A NOTE ON SPACE MAINTENANCE IN THE PRIMARY DENTITION

SPACE MAINTENANCE IN THE PRIMARY DENTITION

Space maintenance can be defined as the provision of an appliance (active or passive) which is concerned only with the control of space loss without taking into consideration measures to supervise the development of dentition.

Space maintainers are appliances used to maintain space or regain minor amounts of space lost, so as to guide the unerupted tooth into a proper position in the arch.

IDEAL REQUIREMENTS

• It should maintain the entire mesio-distal space created by a lost tooth.
• It must restore the function as far as possible & prevent over-eruption of opposing teeth.
• It should be simple in construction.
• It should be strong enough to withstand the functional forces.
• It should not exert excessive stress on adjoining teeth.
• It must permit maintenance of oral hygiene.
• It must not restrict normal growth & development and natural adjustments which take place during the transition from deciduous to permanent dentition.
• It should not come in the way of other functions.

A Note On Definition, Diagnosis, Treatment & Prognosis Of Dental Trauma

Enamel Infraction

Definition: incomplete fracture (crack) of the enamel without loss of tooth structure.

Diagnosis: normal gross anatomic and radiographic appearance; craze lines apparent, especially with transillumination.

Treatment objectives: to maintain structural integrity and pulp vitality.

General prognosis: Complications are unusual.

Crown fracture–uncomplicated

Definition: an enamel fracture or an enamel-dentin fracture that does not involve the pulp.

Diagnosis: clinical and/or radiographic findings reveal a loss of tooth structure confined to the enamel or to both the enamel and dentin.

Treatment objectives: to maintain pulp vitality and restore normal esthetics and function. Injured lips, tongue, and gingiva should be examined for tooth fragments. When looking for fragments in soft tissue lacerations, radiographs are recommended. For small fractures, rough margins and edges can be smoothed. For larger fractures, the lost tooth-structure can be restored.

 General prognosis: The prognosis of uncomplicated crown fractures depends primarily upon the concomitant injury to the periodontal ligament and secondarily upon the extent of dentin exposed. Optimal treatment results follow timely assessment and care.

Crown fracture–complicated

Definition: an enamel-dentin fracture with pulp exposure.

Diagnosis: clinical and radiographic findings reveal a loss of tooth structure with pulp exposure.

Treatment objectives: to maintain pulp vitality and restore normal esthetics and function. Injured lips, tongue, and gingiva should be examined for tooth fragments. When looking for fragments in soft tissue lacerations, radiographs are recommended.

• Primary teeth: Decisions often are based on life expectancy of the traumatized primary tooth and vitality of the pulpal tissue. Pulpal treatment alternatives are pulpotomy, pulpectomy, and extraction.

• Permanent teeth: Pulpal treatment alternatives are direct pulp capping, partial pulpotomy, full pulpotomy, and pulpectomy (start of root canal therapy). There is increasing evidence to suggest that utilizing conservative vital pulp therapies for mature teeth with closed apices is as appropriate a management technique as when used for immature teeth with open apices.

General prognosis: The prognosis of crown fractures appears to depend primarily upon a concomitant injury to the periodontal ligament. The age of the pulp exposure, extent of dentin exposed, and stage of root development at the time of injury secondarily affect the tooth’s prognosis. Optimal treatment results follow timely assessment and care.

Crown/root fracture

Definition: an enamel, dentin, and cementum fracture with or without pulp exposure.

Diagnosis: Clinical findings usually reveal a mobile coronal fragment attached to the gingiva with or without a pulp exposure. Radiographic findings may reveal a radiolucent oblique line that comprises crown and root in a vertical direction in primary teeth and in a direction usually perpendicular to the central radiographic beam in permanent teeth. While radiographic demonstration often is difficult, root fractures can only be diagnosed radiographically.

Treatment objectives: to maintain pulp vitality and restore normal esthetics and function.

• Primary teeth: When the primary tooth cannot or should not be restored, the entire tooth should be removed unless retrieval of apical fragments may result in damage to the succedaneous tooth.

• Permanent teeth: The emergency treatment objective is to stabilize the coronal fragment. Definitive treatment alternatives are: to remove the coronal fragment followed by a supragingival restoration or necessary gingivectomy, osteotomy, or extrusion (surgical or orthodontic) to prepare for restoration. If the pulp is exposed, pulpal treatment alternatives are pulp capping, pulpotomy, and root canal treatment.

General prognosis: Although the treatment of crown-root fractures can be complex and laborious, most fractured permanent teeth can be saved. Fractures extending significantly below the gingival margin may not be restorable. 

Root fracture

Definition: a dentin and cementum fracture involving the pulp.

Diagnosis: Clinical findings reveal a mobile coronal fragment attached to the gingiva that may be displaced. Radiographic findings may reveal 1 or more radiolucent lines that separate the tooth fragments in horizontal fractures. Multiple radiographic exposures at different angulations may be required for diagnosis. A root fracture in a primary tooth may be obscured by a succedaneous tooth.

