Module 29 - Orthodontics and Oral Surgery 160306

8/12/2019 Module 29 - Orthodontics and Oral Surgery 160306

1/31

National Orthodontics Programme Module 29 Orthodontics & Oral SurgeryBritish Orthodontic Society 1

National Orthodontics Programme

British Orthodontic Society

WWWeee lllcccooo mmm eee ttt ooo MMMooo ddd uuu llleee 222 999

OOOrrr ttt hhh ooo ddd ooo nnn ttt iiiccc sss aaa nnn ddd OOOrrr aaa lll SSS uuu rrr ggg eee rrr y y y

About the National Orthodontics ProgrammeThe National Orthodontics Programme was launched in December 2004 following a successful BritishOrthodontic Society Foundation Award application. A primary aim of the project was to develop a modularlearning resource housed in a Virtual Learning Environment for postgraduates in orthodontics(www.ole.bris.ac.uk ). This consists of 40 online modules and a series of online assessments. Theresource aims to maximize the use of academic staff time and significantly reduce the amount of travellingto teaching bases by Specialist Registrars.

The resource has been developed by all UK dental schools as authors or co-authors. It is at the discretion ofeach dental school as to how the resource is best used in their courses.

We hope you enjoy using this unique and pioneering resource.
http://www.ole.bris.ac.uk/http://www.ole.bris.ac.uk/


2/31


Personal Welcome

Welcome to Module 29. This Module is designed to provide a foundation in the understanding of treatmentneeds of those patients who require combined orthodontic and surgical management. In particular it shouldprovide:

1. A thorough knowledge of the theory, indications and applications of combined orthodontic/oralsurgery treatments.

2. Specific aspects involved in orthodontic treatment of orthognathic/surgical cases.

Before commencing this module you should have completed

Module 11 - Cephalometrics

At the end of this module you should be able to Understand the indications and sequences of combined orthodontic and surgical treatment for

dentofacial deformity.

Diagnose skeletal disproportion that is of such severity that routine orthodontic procedures cannotachieve a result without the use of combined orthodontics and surgery.

Plan treatment for facial disharmony. Have an understanding of the practical clinical skills needed to use orthodontic appliances in

orthognathic cases.

Understand the surgical techniques and the consequences and sequelae of surgery. Diagnose some common dentoalveolar problems, understand dentoalveolar surgical procedures and

carry out associated orthodontic treatment.

For module support and guidance, Use the discussion board available on Blackboard.

Module AuthorsNicola Parkin / Fiona Dyer / Melanie Stern / Derrick Willmot

What you will learnThis module will take you through 6 sections addressing the interplay between orthodontics and surgicaltreatment

1. The indications and sequences of combined orthodontic and surgical treatment for dentofacialdeformity.

2. The range of facial disharmony and diagnostic procedures used to identify the site of facialdisharmony and know how treatment is planned.

3. Pre-surgical orthodontic procedures and techniques used to decompensate the dentition, co-ordinate the arches and prepare the patients for surgery.

4. The surgical procedures used for Orthognathic surgery.

5. Post surgical orthodontics

6. Dentoalveolar procedures in relations to: Exposure of maxillary incisorsExposure of impacted canine teeth


3/31


Assessment

The assessment of this module will be made through a combination of tasks for self-directed learning,shared discussion and quiz at the end of the module to be returned to the coordinator. At the end of yourtraining programme you may also be assessed by means of a specific written examination and/or viva orpart of a written question and or viva, which examines the involvement of orthodontists in multidisciplinaryorthodontic oral surgical care.

Your experience should include attendance at joint orthognathic clinics and treatment of patients ofcombined orthodontic /oral surgery care. All should have had additional experience with the in patientmanagement of orthognathic patients in the immediate post-operative period and have observed (and orassisted) during the surgical procedure.

It is the module coordinators opinion however that three years of specialist training in orthodontics does notqualify you to diagnose and successfully treat patients needing orthognathic care. It is recommended that afurther 2 years of training in the form of a FTTA placement is required in order to achieve competence inthis skill.

Timing

The total time required for the Module and assessment is 15 hours .

The discussion board for this module is available on Blackboard(www.ole.bris.ac.uk )

Section 1: Overview of Indications and Sequences in Orthognathictreatment

Indications

Dentofacial problem too severe for orthodontics alone. Orthognathic surgery is carried out in non-growing adults, surgery in growing children is prone to

relapse owing to reversion of the original growth pattern. In growing children with cranio-facial syndromes and severe dentofacial abnormalities, distraction

osteogenesis may be considered.

Examples of indications

1. Severe anteroposterior discrepancies (Class 2/Class III malocclusions)

2. Vertical discrepancies (AOB/deep overbite)

3. Transverse discrepancies

4. Skeletal Asymmetry


4/31


Sequences of treatment

Diagnosis Treatment planning

Orthodontic preparation for surgery (presurgical orthodontics). Duration 6-18 months. Surgical procedure (Osteotomy) Post-surgical orthodontics. Duration 3-6 months. Retention

Now read Chapter 22 of the Third Edition of Contemporary Orthodontics by W R Proffit Pages 674 709.This will give you an overview of Combined Surgical and Orthodontic Treatment before examining somespecific issues in the rest of the module.

Take 2 hours

Section 2: Diagnosis of facial disharmony

Introduction

Welcome to section 2. This section considers the range of facial disharmony and disproportion, thediagnostic procedures used to identify the site of facial disharmony, the presurgical orthodontic proceduresand techniques used to decompensate the dentition and prepare the patient for surgery.

Aims

Be able to diagnose the site of disharmony using various diagnostic guides and know how treatment isplanned.

Cephalometric Analysis of the facial Skeleton

The relationships of the various parts of the facial skeleton can be visualised by direct examination of thepatient. The use of a cephalometric technique during orthognathic procedures is for three reasons:

1. To provide precise details of the relationships of the parts of the dentofacial complex as part of thediagnosis.

2. To plan tooth angulation movements and osteotomy cuts and movements prior to treatmentcommencement.

3. To provide baseline data against which later treatment response can be measured.


5/31


A wide range of cephalometric techniques and analyses are used in different units throughout the UnitedKingdom and indeed the World.

Tracing versus digitisation

Tracings allow easier visualisation of the pattern of relationships and easier identification of landmarks usedin measurements. There is nothing conceptually different between hand tracing and measuring linear andangular relationships by hand or on a computer but the latter adds the convenience of speed and storage.(Harradine and Birnie 1985)

A range of computerised systems are used in the United Kingdom. Typical systems are OPAL, Dolphinand Quick Ceph. The above picture shows the Quick Ceph computerised cephalometric analysis andplanning system.

