Phase I Orthodontic treatment

Early Orthodontic TreatmentVictoria J Lynskey, DMD, MDS

Associate Clinical Professor, UCSF

Objectives

•Define Early Tx•When you should refer a patient•Who is (and is not) a good candidate for Early tx•What common problems are addressed in Early tx•What options are available to treat Early Patients•How to determine success

Definitions of Early treatment

• Phase Therapy: early dental problems that left alone will create an unhealthy environment for the growth and development of the teeth, gums, bone and jaws

• Preventative/ Prophylactic: Prevent a problem from happening• Interceptive Orthodontics: Intercept a developing problem• Growth Modification: timing treatment to maximize and guide the

growth of the jaw bones that support the teeth

Treatment Phasesfor Early/Interceptive Orthodontics

• Phase I (12-15 months)

• Maintenance Phase (12-24 mo)

• Phase II (12-15months)

Phase I active treatment Maintenance Phase II active treatment

12-15 months 12-24 months 12-18 months

The Big Question is …When and Who is a candidate for Early Treatment

What is normal in a 7-year old

Class I Dental & Skeletal occlusion

“Ugly-duckling” stage (spacing and or minor OB/OJ concerns

During transitional dentition, perfect tooth alignment is not to be expected and is not cause for alarm.

Transition from Primary to Permanent Dentition

What is NOT Normal

• Sagital relationships such as– Class II, dental and

skeletal– Class III, dental,

skeletal and functional shifts

Class II Skeletal Relationship

Growth Plan: Herbst/Forsus, HG

Extraction Plan + FFA; or HPHG

• 32% of malocclusions are Class II, but they are 70% of what orthodontists treat

•The upper jaw is ahead of the lower jaw (XS OJ or “buck teeth)

•In skeletal Class II, the jaws are malaligned. Treatment can include redirecting the eruption of teeth during jaw growth

•Excessive OJ leads to risk of trauma in protrusive teeth.

•The upper jaw may be over developed, but more often, the lower jaw is under-developed.

•Untreated, skeletal malocclusions may require orthognathic surgery to correct the jaw position after growth is complete

Class III Skeletal Relationship

Midface deficiencies and maxillary constriction is usually dx in the

mixed dentition

Mandibular Prognathism usually dx in adult (permanent dentition)

• Characterized by anterior crossbite

•Approximately 3% of the malocclusions

•Can be caused by lack of growth in the upper jaw or excessive growth in the lower jaw (seen later in development)

•Early treatment of maxillary sagital problem often includes a transverse component

•Early Class III treatment is best at age 7-10 as it requires significant compliance with extra-oral headgear

•Early Txt for Class III is primarily to affect maxillary growth.

•Requires RPE plus PHG and often FFA. Class III: Protraction/ reverse Pull (often used with an RPE to aid in skeletal movement)

Protraction Headgear

Functional Shifts

The position of the teeth affect the position of the jaw. When there is a premature contact (see the canine) it can cause the jaw to shift so that the teeth can contact. This can be habit forming and may result in unwanted asymmetric growth.

Habits, Medical Problems

• Finger, thumb, Tongue thrust• Speech discrepancies• Mouth breathing due to airway constriction

(tonsils, adenoids)• TMJ dysfunction, rheumatoid arthritis, and

growth hormone abnormalities may cause orthodontic problems

Vertical Relationships-Open bites

• Dental vs Skeletal

• Habits such as finger/thumb sucking, tongue thrust, or airway obstruction

• May result in chewing difficulty and speech problem

• Tx may require ENT, habit therapy and habit appliances

Vertical Relationships- Deep Bites

• Potential for abnormal tooth wear and gingival impingements

• May be skeletal cause: vertical maxillary excess or excessive curve of Spee

• This can be one of the most damaging of malocclusions

Crossbite: Anterior

• Skeletal vs dental• Can result from orthopedic problems or functional shifts• All of these may damage the teeth and can cause long term gingival

problems• These need to be corrected early to avoid damage to teeth and

gums

Crossbite: Posterior• Often found in patients with a

narrow maxilla• A posterior crossbite may also

cause a functional shift• It may also appear as a

unilateral crossbite• These are easily treated in the

growing child

Arch Length - crowding

• Causes– Early loss of primary teeth– Decay, genetics– Tooth size problems– Missing teeth – Eruption problems

Arch Length-crowding Premature loss of Primary Teeth

• Missing primary teeth, but adequate space for secondary dentition= space maintainer – Band and loop– Lingual Arch– Distal Shoe– Nance