Treatment objectives:

• Primary teeth: Treatment alternatives    include extraction of coronal fragment without insisting on removing apical fragment or observation. It is not recommended to reposition and stabilize the coronal fragment.

• Permanent teeth: Reposition and stabilize the            coronal fragment in its anatomically correct position as soon  as possible to optimize healing of the periodontal ligament and neurovascular supply while maintaining esthetic and functional integrity.

General prognosis: Pulp necrosis in root-fractured teeth is attributed to displacement of the coronal fragment and mature root development. In permanent teeth, the location of the root fracture has not been shown to affect pulp survival after injury. Therefore, preservation of teeth with root fractures occurring in the tooth’s cervical third should be attempted. Young age, immature root formation, positive pulp sensitivity at time of injury, and approximating  the dislocation within 1 mm have been found to be advantageous to both pulpal healing and hard tissue repair of the fracture.

Concussion

Definition: injury to the tooth-supporting structures without abnormal loosening or displacement of the tooth.

Diagnosis: Because the periodontal ligament absorbs the injury and is inflamed, clinical findings reveal a tooth tender to pressure and percussion without mobility, displacement, or sulcular bleeding. Radiographic abnormalities are not expected.

Treatment objectives: to optimize healing of the periodontal ligament and maintain pulp vitality.

General prognosis: For primary teeth, unless associated infection exists, no pulpal therapy is indicated. Although there is a minimal risk for pulp necrosis, mature permanent teeth with closed apices may undergo pulpal necrosis due to associated injuries to the blood vessels at the apex and, therefore, must be followed carefully.

Subluxation

Definition: injury to tooth-supporting structures with abnormal loosening but without tooth displacement.

Diagnosis: Because the periodontal ligament attempts to absorb the injury, clinical findings reveal a mobile tooth without displacement that may or may not have sulcular bleeding. Radiographic abnormalities are not expected.

Treatment objectives: to optimize healing of the periodontal ligament and neurovascular supply.

• Primary teeth: The tooth should be followed for pathology.

• Permanent teeth: Stabilize the tooth and relieve any occlusal interferences. For comfort, a flexible splint can be used. Splint for no more than 2 weeks.

General prognosis: Prognosis is usually favorable. The primary tooth should return to normal within 2 weeks. Mature permanent teeth with closed apices may undergo pulpal necrosis due to associated injuries to the blood vessels at the apex and, therefore, must be followed carefully.

Lateral luxation

Definition: displacement of the tooth in a direction other than axially. The periodontal ligament is torn and contusion or fracture of the supporting alveolar bone occurs.

Diagnosis: Clinical findings reveal that a tooth is displaced laterally with the crown usually in a palatal or lingual direction and may be locked firmly into this new position. The tooth usually is not mobile or tender to touch. Radiographic findings reveal an increase in periodontal ligament space and displacement of apex toward or though the labial bone plate.

Treatment objectives:

• Primary teeth: to allow passive or spontaneous repositiong if there is no occlusal interference. When there is occlusal interference, the tooth can be gently repositioned or slightly reduced if the interference is minor. When the injury is severe or the tooth is nearing exfoliation, extraction is the treatment of choice.

• Permanent teeth: to reposition as soon as possible and then to stabilize the tooth in its anatomically correct position to optimize healing of the periodontal ligament and neurovascular supply while maintaining esthetic and functional integrity. Repositioning of the tooth is done with digital pressure and little force. A displaced tooth may need to be extruded to free itself from the apical lock in the cortical bone plate. Splinting an additional 2 to 4 weeks may be needed with breakdown of marginal bone.

General prognosis: Primary teeth requiring repositioning have an increased risk of developing pulp necrosis compared to teeth that are left to spontaneously reposition. In mature permanent teeth with closed apices, pulp necrosis and pulp canal obliteration are common healing complications while progressive root resorption is less likely to occur.

Intrusion

Definition: apical displacement of tooth into the alveolar bone. The tooth is driven into the socket, compressing the periodontal ligament and commonly causes a crushing fracture of the alveolar socket.

Diagnosis: Clinical findings reveal that the tooth appears to be shortened or, in severe cases, it may appear missing. The tooth’s apex usually is displaced labially toward or through the labial bone plate in primary teeth and driven into the alveolar process in permanent teeth. The tooth is not mobile or tender to touch. Radiographic findings reveal that the tooth appears displaced apically and the periodontal ligament space is not continuous. Determination of the relationship of an intruded primary tooth with the follicle of the succedaneous tooth is mandatory. If the apex is displaced labially, the apical tip can be seen radiographically with the tooth appearing shorter than its contralateral. If the apex is displaced palatally towards the permanent tooth germ, the apical tip cannot be seen radiographically and the tooth appears elongated. An extraoral lateral radiograph also can be used to detect displacement of the apex toward or though the labial bone plate. An intruded young permanent tooth may mimic an erupting tooth.

Treatment objectives:

• Primary teeth: to allow spontaneous reeruption except when displaced into the developing successor. Extraction is indicated when the apex is displaced toward the permanent tooth germ.