Task for a demonstration of your local cephalometric system from your Consultant or FTTA and then tryplanning a case yourself.

Template versus measurement analysis

Figure 1


6/31


The object of diagnosis in dentofacial disharmony cases is to display, detect and quantify thedisproportionate relationships between the naso-maxillary complex, the mandible, the maxillary dentitionand the mandibular dentition and study the relationship with the cranial base. This can be done bymeasurement analysis but an alternative method is the display normal data in the form of a template. Aprepared template such as normal data from the Bolton Analysis can be superimposed upon cephalometricdata either as acetate tracings in the clinic or as computerised data in software. A hand-tracedsuperimposition is shown on page 5.

The above superimposition indicates that the principle cause of disharmony is the mandibular prognathism.

Aesthetic analysis of the face - What is important in examination of aesthetics?Symmetry, balance and morphology

Right-left symmetry. Few faces are perfectly symmetrical however obvious asymmetries should benoted. These may be limited to the lower face or may include the eyes and eyebrows.

General facial balance refers to the upper, middle & lower facial thirds being nearly equal in verticalheight.

General facial morphology.

The aesthetic facial evaluation is carried out with the patient in natural head position in a systematic fashionusing a millimetre ruler. The patient must be examined both from the side and from the front.

Take 20 minutes to examine the PowerPoint presentation Aesthetic analysis of the face

In pairs, measure and record the measurements overleaf. See power point presentation for help withidentifying the various aesthetic lines and angles. Means are taken from (Arnett and Bergman 1993 Part I;

Arnett and Bergman 1993 Part II).
http://../Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Word/Aesthetic%20analysis%20of%20the%20face.pdfhttp://../Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Word/Aesthetic%20analysis%20of%20the%20face.pdf


7/31


Frontal analysis: Tr = Trichion (hairline)

Gb = Glabella (between eyebrows)

Sn = Subnasale

Me = Menton

Sn Me= 60 68 mm

Gb Sn= 60 - 68 mm

Tr Gb= 60 - 68 mm

Upper lip19 -22 mm

Lower lip42-48 mm

1/3rd

2/3rd

Figure 2

Measurements:

1) Vertical

Upper 1/3rd 60 -68 mm

Middle 1/3rd 60 68 mm

Lower 1/3rd 60 68 mm

Upper Lip Height 19 -22 mm

Interlabial gap 1 5 mm

Lower Lip height (lower stomion menton) 42 -48 mm

Upper Lip height : Lower Lip Height Ratio 1:2

Maxillary incisor show at rest * 2 5 mm

Mxillary incisor show smiling ; Crown

Gingival

8mm

2mm

* greater in females


8/31


2) Midlines

Nasal bridge & tip: look for deviations

Maxillary incisors to midline

Mandibular incisors to midline

Chin point to midline

3) Others

Facial levels: level of maxillary & mandibular canine tips

Width of alar base: This should be approximately the same as inter-canthal width (34mm)

Malar eminence: Flat, normal, prominent

Eyes: ocular imbalance, presence of scleral show often indicates midfacial deficiency

Profile analysis

Figure 3

NLA (90-110)

E plane (lower lip-2 +/-2)

Depth of labiomentalfold (approx 4mm)

Throat length approx56mm


9/31


Upper 1/3

Shape of forehead: Note any frontal bossing or supra-orbital hypoplasia.

Middle 1/3

Naso Labial Angle (94-110 degrees). Formed tangentially between the columella and upper lip. When thisangle is abnormal, care must be taken to distinguish between an upper lip posture problem and an abnormalcolumella angulation.

Lower 1/3

Lip protrusion: Rickettss e-plane/Steiner s-plane

Labiomental fold: deep, average, shallow

Prominence/shape of pogonion

Neck-throat angle & length (length approx 56mm)

Psychological assessment

Psychological assessment is also a vital part of the overall assessment and allows identification of anypotential problems at an early stage (Cunningham and Feinmann 1998). Those patients that show signs ofBody Dismorphic Disorder, inappropriate motivation to seek treatment or that present with associatedpsychiatric disorders should be assessed by a psychologist.

Planning orthodontic and surgical movements with cephalometrics

Historically hand tracings were used to plan treatment by a cut and paste method. Below is an acetateshowing predicted movements using this method. The methodology is clearly outlined in ContemporaryOrthodontics by Proffitt pages 625-628.

Figure 4

Modern computerised platforms allow the superimposition of the cephalometric tracing and the digital lateralphotograph to form a composite. From this composite, movements performed in orthognathic surgery can

be simulated. This is particularly useful for providing the patient with information on their final appearance.It must however be emphasised that the prediction is an estimate of the final appearance and by no meansis the same as the actual result.


10/31


Below is a prediction using the Dolphin programme. The simulation is a mandibular forward slide. Aprediction log may be printed out together with the simulation.

Figure 5a Figure 5b

Can you produce a similar output from your local system?

Section 3: Pre-surgical orthodontic procedures

Introduction

Pre-surgical orthodontic treatment is essential for the combined orthodontic/orthognathic case. Theorthodontic treatment objectives for an orthognathic case are, in the vast majority of cases, entirely oppositethose that might be employed if the case were to be treated by conventional orthodontic methods. Theoverall objective is to allow maximum possible correction of the underlying skeletal deformity with minimal

occlusal interferences by orthodontic decompensation. Jacobs and Sinclair 1983.

The aims of pre-surgical orthodontics

1. Dental decompensation to return incisors to their normal inclinations relative to the alveolar base. Itmay also be necessary to decompensate transversely if surgical expansion is planned. This willinvolve uprighting of the premolars and molars.

2. Level and align. Relieve all crowding. This will lead to the need for extractions in the majority ofcases where space is required to relieve crowding and return incisors to normal inclinations.

3. Arch co-ordination Many cases require expansion of the upper arch prior to surgery. This may becarried out orthodontically (if the discrepancy is small) or surgically.

4. Flatten curves (where indicated).


11/31


5. Maintain curves (where indicated).

6. Produce three planes in one arch for segmental surgery.

7. Band and bond all teeth which are fully erupted and will be fully functional after surgery.

8. Correction of centrelines if this is not to be done surgically.

9. Provide a stable occlusal result with good interdigitation for improved stability of the surgical result.

Prior to the commencement of any orthodontic treatment full records should be taken. It is essential for allolder adult patients that this includes a full pocket depth charting and assessment of the periodontal status.No orthodontic treatment can proceed if there is any active periodontal disease. Further problems arise inadults with the status of their dentition with heavily restored posterior and anterior teeth, crowns and evenbridges. Restorative opinion may be required to determine the long-term prognosis of all teeth, if requiredbridges should be sectioned prior to placement of orthodontic appliances.

