nasoalveolar moulding / orthodontic courses by indian dental academy

Orthodontic management of cleft lip and palate

INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

www.indiandentalacademy.com

NASOALVEOLAR MOLDING


• BASICS OF NASOALVEOLAR MOLDING

• NAM IN UNILATERAL CLCP

• NAM IN BILATERAL CLCP

• ADVANTAGES OF NAM

• COMPLICATIONS OF NAM


DISADVANTAGES OF TRADITIONAL INFANT

ORTHOPAEDICS

• Deformity of the nasal cartilages in unilateral and bilateral cleft lip and palate

• Deficiency of the length of the collumela in bilateral cleft lip and palate


• The technique was described by –

• Grayson ( 1993)• Brechet ( 1995)• Santiago ( 1997)• Cutting ( 1998)


Technique

• It mainly uses acrylic stents attached to a vestibular shield of a oral molding plate to mold the nasal cartillages into a more normal form and position during the neonatal period

• This takes advantage of the malleability of the immature nasal cartilages and its ability to maintain a permanent correction in form.


• In addition the collumela is also non surgically corrected using tissue expansion principles.

• This correction is achieved by gradual expansion of the nasal stents and application of tissue expanding elastic forces that are applied to the prolabium


Objectives of Nasoalveolar Molding

• Active molding and repositioning of the deformed nasal cartilages and alveolar process

• Correction of the deficient collumela mainly in bilateral cases.


Correction of unilateral oronasal cleft deformity

• The lower lateral alar cartilage is depressed and concave in the alar rim and is separated from the contra lateral cartilage high in the nasal tip

• The nasal tip is displaced and depressed and there is also resultant overhang of the nostril apex


• The collumela and nasal septum are inclined with the base deviated to the non cleft side.

• In addition the orbicularis oris fibres in the lateral lip segments contracts into a bulge with some fibres running superiorly over the cleft towards the nasal tip


OBJECTIVES OF PNAM

• To correct and align and approximate the intra oral alveolar segments

• To correct the deformed nasal cartilages• To correct the nasal tip and alar base on the

affected side. • To correct the position of the philtrum and

collumela.


• These corrections are achieved using an intra oral molding plate,with a nasal stent rising from the labial vestibular flange.


Procedure

• Impressions of the infant are made using an elastomeric impression material

• Impressions of the cleft are useful in assessing pre and post alveolar molding results and also in fabrication of the nasal stent.


Fabrication of molding plate

• A molding plate is fabricated using conventional acrylic resin


• The molding plate is secured to the palate and alveolar process through external strapping (surgical adhesive tapes) to the cheeks and to an acrylic extension from the oral plate between the lips below the cleft.


Modification of the molding plate

• The molding plate is modified at weekly intervals to gradually approximate the alveolar segments and reduce the size of the cleft gap.

• This is achieved by removal of acrylic resin in areas where alveolar segments are to move and application of soft liner in areas where alveolar bone is to be reduced.


• The ultimate aim of he selective removal and addition of the acrylic material is to align the alveolar segments and to achieve the closure of the alveolar cleft gap

• This is similar to the Zurich type molding plate described by Hotz (1969)


• The effectiveness of the molding therapy is enhanced by supporting the palatal tissues and by taping the lip segments together across the cleft.

• Maintaining the tight lip apposition with the external tape provides orthopaedic benefits and reduces the consequent scar.


• The lip adhesion alone provides uncontrolled orthopaedic effects but the lip tape adhesion along with the molding plate produces controlled approximation of the alveolar segments.

• Taping the lip segments also helps the alignment of the nasal base region by bringing the collumela towards the mid saggital plane and by improving the symmetry of the nostril apertures.


NASAL STENT

• When the alveolar cleft width has reduced to less than 6 mm then the nasal stent is added to the molding plate so that nasal cartilage molding may start

• Any attempt to close the deformity if the cleft is large may result in undesirable increase in the size of lateral nasal wall


• The nasal stent is a projection of acrylic from the labial flange of the molding plate.