• Permanent teeth: to reposition passively (allowing re-eruption to its preinjury position), actively (repositioning with traction), or surgically and then to stabilize the tooth with a splint for up to 4 weeks in its anatomically correct position to optimize healing of the periodontal ligament and neurovascular supply while maintaining esthetic and functional integrity. For immature teeth with more eruptive potential (root ½ to ²/³ formed), the objective is to allow for spontaneous eruption. In mature teeth, the goal is to reposition the tooth with orthodontic or surgical  extrusion and initiate endodontic treatment within the first 3 weeks of the traumatic incidence.

General prognosis: In primary teeth, 90% of intruded teeth will re-erupt spontaneously (either partially or completely) in 2 to 6 months. Even in cases of complete intrusion and displacement of primary teeth through the labial bone plate, a retrospective study showed the reeruption and survival of most teeth for more than 36 months. Ankylosis may occur, however, if the periodontal ligament of the affected tooth was severely damaged, thereby delaying or altering the eruption of the permanent successor. In mature permanent teeth with closed apices, there is considerable risk for pulp necrosis, pulp canal obliteration, and progressive root resorption. Immature permanent teeth that are allowed to reposition spontaneously demonstrate the lowest risk for healing complications. Extent of intrusion (7 mm or greater) and adjacent intruded teeth have a negative influence on healing.

Extrusion

Definition: partial displacement of the tooth axially from the socket; partial avulsion. The periodontal ligament usually is torn.

Diagnosis: Clinical findings reveal that the tooth appears elongated and is mobile. Radiographic findings reveal an increased periodontal ligament space apically.

Treatment objectives:

 •Primary teeth: to allow tooth to reposition spontaneously or reposition and allow for healing for minor extrusion (<3 mm) in an immature developing tooth. Indications for an extraction include severe extrusion or mobility, the tooth is nearing exfoliation, the child’s inability to cope with the emergency situation, or the tooth is fully formed.      

• Permanent teeth: to reposition as soon as possible and then to stabilize the tooth in its anatomically correct position to optimize healing of the periodontal ligament and neurovascular supply while maintaining esthetic and functional integrity. Repositioning may be accomplished with slow and steady apical pressure to gradually displace coagulum formed between root apex and floor of the socket. Splint  for up to 2 weeks.

General prognosis: There is a lack of clinical studies evaluating repositioning of extruded primary teeth.6 In permanent mature teeth with closed apices, there is considerable risk for pulp necrosis and pulp canal obliteration. These teeth must be followed carefully.

Avulsion

Definition: complete displacement of tooth out of socket. The periodontal ligament is severed and fracture of the alveolus may occur.

Diagnosis: Clinical and radiographic findings reveal that the tooth is not present in the socket or the tooth already has been replanted. Radiographic assessment will verify that  the tooth is not intruded when the tooth was not found.

Treatment objectives:

•Primary teeth: to prevent further injury to the developing successor. Avulsed primary teeth should not be replanted because of the potential for subsequent damage to developing permanent tooth germs.     

• Permanent teeth: to replant as soon as possible and then to stabilize the replanted tooth in its anatomically correct  location to optimize healing of the periodontal ligament  and neurovascular supply while maintaining esthetic and functional integrity except when replanting is contra-indicated by:

1.  The child’s stage of dental development (risk for ankylosis where considerable alveolar growth has to take place);

2.   Compromising medical condition; or

3.   Compromised integrity of the avulsed tooth or supporting tissues.

 Flexible splinting for 2 weeks is indicated. Tetanus  prophylaxis and antibiotic coverage should be considered. Treatment strategies are directed at avoiding inflammation that may occur as a result of the tooth’s attachment damage and/or pulpal infection.

General prognosis: Prognosis in the permanent dentition is primarily dependent upon formation of root development and extraoral dry time. The tooth has the best prognosis if replanted immediately. If the tooth cannot be replanted within 5 minutes, it should be stored in a medium that will help maintain vitality of the periodontal ligament fibers. The best (ie, physiologic) transportation media for avulsed teeth include (in order of preference) Viaspan, Hank’s Balanced Salt Solution (tissue culture medium), and cold milk. Next best would be a non-physiologic medium such as saliva (buccal vestibule), physiologic saline,  or water. Although water is detrimental to cell viability due to its low osmolality and long term storage (ie, more than 20 minutes) in water has an adverse effect on periodontal ligament healing, it is a better choice than dry storage. Limited tooth storage in a cell-compatible medium prior to replantation has produced similar healing results as compared with immediately-replanted teeth.

The risk of ankylosis increases significantly with an extraoral dry time of 20 minutes An extraoral dry time of 60 minutes is considered the point where survival of the root periodontal cells is unlikely. In permanent avulsed teeth, there is considerable risk for pulp necrosis, root resorption, and ankylosis.

Additional considerations: Recent evidence suggests that success of replantation is dependent upon many factors, some of which the clinician can manipulate in a manner that favors more successful outcomes. Decision trees for acute management of avulsed permanent incisors have been developed with up-to-date information in an easy to use  flowchart format.

