1. Croissance et Dveloppement MDD 20049 4-0 Estimation de la maturit physique

2. Le dveloppement dentaire est assez bien corrl avec lge chronologique bien que survenant indpendamment Le dveloppement dentaire est moins bien corrl avec le maturation physique Estimation de lge squelettique Rx main-poignet Rx vertbre cervicaleDr Sylvain Chamberland; sylvainchamberland.com2 3. Dveloppement dentaire Indpendant de la maturit somatique ou sexuelle Faible association avec la maturit physique Corrlation ge chronologique et dveloppement physique: r = 0,8. Valeur explicative: 64% Corrlation entre ge dentaire et chronologique: r =0,7 Valeur explicative: ~ 50% Dr Sylvain Chamberland; sylvainchamberland.com3 4. Estimation de la maturit physique chez la lleSemin. Orthod. 1997; 3: 212-221 Dr Sylvain Chamberland4 5. Estimation de la maturit physique chez le garonSemin. Orthod. 1997; 3: 212-221 Dr Sylvain Chamberland5 6. Rx main-poignet Identication du ssamode Apparat avant le pic de croissance Si absence de cartilage entre piphyse et diaphyse:Val, Pou 15a 5 m Croissance termineDr Sylvain Chamberland6 7. 2e phalange: capping de la diaphyse Fusion de la phalange distale Prsence de cartilage entre piphyse et diaphyseShad, Labr 12a 5 m Croissance disponibleDr Sylvain Chamberland; sylvainchamberland.com7 8. Toutefois Le pic de croissance ladolescence des dimensionsfaciales nest pas corrl de faon consistante avec la croissance de la stature et la maturit physique tel que dtermin par les rx de poignet Moore et al, Skeletal maturation and craniofacial growth,AJODO 1990; 98: 33-40Dr Sylvain Chamberland; sylvainchamberland.com8 9. Le timing de certains types de traitement orthodontique forte composante orthopdique (correction cl II ou cl III, expansion palatine) est intimement li lidentication dacclration ou dintensication de la croissance pouvant contribuer la correction du dbalancement squelettiqueLefcacit des thrapies fonctionnelles dpends de la rponse du cartilage condylien qui, son tour, dpends du taux de croissance mandibulaireLvaluation de la maturation squelettique mandibulaire et du potentiel de croissance de lindividu fournit des informations essentielles sur lanticipation du rsultat du traitementDr Sylvain Chamberland; sylvainchamberland.com9 10. Indicateur biologique de maturit squelettique Augmentation en hauteur (grandeur) du corps (stature) Prsente le moins de variabilit dans lestimation de lge squelettique Dveloppement et ruption dentaire Caractres sexuels secondaires (menstruations, poitrine, muede la voie) Maturation des vertbres cervicaux Dr Sylvain Chamberland; sylvainchamberland.comEfcace pour dmontrer le pic de croissance de ladolescence tant pour le garon que pour la lle10 11. 338 Franchi, Baccetti, and McNamaraAmerican Journal ofMaturation des vertbres cervicales AFig 4. Distribution o stage 3 in cervica females (Cvs3 femacroissance Pic de du temps) en hauteur CVS3-CVS4 (93,5%significant decelerat Cvs4 to Cvs5 when DISCUSSIONB A: groupe complet(n= 24) B: sous-groupe de 15 lles (~ 11 ans) C: sous-groupe de 9 garons (~ 12-13 ans)Pic de croissance mandibulaire CVS3-CVS4C Fig 3. Individual changes in body height at intervals between stages in cervical vertebral maturation (A) in 24 subjects examined, (B) in subgroup of 15 females, and (C) in subgroup of 9 males.Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showedThe issue of mandibular deficien contemporary ortho ment timing in Class misleading variabl some kind of categ rather than individ demonstrated clearl skeletal maturity is pedics, as the greate appliances occur wh is included in the tr A few biologic appraisal of individ quently, for the detec the mandible.2,4,6,11 statural height prese assessment of skelet of growth, thus show logic indicator of sk tation of this method measurements repea months) to construc velocity. Radiograph overcome this limita skeletal maturation o The features of an i G:12 a 8 m 14a 2 m F: 11 a 4 m 12 a 10 m Dr Sylvain Chamberland11 12. Distribution de lge chronologique au stade 3 338 Franchi, Baccetti, and McNamaraAmerican Journal of Orthodontics and Dentofacial Orthopedics September 2000 Filles: 8a 6 m 11a 5 m Garons: 10a 14 aA Donc, lge chronologique nest pas un bon indicateurFig 4. Distribution of individual chronological age at stage 3 in cervical vertebral maturation (Cvs3) in females (Cvs3 females) and males (Cvs3 males).de la maturation squelettique et ainsi de lestimation du timing du traitement orthodontiquesignificant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. DISCUSSIONBDr Sylvain Chamberland; sylvainchamberland.com C Fig 3. Individual changes in body height at intervals between stages in cervical vertebral maturation (A) in 24 subjects examined, (B) in subgroup of 15 females, and (C) in subgroup of 9 males.Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration during theThe issue of optimal treatment timing for mandibular deficiencies is a widely debated topic in contemporary orthodontics. The definition of treatment timing in Class II disharmony too often relies on misleading variables such as chronological age or some kind of categorization of dentitional phases rather than individual biologic factors. It has been demonstrated clearly that the evaluation of individual skeletal maturity is fundamental in dentofacial orthopedics, as the greatest effects of functional/orthopedic appliances occur when the peak in mandibular growth is included in the treatment period.1,8-10 A few biologic indicators are available for the appraisal of individual skeletal maturity and, consequently, for the detection of the pubertal growth spurt in the mandible.2,4,6,11-17 Among these, the changes in statural height present with the least variability for the assessment of skeletal age throughout the progression of growth, thus showing the highest reliability as biologic indicator of skeletal maturity. The practical limitation of this method, however, is that it requires several measurements repeated at regular intervals (eg, every 3 months) to construct an individual curve of growth velocity. Radiographic methods have been proposed to overcome this limitation that allow for an appraisal of12 13. 317IMPROVED CVM METHOD Mthode initiale changes can be observed in the vertebrae during this entire interval, which covers the period when orthodontic/orthopedic treatment is typically performed in the growing patient. Based on the ndings of earlier investigations22,23,27,28 in 1972, Lamparski29 created separate standards of cervical vertebral maturation for female and male subjects as related to both chronological age and skeletal maturation height, Franchi et al, Mandibular growth as related to cervical vertebra maturation and body observed in the hand-wrist radiograph. The method analyzed size and AJODO 2000; 118: 335-40 shape changes in the bodies of ve cervical vertebrae (from the second one through the sixth). Hassel and Farman30 reviewed lateral cephalometric and left hand-wrist radiographs from the Bolton-Brush Growth Study at Case Western Reserve University to develop an index based on the Bacetti T. et al, The cervical vertebra maturation (CVM) method for the assessment of optimal lateral proles of the second, third, and fourth cervical vertreatment timing in dentofacial orthopedics, Semin. Orthod. 2005; 11: 119-129 tebrae. These researchers, as well as Pancherz and Szyska31 who further evaluated Hassel and Farmans index in relation to increases in body height, stated that the cervical vertebral analysis had a comparable high reliability and validity as the hand-wrist bone analysis in the assessment of individual skeletal maturity. As for the relationship of cervical vertebral maturation and mandibular growth changes, OReilly and Yanniello32 evaluated annual lateral cephalometric radiographs of 13 Caucasian girls from 9 to 15 years of age and found statistically signicant increases in mandibular length, corpus length, and ramus height in association with specic maturation stages in the cervical vertebrae according to the method of Lamparski.29 More recently, Franchi and coworkers12,13 conrmed the validity of six CVM stages as a biologic indicator for both mandibular and somatic skeletal maturity in 24 growing untreated subjects. The original method by Lamparski29 was adopted with a modication allowing for the appraisal of skeletal age in both boys and girls, regardless of chronological age (Figure 1). The main features of the CVM method as described by Franchi and coworkers12,13 included: 6 stades de formationsFIGURE 1. Developmental stages of cervical vertebrae. Stage 1 (Cvs 1): the inferior borders of the bodies of all cervical vertebrae are at. The superior borders are tapered from posterior to anterior. Stage 2 (Cvs 2): a concavity develops in the inferior border of the second vertebra. The anterior vertical