Arch Length-crowdingIrregular lower incisors

• Irregular Incisors, no arch-length/space discrepancy.• Large Incisors + large primary molars +small premolars=

no space issues, but transient crowding & rotations of the permanent incisors

• Up to 2mm of crowding may resolve spontaneously• For 3-4mm of anterior crowding, IPR lower C’s and place lingual arch **

Arch length-Crowding: Delayed/blocked premolar development

• Aligned Incisors, no arch-length/space discrepancy.• Erupting canine width+ erupting 1stPM width + large

primary 2nd molar width=transient crowding & rotations of the erupting canines and premolars

• For posterior arch crowding, IPR lower E’s, hemi-section or extract and place lingual arch

Arch Length-crowding Localized space loss

• Localized space loss (3mm or less); Space Regaining• Maxillary Regaining: tipping vs bodily movement

– Headgear or intra-oral appliance– FFA

Arch Length-crowding Localized space loss

• Localized space loss (3mm or less); Space Regaining• Mandibular Regaining

– FFA or lip bumper

Arch Length-crowding Midline discrepancy

• Premature loss of a primary tooth results in a midline shift

• Tx with fingerspring or FFA

Arch Length-crowding Severe

• Serial/Guided eruption (>10mm)– No skeletal abnormality exists

(Class I)– >10mm crowding– Influence first premolars to

erupt prior to canines. For mandible this means ext D’s at ½ to 2/3 root formation on 4’s.

– Overbite might increase during guidance but can be tx after eruption of all permanent teeth in a comprehensive phase.

Arch Length - SpacingMaxillary Midline Diastema

• Normal diastema = “ugly duckling stage”• Larger diastema: >2mm =FFA

– Supernumeraries– Missing permanent lateral incisors– Tooth size discrepancy– Tongue thrust– Excessive tissue in the frenum

Tx indicated for 1) when the centrals inhibit eruption of the laterals or canines, or 2) esthetic issues (behavioral), 3) protrusion and trauma risk

Studies prove that stability of the end result is improved if a large diastema is corrected before the full eruption of the permanent dentition

Abnormal eruption sequence Ectopically-erupting teeth

• Lateral incisor/canine

• First molar

Congenitally missing permanent teeth

Congenitally missing permanent teeth

• Mandibular second premolars:– Retention– Ankylosis

•Delayed eruption•Manage until it interferes with eruption or drift of other teeth, then extracting and placing space maintainer if necessary•Monitor 1) tipping of molars over distal marginal ridges of the ankylosed teeth 2) super-eruption of opposing teeth

Ankylosed Teeth

Ankylosis: Fusion of the tooth to the bone

Primary Failure of eruption: Failure of permanent teeth to grow normally

Result: 1) Adjacent teeth continue to erupt & can tip forward, over the primary teeth resulting in space loss; 2) the primary molars appear to sink as the rest of the teeth and jaws continue to grow and develop. This will cause a significant discrepancy in the alveolar bone height, an issue during replacement when permanent teeth are missing

Early Treatment Rationale

• Phase I (12-15 months)

• Maintenance Phase (12-24 mo)

• Phase II (12-15months)

Phase I active treatment Maintenance Phase II active treatment

12-15 months 12-24 months 12-18 months

The Big Question is …When and Who is a candidate for Early Treatment

Crossbite: Posterior• Skeletal vs Dental

• Unilateral/ bilateral

Orthodontic TerminologySagital Dimension (AP)

• Dental (Angle Classification):– Overjet(OJ): distance between the

upper & lower front teeth(mm)– Molar position– Canine position

OJ Class II, Div 1 Class II, Div.2

• Skeletal: relation of maxilla and/or mandible to the skull

• Goal: to “affect mandibular growth” or dental compensation.

Jaw Deformities

• Class II: Growth modification

Extraction Plan + FFA Growth Plan: Herbst/Forsus, HG

Craniofacial Anomalies• Cleft Lip & Palate• Syndromes: Hemifacial Microsomia, Craniosynostosis,

Crouzon’s, Treacher-Collins, etc.

Benefits of Early Treatment

• Young patients may be more cooperative and follow instructions

• Increased stability• Habit modification• Reduce extractions• Reduced risk of tooth trauma (protruded teeth)• Reduced periodontal trauma (crossbites and

guiding eruption into attached gingiva)• Growth modification (sagitally, transverse,

asymmetric jaw growth)

Benefits of Early Treatment

Benefits of Early Treatment

• RPE + FFA to create space for U2’s and LR2

Benefits of Early Treatment

Benefits of Early Treatment

Disadvantages

• Time: most patients that require a phase I for moderate to severe dental or jaw growth modification will require a second phase.

• Money: increased cost to staging treatment into 2 phases is approximately $600

• OHI: poor motor skills may require more parental involvement.

• Emergencies: higher risk of working on the weekend

Questions

Thank You!