Revascularization: An immature (ie, open apex) tooth has  the potential to establish revascularization when there is a minimum of a 1.0 mm apical opening. Complete pulpal revascularization has been shown to occur at a rate of 18% among immature teeth. It appears that antibiotic treatment reduces contamination of the root surface and/or pulp space, thereby creating a biological environment that aids revascularization. On the other hand, a mature tooth (ie, closed apex or apical opening <1 mm) has little or no chance of revascularization. Researchers have demonstrated that immature teeth soaked in doxycycline solution have a greater rate of pulp revascularization.

Periodontal ligament (PDL) management – transitional therapy: When a tooth has been out of the oral cavity and in a dry environment for greater than 60 minutes, the PDL has no chance of survival. If such a tooth is replanted, it is likely to undergo osseous replacement resorption and, over time, the tooth will become ankylosed and ultimately will be lost. Because pediatric dentists need to consider the growth and development of the child patient, the goal for a tooth that has been avulsed for greater than 60 minutes with dry storage is to delay the osseous replacement and, hence, ankylotic process as long as possible. To slow down this process, the remaining PDL should be removed because otherwise it becomes a stimulus for inflammation that accelerates infection-related resorption. The remaining PDL can be removed by several methods: gentle scaling and root planning, soft pumice prophylaxis, gauze, or soaking the tooth in 3% citric acid for 3 minutes. This should be followed by a sodium fluoride treatment for 20 minutes. The rationale for this fluoride soak is based upon evidence that this procedure will delay, but not prevent, ankylosis; fluoroapatite is more resistant to ankylosis than hydroxy-apatite. When teeth are soaked in fluoride before replantation, it has been shown to reduce significantly the risk of resorption after a follow-up of 5 years. Despite these recommendations, teeth that have been out of the  oral cavity for greater than 60 minutes with dry storage  have a poor prognosis and will not survive long term.

Possible contraindications to replantation: There are possible contraindications to tooth replantation. Examples are  immunocompromised health, severe congenital cardiac anomalies, severe uncontrolled seizure disorder, severe mental disability, severe uncontrolled diabetes, and lack of alveolar integrity.

Current research: Antiresorptive-regenerative therapies may have potential for enhancing the prognosis of avulsed teeth.

Treatment strategies are directed at avoiding or minimizing inflammation, increasing revascularization, and producing hard barriers in teeth with open apices. New treatment strategies also are directed at specific clinical challenges that include decoronation as an approach to treat ankylosis in growing children and transplantation of premolars as an approach for replacing avulsed teeth. Dental practitioners should follow current literature and consider carefully evidence-based recommendations that may enhance periodontal healing and revascularization of avulsed permanent teeth.

An Introduction to Dental Trauma Management

Facial trauma that results in fractured, displaced, or lost teeth can have significant negative functional, esthetic, and psychological effects on children. Dentists and physicians should collaborate to educate the public about prevention and treatment of traumatic injuries to the oral and maxillofacial region.

The greatest incidence of trauma to the primary teeth occurs at 2 to 3 years of age, when motor coordination is developing. The most common injuries to permanent teeth occur secondary to falls, followed by traffic accidents, violence, and sports. All sporting activities have an associated risk of orofacial injuries due to falls, collisions, and contact with hard surfaces. The AAPD encourages the use of protective gear, including mouthguards, which help distribute forces of impact, thereby reducing the risk of severe injury.

Dental injuries could have improved outcomes if the public were aware of first-aid measures and the need to seek immediate treatment. Because optimal treatment results follow immediate assessment and care, dentists have an ethical obligation to ensure that reasonable arrangements for emergency dental care are available. The history, circumstances of the injury, pattern of trauma, and behavior of the child and/or caregiver are important in distinguishing nonabusive injuries from abuse.

Practitioners have the responsibility to recognize, differentiate, and either appropriately manage or refer children with acute oral traumatic injuries, as dictated by the complexity of the injury and the individual clinician’s training, knowledge, and experience. Compromised airway, neurological manifestations (eg, altered orientation), hemorrhage, nausea/vomiting, orsuspected loss of consciousness requires further evaluation by a physician.

To efficiently determine the extent of injury and correctly diagnose injuries to the teeth, periodontium, and associated structures, a systematic approach to the traumatized child is essential. Assessment includes a thorough medical and dental history, clinical and radiographic examination, and additional tests such as palpation, percussion, sensitivity, and mobility evaluation. Intraoral radiography is useful for the evaluation of dentoalveolar trauma. If the area of concern extends beyond the dentoalveolar complex, extraoral imaging may be indicated. Treatment planning takes into consideration the patient’s health status and developmental status, as well as extent of injuries. Advanced behavior guidance techniques or an appropriate referral may be necessary to ensure that proper diagnosis and care are given.

All relevant diagnostic information, treatment, and recommended follow-up care should be documented in the patient’s record. A standardized trauma form can guide the practitioner's clinical assessment and provide a way to record the essential aspects of care in an organized and consistent manner. Well-designed and timely follow-up procedures are essential to diagnose and manage complications.