height of the bodies increases. Stage 3 (Cvs 3): a concavity develops in the inferior border of the third vertebra. Stage 4 (Cvs 4): a concavity develops in the inferior border of the fourth vertebra. Concavities in the lower borders of the fth and of the sixth vertebrae are beginning to form. The bodies of all cervical vertebrae are rectangular in shape. Stage 5 (Cvs 5): concavities are well dened in the lower borders of the bodies of all 6 cervical vertebrae. The bodies are nearly square in shape and the spaces between the bodies are reduced. Stage 6 (Cvs 6): all concavities have deepened. The bodies are now higher than they are wide. (Modied from OReilly and Yanniello.31) La plus grande augmentation du corps en hauteur survienta protective radiation collar. (2) To avoid denitions of stages based on a comparative assessment of between-stage changes, so that stages can be identied easily in a single cephalogram. The aim of the present work, therefore, is to present an improved version of the CVM method and its validity for the appraisal of mandibular skeletal maturity in the individual patient.entre le stade 3 (quand une concavit se dveloppe sous le bord infrieur de C3) et le stade 4 (quand une concavit se dveloppe sur le bord infrieure de C4) chez le garon et la lle a. In nearly 95% of North-American subjects, the growth interval between stage 3 and stage 4 in CVM coincides with the pubertal peak in both mandibular growth and body height. b. Reproducibility of recorded data (identication of CVM stages) is as high as 98.6%. c. The method is useful for the anticipation of the pubertal peak in mandibular growth. The peak has not been reached if either stage 1 or stage 2 in CVM is recorded in the individual patient.SUBJECTS AND METHODSThe total sample (706 subjects) that comprises the cephalometric les of the University of Michigan Elementary and Secondary School Growth Study33 was evaluated. Due to the longitudinal nature and to the aim of the present investigation, subjects with less than six consecutive cephalometric observations (n 5 492) were excluded from the study. Total mandibular length (Co-Gn) was measured on the longitudinal sets of annual lateral cephalograms for each of the 214 remaining subjects. The lateral cephalograms were analyzed by means of a digitizing tablet (Numonics, Lansdale, Penn) and digitizing software (Viewbox, ver 2.6 Kassa, Greece). The maximum increase in Co-Gn between 13 two consecutive cephalograms was used to dene the peak in mandibular growth at puberty in the individual subjects. Two consecutive cephalograms comprising the interval of maximum mandibular growth, together with two earlier consecutive cephalograms and two later consecutive cephalograms had to be available for each subject and were Le pic de croissance de la stature entre cvs3 et cvs4 Dr Sylvain Chamberland; sylvainchamberland.comcorrespond la plus grande augmentation de mesures mandibulaires However, a few improvements of the original CVM analysis were still needed to make the method easier and applicable to the vast majority of patients: (1) To use a more limited number of vertebral bodies to perform the staging (as suggested by Hassel and Farman30). In particular, the method should include only those cervical vertebrae (C2, C3, and C4) that can be visualized when the patient wearsAngle Orthodontist, Vol 72, No 4, 2002 14. Mthode simplie CVM Bacetti T. et al, An improved version of the cervicalvertebra maturation (CVM) method for the assessment of mandibular growth, A.O. 2002; 72: 295-301 338 Franchi, Baccetti, and McNamaraAmerican Journal of Orthodontics and Dentofacial Orthopedics September 2000ABacetti T. et al, Growth in the untreated cl III subjects, Semin. Orthod. 2007;13: 130-142 Fig 4. Distribution of individual chronological age at stage 3 in cervical vertebral maturation (Cvs3) in females (Cvs3 females) and males (Cvs3 males).Dr Sylvain Chamberlandsignificant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. DISCUSSIONBThe issue of optimal treatment timing for mandibular deficiencies is a widely debated topic in contemporary orthodontics. The definition of treatment timing in Class II disharmony too often relies on misleading variables such as chronological age or14 15. 