Journal of the Formosan Medical Association (2013) 112, 801e806 Available online at www.sciencedirect.com journal homepage: www.jfma-online.com CASE REPORT Orthodontic treatment for a mandibular prognathic girl of short stature under growth hormone therapy Chin-Yun Pan a,b, Ting-Hung Lan a,b,c, Szu-Ting Chou a,b, Yu-Chuan Tseng a,b, Jenny Zwei-Chieng Chang d,e, Hong-Po Chang a,b, * a Department of Dentistry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan b School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan c Department of Dentistry, Antai Tian-Sheng Memorial Hospital, Tong-Kang Town, Pingtung County, Taiwan d Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan e Department of Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan Received 7 April 2010; received in revised form 30 May 2010; accepted 30 May 2010 KEYWORDS growth hormone; idiopathic short stature; mandibular prognathism; maxillary deficiency; skeletal Class III malocclusion This report presents a case of a 12-year-old girl with maxillary deficiency, mandibular prognathism, and facial asymmetry, undergoing growth hormone (GH) therapy due to idiopathic short stature. Children of short stature with or without GH deficiency have a deviating craniofacial morphology with overall smaller dimensions; facial retrognathism, especially mandibular retrognathism; and increased facial convexity. However, a complete opposite craniofacial pattern was presented in our case of a skeletal Class III girl with idiopathic short stature. The orthodontic treatment goal was to inhibit or change the direction of mandibular growth and stimulate the maxillary growth of the girl during a course of GH therapy. Maxillary protraction and mandibular retraction were achieved using occipitomental anchorage (OMA) orthopedic appliance in the first stage of treatment. In the second stage, the patient was treated with a fixed orthodontic appliance using a modified multiple-loop edgewise archwire technique of asymmetric mechanics and an active retainer of vertical chin-cup. The treatment led to an acceptable facial profile and obvious facial asymmetry improvement. Class I dental occlusion and coincident dental midline were also achieved. A 3½-year follow-up of the girl at age 18 showed a stable result of the orthodontic and dentofacial orthopedic treatment. Our case shows that * Corresponding author. Department of Dentistry, Kaohsiung Medical University Hospital, 100 Tzyou 1st Road, Kaohsiung 80756, Taiwan. E-mail address: hopoch@kmu.edu.tw (H.-P. Chang). 0929-6646/$ - see front matter Copyright ª 2012, Elsevier Taiwan LLC & Formosan Medical Association. All rights reserved. http://dx.doi.org/10.1016/j.jfma.2012.07.021
802 C.-Y. Pan et al. the OMA orthopedic appliance of maxillary protraction combined with mandibular retraction is effective for correcting skeletal Class III malocclusion with midface deficiency and mandibular prognathism in growing children with idiopathic short stature undergoing GH therapy. Copyright ª 2012, Elsevier Taiwan LLC & Formosan Medical Association. All rights reserved. Introduction Growth hormone (GH) is a polypeptide hormone, secreted by the anterior part of the hypophysis, and plays a major role in craniofacial and skeletal growth. 1 Since biosynthetic human GH obtained by genetic recombination became widely available in 1985, 2 clinicians have been working to extend the use of recombinant human GH for short-stature children with classic GH deficiency to as many categories of short-stature children as possible. Therefore, its application in children was widened to various diseases such as Turner or Noonan syndromes, chronic renal failure, children born small for their gestation age, PradereWilli syndrome, and idiopathic short stature. 1,2 Cephalometric studies of children with GH deficiency have shown the following craniofacial characteristics: small anterior and posterior cranial base dimensions, steep mandibular plane angle, and small mandibular sizes including the total mandibular length and smaller ramal height. 