After a primary tooth has been injured, the treatment strategy is dictated by the concern for the safety of the permanent dentition. If determined that the displaced primary tooth has encroached upon the developing permanent tooth germ, removal is indicated. In the primary dentition, the maxillary anterior region is at low risk for space loss unless the avulsion occurs prior to canine eruption or the dentition is crowded. Fixed or removable appliances, while not always necessary, can be fabricated to satisfy parental concerns for esthetics or to return a loss of oral or phonetic function.

When an injury to a primary tooth occurs, informing parents about possible pulpal complications, appearance of a vestibular sinus tract, or color change of the crown associated with a sinus tract can help assure timely intervention, minimizing complications for the developing succedaneous teeth. Also, it is important to caution parents that the primary tooth’s displacement may result in any of several permanent tooth complications, including enamel hypoplasia, hypocalcification, crown/root dilacerations, or disruptions in eruption patterns or sequence. The risk of trauma-induced developmental disturbances in the permanent successors is greater in children whose enamel calcification is incomplete.

The treatment strategy after injury to a permanent tooth is dictated by the concern for vitality of the periodontal ligament and pulp. Subsequent to the initial management of the dental injury, continued periodic monitoring is indicated to determine clinical and radiographic evidence of successful intervention (ie, asymptomatic, positive sensitivity to pulp testing, root continues to develop in immature teeth, no mobility, no periapical pathology). Initiation of endodontic treatment is indicated in cases of spontaneous pain, abnormal response to pulp sensitivity tests, lack of continued root formation or apexogenesis, or breakdown of periradicular supportive tissue. To restore a fractured tooth’s normal esthetics and function, reattachment of the crown fragment is an alternative that should be considered.

To stabilize a tooth following traumatic injury, a splint may be necessary.

Flexible splinting assists in healing.

Characteristics of the ideal splint include:

1. easily fabricated in the mouth without additional trauma;

2. passive unless orthodontic forces are intended;

3. allows physiologic mobility;

4. nonirritating to soft tissues;

5. does not interfere with occlusion;

6. allows endodontic access and vitality testing;

7. easily cleansed;

8. easily removed.

Instructions to patients having a splint placed include to:

1. consume a soft diet;

2. avoid biting on splinted teeth;

3. maintain meticulous oral hygiene;

4. use chlorhexidine/antibiotics if prescribed;

5. call immediately if splint breaks/loosens.

Dental Anatomy Lecture Note On Deciduous Teeth

Lecture Note On Deciduous Teeth

Deciduous Teeth

Dental Aspects in the Management of Infants with Cleft Lip and Palate

Dental Aspects in the Management of Infants with Cleft Lip and Palate

 Children with cleft lip and palate present  peculiar dental characteristics since birth. Ideally, any child should have the first contact with the dental professional during the first year of life. This approach has revealed beneficial effects on the oral health of children, especially concerning the prevention of dental caries. However, for this specific population group, the main concern of families during early childhood is the accomplishment of primary repair surgeries, which follows specific protocols at each cleft center. Usually, lip repair is performed at 3 to 6 months of age, and palate repair is accomplished at the age of 1 year.

As described, there are several types of  clefts that affect different structures, consequently causing different extents of dental disorders. This section of the chapter describes the main aspects of infants with cleft lip and palate and the dental management at this stage.

 Breastfeeding

 This aspect raises several doubts when dealing with infants with clefts. The mothers and even the health professionals do not believe that the child may be breastfed, as evidenced by studies demonstrating that a low percentage of children with clefts receive breastfeeding. However, breastfeeding should always be encouraged and may be possible depending on the effort and motivation of the mother, who should receive adequate counseling.

For infants with isolated cleft lip, the greatest challenge for breastfeeding is the grasping and sealing of the nipple for suction. In this case, the mother may be guided to promote the sealing herself with the breast. With regard to cleft lip and palate and isolated cleft palate, the infant is unable to establish  the necessary intraoral negative pressure when positioning the tongue between the nipple and the palate, due to the presence of the palatal cleft. In these cases, the possibility of breastfeeding will depend on the mother motivation for the attempts and the infant adaptation to this situation. Despite these difficulties, breastfeeding should always be attempted and  encouraged by the health professionals involved in the care to newborns, because it involves important emotional and physiological aspects for both the mother and the infant.

If breastfeeding is impossible, the infant must be fed using a baby bottle. Rubber bottle nipples should be used, because silicone nipples are more rigid and may cause ulcerative lesions on the nasal septum exposed by the cleft palate. 

The nipple should have orthodontic shape and a 0.8- to 1-mm orifice to allow the milk to flow in drops. This way, the infant will have to suck strongly and will exercise the orofacial musculature. Other options for infant feeding that avoid the contact with the bottle nipple are the use of disposable plastic glasses and spoons. In both cases, the infant should be fed offering small quantities.

In any case, the infant should be always kept half-seated during feeding  to reduce the risk of choking and milk reflux to the auditory tube, which at this age presents horizontal positioning aligned with the soft palate. The auditory tube dysfunction and the communication between the oral and nasal cavities caused by the cleft predispose these infants to higher risk of recurrent ear infections, which may damage the hearing function in the.

