Orthodontics Current Concepts in Diagnosis and Treatment Planning

Orthodontics: Current Concepts in Diagnosis and Treatment Planning Dr shabeel pn

Questions that make ya go…. ’uhhhh’ Which teeth should be the main tooth in contact during function? CANINES What dimension of the face/head is the first to stop growing? Antero-Posterior? (Front to back) Width? (Side to Side) Vertical? (Length) At what age, when looking at a Panoramic Radiograph, if the 3 rd molars are not present will they not be there in the future? 15 Yrs If a tooth is missing or extracted at what age can they proceed with implant replacement? ~18 -19 girls, ~19 -20 boys What dimension of the face has to be completely done growing before the implant is placed? VERTICAL What X-Ray gives us growth information? HAND-WRIST

Orthodontist are Responsible for; • Monitoring growth and development • Correcting problems associated with growth and development – Syndromes – Down’s, Apert’s, Crouzon’s, Hemifacial Microsomia, etc – Cleft Lip and Palate – Congentially missing teeth – Jaw growth issues (genetic or environmental) – Eruption problems – Correcting functional relationships of the teeth – Improving Esthetics

PART I. Touching the Surface Orthodontics; Necessary or Not? Eruption timing of the teeth Defining Ideal GEOMETRIC Relationships of the permanent dentition (Lines/planes/angles) **All Patient Photos Used With Permission

PART II. What to look for… l l Age <6 Age 6 -8 Age 9 -11 Age 11 - Adult (primary) (early mixed) (late mixed-permanent)

Part III: Diagnosis and the Extraction/Non -Extraction Situation Depends on Time…. May start with this next time

Orthodontics; Necessary or Not? • Need to identify and inform if there is anything outside the envelope of ‘ideal’ alignment/function. • It is up to them to take the next step to seek out their options, but relieves you from responsibility of not informing them of the potential problems associated with a less-than ideal functional bite

What are the potential problems? • Abnormal Wear of the teeth – Abfraction/Abrasion • Failure of restored teeth/crowns/bridges

Abnormal Wear Abfraction Abrasion

What are the potential problems? • Abnormal Wear of the teeth – Abfraction/Abrasion • Failure of restored teeth/crowns/bridges • Loss of periodontal support • TM joint problems associated with abnormal jaw posturing during function

What are the potential problems? • Abnormal Wear of the teeth – Abfraction/Abrasion • Failure of restored teeth/crowns/bridges • Loss of periodontal support • TM joint problems associated with abnormal jaw posturing during function • Inability to clean teeth

Defining Ideal • Geometric tooth relationships – Static - at rest when all the teeth are in contact • Function – not able to touch this today – Dynamic – during chewing If we understand the IDEAL adult goal it will be easier to identify problems during growth

Geometric relationships (static) • Positive Overjet; Anterior and Posterior • Near Level Curve of Spee • Sufficient canine vertical overlap to ensure canine guidance • Overbite dictated by protrusive disclusion • Cusps of Molars on a PLANE

Midlines in good alignment

Overbite ~15% (1. 5 -2 mm), No black triangles at incisal embrasures

Angulation of the anterior teeth increases from the midline

Reasonably Level Curve of Spee

Angulation of Posterior segment near vertical from Buccal View

FACIAL PROPORTIONS and SOFT TISSUE SUPPORT

1/3 Upper Facial Height = Lower Facial Height

1/3 2/3 Upper Lip Length = ½ Lower Lip Length

A YOUTHFUL smile shows all of the upper incisor length (and some gingival tissue)

Lips touching a line connecting center nose to chin point

PART II. What to look for… l l Age <6 Age 6 -8 Age 9 -11 Age 11 - Adult (primary) (early mixed) (late mixed-permanent)

Age <6 (Primary Dentition) • Skeletal/Dental Class III • • – (Midface deficient/Mand excess) Crossbite Anterior/Posterior Functional shift Habits (tongue thrust/thumb sucking) Open bite • No space at age 5 -6 = Crowding 100% of the time

Age 6 -8 • Eruption of: – 1 st Molars • Dental-Class I, III Fact: If the molars are a full step Class II they will NOT correct to a class I – Central Incisors • Adequate room • Rotations/crossbite • Diastema – Lateral Incisors • Adequate room • Rotations/crossbite Result: Will have either • Class II Div 1 with increased Overjet, possible spacing Or • Class II Div 2 with maxillary crowding, deep bite and blocked out teeth

Class II, Div I • Gl’ Facial Angle (Glabella’-A’-Pg’) in a Class I profile is ~168 degrees. – with a reasonable variation • A’ Deficient Mandibular Body Length (She also has an advanced soft tissue A Point – due to flaring of incisors) • Pg’

Class II, Div I MB cusp of Maxillary 1 st molars in B Groove of Mandibular 1 st molars What is the most probable cause of the flaring and space?

Class II, Div I The Lower Lip

Class II, Div 2 Deep Bite Always Present Both arches tend to be crowded, with blocked out teeth

Age 6 -8 Continued • Width – Positive overjet in all dimensions – Anterior or posterior crossbites present? – Functional shifts? • Anterior-Posterior Jaw Relationships – Overjet (-/+) – Deficient Maxilla/Excessive Mandible (Skeletal-Class III) – Excessive Maxilla/Deficient Mandible (Skeletal-Class II) • Habits – Thumb/finger sucking, Tongue thrust

Age 7 Narrow Upper Arch 1. 5 mm diastema Crowding of laterals

AGE 7

Functional Shift - Lateral Shift to the Right • Lower midline off in the same direction as shift • Shift is ALWAYS to the crossbite side when unilateral crossbite present

Tongue Thrust

Age 9 -11 • Eruption of: – Mandibular canines (~age 9) • Space available – Max/Mand 1 st Premolars (~age 10) • Space available – Max/Mand 2 nd Premolars (~age 11 ) • E-Space!!! – very useful for uncrowding and correcting Molar class

E-Space 2 3 1 1 2 A B 3 C 4 D 5 6 4 E E- Space ~1. 3 mm/side 6

Age 11 -12 • Eruption of: – Maxillary canines • Space available • High Incidence of Impaction – 2 nd Molars • Impacted/Ectopic Eruption • Significant cause for functional interferences in adult dentition

Crowding/Blocked out Canines

Impacted Canines

Age 11 - Adult • Determine – – – Dental-Class (molars and canines) Skeletal-Class OJ/OB Alignment Space/Crowding Canine guidance (FUNCTION!!!)

Adult • Vertical Facial Development • • • – Excessive/deficient tooth display on smiling – Gummy smile Bite Tend to Deepen With Age (OB) Lower Anterior Crowding (not caused by 3 rds) Bruxism TMJ Disorders Interferences Third molar issues