338 Franchi, Baccetti, and McNamaraAmerican Journal of Orthodontics and Dentofacial Orthopedics September 2000A CVMS 1Fig 4. Distribution of individual chronological age at stage 3 in cervical vertebral maturation (Cvs3) in females (Cvs3 females) and males (Cvs3 males).significant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. DISCUSSIONBCThe issue of optimal treatment timing for mandibular deficiencies is a widely debated topic in contemporary orthodontics. The definition of treatment timing in Class II disharmony too often relies on misleading variables such as chronological age or some kind of categorization of dentitional phases rather than individual biologic factors. It has been demonstrated clearly that the evaluation of individual skeletal maturity is fundamental in dentofacial orthopedics, as the greatest effects of functional/orthopedic appliances occur when the peak in mandibular growth is included in the treatment period.1,8-10 A few biologic indicators are available for the appraisal of individual skeletal maturity and, consequently, for the detection of the pubertal growth spurt in the mandible.2,4,6,11-17 Among these, the changes in statural height present with the least variability for the assessment of skeletal age throughout the progression of growth, thus showing the highest reliability as biologic indicator of skeletal maturity. The practical limitation of this method, however, is that it requires several measurements repeated at regular intervals (eg, every 3 months) to construct an individual curve of growth velocity. Radiographic methods have been proposed to overcome this limitation that allow for an appraisal of skeletal maturation on the basis of a single observation. The features of an ideal radiographic indicator should Bord infrieur des 3 vert.cerv. = plat Possibilit de concavit du bord infrieure de C2 dans la moitiFig 3. Individual changes in body height at intervals between stages in cervical vertebral maturation (A) in 24 subjects examined, (B) in subgroup of 15 females, and (C) in subgroup of 9 males.Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showeddes cas Le corps de C3 et C4 est trapzode (bord suprieur taperpostro-antrieurment) Le pic de croissance mandibulaire surviendra dans plus dun anDr Sylvain Chamberland; sylvainchamberland.com15 16. 338 Franchi, Baccetti, and McNamaraAmerican Journal of Orthodontics and Dentofacial Orthopedics September 2000A CVMS IIFig 4. Distribution of individual chronological age at stage 3 in cervical vertebral maturation (Cvs3) in females (Cvs3 females) and males (Cvs3 males).significant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. DISCUSSIONBCThe issue of optimal treatment timing for mandibular deficiencies is a widely debated topic in contemporary orthodontics. The definition of treatment timing in Class II disharmony too often relies on misleading variables such as chronological age or some kind of categorization of dentitional phases rather than individual biologic factors. It has been demonstrated clearly that the evaluation of individual skeletal maturity is fundamental in dentofacial orthopedics, as the greatest effects of functional/orthopedic appliances occur when the peak in mandibular growth is included in the treatment period.1,8-10 A few biologic indicators are available for the appraisal of individual skeletal maturity and, consequently, for the detection of the pubertal growth spurt in the mandible.2,4,6,11-17 Among these, the changes in statural height present with the least variability for the assessment of skeletal age throughout the progression of growth, thus showing the highest reliability as biologic indicator of skeletal maturity. The practical limitation of this method, however, is that it requires several measurements repeated at regular intervals (eg, every 3 months) to construct an individual curve of growth velocity. Radiographic methods have been proposed to overcome this limitation that allow for an appraisal of skeletal maturation on the basis of a single observation. The features of an ideal radiographic indicator should Concavit sur le bord infrieur de C2 et C3 Corps de C3 et C4 sont soit trapzodes ou rectangulairesFig 3. Individual changes in body height at intervals between stages in cervical vertebral maturation (A) in 24 subjects examined, (B) in subgroup of 15 females, and (C) in subgroup of 9 males.Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showedhorizontalement Le pic de croissance mandibulaire survient moins dun an aprsce stadeDr Sylvain Chamberland; sylvainchamberland.com16 17. 