Another important aspect from a dental standpoint concerns the utilization of the baby bottle and the early introduction of sugar in  the diet, which may favor and increase the occurrence of caries. Ideally, if a baby bottle is used to feed the infant, sugar should not be added to the formula or milk to delay the first contact with sugar. This represents a healthy dietary habit from a nutritional standpoint and is also beneficial for the prevention of caries.

 Common Oral Characteristics in Early Childhood

 The most common tooth abnormalities in infants with clefts involve the tooth eruption and are related with the extent of the defect. The natal or neonatal teeth are the most prevalent at this age range, affecting 2% of children with unilateral cleft lip and palate and 11% of children with bilateral cleft lip and palate. These teeth are usually located at the cleft area and  most present mobility due to the poor bone implantation, since in general no root formation occurs. These teeth should be extracted dueto the high risk of aspiration of these teeth, considering the communication between the oral and nasal cavities in the presence of an unrepaired cleft.

The gingival cysts of the newborn are also commonly observed in children with cleft lip and palate, similarly to infants without clefts. They present a nodular aspect with yellow-whitish color and may occur on the alveolar ridge, mucosa, or on the palate. No specific treatment is required for these cysts rather than follow-up until spontaneous regression of the lesion.

Preventive Treatment

 Before tooth eruption, the preventive treatment comprises cleaning of the oral cavity with gauze, a cloth or cotton swabs moistened with saline or filtered water. The hygiene should be performed on all regions of the mouth, including the alveolar ridges, oral mucosa, inner part of the cleft and the tongue. The parents should be instructed to examine the child’s mouth frequently and search for professional advice if any abnormality is observed. After eruption of the first tooth, the preventive procedure should be performed using a toothbrush or performing professional prophylaxis, always reinforcing the utilization of fluoride dentifrice only after 1 year of age and in a quantity corresponding to 1/4 of a rice seed. The toothbrush should have extra soft bristles, small and rounded head and a good handle to be used by an adult. If the child presents teeth with enamel hypoplasia, which is very common in patients with cleft lip and palate, these teeth should receive application of fluoride varnish or even preventive restorations by filling the defect with glass ionomer cement.

Restorative Treatment

 When the infant requires restorative treatment, it is usually performed under physical restraint, with the help and consent from the parents or caretakers. Negative behavior is expected after 1 year of age, and the child commonly cries to relieve the stresses related to the environment, procedures and the physical restraint itself. The restraint is necessary to protect the child.

Extraction of Natal/Neonatal Teeth

 As previously described, when the infant presents this alteration, extraction of these teeth is indicated in most cases because the tooth usually presents mobility  and poses the risk of aspiration. The procedure is performed only with application of topical anesthesia after careful drying of the mucosa, since the tooth does not present bone implantation. The extraction may be performed with a spatula n. 7 and hemostasis is achieved by compressing the site with sterile gauze, without need of suture.

OPERATIVE TREATMENT OF PRIMARY TEETH....A NOTE

Pit and fissure caries

Pit and fissure caries is less of a problem in primary teeth than in permanent ones. The fissures are usually much shallower and less susceptible to decay, so the presence of a cavity in the occlusal surface of a primary molar is a sign of high caries activity. Because of this it is quite likely that the children who require treatment of these surfaces will be young. However, treatment is not difficult and can usually be accomplished without problem. Infiltration analgesia should be given together with supplemental intrapapillary injection. Caries is removed using a 330 bur in a high-speed handpiece. For restoration although, as indicated above, silver amalgam has not so far been bettered in clinical trial because occlusal caries in the primary dentition indicates high caries activity, the material of choice may be a resin-modified glass ionomer cement with its possible caries preventive properties.

Approximal caries

Silver amalgam

Failure of amalgam itself as well as faults in the cavity design have been the most commonly reported causes of failure of approximal restorations in primary teeth. Attempts to overcome these deficiencies and to improve durability have come through alteration in cavity design and the choice of material used. A reduction in the size of the occlusal lock, rounded line angles, and minimum extension for prevention all result in less destruction of sound tooth tissue. In addition, the 'minimal' approximal cavity with no occlusal 'dovetail' has been described for both amalgam and adhesive restorations, and incorporates some mechanical retention in the form of small internal resistance grooves placed with a very small round bur just inside the enamel-dentine junction.

It is unlikely that the 'perfect cavity design' exists for an amalgam restoration in primary molars due to certain anatomical features:

1. Widened contact areas make a narrow box difficult to achieve.

2. Thin enamel means that cracking and fracture of parts of the crown are more common.

3. Primary teeth may undergo considerable wear under occlusal stress themselves and this in turn will affect the restorations.

It is therefore necessary to investigate other materials for use in restoring the primary dentition.

Composite resin

Composite resin has been used quite widely to restore primary teeth and results are generally acceptable. Cavity design is usually a modified approximal design with bevelling of the margins to increase the amount of enamel available for etching and bonding.

