Transcript
1 YEAR M.Sc.D ENDODONTICS
MAXILLARY CENTRALMAXILLARY CENTRAL INCISORINCISOR
CONTENTSCONTENTS
ANATOMY OF TOOTH
MORPHOLOGY OF TOOTH
VARIATIONS OF TOOTH
ANOMALIES OF TOOTH
ENDODONTIC CORELATION
CENTRAL INCISOR
• The maxillary central incisor is a human tooth in the front maxilla, and is usually the most visible of all teeth in the mouth.
• their function is for shearing or cutting food during mastication .
• Instead, the surface area of the tooth used in eating is called an incisal ridge or incisal edge.
• Formation of these teeth begin at 14 weeks in utero for the deciduous set and 3–4 months of age for the permanent set.
INTRODUCTION
INTRODUCTION
• Human dentition is diphyodont• Primary (deciduous/ predecessor) dentition• Formula: I 2/2 C 1/1 M 2/2• Eruption: 6 months - 28±4 months• Shedding: 6 to12 years• Secondary (permanent/successor) dentition• Formula: I 2/2 C 1/1 P 2/2 M 3/3• Eruption: 6 to (18-25) years
Tooth anatomy
Labial Palatal Mesial distal
Average time of eruption: 7 to 8 yearsAverage age of calcification: 10 years
Average length: 22.5 mm
External anatomy• Conical and rapidly tapering toward the
apex, the root morphology is quite distinctive.
• Root is slightly triangular at the cervical aspect, gradually becoming round as it approaches the apical foramen.
• Multiple canals are rare, but accessory and lateral canals are common.
• Average length : 22.5mm
• greatest length :27mm
• Least length:18mm
Tooth length determination
• Labial aspect The widest MD of all incisors – type trait 3 mamelons Middle is the smallest in width Mesial has a raised shoulder Distal has a low shoulder 2 labial lobe grooves 90º mesioincisal line angle – type trait Rounded distoincisal line angle Mesial contour straight, distal is somewhat rounded and both converge cervically Mesial height of contour (contact point) within incisal third Distal HOC at junction between incisal & middle thirds CEJ convex cervical Root is conical & inclined distally
EXTERNAL FEATURESEXTERNAL FEATURES
EXTERNAL FEATURES• Lingual aspect• Scoop-like surface• Lingual fossa bordered by (all more prominent in
max.) * Mesial & distal marginal ridges• * Cingulum• CEJ more convex than labial& summit toward distal Root is narrower seen from lingual• Mesial aspect * Chisel-shaped * Labial HOC in the cervical third * CEJ curved incisally (the most pronounced) – type
trait * Incisal edge coincides with long axis * Root is conical
• Distal aspect * CEJ is less curved than seen from mesial
• Incisal aspect * Triangular outline * Labial outline is slightly convex Meets M+L outlines at sharp line angles
* Mesial outline is longer than distal * Labial lobe grooves
Arch traitsCrown
• Wider MD• Smaller height / width proportion• Greater MD / LL proportion
Root
• Greater MD / LL proportion• Conical root in central incisors
Type traits
• Size• Height / width proportion in crown• MD / LL proportion in crown and root
INTERNAL ANATOMYPULP CHAMBER
PULP HORN
ROOT CANALS
ACCESSORY CANALS
LATERAL CANALS
APICAL FORAMEN
Pulp chamber• Location centre of the crown• 3 pulp horns• Chamber ovoid mesio distally• Pulp chamber follows the contour • Broad mesiodistally- broadest part incisally• There is no distinct division between root canal and pulp chamber
ROOT CANAL
• 1 root and one root canal• Conical in shape• Lateral canal in the apical third • Majority canals are straight (75%)• Distally (8%)• Palatally(4%)• Mesially(4%)• Labally(9%)
Root canal
Root canal of central incisor
Root canal system
Single root canal system
Schilder –collateral circulation- portal of exit –Steriomicroscopic study of root apices –av major foramen 0.4mm,
Accessory foramina-0.2mm12% showed accessory canals
Root canals & apical foramen were displaced distolabially
Lateral canals were found half of specimens
VERTUCCIS CLASSIFICATION OF ROOT CANAL SYSTEM
SERT AND BAYIRILS ADDITIONAL CANAL TYPES TO VERTUCCS CLASSIFICATION OF ROOT CANAL
CLASSIFFICATION AND PERCENTAGE OF ROOT CANALS IN THE MAXILLARY TEETH
MAXILLARY CENTRAL MAXILLARY CENTRAL INCISORINCISOR
NO OF TEETHNO OF TEETH
TYPE 1TYPE 1 100100
TYPE 11 (2-1)TYPE 11 (2-1) OO
TYPE III (1-2-1)TYPE III (1-2-1) 00
TOOTH WITH ONE CANAL AT TOOTH WITH ONE CANAL AT APEXAPEX
100100
TYPE IV 2CANALSTYPE IV 2CANALS OO
TYPE V(1-2)TYPE V(1-2) 00
TYPE VI(1-2-1)TYPE VI(1-2-1) 00