• Through gradual addition of acrylic the sent is positioned underneath the apex of alar cartilage on the cleft side

• The dome of the alar cartilage is elevated to normal position and symmetry.

• The stent should be located midway between the middle of the cleft lip segments


• At the tip of the stent soft liner is added so that tissue breakdown does not occur when positive pressure is added to the nasal lining.

• The stent performs as a custom tissue expander for cleft side of the collumela

• The elevation of the nasal tip on the cleft side will also increase the patency of the nostril aperture.


• Through gradual modification of the nasal stent the shape of the cartilaginous septum,alar cartilage tip and lateral and medial crus are carefully molded to resemble the normal shape of these structures.

• when properly taped temporary blanching of the tissue overlying the tip of the nasal stent occurs as the infant suckles and activates the appliance.


• Elevation of the nasal soft tissue results in an intra oral molding plate that is conducted down the nasal stent results in more effective molding of the alveolar segments.

• Lip taping is still continued after the placement of the nasal stent

• At the closing of moulding the collumela, philtrum and alveolar segments should be aligned to facilitate the surgical restoration of normal anatomic relationships.


GOALS

• To approximate the gingival tissues on either side of the cleft.

• However a successful surgical result is obtained when a small cleft remains between the segments.

• PNAM allows a single surgical repair of the deformity of the nasolabial complex with successful results.


Advantages of PNAM

• Ability to guide the alveolar segments to a more normal position prior to surgery.

• Reduction of the cleft gap facilitates the primary gingivoperiosteal closure of the cleft defect,because there is a greater probability that a complete osseous bridge formation will happen when cleft width is reduced.


• The combined action of the nasoalveolar molding plate and non surgical lip approximation with surgical taping results in a predictable correction of the nasal,alveolar and soft tissue deformities.

• As a result under surgical repair the lip and nose heals under minimal tension with no or minimal scar formation.


Benefits in unilateral clefts

• Restoration of the collumela from a more oblique to a midline position which also results in improved projection of the nasal tip and alar cartilage symmetry.

• The collumela base is no longer deviated to the non cleft side as it uprights and takes up normal convexity.


• The nasal cartilage on the cleft side is fashioned to be similar to the one of the non affected side as the alar cartilage is molded to a more normal convex shape.

• The nasal tip is directed anteriorly and upwards , this is possible because tissue expansion allows to include the inherent tissue defects n the cleft side.

• All these are achieved without surgery and reduce the need for additional soft tissue surgeries and alveolar bone grafting . Thus reducing consequent trauma and tissue scarring.


BILATERAL ORO NASAL CLEFTS

• The lower cartilages have failed to migrate to the nasal tip to stretch the collumela

• Pro labium also lacks muscle thickness and is positioned directly behind the collumela.

• The alar cartilages are positioned along the alar margin and are stretched over the cleft in a flared fashion.


• The premaxilla is suspended from the tip of the nasal septum where as the lateral segments remain behind.


OBJECTIVES

• Lengthen the collumela

• Reposition the alar cartilages towards the tip

• Align the alveolar segments and pre maxilla to form a more normal maxillary arch.


• Soft tissue and cartilaginous correction are achieved through a conventional molding plate.

• The nasal stents also stretch the lower nasal lining,thereby allowing the domes of the lateral lateral cartilages to be approximated under minimal tension during surgical repair.

• The device and its stents are secured with adhesive surgical tapes and elastics.


PROCEDURE

• Impressions are taken using elastomeric impression material

• Molding plate is fabricated that encompasses the lateral alveolar segments and pre maxilla.

• The everted pre maxilla is positioned between the lateral alveolar segments by modification of the molding plate.


• A surgical adhesive tape and elastics is used to secure the molding plate actively against the alveolar process and pre maxilla.

• Through modifications of the internal molding plate and elastic forces applied by the elastics attached to the adhesive tapes the pre maxilla is placed in a keystone position between the lateral alveolar segments.

• The molding plate is adjusted weekly to position the alveolar segments as the pre maxilla is retracted.