Any tooth size discrepancies should also be established early on to enable the orthodontic treatment plan toaccommodate these discrepancies by either maintaining disto-lateral spaces or enamel reduction in the lowerarch. Unless these tooth tissue discrepancies are accounted for then the anterior occlusal interdigitation isliable to suffer post-operatively. Achieving a Class I canine relationship immediately postoperatively isimportant for stability.

The Orthodontic Appliance Pre-surgery

Some thought to the type of orthodontic appliance should be made at the initial planning phase. An 022slot should be used to allow the use of full thickness wires; 21 x 25 wires are often used during thefinishing stage. The authors discourage the use of ceramic brackets in orthognathic cases due to theirpotential for fracture especially post-operatively when the forces may be high (Sinclair, Thomas and Tucker

1993). The improvement in cosmetic/aesthetic appearance overall is minimal when the patient undergoestheir definitive surgical care. The use of smaller brackets may also be difficult as these have a reducedsurface area and are potentially more prone to debond failures. Brackets used during orthognathic surgeryneed to have a reasonable profile to allow the placement of auxiliaries. In the final stages wire ligatures areplaced often in combination with Kobiashy ligatures and seating elastics. Our unit is now using low frictionself-ligating brackets, these allow rapid decompensation, increased cleanliness and eliminates the need toreplace modules with stainless steel ligatures.

The authors also prefer to band all posterior teeth as this enables better rotational and torque control.Bonding terminal molars has been reported to lead to failure during the surgical phase and the author isaware of a case where this has resulted in loss of a bond in the surgical site.

Brackets should be placed as for standard orthodontics on the FACC point. Modifications to bracket

placement such as changes in torque for palatally placed upper lateral incisors with the placement of upperlateral brackets upside down should still be employed.

The methods used to prepare a case fully prior to orthognathic surgery will be dealt with in the following 4sections:

1. Intra-arch.

In the initial phases of orthodontic decompensation the objectives are similar to those of conventionalorthodontic mechanics. A space analysis of the models is required to determine the need for space creationand the need for orthodontic extractions. The extraction pattern demanded in an orthognathic case is theoften the reverse of that seen in a comparable orthodontic case. The classic pattern of compensating

extractions in a Class II case with extraction of upper fours and lower fives is often reversed in a class IIskeletal pattern case as we aim to return the incisors to their normal inclinations, retroclining proclined lowerincisors and often maintaining or proclining upper incisors. The objective of this extraction pattern is to


12/31


maximise the overjet and to achieve at least a full-unit Class II molar and canines relationship, thus allowingmaximum possible surgical correction of the underlying skeletal deformity.

Intra-arch mechanics in orthognathic cases should be designed to achieve the ultimately desired post-surgical interdigitation and allow for the establishment of Class I canine and molar relationships aftersurgical treatment. Levelling and aligning may take time especially in adult cases where the molars are

mesially tipped or rotated. Beware of premature contacts arising due to dumping of palatal cusps when allterminal molars are engaged in the appliance. This is the result of inadequate torque control and is seenparticularly with the inclusion of third molars.

During this initial phase of treatment the patients malocclusion will appear worsened and the patient shouldbe carefully advised of this change before commencing care.

Figure 6a Figure 6b

The above patient demonstrates the effect of pre-surgical orthodontics on the profile.

Levelling of the occlusal plane is not always indicated prior to orthognathic surgery hence the necessity tohave a thorough understanding of the plan prior to starting orthodontic care. In many cases maintainingcurves with curved archwires is indicated and examples where this is necessary will be dealt with later in thissection.

Normally by the end of this phase extraction spaces should be closed (unless segmental surgery) and thefixed appliances have full thickness archwires in place (either 19 x 25 SS or 21x 25 SS). Residual spaces mayhowever remain in a case with tooth size discrepancies with small disto-lateral spaces in the maxilla.

2. Anteroposterior (sagittal) objectives

Dentoalveolar compensation of the teeth is found in most malocclusions in which there is a severeunderlying skeletal deformity. This is essentially the effort of the teeth to maintain some occlusal contact andinterdigitation by the teeth compensating in their positions for the skeletal problem.

This effect is seen transversely with flaring of the upper molars and the rolling lingually of the lower molarsin an attempt to compensate for transverse discrepancies between the arches. This effect is also evident inthe AP or sagittal dimension.

With Class II skeletal cases commonly seen dental compensations include lower incisor proclination and theupper incisors often appear upright (Figure 1). With Class III skeletal cases lower incisor retroclination dueto the force of the lower lip and upper incisor proclination is commonly seen (Figure 2). Thesecompensations will need correcting during the presurgical orthodontic phase.


13/31


Figure 7: Decompensation of class II case Figure 8: Decompensation of class III case

As discussed previously extractions may be indicated in order to decompensate or normalise these incisorinclinations. The exception to this is with Class III cases where the lower incisors need uprighting. In manyclass III malocclusions the lower incisors can be returned to normal positions without the need forextractions, however, care must be taken in mildly crowded cases where there amount of alveolar bone andginigival support may limit the amount of proclination the lower incisors can be subjected to. To avoidcompromised periodontal gingival health it may be necessary to extract either premolars or even a lowerincisor (in a class III case) to enable alignment of the lower labial segment accepting that fulldecompensation may not be possible.

Figure 9a and Figure 9b

The use of intra arch mechanics is commonly required prior to surgery as the full decompensation isachieved with Class II or Class III elastics bilaterally. Elastics should only be used on full thickness 19 x 25SS archwires. Therefore Class II elastics are often required in Class III cases to procline the lower incisorsand retrocline the uppers. Conversely, Class III elastics in Class II cases retrocline the lower incisors andprocline the uppers.

Figure 10: Class III elastics toattempt to increase theoverjet and achive fullunit Class II buccalsegment relationships.

With maximum decompensation, allowing full skeletal correction to be achieved, significant facial changescan be achieved:


14/31


Figures 11a to 11g.

3. Transverse Objectives

The need for maxillary expansion during the presurgical phase depends on whether the problem manifestedis skeletal or dental in nature. The pre-treatment models are then hand articulated into the proposedposition to enable an estimate as to the amount of expansion required.