338 Franchi, Baccetti, and McNamaraAmerican Journal of Orthodontics and Dentofacial Orthopedics September 2000AFig 4. Distribution of individual chronological age at stage 3 in cervical vertebral maturation (Cvs3) in females (Cvs3 females) and males (Cvs3 males). CVMS IIIsignificant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. DISCUSSIONBThe issue of optimal treatment timing for mandibular deficiencies is a widely debated topic in contemporary orthodontics. The definition of treatment timing in Class II disharmony too often relies on misleading variables such as chronological age or some kind of categorization of dentitional phases rather than individual biologic factors. It has been demonstrated clearly that the evaluation of individual skeletal maturity is fundamental in dentofacial orthopedics, as the greatest effects of functional/orthopedic appliances occur when the peak in mandibular growth is included in the treatment period.1,8-10 A few biologic indicators are available for the appraisal of individual skeletal maturity and, consequently, for the detection of the pubertal growth spurt in the mandible.2,4,6,11-17 Among these, the changes in statural height present with the least variability for the assessment of skeletal age throughout the progression of growth, thus showing the highest reliability as biologic indicator of skeletal maturity. The practical limitation of this method, however, is that it requires several measurements repeated at regular intervals (eg, every 3 months) to construct an individual curve of growth velocity. Radiographic methods have been proposed to overcome this limitation that allow for an appraisal of skeletal maturation on the basis of a single observation. The features of an ideal radiographic indicator should Concavit du bord infrieur de C2, C3 et C4 C Les corps de C3 et C4 sont rectangulaires horizontalementFig 3. Individual changes in body height at intervals between stages in cervical vertebral maturation (A) in 24 subjects examined, (B) in subgroup of 15 females, and (C) in subgroup of 9 males.Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showed Le pic de croissance mandibulaire est survenu entre 1 et 2 ansavant ce stadeDr Sylvain Chamberland; sylvainchamberland.com17 18. 338 Franchi, Baccetti, and McNamaraAAmerican Journal of Orthodontics and Dentofacial Orthopedics September 2000CVMS IVFig 4. Distribution of individual chronological age at stage 3 in cervical vertebral maturation (Cvs3) in females (Cvs3 females) and males (Cvs3 males).significant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. DISCUSSIONBThe issue of optimal treatment timing for mandibular deficiencies is a widely debated topic in contemporary orthodontics. The definition of treatment timing in Class II disharmony too often relies on misleading variables such as chronological age or some kind of categorization of dentitional phases rather than individual biologic factors. It has been demonstrated clearly that the evaluation of individual skeletal maturity is fundamental in dentofacial orthopedics, as the greatest effects of functional/orthopedic appliances occur when the peak in mandibular growth is included in the treatment period.1,8-10 A few biologic indicators are available for the appraisal of individual skeletal maturity and, consequently, for the detection of the pubertal growth spurt in the mandible.2,4,6,11-17 Among these, the changes in statural height present with the least variability for the assessment of skeletal age throughout the progression of growth, thus showing the highest reliability as biologic indicator of skeletal maturity. The practical limitation of this method, however, is that it requires several measurements repeated at regular intervals (eg, every 3 months) to construct an individual curve of growth velocity. Radiographic methods have been proposed to overcome this limitation that allow for an appraisal of skeletal maturation on the basis of a single observation. The features of an ideal radiographic indicator should Concavit des bords infrieurs de C2, C3, C4 encore visible Au moins une des deux vertbres C3 ou C4 a une forme carrC Fig 3. Individual changes in body height at intervals between stages in cervical vertebral maturation (A) in 24 subjects examined, (B) in subgroup of 15 females, and (C) in subgroup of 9 males. Sil nest pas carr, le lautre vertbre est encore rectangulaireCvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showedhorizontale Le pic de croissance mandibulaire est termin depuis moins de1 an avant ce stadeDr Sylvain Chamberland; sylvainchamberland.com18 19. 