untitled

Transcription

1 Comparison of the Skeletal and Dental Effects between 2-Band and 4-Band Rapid Maxillary Expander 療 (Allen Chih-Yu Chen) (Jenny Hwai-Jen Fong) 立 臨 論 National Yang-Ming University Dental School Institute of Clinical Dentistry Master Thesis 年六 June 2004

2 錄 錄 錄 III IV V VII (Indication) 療 臨 料 料 I -

3 療 Band 4-band Expander 療 Band 4-band Expander 療 例 論 年 X 精 度 療 療 療 療 例 臨 六 論 參 II -

4 錄 量 III -

5 錄 料 band expander 療 band expander 療 六 2-band expander 4-band expander 療 band expander 4-band expander 療 例 立 band expander 4-band expander 療 例 立 錄 療 料 錄 療 量數 料 IV -

6 臨 療 療 療 療 列 數 Hyrax 更 來 療 24 臨 15 (8 7 女 年 ) 9 (2 7 女 年 ) 列 療 療 X 不 療 量 量 兩 都 異 量 兩 異 - V -

7 療 - VI -

8 年來 來 療 列 療 列不 療 更 列不 離 利 1 療 念落 臨 落 (Rapid maxillary expansion) 力量 拉 來 横 (Perimeter) 拉 沈 (Orthopedic effect) 2 行拉 度便 理若 更 便 療 類 例 療 臨 臨 列 連 臨 落 Hyrax expander 更 金 力量 若 不 令 -1-

9 金 金 兩 不 數量 (Anchor teeth) 不 -2-

10 (Maxillary expansion) 1860 年 Angell 來 論 3 Angell 了 列 Brown 4 療 塞 3,5 療 1961 年 Haas 了 列 臨 6-8 Isaacson 9 Melson 10,11 Timms 7,12 臨 臨 療 度 年來不 療 療 更 不. (Active part) (Anchor part) 聯 Connector 螺 (Jackscrew) 力量 來 連 (Retention) 力量 Hass 7 Jackscrew 力量不 -3-

11 Hass expander 力量 力 更 Hyrax expander 金 金 Isaacson 了 Minn expander 12 螺 McNamara 13 金 McNamara 13. (Indication) ( ) 異 見 不 異 隆 (Palatal vault) 類異 例 都 療 見 不論 列 列都 Kurol 14 北 率 23.3% 數 -4-

12 (Functional) (Dental) (Skeletal) 15 見 Initial contact (Maximal intercuspation) 16 度不 15 横 了 療 度便 17 列 列 來更 列 便 列 來 列 24 連 年來 Pirttiniemi 20 Thilander 21,22 更 列 若不 不 力 25 不 ( ) 不 療 不 療 例 Premaxilla 更 了 (Intermolar width) (intercanine width) -5-

13 度 了 了 例 來 降 了 療 ( ) McNamara 類 異 見 26 論 來 異 不 McNamara 論 了 來 13,26 ( ) 異 例 狀 類 了 臨 了 狀 落 不 不 列 異 例 來 不 -6-

14 療 療 類 不 來 (Facemsak) 異 ( ) 例 (Dentofacial deformity) 見 裂 不 類 療. 來 都 連 類 力 (Tensile force) 力 拉 沈 (Deposition) (Remodeling) (Maxilla) (Palatine bone) 度 (Occlusal) (Posterioanteiror, PA) X 更 力量 不 都 (Nasomaxillay complex) -7-

15 Frontal Ethmoid Nasal Lacrimal Inferior chocha Vomer Zygoma Palatine Maxilla 聯 力量 力量 12,27,28 Jafari 29 (Finite Element Analysis) 了 (Apex of nasal bone) 兩 連 力量 不 離 拉 力量 27 力 Melson 10 年 行拉 行 力量 連 力量 (Buccal tipping) 臨 離 28 令 (Dentoalveolar structure) 離 了 10,30. 療 臨 不 -8-