• The pre maxilla is positioned by modifying the molding plate by adding soft resin liners anterior to the pre maxilla and removal posterior to the pre maxilla.


Second stage

• Approximately three weeks after fabrication of the plate.

• Nasal stents are built up from the anterior of the oral molding plate to enter the nasal aperture.


• The nasal stent elevate the nasal cartilages and prevent the downward pull by the tapes placed on the pro labium


• A horizontal pro labial band pulls back on the collumela at the base of the nasolabial fold.

• The bands force is used to preserve the nasolabial angle at the junction of the collumela base and the philtrum as the collumela is lengthened.

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• The nasal stent supports the nasal tip and exerts tissue expanding forces that are directed to the collumela and nasal lining

• The stents are also modified to give convexity to the alar cartilages.

• The stent also advance the medial and lateral crus of the alar cartilages into the nasal tip while lengthening the collumela.


• Nasal stent is bifid with a superior and inferior lobe.

• The superior lobe enters the nostril and pressing up and forward against the nasal lining behind the dome of alar cartilage.

• The lower lobe is positioned under the apex of the nostril aperture,pressing up against the soft tissue triangle.


• Surgical tape attached from the prolabium to the anteroinferior part of the molding plate pulls down and reshapes the collumela.


• Attached across the nasal stent is the horizontal prolabial band that pushes against the collumela and further lengthens it.

• The prolabial band is made of a chain of elastics and coated with a denture liner to prevent ulceration of the tissue

• It is contoured on the tissue to restrict the width of the collumela.

• It is attached to metal pins on the molding plate (nasal stents) and stretched.


How is the collumela lengthened ?

• The stretching force applied by the adhesive tape.

• The horizontal posteriorly directed froce by the elastic band ( pro labial band)

• Upward and anterior force applied to the nasal tip by the nasal stent.


• One of the biggest benefits of builateral nasoalveolar molding is the lengthening of the collumela.

• About 4mm to 7mm lengthening of collumela can be achieved by this procedure.

• Nasoalveolar molding without collumelar lengthening may require surgical correction.

• Surgical correction may result in scar tissue and may damage the anatomy of the nasolabial complex.


• This also improves the esthetics of the nasolabial complex.

• It stretches the nasal lining and allows the surgeon to approximate the domes of the lower alar cartilages with lesser dificulty.


COMPLICATIONS

• Soft tissue breakdown may occur in areas of modification of the plate if they are not properly polished

• Ulceration may developed and this can be prevented by adding tissue lubricant or by proper polishing of the plate.

• If tapes and elastics are not applied then the plate will not be adequately retained


• If the appliance is lost or not worn then the previously closed cleft area may relapse due to tongue pressure.

• Occasionally the labial surface of the central incisor may erupt prematurely due to molding pressure.

• Ectopic tooth bud may be seen on the lateral aspect of the pre maxillary segment which might have to removed to prevent aspiration.


Maull et al ( 1999)

• Did a study on patients who underwent nasoalveolar molding and claimed that there was an increase in symmetry of nasal structures following nasoalveolar molding.


Cutting et al (1998)

• Showed that NAM combined with a modified surgical technique improved the esthetics of both unilateral and bilateral cleft patients.


CONCLUSION

• Pre surgical reduction of alveolar cleft allows the surgeon to perform a gingivoparietoplasty.

• This procedure reduces the need for alveolar bone grafts in more than 60% of cases in mixed dentition.


• The pre surgical alignment and correction and alignment of nasal structures reduces the need for primary nasal surgery and thereby reducing the scar formation and more consistent post operative results.


• In bilateral cases the need for secondary elongation of collumela by surgery is eliminated and consequent scar formation at the lip collumela junction is prevented.

• NAM combined with a modified surgical procedure addresses the needs of the lip-nasal-alveolar complex in a single surgery and reduces the number of surgeries an individual has to undergo in a life time.


Thank you


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nasoalveolar moulding / orthodontic courses by indian dental academy

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