The use of rubber dam is essential if a dry field is to be achieved. This fact together with the material's relative expense probably reflects the lack of widespread use of composite resin in many countries.

Glass ionomer cement

More studies have been conducted using glass ionomer cements than composite resins. However, the cavity designs used in the different studies vary considerably and it is difficult to draw firm conclusions. Certainly, glass ionomer cement will undergo significantly more loss of anatomical form than amalgam in the approximal area, and as such conventional glass ionomers have not been shown to be as durable as amalgam. However, the operator will need to balance this fact with the obvious mechanical and chemical advantages of the cement namely its ability to bond to enamel and dentine, thus requiring a more conservative preparation, and its ability to act as a reservoir of fluoride.

Compomers

Compomers are now widely used in general dental practice for the restoration of approximal lesions in primary teeth. After good initial results, longer follow-up periods have shown that this material indeed lived up to its early promise and good survival rates have been reported for restorations in primary molars. However, it must be placed in cavities prepared to the usual principles of cavity design for a most favourable outcome.

Stainless-steel crowns

Stainless-steel crowns should be considered whenever posterior primary teeth (especially first molars) require restoration. They were originally developed to provide a 'restoration of last resort' for those teeth that were not salvageable by any other means. At the time that they were introduced in the early 1950s the only alternatives were silver or copper amalgam or a selection of cements, materials completely unsuited to the restoration of grossly carious teeth or those that had been weakened by pulp treatment. Over the years, it has become apparent that the life expectancy of these crowns is far better than any other restoration for primary posterior teeth and that they come close to the ideal of never having to be replaced prior to exfoliation. In addition, they are less demanding technically than intracoronal restorations in primary teeth.

They should therefore now be considered for any tooth where the dentist cannot be sure that an alternative would survive until the tooth is lost. It is unfair to put a child through more treatment situations than necessary because a less successful material, which needs frequent replacement, was chosen.

Anterior teeth

The treatment of decayed primary incisors depends on the stage of decay and the age and co-operation of the patient. In the preschool child, caries of the upper primary incisors is usually as a result of 'nursing caries syndrome' due to the frequent or prolonged consumption of fluids containing fermentable carbohydrate from a bottle or feeder cup. The lower incisors are rarely affected as they are protected during suckling by the tongue and directly bathed in secretions from the submandibular and sublingual glands. In 'nursing caries' the progression of decay is rapid, commencing on the labial surfaces and quickly encircling the teeth. It is impossible to prepare satisfactory cavities for restoration and after a comprehensive preventive programme the most suitable form of restoration is the 'strip crown technique'. This utilizes celluloid crown forms and a light-cured composite resin to restore crown morphology. Either calcium hydroxide or glass ionomer cement can be used as a lining and the high polishability of modern hybrid composites make them aesthetically, as well as physically, suitable for this task.

In older children over 3 or 4 years of age new lesions of primary incisors, although not usually associated with the use of pacifiers, do indicate high caries activity. Such lesions do not progress so rapidly and usually appear on the mesial and distal surfaces, here a glass ionomer cement or composite resin can be used for restoration. Glass ionomer lacks the translucency of composite resin but has the useful advantages of being adhesive and releasing fluoride.

Fractures of the incisal edges in primary teeth, as in permanent teeth, should be restored with composite resin.

Strip Crowns (3M ESPEE) are a useful aid in the restoration of primary incisors. Unfortunately, owing to their low sales in the United Kingdom and the rest of Europe, the company has discontinued the sale of these crowns and now they are only available on special request. They are however, freely available in the United States. In the authors opinion, these crowns are excellent for building primary incisors where extensive tooth tissue has been lost due to either caries or trauma. The technique for their use is similar to that of such crowns used in permanent teeth; the crowns are easily trimmed with sharp scissors, filled with composite, and seated on a prepared and conditioned tooth. The celluloid crown form can be stripped off after the composite has been cured. 

A Note On Mode of action of fluoride and the caries process

The use of fluorides date back to as early as 1874 when the German Erharde suggested the use of potassium fluoride tablets for expectant mothers and children in order to strengthen teeth. This recommendation was without any scientific evidence. What we now know to be dental fluorosis (mottling) was noted by dentists long ago who reported on 'Colorado Stain' without the aetiology of the tooth defect being established.

Mode of action of fluoride and the caries process

The mineral of tooth tissues exists as a carbonated apatite, which contains calcium, phosphate, and hydroxyl ions, making it a hydroxyapatite [Ca₁₀.(PO₄)₆.(OH)₂]. Carbonated portions weaken the structure and render the tissue susceptible to attack. Food remnants and debris mix with saliva and adhere to tooth surfaces as a slimy film known as dental plaque. Oral bacteria, and most importantly certain types of cariogenic bacteria (e.g. Mutans streptococci and Lactobacilli species), metabolize dental plaque and produce acid which lowers the pH of the oral environment. When the pH is below the critical pH for hydroxyapatite (< 5.5), demineralization occurs with a net outward flow of calcium and phosphorous ions from the enamel surface into plaque and saliva. 