3,4 Orthodontists should understand the characteristics of craniofacial morphology in idiopathic short-stature children and the effects of GH therapy on these patients prior to beginning orthodontic treatment. The main purpose of this case report was to present an orthodontic case of skeletal Class III girl, undergoing GH therapy due to idiopathic short stature. Case report A 12-year-old girl came to our hospital with a protruded mandible and everted lower lip as the chief complaint. She had been diagnosed as having idiopathic short stature at age 10. The patient had a normal birth height and weight for her gestational age. However, she showed a slow postnatal growth rate and short stature. The hand-wrist radiograph showed that her skeletal age was delayed by 1 year 2 months compared with the chronologic age of 10. Clinical or laboratory evidence revealed no systemic disease of dysmorphic features. She received GH treatment at a medical center in Kaohsiung for 4 years, starting at age 10. The GH treatment was effective, and she had prominent somatic growth until her menstruation commenced at age 13. The patient was initially 126 mm below the fifth percentile of body height for Taiwanese girls of age 10 5 ; during the GH therapy, she moved up 135.5 mm into the 15th percentile at age 11; and 146 and 151.2 mm at age 12 and 13, respectively; and 154 mm into the 20th percentile when GH therapy ended at age 14, which was maintained through age 15e18 (Fig. 1). The patient s weight, initially 22.2 kg, increased to 26.5 kg below the fifth percentile of body height for Taiwanese girls of age 10 and 11, respectively, and increased to 32, 35.6, and 37.2 kg around the fifth percentile, and then to 38.5, 39.5, and 41 kg which were below the fifth percentile of age 14, 15, and 18, respectively (Fig. 2). 5 Orthodontic examination showed that the girl had anterior crossbite and skeletal Class III malocclusion (T1) (Fig. 3 and Table 1). She had a concave facial profile with maxillary deficiency and mandibular prognathism, and facial asymmetry with the mandible deviated to the right Figure 1 Height growth curve 5 for patient. Figure 2 Weight growth curve 5 for patient.
Mandibular prognathic girl of short stature 803 Figure 3 Pretreatment extraoral and intraoral photographs. side. We used the occipitomental anchorage (OMA) orthopedic appliance for maxillary protraction and mandibular retraction 6,7 in the first stage of treatment (T2), which lasted for 6 months. In the second stage (T3), the patient Table 1 Cephalometric measurements. T1 T2 T3 T4 SNA ( ) 82 82 83 83 SNB ( ) 85 83 84 84 ANB ( ) e3 e1 e1 e1 A-Nv (mm) 0 0.5 3.5 3.0 B-Nv (mm) 5.5 3.0 6.0 6.0 Pg-Nv (mm) 5.5 3.1 7.5 7.5 S-N (mm) 64 65.5 65.5 65.5 N-Me (mm) 113.5 120 120 120.5 N-A (mm) 58 58.5 58.5 59 A-Me (mm) 55.5 61.5 61.5 62 S-Go (mm) 65.5 66.5 68 68 PFH/AFH (%) 57.7 55.4 56.7 56.4 Ptm-A (NF) (mm) 44 45.5 48 48.5 Ar-Go (mm) 41.5 41.5 42.5 42.5 Ar-A (mm) 78.5 79.5 80 81 Ar-Gn (mm) 109 111.5 113 114 Mx/Mn (%) 72 71.3 70.8 71.1 Go-Gn (mm) 75 78 79.5 79.5 SN-MP ( ) 37 41 40 39.5 U1-SN ( ) 115 118 118 117.5 IMPA ( ) 80.5 84.5 77 77 T1 Z prior to treatment; T2 Z after orthopedic treatment; T3 Z after orthodontic treatment; T4 Z 3½-year follow-up. was treated with a fixed orthodontic appliance using a modified multiple-loop edgewise archwire (MEAW) technique and an active retainer of vertical chin-cup for 2 years and 6 months. The modified MEAW technique used asymmetric mechanics for correcting facial asymmetry and dental midline deviation, 8,9 which involved extrusive mechanics on the right side and intrusive mechanics on the left side. The treatment achieved an acceptable facial and more convex profile, and obviously improved facial asymmetry (Fig. 4). Class I dental occlusion with coincident dental midline was also achieved. A follow-up of 3 years and 6 months of the girl at age 18 (T4) showed that the result of the orthodontic and dentofacial orthopedic treatment was stable (Fig. 5). Discussion Craniofacial morphology of children of idiopathic short stature is similar to those with GH deficiency, although less pronounced. 10 Children of short stature with or without GH deficiency have a deviating craniofacial morphology with overall smaller dimensions; facial retrognathism, especially mandibular retrognathism; increased facial convexity; and increased posterior rotation of the mandible. 11 Craniofacial changes induced by GH treatment yield a more prognathic growth pattern, a more anterior position of the jaws in relation to the cranial base, and increased anterior rotation of the mandible. Mandibular body length and anterior face height of the GH-treated children with mandibular retrognathism are greater than those in the normal control group. 12
804 C.-Y. Pan et al. Figure 4 Post-treatment extraoral and intraoral photographs. Figure 5 Three-and-a-half-year follow-up extraoral and intraoral photographs.