16 療 類 (1) (Form) (2) 度 (Rate) (3) 療 年 (Age) 論 ( ) 來 (Rididity) (Stability) 12,31 (Removable) (Fixed) Maxillary Schwartz appliance Crozat appliance Hyrax Haas Minn appliance 12,32,33 行 2-4 若不 Hyrax Haas 螺 見 金 1-2 類 金 螺 力量 Quadhelix NiTi Expander 34,35 ( ) 度 度 量 度 Hyrax expander 類 mm 螺 力量 ,36 力量 PDL -9-

17 力 (Adaptive growth) Quadhelix 度 mm 螺 量 力量 横 ( ) 年 臨 都 來 沈 (Bony deposition) (Tipping) 12,27 Baccetti 40 不 年 療 理 不 療 40 Cotton 41 Hicks 38 理 例 例 來 (Pterygomaxillary suture system) 力 11,27,28 Melson 11 不 年 Cadaver 切 年 Bell Brin 42 了 年 了年 了 不 度 量 -10-

18 43,44 年 不 (Surgical-assisting maxillary expansion) 勒福 (LeFort I osteotomy) 43,49 (Distraction osteogenesis) 臨 療 26,40,51 16,17,52 療 27 列 列 横 異 列 度不 露 不 都 臨 Hyrax expander 例 金 列 例 臨 更 金 臨 數量 了 (Path of insertion) 利 了 度 了 療 臨 -11-

19 數量 臨 了 便 不 數量 療 異 -12-

20 類 若 異 異 數 都 理 療 療 降 類 療 都 列 Hyrax appliance 數 Hyrax 4-band expander 列 良 2-band expander 2-Band expander 療 4-band expander 異 -13-

21 料. (Prospective) 來 臨 例 北 靈 療, 女 : (1) 療 (2) (3) Edge to edge (4) 度不 (Maxillary skeletal transverse deficiency) (5) 療 度不 13,53-56 臨 行 參 57 不 了 列 度不 (Dental compensation) (Buccal flaring) 例 -14-

22 . ( ) Hyrax 金 Expansion screw 數量 2-band expander 4-band expander 列 度 落 度不 兩 ( 若 ) inch 不 ( ) 料 療 異 料 療 療 (T1) 臨 Edge to edge 令 錄 療 (T2) 療 列 料 1. Clinical examination 臨 料 年 -15-

23 療 螺 數 2. Intraoral and extraoral photograph 3. 療 (T1) 療 (T2) X (Posterioanterior cephalometric film) 療 X 行 X 蘭 福 行 X 行 路 列 (1) 見 (2) (3) 兩 ( ) (4) 見 (Anterior ethmoidal cells) (5) 見 裂 (Superior orbital fissure) 療 (T1) 療 (T2) 臨 ( ) 料 理 料 量 療 HB (Landmark) 量 離 -16-

24 列 14 ( ) U1 U3c 切 U3g U4c U4g U6c U6g 量 離 2. X (1) 利 0.5 HB 量 離 量 度 精 X 10 ( ) Mo: Medioorbital, Nc: Nasal cavity, 梨狀 (Piriform aperture) Mx: Maxillare, (maxillozygomatic process) Ma: Maxillary alveolae, U1a: Upper incisor apex, -17-

25 X 量 離 X 量 2 ( ) U1 ang: U6 ang: 連 (2) 率 X X 離 X 率 X 度 率 若 不 率 X 料 參 率 量 數 不 X 量 X 量數 來 率 X 率 10.65% 數 M-D width of upper incisors of PA film ( -1) 100%= Magnification (M) M-D width of upper incisors of Cast 量數 率 量數 -18-

26 (3) 率 量 -19-

27 . 料 ( ) (Error test) 1. X X 量 了 10 x 行 量數 59 SPSS 11.0 數 (Intraclass correlation coefficient ri) 60 若 料 異數 ri 95% 0.75 兩 2. 量 不 量 了 10 行 量 數 59 SPSS 11.0 數 60 若 料 異數 ri 95% 0.75 兩 錄 料 年 療 (Mean) (Standard deviation SD) -20-