This is particularly relevant for Class II skeletal patterns were the initial presenting malocclusion has notransverse discrepancy. Posturing the mandible forward to and edge-to-edge position reveals the true natureof the transverse problem and in many cases maxillary arch expansion will be required. Conversely in ClassIII cases in centric relation the malocclusion may suggest a transverse discrepancy with bilateral crossbiteshowever in edge-to-edge relationship the transverse relation is no longer a concern and expansion is notindicated.


15/31


Methods of maxillary arch expansion relate to 3 factors:

1. The amount of discrepancy and the amount of expansion required.

2. The torque of the buccal segments, i.e. are the buccal segments flared in an effort to compensatefor a transverse discrepancy

3. The proposed surgical procedure. (i.e. single jaw, segmental).

In some cases a Quad Helix palatal arch may provide sufficient upper arch expansion. However expansiongreater then 4 mm is difficult to achieve with this technique and expansion with molar flaring may result. Toachieve more skeletal than dental expansion the need for a Rapid Palatal Expansion appliance should bemade. In adolescents prior to 15 years it is possible to be effective with these appliances achieving goodskeletal changes with minimal dental side effects. As the mid palatal suture fuses and the resistance aroundthe zygomatic buttress increases, the ability to produce stable expansion reduces and surgery is required.Surgical expansion may be in the form of SARPE (surgically assisted rapid palatal expansion). This procedureinvolves para-sagittal cuts to release pressure from the circum-maxillary structures and separating themaxillae by malleting a thin osteotome between the upper incisors (Betts 1995, Curtin & Cuenin 1999). It is

normally performed prior to placement of fixed appliances and requires an additional general anaesthetic. Analternative of surgically expanding the maxilla is to carry out a segmental approach. This is executed at thesame time as the definitive osteotomy. The maxilla is segmentalised using a horse-shoe shaped midline splitas shown in the diaghram below. It is believed that more expansion can be achieved using SARPE, especiallyin the anterior (inter-canine) region but little is known with regards to the difference in stability.

Figure 12: Expansion of themaxilla using asegmental

approach.The cuts are mostcommonly made distalto the lateral incisorsbut can also be madedistal to 3s & 4s,depending onarchform and wherethe expansion isrequired.

Correcting the transverse dimension is very difficult and surgeons still are unsure about stability regardlessof technique. The literature is week with regard to long term effects of surgical expansion. It is generallyrecommended to overcorrect with the aim of building in surgical and orthodontic relapse.

Take 2 hours to review the literature below and make notes:

Proffit WR. Contemporary Orthodontics. 1999; Cureton and Cuenin: Chapter 8 Pages256-260, Chapter 16 pages 534-538.


16/31


4. Vertical Objectives

The main objectives for orthodontic treatment prior to orthognathic surgery are to avoid adverse dentalrelapse potential together with maximising the speed and efficiency of treatment (Jacobs and Sinclair 1983).

a) Open Bite / High Angle cases

Maximising pre-surgical orthodontics will lead to minimal post-surgical mechanics being required. This isimportant for cases where the lower face height is to be reduced during treatment for example in open bitecases. Where only minimal to moderate curves, in either arch, are evident at the commencement oftreatment then it may be appropriate to level the arches with continuous arch wires.

The overall aim is to avoid extrusion of the anterior region and intrusion of the posterior region during thepre-surgical orthodontic phase. In cases with marked curves pre-operatively this can only be avoided by asegmental procedure.

b) Deep Bite Cases with Short Anterior Face heightIn these cases the levelling of the mandibular occlusal plane should be delayed until after the surgicalprocedure. The maxillary arch however can be levelled prior to surgery. Maintaining the curve during thepre-surgical phase will allow the maximum increase in the anterior face height and the best aestheticimprovement for the patient as possible.

Following surgery and the achievement of a three point contact, vertical elastics or box elastics can beused to level the occlusal plane and achieve full buccal segment interdigitation. There is some debate as towhether a full thickness surgical archwire or more flexible archwire should be in place in the non-levelledmandibular arch at the time of the operation. Certainly a flexible archwire will be necessary in the post-operative phase to allow levelling. However, it may be difficult to achieve the correct incisor inclination onflexible archwire alone.

Timing of surgery

The majority of orthodontists in the UK carry out most of the orthodontics prior to surgery with the aim ofthe models fitting together optimally so that very little active therapy needs to be done post-surgery.

Advantages are as follows: Good buccal interdigitation achieved in the early period will have a positive effect on stability. Surgical planning can be more precise. We feel that there is a psychological advantage to the patient in having appliances removed soon

after surgery.

However (Lee 1994) suggested that there is a considerable advantage in delaying the major component oforthodontic treatment until after the surgery. This may certainly be true where a strap like lower lipprevents decompensation of the lower incisors. Lee found a reduction in overall treatment time and felt thatthis was due to more biologically favourable tooth movement, more predictable occlusal results and bettermanagement by the orthodontist.

Luther, Morris and Hart (2003) reported on 65 consecutively treated cases finding that the mean duration ofpre-operative orthodontics was 17 months (range 7-47 months). The need for extractions added only 0.3months to the treatment time. Neither age nor sex had a significant effect on the duration of treatment.There was a suggestion that the starting malocclusion may affect the length of treatment but with the smallnumbers recorded it was difficult to make any conclusions.


17/31


18/31


Figure 13a Figure 13b

Holding rims together with canines in class I allows inspection of the post-op result. This case requiresbuccal root torque to lift the palatal cusp of the upper molars further arch levelling; the aim is to achieveimproved buccal interdigitation so that the amount of post op orthodontics is reduced.

Pre-planning Lateral Cephalogram

This radiograph must confirm that the goals of incisal inclination have been achieved prior to surgery.

If further decompensation is required at this stage then the use of elastics and interdental stripping can thenbe discussed to further adjust the incisor inclination.

Photographs

The use of photographs at this stage will be essential especially if a prediction planning program isemployed. Care must be taken to ensure that the profile view taken is identical to the profile held during thelateral cephalogram. The soft tissues should be relaxed and lip incompetence evident if this is the case.

Two Weeks Prior to Surgical Date At this date the patient should be asked to return for impressions for the splint construction.

Rectangular SS archwires (0.19 x 0.025 SS minimum) should be in situ and all elastic modules removed andwire ligatures placed with care. In all of our surgical cases we routinely place surgical hooks between theposterior and anterior teeth. We prefer the use of crimpable hooks as these can be easily placed with thewires in or out of the mouth (although in practice are better out of the mouth with the wires correctlymarked as to their placement position). These hooks aid the surgeons, giving sufficient traction sites for thesurgeon to use in the final placement of the jaws. They are also relatively comfortable for the patients asthey have a smooth ball at the end. Sandy, Irvine and Leach (2001) recommend placing the crimpable hooksonto a bracket pad prior to placement on the wire as they can be very fiddly to work with. The archwiresshould be passive, this means that rectangular SS archwires should have been in place for a minimum of 3months. A common fault is not to leave heavy archwires in for long enough before the impression isrecorded for the immediate wafer.