Mandibular prognathic girl of short stature 805 Studies observed a relatively high prevalence of Class III malocclusion, from 15% to 23%, in Asian populations. 13 In contrast, most studies have reported an incidence of below 5% for this class of malocclusion in Caucasian populations. Class III malocclusion is thus a common clinical problem in orthodontic patients of Asian or Mongoloid descent. Class III malocclusion is generally a skeletal type of occlusal variation, and treatment of a skeletal Class III condition in growing children remains one of the most challenging problems confronting the practicing orthodontist. Craniofacial morphology with a polygenic, quantitative trait has a significant genetic component, but it is also influenced by environmental factors and functional adaptations. 14,15 Researchers have recently reported that single-nucleotide polymorphisms (SNPs) in the growth hormone receptor (GHR) gene are associated with mandibular ramus height in Japanese, Korean, and Han Chinese population. 15e18 The SNPs of the GHR gene are likely to be different in different ethnic groups. This might partly explain the differing craniofacial morphology among different ethnicities. Although GH stimulates overall growth of the craniofacial complex, it is most effective in those regions where cartilage-mediated growth occurs, such as the condylar cartilage of the mandible, and in regions adapting for this cartilage growth. 19,20 Growth increment is most marked in posterior face height, which reflects mandibular growth. Accelerated mandibular growth caused by GH therapy might affect orthodontic treatment. Correcting the anterior crossbite and prognathic mandible in patients of skeletal Class III cases during GH therapy is difficult. Considering that GH has a greater effect on the mandible than on the maxilla and mandibular growth is unpredictable, we should plan a more active treatment for the patient. After correction of anterior crossbite, the maxillary length (Ptm-A/NF), projected on the nasal floor or palatal plane, increased by 1.5 mm (from 44 to 45.5 mm) during OMA orthopedic therapy with maxillary protraction and mandibular retraction (T2), and then this length increased by 2.5 mm (from 45.5 to 48 mm) during orthodontic treatment with an active retainer of vertical chin-cup (T3). The effective mandibular length (Ar-Gn) increased by 4 mm (from 109 to 113 mm) during the same period (T2 and T3) (Table 1 and Fig. 6), while the normal effective mandibular length should increase by 6 mm (from 105 to 111 mm) during the same period. 21 The effective mandibular length (Ar-Gn) increased by 4 mm (from 109 to 113 mm) during OMA orthopedic therapy (T2) and orthodontic treatment with an active retainer of vertical chin-cup (T3) at the same time during GH therapy, and then increased by 1 mm up to 114 mm during follow-up at 18 years of age (T4) (Table 1 and Fig. 6), while the normal effective mandibular length for Taiwanese girls should increase by 6 mm (from 105 to 111 mm) and then by 2 mm up to 113 mm at 18 years of age. 21 Therefore, the effective mandibular length diminished by 2 mm mainly due to the effect of mandibular retraction of OMA orthopedic therapy and an active retainer of vertical chin-cup. The OMA orthopedic appliance of maxillary protraction combined with mandibular retraction is effective for correcting skeletal Class III malocclusion with midface Figure 6 Superimposed cephalometric tracing before and after treatments. T1 Z prior to treatment; T2 Z after occipitomental anchorage orthopedic therapy; T3 Z after orthodontic treatment with an active retainer of vertical chin-cup. deficiency and mandibular prognathism in growing children. 6,7 The OMA appliance corrected the mesial jaw (skeletal Class III) relationship and anterior crossbite (negative incisal overjet) of the girl undergoing GH therapy. After orthopedic treatment, a vertical chin-cup was used as an active retainer in the second stage of orthodontic treatment. At the end of the treatment, the patient of 15 years was beyond the pubertal growth spurt, with only minor growth remaining. GH therapy enhanced growth in both craniofacial complex and stature. The effective mandibular length and anterior face height values approached the norms at the end of the treatment. The increase did not result in a Class III skeletal or dental relationship, nor was the increase worse for facial appearance. The patient s father and mother s body heights are 165 cm and 154 cm, respectively, and the achieved adult height of the patient is 154 cm. However, the patient s elder brother s height is 180 cm. Our case showed that GH therapy is effective for improving the achieved adult height of the patient with idiopathic short stature. Acknowledgments This work was supported by the Taiwan Association of Orthodontists. The authors would like to thank Dr Yi-Ching Poon for her help with the preparation of the manuscript.