28 (Range) 2-band expander 4-band expander 療 量數 連 量 (Mean) (Standard deviation SD) (Range) ( ) 論 2-band expander 4-band expander 兩 不 療 T2-T1 t (Paired t test) 療 量 療 異 (Difference between stages) 療 療 t P 0.05 ( <0.025 ) 異 療 立 t (Independent t test) 兩 量 異 (Difference between two groups) t P 0.05 ( <0.05 ) 異 ( ) 療 例 量 離 例 不 螺 量 量不 -21-

29 . 數 女 年 數 女 年 女 料 見 錄 量 料 見 錄 X 不 X 行 量 數 ri 0.95 ( ) 0.75 度 都 -22-

30 療 列 2-band expander 4-band expander 療 X 量 t 療 2-band expander (U1) 3.1mm (U3c U3g) (U4c U4g) (U6c U6g) 不論 量 都 數 不 不 (Mo) 療 (Mx) 梨狀 (Nc) (Ma) 度 度 (U1 ang) 療 度 (U6 ang) 了 兩 4-band expander 療 X 量 2-band expander 了 度 都 不論 數 療 都 不 療 臨 都 -23-

31 2-Band Expander 4-band Expander 療 六列 了 療 立 t 療 異 4-band expander (U4c) (U4c U6c) 2-band expander 數 (U4g U6g) 量 量 療 不 異 參 度 2-band expander band expander 度 異 都 Ma 都 4mm 不論 Ma Mx Nc 都 異 類 -24-

32 . 2-Band Expander 4-band Expander 療 例 例 離 量 例 療 量 例 2-band expander band expander 1.21 ( ) ( ) ( ) 例 來 例 例 都 1 量 4-band expander 1 2-band expander 0.93 異 療 例 (Nc) 都 0.34 (Mx) 例 異 (Ma) 例 例 -25-

33 論 行 年 療 年 療 利 X 不 異 臨 臨 療 料 療 度 度 參 不 臨 例 例 臨 行 臨 療 行 理 類 例 更 數 來更 力 年 年 異 -26-

34 臨 ( ) 度 若 臨 4-band expander 若 不 2-band expander 臨 2-band expander 列 臨 數 不 列 (Early mixed dentition) 4-band expander 列 (Late mixed dentition) 年 4-band expander 略 2-band expander 療 臨 不易 年 略 不 來 更 不 年 理 年 年 療 論 40,53,64-67 Baccetti 40 療 不論 量 療 異 5 年 療 都 療 40 了 Melson 療 力 11 X 精 度 -27-

35 數 不 量 了 68 度 立 臨 不 ; X 率 異 61 了 X 都 率 降 (Systemic error) 69 都 率 X 量 料來 精 Baumrind Frantz X 來 X 讀 不 70 (Random error) 來 59 Intraclass Correlation Coefficient (ICC) 度 (Reliability) 都 療 療 都 5mm 療 略 不 -28-

36 2-band expander 5.8mm 4-band expander 7.3mm 量 不 Schiffman 71 了 列 論 量 6mm Herold 3.9mm 不 螺 量 不 異 不 螺 量 72,73 數 異 (U6g) 量 量 不 了 了 量不 度 不 連 不 度 數 來 狀 異 量 不 量 度 Hick 38 度 Handelman 73 Herold 74 年 2-Band Expander Band Expander 臨 度 2-Band Expander ( Relapse) -29-

37 療 臨 Quadhelix 療 不易 37 Transeptal fiber 力 7,39,75 兩 療 都 兩 2-Band 4-Band 都 2.5mm Lamparski 76 2-band (point) expander 1.9mm 更 2-band expander Lamparski 略 不 更 療 量 4-band expander 量 mm 2-band expander mm 來 1mm 療 異 兩 度 異 2-band expander band expander 了 度 行 療 -30-

38 列 (Stability) 量 77 療 (Orthopedic effect) 行 兩 療 都 都 2-band expander 4-band expander 量 異 t 2-band expander 異 (P=0.68) 4-band expander (P=0.96) Lamparski 76 論 療 不 療 兩 都 2-band expander 量不 4-band expander 4-band expander 4-band -31-