338 Franchi, Baccetti, and McNamaraAAmerican Journal of Orthodontics and Dentofacial Orthopedics September 2000 CVMS VFig 4. Distribution of individual chronological age at stage 3 in cervical vertebral maturation (Cvs3) in females (Cvs3 females) and males (Cvs3 males).significant deceleration of growth during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. DISCUSSIONB La concavit des bords infrieurs de C2, C3, C4 est encore The issue of optimal treatment timing for mandibular deficiencies is a widely debated topic in contemporary orthodontics. The definition of treatment timing in Class II disharmony too often relies on misleading variables such as chronological age or some kind of categorization of dentitional phases rather than individual biologic factors. It has been demonstrated clearly that the evaluation of individual skeletal maturity is fundamental in dentofacial orthopedics, as the greatest effects of functional/orthopedic appliances occur when the peak in mandibular growth is included in the treatment period.1,8-10 A few biologic indicators are available for the appraisal of individual skeletal maturity and, consequently, for the detection of the pubertal growth spurt in the mandible.2,4,6,11-17 Among these, the changes in statural height present with the least variability for the assessment of skeletal age throughout the progression of growth, thus showing the highest reliability as biologic indicator of skeletal maturity. The practical limitation of this method, however, is that it requires several measurements repeated at regular intervals (eg, every 3 months) to construct an individual curve of growth velocity. Radiographic methods have been proposed to overcome this limitation that allow for an appraisal of skeletal maturation on the basis of a single observation. The features of an ideal radiographic indicator shouldvisibleC Au moins une vertbre de C3 ou de C4 est rectangulaireFig 3. Individual changes in body height at intervals between stages in cervical vertebral maturation (A) in 24 subjects examined, (B) in subgroup of 15 females, and (C) in subgroup of 9 males.Cvs4 when compared with the growth interval Cvs2 to Cvs3, and significant growth deceleration during the interval Cvs4 to Cvs5 when compared with Cvs3 to Cvs4. Ramus height (Co-Goi) and S-Gn also showedverticalement Si elle nest pas rectangulaire, lautre vertbre est carre Le pic de croissance mandibulaire est termin environ 2 ansavant ce stadeDr Sylvain Chamberland; sylvainchamberland.com19 20. SI CVMS 1 est observ Attendre au moins 1 an avant de dbuter un tx orthopdique CVMS II: Stade idal pour dbut tx orthopdique Md augmente de ~5,4 mm dans lanne suivante (CVMS II CVMS III) Entre CVMS 1 et CVMS II Md augmente de ~2,4 mm Entre CVMS III et CVMS IV Md augmente de 1,6 mm Entre CVMS IV et CVMS V Md augmente de 2,1 mmDr Sylvain Chamberland; sylvainchamberland.com20 21. Les traitements des classes II seront le plus efcace si fait durant le pic de croissance mandibulaire Les traitements de cl III avec expansion maxillaire etprotraction sont efcaces sur le maxillaire si cest fait avant le pic mandibulaire (CS 1 et CS 2) Les effets squelettiques de lexpansion palatine rapidepour corriger une dcience transverse sont plus grand si fait aux stades prpubertaires alors que si cest fait durant la pubert ou aprs, les effets seront plutt dento-alvolairesDr Sylvain Chamberland; sylvainchamberland.com21 22. Concavit sur le bord infrieur C2, C3, C4: taper C3: carre Sha.La.12a5mDr Sylvain Chamberland; sylvainchamberland.com22 23. C2: bord infrieur concave C3, C4: bord infrieur plat C3 et C4: taper, trapzode C3 et C4: rectangulaire horizontal Dr Sylvain Chamberland; sylvainchamberland.comGu.Ma.12a4m23 24. Concavit du bord infrieur C3: forme rectangulaire horizontale C4: forme carr Va.Po.15a5mDr Sylvain Chamberland; sylvainchamberland.com24 25. C2, C3, C4: bord infrieur plat C3 et C4: taper, trapzode Ly.Tr. 10a10mDr Sylvain Chamberland; sylvainchamberland.com25 26. C3: concavit bord infrieur C3: carr horizontal, taper antrieurement Ch.C. 13a8mDr Sylvain Chamberland; sylvainchamberland.com26 27. C2, C3, C4: rectangulaire vertical Concavit du bord infrieur Fr.Fe.18a4mDr Sylvain Chamberland; sylvainchamberland.com27