Impressions can then be taken leaving the archwires in place, however, it will be necessary to block out thegingival aspect of the appliances to allow removal of the impressions. Methods used are the application ofwax (ribbon wax or protection wax), or the use of Moretight. In either case the occlusal surfaces of theteeth are the most important details and should be accurate as their replication is critical to the fit of thesurgical wafer.


19/31


A face-bow transfer is required for the majority of cases and should be conducted with care to allow theplacement of the models on a semi-adjustable articulator. Only in this way can the model surgery attempt topredict accurately the necessary surgical movements required. Planning errors are always of concern andmay occur at many stages during the bite registration and face-bow record. The use of semi-adjustablearticulators allows the construction of intermediate and final wafers for two jaw procedures. They also allowchecking the validity of the planned bone cuts and magnitude of movements including autorotation of themandible. A simple-hinge articulator may however, be adequate for a mandibular procedure alone. OMalleyand Milosevic (2000) compared the use of three types of semi-adjustable articulators for planningorthognathic surgery. Both the Denar and Dentatus articulators showed flattening of the occlusal plane by 5 and 6.5 respectively. The authors felt this flattening could affect the positioning of the maxillary incisorsduring surgery adversely. They conclude that whatever articulator is used, clinicians should be able to checkthe accuracy of the mounted study casts, in particular the steepness of the occlusal plane, before thetechnician makes the model.

The planned post-surgical occlusion should be carefully checked on the articulator by the orthodontist priorto manufacture of the wafer. The wafer should be tried in preoperatively to ensure a good fit, if the fit isinadequate, new impressions need to be retaken and the wafer remade. Interestingly in many parts of

America, all model surgery is performed by the surgeon with little or no input from the orthodontist.

Inter-Operative Splint Use

For single jaw surgery only one wafer is required. If a two-jaw procedure is required then an intermediatewafer will be required prior to the final wafer. The intermediate wafer is required to determine the correctpositioning of the maxilla. Once the maxilla is plated then the wafer is removed and the mandibular surgicalcuts undertaken. The final wafer allows confirmation of the mandibular movements in relation to the newlycorrected maxilla once in place the mandible can then be secured.

The best surgical wafers are thin, with minimal occlusal separation with the teeth in their final position.Securing the wafer to the teeth is either by small holes drilled into the lateral aspects of the splint or throughthe creation of small wire loops which are included into the lateral aspects of the wafer. These wafers can

then be wired into place around the fixed appliance. The wafers may remain in place for 1 week to 5 weeksdepending on the preference of the orthodontist and surgeon and whether rigid fixation with plates or IMF isprovided.

Initial placement of the surgical wafer is usually helpful to patients to provide guidance of the mandible intothe correct position in the immediate post-operative phase where proprioception is often difficult. Overall thestability of the occlusion may be enhanced, and during fixation changes in tooth position due to loss ofbands or broken bonds are minimized.

Section 4: Surgical treatment

You should have already read chapter 22 Combined Surgical and Orthodontic Treatment in the ThirdEdition of Contemporary Orthodontics by W R Proffit Pages 674 709. This will have given you anoverview of the surgical treatment.

Further information can be read in:

Harris and Reynolds, Fundamentals of Orthognathic surgery Chapter 5 pages 88-141.

Epker BN, Fish LC. Dentofacial Deformities Integrated Orthodontic and Surgical Correction. J Clin Orthod1987; 21: 654-64.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3482095&query_hl=5&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3482095&query_hl=5&itool=pubmed_docsum


20/31


All surgery is conducted as an inpatient in this country and involves the need for nasal endotracheal tubeintubations. Patients must be fit and well pre-operatively with normal blood film and chest x-ray. The needfor transfusions during or after the operation is extremely unlikely but some units still group and save andcross match as a precaution.

It is essential that even before the orthodontic treatment starts that the patients are full investigated for all

possible medical complications. A history of bleeding should be fully investigated and may prevent theprogression on to surgery. Emotionally unstable patients are difficult to determine and there is certainly acase for suggesting that patients should be routinely seen by a psychologist prior to commencing care.

Each unit will have their own requests for pre-medication and drugs given preoperatively andpostoperatively. The use of post-operative antibiotics appears to be universal for a limited time only. Steroidsare also prescribed to help reduce post-operative swelling these can help the patients feel positive post-operatively only to take a low when the steroids are no longer given.

For an excellent insight to the effects of orthognathic surgery it is recommended that you watch the video Diary of a patient aged 34 by Mrs Tania Murphy who as an Orthodontic SpR underwent Bimaxillaryosteotomy. She leads clinicians to challenge many of the supposedly encouraging words that we routinelygive to patients in the immediate post-operative period.

Obtain a copy of the video to be produced during 2005 and watch it (30 minutes)

Video presentation Diary of a patient aged 34 by Mrs Tania Murphy


21/31


Typical Surgical Procedures

There are many surgical procedures used in combination with orthodontic treatment. The principle commonoperations used in the United Kingdom are briefly reviewed below.

Common operations are:

The Obwegeser sagittal split osteotomy

Described first in 1957 (Trauner and Obwegeser) this versatile operation can be used to move the mandibleforwards or backwards. It is not recommended in patients with anterior open bite without considering asimultaneous maxillary operation to reduce posterior facial height. The diagram (Figure 8) below show thecuts used.

Figure 14

The photographs below show the cuts at operation (courtesy of Mrs F M Dyer and Prof P Robinson).



22/31


The Vertical Sub Sigmoid osteotomy (VSSO)

This can be used to manage mandibular prognathism. The main advantage is that there is a much lowerincidence of paraesthesia than with the Sagittal Split procedure. Nationally permanent paraesthesia is approx5% for VSSO versus 25% BSSO. The disadvantage of VSSO is that intermaxillary fixation is required because

access for rigid fixation is very difficult.

Figure 16

The Le Fort 1 Maxillary Osteotomy

A universal operation that allows the surgeon to move the maxilla in all three planes of space at the le fort 1level. It is used to treat maxillary deficiency (AP & vertical) and maxillary excess (vertical). In our hospital,the maxilla has never been set back using this type of procedure. With vertical maxillary deficiency, themaxilla is moved downwards (to increase incisal show). A bone graft is usually required for this procedure.