39 expander 螺 力量 t 2-band expander 異 (P=0.47) 4-band expander (P=0.04) 了 4-band expander 療 來 2-band 4-band 療 不 (Mx) 量 2.27mm 2.05mm Cross and McDonald 量 1.11mm 78 da Silva 2.8mm 79 螺 力量 (Pterygoid plate) 力 量 不 (Ma) 都 4mm 度 了 -32-

40 27 Ma Mx 量 來 力量 ( Bone bending) Handelmen 73 沈 80 (Bone deposition) 73 Solow 81 理 類 率 82,83 都 梨狀 了 1.85 mm 2.10 mm 兩 療 異 Basciftci 84 量 3.47mm Kreb 1.4mm 85 Wertz 1.9mm 75 da Silva 2.087mm 79 數 2-band expander 類 了 12,27,28 兩 療 都 不 都不 了 不 度 12,27,28 例 了 量 -33-

41 Wertz 75 X 量 (ANS) (PNS) 例 2:1 Krebs 85 量 兩 Corss McDonald 78 不 參 例 Pinto 44 療 (Bone-borne) 例 band expander ( Tooth-borne) 例 不 3 5 例 了 度 數 U6g 量 參 量 例 不論 都 若 例 2-band expander 4-band expander 類 例 來 2-band expander 4-band expander 例 都 異 2-band expander ( ) 4-band expander ( ) 量 2-band expander 略 4-band expander 例 (Nc) 都 0.34 (Mx) 例

42 例 都 1:3 例 (Ma) 例 例 來說 例 療 不論 例 行 來 類 Primary dispalcement Secondary displacement 利 例 了 例 量 例 兩 Mx 都 1:3 1/3 2/3 Timms 72 例 58% 略 不 行 度 臨 異 度不 量 不 量 來 臨 Edge to edge 螺 螺 量 不 異 了 不 來 螺 數不 例 了 量 例 來 -35-

43 療 不 螺 量 量 例 臨 Hyrax 了 力 不 易 Band 不 易 異 更不易 了 2 臨 Indirect fabrication 料 12,32 臨 便利 了 療 料 臨 年 療 度 (Path of insertion) 例 復 -36-

44 了 列不 4-band expander 列 度 異 了 類 2-band expander 了 良 療 度 (Rigidity) 12,86 度 (Bonded rapid palatal expander) 度 32,86 4-band expander 度 不 2-band expander 度 度 類 量 例 類 度 量 論 2-Band Expander 4-Band Expander 臨 療 -37-

45 六 論 1. 2-band expander 4-band expander 都 療 2. 療 4-band expander 量 療 量 異 3. 療 不論 都 4. 2-band expander 4-band expander 療 -38-

46 U1 切 U3c 切 U3g U4c U4g U6c U6i -39-

47 X 10 Mo: Medioorbital, Nc: Nasal cavity, 梨狀 (Piriform aperture) Mx: Maxillare, (maxillozygomatic process) Ma: Maxillary alveolar, U1a: Upper incisor apex, -40-

48 量 U1 ang: U6 ang: 連 -41-

49 料 2-band expander 4-band expander 數量 n=15 n=9 8, 女 7 2, 女 7 年 : Mean SD Range

50 Mo Nc Mx Ma U1a U1 ang U6 ang 數 -43-

51 U1 U3c U3g U4c U4g U6c U6g 數 -44-

52 2-band expander 療 2 Band Expander Pretreatment Posttreatment Mean SD Mean SD P Cast analysis (mm) Diastema width (U1) <0.001* Canine Cusp width (U3c) <0.001* Canine gingival width (U3g) <0.001* Premolar width (U4c) <0.001* Premolar gingival width (U4g) <0.001* Molar width (U6c) <0.001* Molar gingival width (U6g) <0.001* PA cephalometric analysis Linear measurement (mm) Orbital width (Mo) Nasal width (Nc) <0.001* Maxillary width (Mx) <0.001* Maxillary alveolar width (Ma) <0.001* Incisor apex width (U1a) <0.05* Angular measurement ( ) Incisor Angulation Molar Angulation <0.02* * P < 0.05 異 -45-