TYPE VII(1-2-1-2)TYPE VII(1-2-1-2) 00
TOTAL WITH 2 CANALS AT TOTAL WITH 2 CANALS AT APEXAPEX
00
TOOTH WITH 2 CANALS AT TOOTH WITH 2 CANALS AT APEXAPEX
00
TYPE VIIITYPE VIII 00
TOTAL WITH 3 CANAL AT TOTAL WITH 3 CANAL AT APEXAPEX
00
• 60% of specimen shows accessory canals
• 45% of specimen shows apical foramen apart from apex
73.5 % -- APICAL 3 OF ROOT
11.5 % -- MIDDLE 3 OF ROOT
15.1 % -- CERVICAL 3 OF ROOT
ACCESSORY CANALS
Anatomic relationships in situ
• lies close to the close labial cortical plate• More prone to fenestration,
dehiscence, abscesses.• Mesioaxial angulations -2 degree• Palatoaxial angulation-29 degree• Incisive canal parallels the long axis of
central incisor
Variations and anomalies Shovel shaped incisors are common in Asian population Incidence of radicular grooves -0.9%
Gemination and fusion
Highest incidence of gemination and fusion
Maxillary incisor with two roots very rare
Combination of anomalies were found-talon cusp, short roots, Dens invaginatus
Solitary median maxillary central incisors
• Multiple midline defects• Unknown etiology• Defers from normal central incisors• Found in the midline of maxillary arch• Aesthetic problem • Associated with cleft lip and cleft palate, heart
disorders ,congenital heart diseases,hypotelorism,hypopitutarism
Hutchinson's syndrome
• Mainly affects incisors• Hutchinson's teeth-congenital syphilis-notch
to form on the incisal edges of the teeth.• Screw driver shaped teeth-Hutchinson's teeth
Hutchinsons incisors keratitis 8 nerve deafness
Hutchinson's syndromeHutchinson's syndrome
Spacing between the tooth –diastema
Between the contacts of the maxillary central incisors
Mainly due to the high frenal attachment
Treatment is frenectomy followed by the ortodontic treatment
DIASTEMA
Talon cusp• Talon cusp is usually defined as an accessory cusp like structure resembling an eagle’s talon in shape.• It projects incisally from the Cingulum area of the incisors
and consists of enamel, dentin and pulpal tissue• The pulp chamber in some cases follows the morphological
variation of the tooth crown • Gorlin and Goodman defined talon cusp as a high accessory
cusp reaching the incisal edge to produce a T-form or a Y-shaped tooth crown.
• The conventional definition of talon cusp was considered only an accessory cusp projecting incisally from the cingulum area of an incisor.
• The current definition of talon cusp includes accessory cusp on the lingual or labial aspect of incisors or canines.
Talon cusp
Labial talon cusp on the maxillary left central incisor.The cusp extended from the cervical region to the incisal edge.
Labial talon cusp on the maxillary left central incisor.The cusp extended from the cervical region to the incisal edge.
Talon cuspTalon cusp
Bifid cingulum
DENTAL ANOMALIES11 and 21 Shovel-shaped,
TEETHTEETH MESIODISTAL MESIODISTAL mmmm
LABIOLINGUALLABIOLINGUALmmmm
VERTICAL mmVERTICAL mm
CENTRAL CENTRAL INCISORINCISOR
0.37 0.37 0.4280.428 0.8630.863
MEAN PERPENDICULAR DISTANCE FROM ROOT APEXTO APICAL CONSTRICTION WITH MESIO DISTAL AND LABIO LINGUAL DIAMETERS AT CONSTRICTION
SIZE OF APICAL FORMINA
TEETHTEETH MEAN VALUEMEAN VALUE
MAX- INCISORMAX- INCISOR 289.4 U289.4 U
MEDIAN CANAL DIAMETER IN mm AT 1,2,5 mm FROM APEX
ENDODONTIC CORELATION
The lingual view shows the incisally repositioned access with the rotary notch. From the lateral view, the darker wedge-shaped portion of the access shows how incisally this notch may be placed. With the repositioned access, very little cervical dentin needs to be removed
ACCESS CONSIDERATIONS
ACCESS SHAPE
ACCESS CONSIDERATIONS
ERRORS IN CLEANING AND SHAPING
PRECURVING THE FILES
precurving the files and using balance force technique will preventledge formation
ACCESS OPENING CONSIDERATIONS
Rotary notch in the access opening .this notch allows more straight Line access and prevents instrument breakage
Residual pulp horn, immature pulp should be removed
references• INGLE – ENDODONTICS 6 EDITION• COHEN PATHWAYS OF PULP 9 EDITION• WOLFES DENTAL ANATOMY• GROSSMAN -11 EDITION• COLOUR ATLAS OF ENDODONTICS- WILLIAM .T.JOHNSON.• WWW.WIKIPEDIA.COM• JOURNAL OF ORAL SCIENCE VOL45,47-50,2003• BRITISH DENTAL JOURNAL SHAFER ORAL PATHOLOGYTHE ON LINE ANGLE ORTHONTIST, VOL77-NO.1,PP176-180WWW.BIBLIOTECA.UNIVERSIA.NET
Thank you
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