When the pH returns to 7.0, remineralization occurs with a net inward flow of ions into the enamel surface. If fluoride is present during remineralization, it is incorporated to form fluorapatite [Ca₁₀.(PO₄)₆.F₂], which is more stable and resistant to further acid attacks. The process of demineralization and remineralization is an ongoing one and frequently referred to as 'the ionic see-saw' or 'tug-of-war'. This is now widely believed to be the most important preventive action of fluoride, and a constant post-eruptive supply of ionic fluoride is thought to be most effective.

A number of mechanisms have been proposed to explain the action of fluoride.

The first is that fluoride has an effect during tooth formation by substitution of hydroxyl ions for fluoride ions, thereby reducing the solubility of the tooth tissues.

Second, fluoride can inhibit plaque bacterial growth and glycolysis. At pH 7.0, fluoride ions are precluded from entering bacteria. However, at pH 5.0, fluoride exists as hydrofluoric acid, which crosses the bacterial cell membrane to interfere with its metabolism, by specifically inhibiting the enzyme enolase in the glycolytic pathway. 

Third fluoride inhibits the demineralization of tooth mineral when present in solution at the tooth surface. 

Fourth, fluoride enhances remineralization by combining with calcium and phosphate to form fluorapatite. Fluoride enhances crystal growth, stabilizes and makes the tissue resistant to further acid attack.

Enamel apatite demineralizes when the pH drops to pH 5.5. However, when fluorapatite is formed during remineralization, it is even more resistant to demineralization as the critical pH for fluorapatite is pH 3.5. Therefore, it is most important to have an intraoral source of fluoride when remineralization is taking place. Lastly, fluoride affects the morphology of the crown of the tooth, making the coronal pits and fissures shallower. Such shallower pits and fissures will be less likely to collect food debris, allow stagnation and become decayed. The most important of these mechanisms is that when fluoride is present in the oral environment at the time of the acid attack it inhibits demineralization and promotes remineralization.

As early as 1890, Miller drew attention to the dissolutive process of dental caries and directed efforts to inhibit dissolution. The clinical findings of the anti-caries activity of drinking water with fluoride caused researchers to seek reasons for this. The finding that fluoride-treated enamel had a lower solubility led many to consider this as a cause and effect relationship. The anti-caries action of fluoride was thought to be one of preventing dissolution of enamel, and efforts were made to incorporate more and more amounts of fluoride into surface enamel. 

The first topical agent used, after water fluoridation, was a 2% sodium fluoride solution and there was a greater uptake of fluoride into enamel from acidified solutions. Numerous fluoride preparations with varying concentrations of fluoride were employed for topical application and used as anti-caries agents. It was noted that there was not much difference in the caries reductions reported from the topical fluoride studies despite great variations in the fluoride concentrations used. In addition, the difference in the levels of fluoride in surface enamel of residents of fluoridated and non-fluoridated areas was limited. Therefore, it is difficult to explain the 50% reduction of caries observed, on the basis of the fluoride level in the surface enamel. Furthermore, there has been no study to show any clear-cut inverse relationship between fluoride content of surface enamel and dental caries.

All the available evidence is that caries results from the presence of an acidogenic plaque on elements of the tooth mineral. The diffusion of acidic components into the tooth mineral is accompanied by the reverse diffusion of components of the mineral. During the carious process there is a preferential loss of calcium, accompanied by dissolution of magnesium and carbonate. The first clinical sign of enamel caries is the so-called 'white spot' lesion, where an apparently sound surface overlies an area of decalcification. The remineralization effect of fluoride has since come into favour. It has been reported that attacked enamel could re-harden on exposure to saliva and that softened enamel could be re-hardened by solutions of calcium phosphates in vitro. However, it is now known that it is the presence of fluoride in the oral cavity, and in particular, its presence in the liquid phase at the enamel-plaque interface, that is of most importance.

In the past it was thought that the systemic action of fluoride was important for caries prevention. This view has completely changed and it is now known that it is the topical action of fluoride that is essential for caries prevention. It is the presence of fluoride in the liquid phase at the plaque-enamel interface that is of most importance. Studies have shown that even low levels of fluoride (0.10 ppm) were effective in preventing the dissolution of enamel. It has been stated that the activity of the fluoride ion in the oral fluid that is important in reducing the solubility of the enamel rather than a high content of fluoride in the enamel. Saliva, the fluid that bathes the teeth has been extensively studied. The level of fluoride in saliva is thought to be important for caries prevention and it has been shown that caries susceptible subjects had salivary fluoride levels of <0.02 ppm, whereas caries resistant subjects had levels of >0.04 ppm.

Key Points
Fluorides
· It is the activity of the fluoride ion in the oral fluid that is of most importance in reducing enamel solubility rather than having a high content of fluoride in surface enamel.
· A constant supply of low levels of intraoral fluoride, particularly at the saliva/ plaque/enamel interface, is of most benefit in preventing dental caries.

There are a vast number of fluoride products that are available for systemic and topical use. They can be applied professionally by the dental team or by the patient at home.