53 4-band expander 療 4 band Expander Pretreatment Posttreatment Mean SD Mean SD P Cast analysis (mm) Diastema width (U1) Canine Cusp width (U3c) Canine gingival width (U3g) Premolar width (U4c) Premolar gingival width (U4g) Molar width (U6c) Molar gingival width (U6g) PA cephalometric analysis Linear measurement (mm) Orbital width (Mo) Nasal width (Nc) Maxillary width (Mx) Maxillary alveolar width (Ma) Incisor apex width (U1a) Angular measurement ( ) Incisor Angulation (U1 ang) Molar Angulation (U6 ang) * P < 0.05 異 -46-

54 六 2-band expander 4-band expander 療 2-band Expander 4-band Expander Mean SD Mean SD P Cast analysis (mm) Diastema width (U1) Canine Cusp width (U3c) Canine gingival width (U3g) Premolar width (U4c) * Premolar gingival width (U4g) Molar width (U6c) * Molar gingival width (U6g) PA cephalometric analysis Linear measurement (mm) Orbital width (Mo) Nasal width (Nc) Maxillary width (Mx) Maxillary alveolar width (Ma) Incisor apex width (U1a) Angular measurement ( ) Incisor Angulation Molar Angulation * P < 0.05, 異 -47-

55 2-band expander 4-band expander 療 例 立 -48-

56 2-band expander 4-band expander 療 例 立 -49-

57 錄 療 料 年 療 李 -50-

58 錄 療 量數 料 率 李 -51-

59 -52-

60 -53-

61 -54-

62 -55-

63 參 1. Carlson DS. Biological rationale for early treatment of dental facial deformity. Am J Orthod Dentofacial Orthop 2001;121: Profitt W. Contemporary orthodontics. St Louis: Mosby CV; Gray LP. Results of 310 cases of rapid maxillary expansion selected for medical reasons. J Laryngol Otol 1975;89: Brown G. The application of orthodontia principles to prevention of nasal disease. Dental Cosmos 1903;45: Gray LP, Brogan WF. Septal deformity malocclusion and rapid maxillary expansion. Orthodontist 1972;4: Haas AJ. Gross reaction to widening of the maxillary dental arch of the pig by splitting the hard palate. Am J Orthod 1959;45: Haas AJ. Palatal expansion: just the beginning of dentofacial orthopedics. Am J Orthod 1970;57: Haas AJ. Rapid expansion of the maixllary dental arch and nasal cavity by opeing the midpalatal suture. Angle Orthod 1965;31: Isaacson R. Some effects of rapid maxillary expansion on cleft lip and palate patients. Angle Orthod 1964; Melsen B. A histological study of the influence of sutural morphology and skeletal maturation on rapid palatal expansion in children. Trans Eur Orthod Soc 1972: Melson B. Palatal growth study on human atopsy material. A histologic microradiographic study. Am J Orthod 1975;68: Timms DJ. Rapid maxillary expansion. Chicago: Quintessence publishing; 1981: p McNamara JA, Jr. Orthodontic and orthopedic treatment in the mixed -56-