806 C.-Y. Pan et al. References 1. Krysiak R, Gdula-Dymek A, Bednarska-Czerwinska A, Okpien B. Growth hormone therapy in children and adults. Pharmacol Rep 2007;59:500e16. 2. Shimon I. Growth hormone replacement for adult growth hormone deficiency. Expert Opin Pharmacother 2003;4: 1977e83. 3. Poolee AE, Greene IM, Buschang PH. The effect of growth hormone therapy on longitudinal growth of the oral facial structures in children. Prog Clin Biol Res 1982;101:499e516. 4. Cantu G, Buschang PH, Gonzalez JL. Differential growth and maturation in idiopathic growth-hormone-deficient children. Eur J Orthod 1997;19:131e9. 5. Chen W, Tsai CY, Chen AC, Wu SF, Lin TW, Lin HC. Growth charts of Taiwanese youth: norms based on health-related physical fitness. Mid Taiwan J Med 2003;8(Suppl. 2):S85e93. 6. Chang HP, Lin HC, Liu PH, Chang CH. Geometric morphometric assessment of treatment effects of maxillary protraction combined with chin cup appliance on the maxillofacial complex. J Oral Rehabil 2005;32:720e8. 7. Lin HC, Chang HP, Chang HF. Treatment effects of occipitomental anchorage appliance of maxillary protraction combined with chincup traction in children with Class III malocclusion. J Formos Med Assoc 2007;106:380e91. 8. Chang HP. Orthodontic and orthopedic treatment of mandibular lateral displacement. J Taiwan Assoc Orthod 1995;7:19e24. 9. Pan JY, Chang HP. Orthodontic treatment of mandibular prognathism and lateral displacementda case report. J Taiwan Assoc Orthod 2007;19:56e63. 10. Spiegel RN, Sather AH, Hayles AB. Cephalometric study of children with various endocrine diseases. Am J Orthod 1971; 59:362e75. 11. Kjellberg H, Beiring M, Wikland KA. Craniofacial morphology, dental occlusion, tooth eruption, and dental maturity in boys of short stature with or without growth hormone deficiency. Eur J Oral Sci 2000;108:359e67. 12. Kjellberg H, Wikland KA. A longitudinal study of craniofacial morphology in idiopathic short stature and growth hormonedeficient boys treated with growth hormone. Eur J Orthod 2007;29:243e50. 13. Chang HP, Tseng YC, Chang HF. Treatment of mandibular prognathism. J Formos Med Assoc 2006;105:781e90. 14. Chou ST, Tseng YC, Pan JY, Chang JZ, Chang HP. Craniofacial skeletal dysplasia of opposite-sex dizygotic twins. J Formos Med Assoc 2011;110:342e6. 15. Yamaguchi T, Maki K, Shibasaki Y. Growth hormone receptor gene variant and mandibular height in the normal Japanese population. Am J Orthod Dentofacial Orthop 2001;119:650e3. 16. Zhou J, Lu Y, Gao XH, Chen YC, Lu JJ, Bai YX, et al. The growth hormone receptor gene is associated with mandibular height in a Chinese population. J Dent Res 2005;84:1052e6. 17. Kang EH, Yamaguchi T, Tajima A, Nakajima T, Tomoyusu Y, Watanabe M, et al. Association of the growth hormone receptor gene polymorphisms with mandibular height in a Korean population. Arch Oral Biol 2009;54:556e62. 18. Tomoyasu Y, Yamaguchi T, Tajima A, Nakajima T, Inoue I, Maki K. Further evidence for an association between mandibular height and the growth hormone receptor gene in a Japanese population. Am J Orthod Dentofacial Orthop 2009;136: 536e41. 19. Pirinen S. Endocrine regulation of craniofacial growth. Acta Odontol Scand 1995;53:179e85. 20. van Erum R, Mulier M, Carels C, Verbeke G, de Zegher F. Craniofacial growth in short children born small for gestational age: effect of growth hormone treatment. J Dent Res 1997;76: 1576e86. 21. Fan YC. A study of radiographic cephalometric analysis and Taiwanese standards. Thesis, Graduate Institute of Dentistry, National Taiwan University, 1995.