to these medical and dental problems, patients with craniofacial synostosis are likely to have psychosocial problems because of their appearance. Physical appearance is significantly related to psychosocial well-being in children and young adolescents. Children with craniofacial anomalies are reported to have fewer social activities, problematic peer relationships, and psychological adjustment problems.4Kapp-Simon K.A. Simon D.J. Kristovich S. Self-perception, social skills, adjustment, and inhibition in young adolescents with craniofacial anomalies.Cleft Palate Craniofac J. 1992; 29: 352-356Crossref PubMed Scopus (130) Google Scholar, 5Kapp-Simon K.A. McGuire D.E. Observed social interaction patterns in adolescents with and without craniofacial conditions.Cleft Palate Craniofac J. 1997; 34: 380-384Crossref PubMed Scopus (85) Google Scholar, 6Pope A.W. Ward J. Self-perceived facial appearance and psychosocial adjustment in preadolescents with craniofacial anomalies.Cleft Palate Craniofac J. 1997; 34: 396-401Crossref PubMed Scopus (77) Google Scholar It is also believed that, if correction of the deformities could occur at a younger age, there would be fewer psychosocial problems.7Pertschuk M.J. Whitaker L.A. Social and psychological effects of craniofacial deformity and surgical reconstruction.Clin Plast Surg. 1982; 9: 297-306PubMed Google Scholar Distraction osteogenesis has become a popular treatment of choice to correct severe skeletal discrepancies in the maxillofacial region over the past decade. This technique has been applied to treat severe midfacial hypoplasia related to cleft lip and palate or other syndromes.8Van Sickels J.E. Distraction osteogenesis versus orthognathic surgery.Am J Orthod Dentofacial Orthop. 2000; 118: 482-484Abstract Full Text Full Text PDF PubMed Scopus (14) Google Scholar Diagnosis and etiologyThe patient was referred to Children’s Medical Center of Dallas, Texas, at the age of 2 with a chief complaint of facial abnormalities. She had marked midfacial hypoplasia, mild hypertelorism, broad thumbs, and large toes (Fig 1). After a thorough examination, she was diagnosed with Pfeiffer’s syndrome. The physical examination showed no signs of neurologic problems or increased intracranial pressure. Neither were there signs or symptoms of upper airway constriction or obstructive sleep apnea. Therefore, no treatment was deemed necessary at that time. At the age of 4, orbital hypertelorism was corrected by a craniofacial surgeon (Fig 2). The patient recovered well from the surgery and continued to be followed by the craniofacial team annually.At the age of 11 years, the patient began complaining of both masticatory and psychosocial problems because of severe midfacial retrusion. Therefore, a surgical- orthodontic plan was developed to address these problems. The facial examination showed a severely concave profile, decreased lower facial height, and deficient incisal display on full smile. Dentally, she was in the late mixed dentition. She exhibited Class III molar and canine relationships, a negative overjet of –10 mm, an overbite of 50%, and severe maxillary and mandibular anterior crowding. Cephalometrically, she had a retrusive maxilla with an ANB angle of –1°, a flat mandibular plane angle, a relatively normal anteroposterior position of the mandible, and proclined mandibular incisors (Fig 3, Fig 4, Table).Fig 3Pretreatment photographs and x-rays.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 4Pretreatment dental casts.View Large Image Figure ViewerDownload Hi-res image Download (PPT)TableCephalometric analysisPretreatementPostdistractionFinalNormValueSDValueSDValueSDSkeletal measurements N-A-Pg5.5−22.64.5−0.94.5−74.5 A-B ‖ OP (mm)−0.5−2.124.22−3.42 SNA8269.1379.5379.73 SNB8079.9478.2481.54 ANB2−10.81.51.31.5−1.81.5 OP-HP9−8.12.502.53.92.5 PP-HP0.53.736.537.13 MP-HP2520.5520.5518.75 Y-axis (SGn-FH)6057.2355.5355.93 UFH (N-ANS/[N-ANS+ANS-Me]) (%)4343.510045.610045.5100 LFH (ANS-Me/[N-ANS+ANS-Me]) (%)5756.510054.410054.5100 Ba-S-N130122.4100120.8100116.6100Dental measurements 1/ (HP)110112.56.5116.36.5118.36.5 /1 (HP)6068.44.5694.570.94.5 1/-(UL) (mm)2.50.41−0.61−0.51 1/1130135.98132.78132.68 /1 (MP)9091.1590.5590.45 /1 (A-Pg) (mm)2.58.720.623.12 /1 (N-Pg) (mm)3.51.62.50.32.50.82.5Soft-tissue measurements Facial convexity (G’-Sn-Po’)13.5−8.25.516.25.58.55.5 UL protrusion (UL-SnPg’) (mm)3.52.51.84.81.85.31.8 LL protrusion (LL-SnPg’) (mm)2.84.61.71.51.72.11.7 Upper lip to E-plane (mm)−3−6.42−2.32−5.22 Lower lip to E-plane (mm)−2.5−1.12.5−3.22.5−4.32.5 Open table in a new tab Pfeiffer’s syndrome is caused by a mutation of a fibroblast growth factor receptor gene, FGFR1 or FGFR2. A mutation of either FGFR1 or FGFR2 causes prolonged signaling, which can promote early maturation of bone cells and premature fusion of bones.3Vogels A. Fryns J.P. Pfeiffer syndrome.Orphanet J Rare Dis. 2006; 1: 19Crossref PubMed Scopus (92) Google Scholar Maxillary hypoplasia causes severe maxillary arch crowding and crossbite. A flat mandibular plane angle and decreased lower facial height also are caused
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