64 dentition. Michigan: Heedham Press; Kurol J, Berglund L. Longitudinal study and cost-benfit analysis of the effect of eraly treatment of posterior crossbite in the primary dentition. European journal of orthodontics 1992;14: Cunha RF, Delbem AC, Costa L, de Abreu MG. Treatment of posterior crossbite in mixed dentition with a removable appliance: reports of cases. ASDC J Dent Child 1999;66: da Silva Filho OG, Ferrari Junior FM, Aiello CA, Zopone N. Correction of posterior crossbite in the primary dentition. J Clin Pediatr Dent 2000;24: Kocadereli I. Early treatment of posterior and anterior crossbite in a child with bilaterally constricted maxilla: report of case. ASDC J Dent Child 1998;65: Kutin G, Hawes RR. Posterior cross-bites in the deciduous and mixed dentitions. Am J Orthod 1969;56: Pinto AS, Buschang PH, Throckmorton GS, Chen P. Morphological and positional asymmetries of young children with functional unilateral posterior crossbite. Am J Orthod Dentofacial Orthop 2001;120: Pirttiniemi P, Raustia A, Kantomaa T, Pyhtinen J. Relationships of bicondylar position to occlusal asymmetry. Eur J Orthod 1991;13: Thilander B, Lennartsson B. A study of children with unilateral posterior crossbite, treated and untreated, in the deciduous dentition--occlusal and skeletal characteristics of significance in predicting the long-term outcome. J Orofac Orthop 2002;63: Thilander B, Rubio G, Pena L, de Mayorga C. Prevalence of temporomandibular dysfunction and its association with malocclusion in -57-

65 children and adolescents: an epidemiologic study related to specified stages of dental development. Angle Orthod 2002;72: Vadiakas GP, Roberts MW. Primary posterior crossbite: diagnosis and treatment. J Clin Pediatr Dent 1991;16: Kutin G, Hawes R. Posterior crossbites in the deciduous and mixed dentition. Am J Orthod 1969;56: Throckmorton GS, Buschang PH, Hayasaki H, Pinto AS. Changes in the masticatory cycle following treatment of posterior unilateral crossbite in children. Am J Orthod Dentofacial Orthop 2001;120: McNamara JA, Jr. Early intervention in the transverse dimension: Is it worth the effort? Am J Orthod Dentofacial Orthop 2002;121: Bell RA. A review of maxillary expansion in relation to rate of expansion and patient's age. Am J Orthod 1982;81: Bishara SE, Staley RN. Maxillary expansion: clinical implications. Am J Orthod Dentofacial Orthop 1987;91: Jafari A, Shetty KS, Kumar M. Study of stress distribution and displacement of various craniofacial structures following application of transverse orthopedic forces--a three-dimensional FEM study. Angle Orthod 2003;73: Staggers JA. Why does a midline diastema develop during rapid palatal expansion? Am J Orthod Dentofacial Orthop 2001;120:12A. 31. Braun S, Bottrel JA, Lee KG, Lunazzi JJ, Legan HL. The biomechanics of rapid maxillary sutural expansion. Am J Orthod Dentofacial Orthop 2000;118: Spolyar JL. The design, fabrication, and use of a full-coverage bonded rapid maxillary expansion appliance. Am J Orthod 1984;86: Viazis AD, Vadiakis G, Zelos L, Gallagher RW. Designs and applications -58-

66 of palatal expansion appliances. J Clin Orthod 1992;26: Corbett MC. Slow and continuous maxillary expansion, molar rotation, and molar distalization. J Clin Orthod 1997;31: Ciambotti C, Ngan P, Durkee M, Kohli K, Kim H. A comparison of dental and dentoalveolar changes between rapid palatal expansion and nickel-titanium palatal expansion appliances. Am J Orthod Dentofacial Orthop 2001;119: Isaacson R. Forces produced by rapid maxillary expansion. Angle Orthod 1964;34: Mossaz-Joelson K, Mossaz CF. Slow maxillary expansion: a comparison between banded and bonded appliances. Eur J Orthod 1989;11: Hicks EP. Slow maxillary expansion. A clinical study of the skeletal versus dental response to low-magnitude force. Am J Orthod 1978;73: Akkaya S, Lorenzon S, Ucem TT. Comparison of dental arch and arch perimeter changes between bonded rapid and slow maxillary expansion procedures. Eur J Orthod 1998;20: Baccetti T, Franchi L, Cameron CG, McNamara JA, Jr. Treatment timing for rapid maxillary expansion. Angle Orthod 2001;71: Cotton LA. Slow maxillary expansion: skeletal versus dental response to low magnitude force in Macaca mulatta. Am J Orthod 1978;73: Brin I, Hirshfeld Z, Shanfeld JL, Davidovitch Z. Rapid palatal expansion in cats: effect of age on sutural cyclic nucleotides. Am J Orthod 1981;79: Profitt WR. Discussion: Immediate postexpansion changes following the use of the transpalatal distractor. J Oral Maxillofac Surg 2001;59: Pinto PX, Mommaerts MY, Wreakes G, Jacobs WV. Immediate -59-