Figure 17

There are many other surgical procedures used. The above must represent the commonest incurrent use. What other procedures do you know of? If you knowledge is weak you shouldfind out about them. Further information in:

Proffit WR, White RP, Sarver DM. Contemporary Treatment of Dentofacial Deformity. 2003; Mosby: ReviewPart III Surgical Treatment page 269 onwards.


23/31


Section 5: Post surgical orthodontics

Post surgical orthodontic usually takes some 3-6 months to complete. The aims of post surgical orthodonticsare:

1. Final tooth positioning

2. Root paralleling

3. Vertical movements of buccal segments with inter-arch elastics

4. Retention

It is important that once any splint (or intermaxillary fixation if used) is removed the orthodontist should seethe patient and place new working archwires to bring the teeth to their final position. Ideally theorthodontist, not the surgeon should remove any splint. Light vertical elastics with any necessary horizontalcomponent with a vector to support the sagittal correction are placed. These override any proprioceptiveimpulses from the teeth and muscles which could cause the patient to seek an undesirable position of inter-cuspation.

Light round wires (e.g. 0.016 steel) with any appropriate 1st or 2nd order bends will achieve minor toothmovements and work well with box elastics.Torque can be maintained with rectangular 0.021 X 0.025 braided steel used in a similar manner.

Retention and Stability

Retention for dental relapse after orthognathic surgery is no different to that for other adult orthodonticpatients. Numerous studies have been carried out on the stability of the jaws after surgical repositioningwith varied results.Stability is believed to depend on the following:

1. Direction of movement

2. Type of fixation used

3. Surgical technique employed

4. Magnitude of movement

5. Adaptive capacity of muscle fibres

6. Buccal interdigitation.

A number of factors can lead to relapse and be broadly placed into Surgical Factors, Orthodontic Factors orPatient Factors.

Surgical Factors can be down to poor planning of the case with inappropriate movements. Large movements

of the jaws increase the risk of surgical relapse. The maxilla is only able to move a maximum of 6mmforward. Movements of the mandible greater than 10mm are difficult to achieve. Distraction of the condylesduring surgery is a constant problem for all surgical cases and the position must be carefully controlledduring the operation. The importance of adequate fixation is essential to maintain the new bony positions.The extrusion of the teeth during the pre-surgical phase will result in relapse in the retention phase withopening of the overbite in anterior open bite cases if care is not taken. Soft tissue effects may also result inpost-treatment changes as teeth are moved into unstable areas of soft-tissue balance.

Patient factors which may lead to relapse may include the failure to attend for follow-up appointments ornon-cooperation with elastic wear post-operatively. Anterior open bite cases are notoriously difficult to treatsuccessfully and these patients should be aware of the potential for relapse.

The most stable surgical procedure is superior positioning of the maxilla and the most unstable islengthening of the height of the mandibular ramus (Proffit, Turvey et al. 1996)


24/31


One year after surgery physiological adaptation and morphological change are usually almost complete. Mostcases are quite stable after 1 year. However the long-term (greater than 5 year) studies show surprisingamounts of cumulative change over time. Long-term changes, especially in high angle Class II patients, arethought to be due to PCR (posterior condylar resorption). This results in a downward and backwardrepositioning of the mandible which clinically manifests as a reduction in overbite and increase in overjet.The decision whether to wear long term retaining devices can be difficult and is subject to much variance ofoperator opinion.

Mobarak KA et al. Mandibular advancement surgery in high angle and low angle Class II patients: Different

long term skeletal responses. Am J Orthod Dentofacial Orthop 2001; 119: 368-81.

Section 6: Dentoalveolar surgical procedures

Introduction

Section 6 considers dento-alveolar procedures in relation to orthodontic treatment. It also describesorthodontic procedures required for their alignment.

Aetiology, diagnosis and treatment options of the palatally displaced ectopic canine are covered in module30.

A) Impacted incisors Aims

To understand the surgical principles of exposing unerupted central incisors and ectopic canines. Be aware of mechanics that can be used in subsequent orthodontic alignment

Surgical management of unerupted central incisors

Surgical exposure can be performed in 3 ways: Excision of mucosa overlying incisor. This is the minimalist approach that may be employed if the

incisor is close to the surface and attached gingival can be preserved at the gingival margin. Apically repositioned flap. Closed eruption procedure. A buccal flap is raised and an orthodontic attachment bonded to the

incisor. The bracket should be bonded as palatally as possible so that early fenestration does notoccur to avoid unfavourable gingival contour. The flap is sutured back into place.

It is likely that position of the incisor (i.e. distance from alveolar crest, rotation and inclination) will be themain factor influencing choice of technique. If the incisor is fairly high and out of attached gingivae, thelatter two techniques should be used. Varnarsdal and Corn (1977) used a split thickness apically repositionedflap on 75 cases and found no marginal bone loss or gingival recession after orthodontic treatment. Someauthors believe the closed eruption technique to be the method of choice (Kokich and Mathews 1993;

Becker, Brin et al. 2002) in terms of aesthetic and periodontal outcomes. It is supposed to replicate naturaltooth eruption. Vermette, Kokich et al. (1995) examined the differences between surgical exposure ofincisors with an apically repositioned flap and using the closed eruption technique. Photographic examinationrevealed vertical relapse of the uncovered teeth in the apically repositioned group. It was concluded that
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsum


25/31


those teeth exposed with an apically repositioned flap have more unaesthetic sequelae than thoseuncovered with a closed eruption technique.

The method of closed eruption has never been the subject of a randomised controlled trial and the costeffectiveness of techniques such as bonding gold chain has obvious implications.

Royal College of Surgeons guidelines on manangement of the UE central incisor.

Orthodontic alignment

2 x 4 appliance. Place pre-surgery if practical. Extraction c/c may be required at time of exposure for space creation. Wait until a rigid wire (0.018 SS or greater) is in situ before applying traction. Use a light accessory

archwire (piggy back) threaded through a link of the gold chain and ligated to the adjacent teeth. Elastic chain or zing string may be used, but beware of oral hygiene issues and potential to apply

too great a force. Following alignment, the incisor should be retained with a bonded retainer to prevent intrusive

relapse.