67 postexpansion changes following the use of the transpalatal distractor. J Oral Maxillofac Surg 2001;59: ; discussion Basdra EK, Zoller JE, Komposch G. Surgically assisted rapid palatal expansion. J Clin Orthod 1995;29: Betts NJ, Vanarsdall RL, Barber HD, Higgins-Barber K, Fonseca RJ. Diagnosis and treatment of transverse maxillary deficiency. Int J Adult Orthodon Orthognath Surg 1995;10: Pogrel MA, Kaban LB, Vargervik K, Baumrind S. Surgically assisted rapid maxillary expansion in adults. Int J Adult Orthodon Orthognath Surg 1992;7: Vanarsdall RL, Jr. Transverse dimension and long-term stability. Semin Orthod 1999;5: Tavares CA, Scheffer M. Surgically assisted rapid palatal expansion (SARPE) prior to combined Le Fort I and sagittal osteotomies: a case report. Int J Adult Orthodon Orthognath Surg 2001;16: Matteini C, Mommaerts MY. Posterior transpalatal distraction with pterygoid disjunction: a short-term model study. Am J Orthod Dentofacial Orthop 2001;120: Spillane LM, McNamara JA, Jr. Maxillary adaptation to expansion in the mixed dentition. Semin Orthod 1995;1: Kurol J, Berglund L. Longitudinal study and cost-benefit analysis of the effect of early treatment of posterior cross-bites in the primary dentition. Eur J Orthod 1992;14: McNamara JA. Maxillary transverse deficiency. Am J Orthod Dentofacial Orthop 2000;117: Nimkarn Y, Miles PG, O'Reilly MT, Weyant RJ. The validity of maxillary expansion indices. Angle Orthod 1995;65:

68 55. Spahl. The clinical management of basic maxillofacial orthopedic allpliance. Littleton: PSG Co.; Worms F. Pont's index and dental arch form. J Am Dent Assoc 1972;85: Gianelly AA. Rapid palatal expansion in the absence of crossbites: added value? Am J Orthod Dentofacial Orthop 2003;124: Kasle. Cranium postrioanterior projection An atlas if dental radiographic anatomy. Pennsylvania: W.B. Saunders Co; p Houston WJB. The analysis of errors in orthodontic measurements. Am J Orthod 1983;83: Portney L, Watins M. Fundations of clinical research: applications to practice. Practice Hall Health; Cortella S. Transverse development of the jaw: Norms for the posterioanterior cephalometric analysis. Am J Orthod Dentofacial Orthop 1997;112: Lux CJ, Conradt C. Transverse development of the craniofacial skeleton and dentitinon between 7 and 15 years of age - alongitudinal posterio-anterior cephalometric study. Eur J Orthod 2004;26: Athanasiou A. Data and patterns of transverse dentofaical structure of 6- to 15-year-old child: a posterioanterior cephalometric study. Am J Orthod Dentofacial Orthop 1992: Sari Z, Uysal T, Usumez S, Basciftci FA. Rapid maxillary expansion. Is it better in the mixed or in the permanent dentition? Angle Orthod 2003;73: Gottlieb EL, Brazones MM, Malerman AJ, Moskowitz EM, Phipps GS, Sarver DM. Early orthodontic treatment, part 2. J Clin Orthod 2004;38:

69 66. Ackerman M. Evidence-based orthodontics for the 21st century. J Am Dent Assoc 2004;135: ; quiz McNamara JA, Jr. Early intervention in the transverse dimension: is it worth the effort? Am J Orthod Dentofacial Orthop 2002;121: Hsiao T-H. A method of magnification correction for anterior radiographic cephalometry. Angle Orthod 1996;67: Hsiao TS, Chang HP. A method of magnigication correction for posterioanterior radiograph cephalometry. Angle Orthod 1997;67: Baumrind FR. The reliability of headfilm measurement. 1. Landmark identification. Am J Orthod 1971;60: Schiffman PH, Tuncay OC. Maxillary expansion: a meta analysis. Clin Orthod Res 2001;4: Timms DJ. A study of basal movement with rapid maxillary expansion. Am J Orthod 1980;77: Handelman CS, Wang L, BeGole EA, Haas AJ. Nonsurgical rapid maxillary expansion in adults: report on 47 cases using the Haas expander. Angle Orthod 2000;70: Herold JS. Maxillary expansion: a retrospective study of three methods of expansion and their long-term sequelae. Br J Orthod 1989;16: Wertz R. Skeletal and dental changes accompanying rapid midpalatal suture opening. Am J Orthod 1970;58: Lamparski DG, Jr., Rinchuse DJ, Close JM, Sciote JJ. Comparison of skeletal and dental changes between 2-point and 4-point rapid palatal expanders. Am J Orthod Dentofacial Orthop 2003;123: Riedel R. A review of the retention problem. Angle Orthod 1960;30: Cross DL, McDonald JP. Effect of rapid maxillary expansion on skeletal, -62-

70 dental, and nasal structures: a postero-anterior cephalometric study. Eur J Orthod 2000;22: da Silva Filho OG, Montes LA, Torelly LF. Rapid maxillary expansion in the deciduous and mixed dentition evaluated through posteroanterior cephalometric analysis. Am J Orthod Dentofacial Orthop 1995;107: Epker B. Correlation of patterns of bone resorption and formation with physical behavior of loaded bone. J Dent Res 1965;43: Solow B. Airway adequacy, head posture, and craniofacial morphology. Am J Orthod 1984;86: Hershey HG, Stewart BL, Warren DW. Changes in nasal airway resistance associated with rapid maxillary expansion. Am J Orthod 1976;69: Warren DW, Hershey HG, Turvey TA, Hinton VA, Hairfield WM. The nasal airway following maxillary expansion. Am J Orthod Dentofacial Orthop 1987;91: Basciftci FA, Mutlu N, Karaman AI, Malkoc S, Kucukkolbasi H. Does the timing and method of rapid maxillary expansion have an effect on the changes in nasal dimensions? Angle Orthod 2002;72: Krebs A. Midpalatal suture expansion studied by the implant method over a seven year period. Trans Eur Orthod Soc Sarver DM, Johnston MW. Skeletal changes in vertical and anterior displacement of the maxilla with bonded rapid palatal expansion appliances. Am J Orthod Dentofacial Orthop 1989;95:

71 Abstract Rapid maxillary expansion (RME) of the constricted maxilla is an important part of the clinician s armamentarium in the correction of posterior crossbite. Early correction of transverse problem has been advocated to obtain beneficial dental and skeletal changes during growth periods and involves a reduced treatment complexity. However, due to the limited tooth number and erupting sequence, it is necessary to modify the design of expander. For example, 2-band instead of 4-band is used in Hyrax expander. The purpose of this study was to compare the maxillary skeletal and dental changes between treatment groups using 2-band or 4-band expander. 24 preadolescent cases with maxillary constriction and posterior crossbite were involved in this study. The 2-band group consisted of 15 cases (8 males and 7 females, age: years ) and the 4-band group consisted of 9 cases (2 males and 7 females, age: years ) in the mixed dentition period. The treatment outcomes were evaluated with pretreatment and posttreament study casts and anterioposterior cephalometric films. Both groups showed significant skeletal and dental effects. There were significantly greater expansions in molar and premolar cusp widths in 4-band group. However, there were no significant differences in other dental and skeletal changes. There were also no differences in relative skeletal and dental changes to the increases in first molar width between two groups. In summary, 2-band expander has similar skeletal and dental effects as conventional 4-band expander. - VII -