Power point presentation on 2 X 4 appliances For completion, an alternative technique involves utilising magnetic forces to align unerupted teeth (SandlerPJ, 1991). The technique involves attachment of a prepared neodymium iron boron magnet to theunerupted tooth using the acid etch technique. A second larger magnet is incorporated to a removableappliance. Careful positioning of the two magnets is essential to ensure optimum direction of pull. It may beadvantageous in terms of patient comfort as no manipulation of wires, springs or elastic chain is required.Magnets produce a low continuous force that increases over time and is apparently very versatile. It ishowever technique sensitive as correct placement of magnets is crucial, it also relies on patient compliance,

full-time wear of the removable appliance is essential.

What do you think has a higher risk of debond, magnet or eyelet? What would be the sequelae to adebonded magnet?
http://../Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Word/Surgical%20treatment%20of%20impacted%20incisors.pdfhttp://../Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Word/Surgical%20treatment%20of%20impacted%20incisors.pdf


26/31


B) Surgical management of impacted canines

The following will be covered: Measures that can be taken to improve the position of a palatally placed canine followin.g diagnosis. Description of two surgical techniques used to align palatally ectopic canines. The most appropriate surgical technique for exposing labially ectopic canines. Mechanics involved in the orthodontic alignment of the ectopic canine.

Interceptive measures to improve the position of the palatally placed canine

Extraction of deciduous canine between the ages of 10-13 with well aligned, uncrowded arches(Ericson and Kurol 1988). This work is not evidence based, no control group was available.

Presently, there is only one controlled clinical trial (Leonardi, Armi et al. 2004). The study comparestwo interceptive approaches; i.e. extraction of the deciduous canine alone and in association withcervical headgear. It was found that the use of headgear in addition to extraction of the deciduouscanine induced successful eruption in 80% of cases. The removal of the deciduous canine inisolation showed 50% success, which was not significantly greater than the success rate in thecontrol group.

One hour Obtain and read the following 2 well recognised articles:

Ericson S, Kurol J. Early treatment of palatally erupting maxillary canines by extraction of the primarycanines. Eur J Orthod 1988; 10: 283-95. Leonardi M et al. Two interceptive approaches to palatally displaced canines: a prospective longitudinalstudy. Angle Orthod 2004; 74: 581-6.

Surgical Techniques used to expose palatal canines

Despite the frequency of canine ectopia, there is a shortage of well- controlled research on the best method

of surgically exposing these teeth (Burden, Mullally et al. 1999). Much of the evidence supporting currentmethods of management has been derived from case studies and a consensus of clinical experience.

In the United Kingdom and elsewhere two different methods of surgical exposure of palatally ectopic canineshave evolved.

One technique involves the surgical excision of the overlying palatal mucosa after removal of thecovering bone. A surgical pack is then placed over the exposed tooth for 7-10 days to prevent re-closure of the tissues during the healing period. Following removal of the surgical pack the ectopiccanine is left to erupt spontaneously for a period of time before orthodontic traction is commenced.This technique is often referred to as the open technique and the canine is moved into the correctposition within the arch above the palatal mucosa.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsum


27/31



The left maxillary canine has been exposed using the open procedure. It is brought into alignment supra-mucosally with initially with elastic chain and later, with an accessory 014 Sentalloy archwire.

An alternative technique involves a similar degree of palatal bone removal but the palatal mucosa isleft intact and no excision of the overlying mucosa is carried out. Instead, an attachment is bondedto the crown of the exposed canine at operation. A gold chain is tied to this attachment and thepalatal mucosa is sutured back into place with the end of the gold chain extending into the mouththrough the wound margin. Orthodontic traction is then applied to the ectopic canine via the goldchain. This technique is referred to as the closed technique. If the canine is situated deep withinbone, it is generally moved into alignment beneath the mucosa.


Closed eruption technique. The canine is moved into position above the mucosa.

Considerable controversy surrounds the exact operative technique employed when surgically exposingpalatally ectopic canines. The more extensive surgical exposure involving excision of palatal mucosa hasbeen criticised for several reasons. Some authors have argued that the periodontal health of the ectopiccanine is compromised when the palatal mucosa is excised (Lappin, 1951; Hitchin, 1956; Kettle, 1958;Johnston, 1969; von der Heydt, 1975; Heaney and Atherton, 1976; Vanarsdall and Corn, 1977; Becker et al.,1983; Kohavi et al., 1984). However, none of the above authors validated their conclusions usingrandomised clinical trials. It has also been argued that the use of surgical packs commits the surgeon to aim

for healing by secondary intention, which is less hygienic and less comfortable for the patient (Becker et al,1996). There is also the risk of mucosal coverage of the excised area overlying the canine following packremoval and the need for re-exposure.


28/31


The more conservative surgical technique where the palatal mucosa remains intact is considered to promotehealing by primary intention obviating the need for a surgical pack. A long-term retrospective study(Quirynen et al, 2000) looked at 38 patients who had received a closed exposure and found that there wereno significant differences between test and control teeth with regard to probing depth and bone levels.However, gingival width was 1mm larger for the control teeth.

Some clinicians feel that the conditions that prevail at operation are not conducive to effective acid-etchbonding (Fournier, 1982). It is felt that the presence of blood and saliva can lead to subsequent bond failurenecessitating a second surgical exposure. Indeed, a recent study, comparing patients treated in twohospitals using different surgical techniques found that the complication rate was lower when the surgicalexposure did not involve bonding an attachment at operation (Pearson et al, 1996). The authors concludedthat the surgical technique which did not include bonding an attachment at operation reduced the operationtime and facilitated day-stay anaesthesia.

Whichever technique is used, it is the way the soft tissues and periosteum are handled intra-operatively thatis crucial, they must be handled with great care and bone removal should be kept to a minimum, withoutexposing the cemento-enamel junction. McDonald and Yap (1982) found that the more bone removed atsurgery, the greater the bone loss after orthodontic treatment.

One hour: Read the ppt. presentation ectopic canines

Familiarise yourself with the following articles:

Burden DJ et al. Palatally ectopic canines: closed eruption versus open eruption. Am J Orthod DentofacialOrthop 1999; 115: 640-4. Pearson et al 1997: Management of palatally impacted canines: the findings of a collaborative study. Eur JOrthod 1997; 19: 511-5. Bishara SE. Impacted canines: a review . Am J Orthod Dentofacial Orthop 1992; 101: 159-71.

Surgical technique for exposing labially impacted canines

Three methods are available: Excisional uncovering Apically repositioned flap (ARP) Closed eruption technique

The technique of choice depends on 4 criteria (Kokich 2004) The labio-lingual position. If the canine is labial, any technique can be used as there is very little or

no bone covering the canine. If the canine is positioned centrally, within the alveolus, the closedprocedure should be employed.

The vertical position of the canine relative to the mucogingival junction. If most of the canine ispositioned coronal to the mucogingival junction, any technique can be used. If the canine ispositioned more apically (as in the photograph below) an excisional technique would beinappropriate because it would not result in any gingival over the labial surface of the tooth after ithad erupted. If the canine is very high, then an ARP should be avoided as there is a risk the caninemay re-intrude after orthodontic treatment due to healing of the ARF.

The amount of gingiva in the area of the impacted canine. If there were insufficient gingival in thearea of the canine, the only technique that predictably would produce more gingiva is an ARF.

Mesio-distal position. If the crown were positioned mesially, over the root of the lateral, an ARFshould be used so that the orthodontist knows exactly where the tooth is being moved to.
http://../Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Word/Ectopic%20canines.pdfhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9386337&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9386337&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=1739070&query_hl=3&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=1739070&query_hl=3&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9386337&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9386337&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://../Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Documents%20and%20Settings/omdma/Application%20Data/Microsoft/Word/Ectopic%20canines.pdf


29/31


If you want to avoid the result shown below, NEVER perform an excisional gingivectomy if the canine ispositioned apical to the muco-gingival junction.


Lack of attached gingivae has lead to an increase in clinical crown height in the final result.

Orthodontic alignment of ectopic canines

Anchorage

Consider the use of a Transpalatal Arch. This may be helpful for antero-posterior, vertical and transverseanchorage, the latter two being particularly important if the canine is considerably displaced in the palate.

Methods of applying traction include:

1) Piggy back technique using a light accessory archwire. Light forces should be used to minimise loss ofalveolar bone support and potential injury to the tooth during traction2) Elastic chain or zing string may be preferable in the early stages, particularly if the canine is verydisplaced.

Regardless of the material used, the direction of the applied force should initially move the impacted toothaway from the roots of the neighbouring teeth. After creating sufficient space for the canine, the spaceshould be maintained by placement of closed coil spring or tying back the teeth either side with a longligature. The base wire should be sufficiently rigid to minimize the rollercoaster effect caused by intrusion ofthe anchor teeth

Removable appliancesMcDonald & Yap (1982) suggested the use of a Hawley type of appliance designed to transfer anchoragedemands to the palatal vault and the alveolar ridge. Such appliances might be useful in patients withmultiple missing teeth when the use of fixed appliances is not recommended.

Using lower arch for anchorage

This may be in the form of lower removable appliance (Orton 1995) or a fixed lower lingual arch (Sinha &Nanda 1999). The advantage of this technique is that the orthodontist has more control over force anddirection of applied traction. For labially impacted canines, try and avoid mechanics that move the toothlabially which could produce bony dehiscence and accelerate migration of the labial gingival margin.

What could be the reason(s) for alignment of the ectopic canine to fail?


30/31


Suggested reading

Arnett GW, Bergman RT. Faci al keys to orthodontic diagnosis and treatment planning. Part II. Am J Orthod

Dentofacial Orthop 1993; 103: 395-411.

Arnett GW, Bergman RT. Facial keys to orthodontic diagnosis and treatment planning. Part I. Am J OrthodDentofacial Orthop 1993; 103: 299-312.

Becker A, et al. Closed-eruption surgical technique for impacted maxillary incisors: a postorthodontic

periodontal evaluation. Am J Orthod Dentofacial Orthop 2002; 122: 9-14.

Burden DJ et al. Palatally ectopic canines: closed eruption versus open eruption. Am J Orthod Dentofacial

Orthop 1999; 115: 640-4.

Cunningham SJ, Feinmann C. Psychological assessment of patients requesting orthognathic surgery and the

relevance of body dysmorphic disorder. Br J Orthod 1998; 25: 293-8.

Cureton SL, Cuenin M. Surgically assisted rapid palatal expansion: orthodontic preparation for clinicalsuccess. Am J Orthod Dentofacial Orthop 1999; 116: 46-59.

Ericson S, Kurol J. Early treatment of palatally erupting maxillary canines by extraction of the primary

canines. Eur J Orthod 1988; 10: 283-95.

Harradine NW, Birnie DJ. Computerized prediction of the results of orthognathic surgery. J Maxillofac Surg

1985; 13: 245-9.

Kokich VG. Surgical and orthodontic management of impacted maxillary canines. Am J Orthod Dentofacial

Orthop 2004; 126: 278-83.

Kokich VG, Mathews DP. Surgical and orthodontic management of impacted teeth. Dent Clin North Am

1993; 37: 181-204.

Lee RT. The benefits of post-surgical orthodontic treatment. Br J Orthod 1994; 21: 265-74.

Leonardi M et al. Two interceptive approaches to palatally displaced canines: a prospective longitudinal

study. Angle Orthod 2004; 74: 581-6.

Mobarak KA et al. Mandibular advancement surgery in high angle and low angle Class II patients: Different

long term skeletal responses. Am J Orthod Dentofacial Orthop 2001; 119: 368-81.

Proffit WR et al. Orthognathic surgery: a hierarchy of stability. Int J Adult Orthodon Orthognath Surg 1996;

11: 191-204.

Vermette ME, et al. Uncovering labially impacted teeth: apically positioned flap and closed-eruption

techniques. Angle Orthod 1995; 65: 23-32; discussion 33.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480709&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480709&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480695&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480695&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12142887&query_hl=4&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12142887&query_hl=4&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9884781&query_hl=9&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9884781&query_hl=9&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10393580&query_hl=11&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10393580&query_hl=11&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3866818&query_hl=3&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3866818&query_hl=3&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=5&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=5&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=7&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=7&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7947581&query_hl=8&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9456622&query_hl=14&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9456622&query_hl=14&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7726459&query_hl=16&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7726459&query_hl=16&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7726459&query_hl=16&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7726459&query_hl=16&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9456622&query_hl=14&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9456622&query_hl=14&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11298310&query_hl=12&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15529490&query_hl=10&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7947581&query_hl=8&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=7&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=7&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=5&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15356485&query_hl=5&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3866818&query_hl=3&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3866818&query_hl=3&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3208843&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10393580&query_hl=11&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10393580&query_hl=11&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9884781&query_hl=9&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9884781&query_hl=9&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10358246&query_hl=6&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12142887&query_hl=4&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12142887&query_hl=4&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480695&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480695&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480709&query_hl=1&itool=pubmed_docsumhttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8480709&query_hl=1&itool=pubmed_docsum


31/31


Discussion Board

Visit the discussion board to discuss any of the thoughts outlined above.

Congratulations - You have now completed Module 29.

Please remember to complete the module assessment so we can keep improving the module content.