Aesthetic Rehabilitation of Non-syndromic oligodontia

Case report

Title of the article: “Esthetic Rehabilitation of Non-syndromic oligodontia-an innovative approach.”

Abstract: This case report describes the esthetic rehabilitation of a 13 year old girl presenting with non-syndromic oligodontia, who compromised in esthetics, occlusal function, development and functional growth of the bones. The oral rehabilitation was performed with direct composite restoration using thermoformed templates along with reinforced polyethylene fibers since it is a viable alternative to re-establish the masticatory function and esthetics, allowing the patient to achieve greater self-esteem and better social acceptance.

Key words: Composite restoration, Oligodontia, Reinforced polyethylene fibers, Thermoformed template.

Introduction:

A tooth is defined as congenitally missing if it has not erupted in the oral cavity and is not visible on the radiograph. All primary teeth should have erupted by the age of 3 and all permanent teeth except third molars between the ages of 12 and 14. Therefore 3-4 year old children are suitable for diagnosis of congenitally missing primary teeth by clinical examination and 12-14 year old children, for diagnosis of permanent missing teeth, excluding the third molars.¹ Dental agenesis is most common developmental anomaly in human, which can occur, in an isolated fashion or as part of a syndrome.²

In the permanent dentition, hypodontia has a prevalence of 1.6% to 9.6%, excluding agenesis of the third molars. Oligodontia has a population prevalence of 0.3% in the permanent dentition. It occurs more frequently in girls at a ratio of 3:2. In the deciduous dentition, hypodontia occurs less often (0.1%-0.9%) and has no significant sex distribution.³ Dental agenesis is classified according to the number of teeth involved and may be classified into hypodontia, oligodontia, and anodontia. Thus, hypodontia is defined as the congenital absence of less than six permanent teeth, full anodontia as the absence of all permanent teeth.⁴

The term oligodontia is generally used when the development of six or more teeth did not occur (KOTSIOMITI et al., 2000), and such a condition may be related to family history, syndromes, traumas, infections, and severe intrauterine or endocrine disorders (KOTSIOMITI et al., 2000; MCDONALD; AVERY, 2000). Oligodontia usually occurs as a part of syndromes. It may occur as a non-syndromic isolated familial trait linked to mutations of the MSX1 and PAX9, or as a sporadic finding.⁵ Non-syndromic oligodontia has been found either sporadic or familial in nature.⁶ Syndromic and non-syndromic form of Oligodontia can be differentiated by ruling out the presence of associated symptoms. Oligodontia presents clinical symptoms depending on the number and location of missing teeth. Positional changes of teeth, variation in their morphology and size may occur in the existing teeth. It may be associated with growth disturbances of the maxillofacial skeleton thus affecting the facial appearance.⁷

The absence of teeth in young patients can cause esthetic, functional, and psychological problems, particularly if the teeth of the anterior region are involved. The most commonly used method of diagnosis of dental anomalies is clinical examination accompanied by radiographic examination.⁸ There are several treatment options for adult and young patients with agenesis although, there are few studies demonstrating treatment in pediatric patients.⁹ The optimal therapy should include an interdisciplinary team approach, and rely on positive interaction between pediatric dentists, orthodontists, oral and maxillofacial surgeons and prosthodontics.¹⁰ The early diagnosis and treatment are important to improve masticatory function, speech, and self-appearance to reduce the psychosocial impact.⁹

This case report describes the dental rehabilitation of a young patient with direct composite restorations using thermoformed templates, which not only act as crown formers to re-establish the anatomical contour of the defective teeth but also control the amount of restorative material used and minimize the patient’s chair side-time. Along with this reinforced polythelene fibers are also used as an interim restoration.

Case Report:

A 13-year-old female patient referred to department of Pedodontics and preventive dentistry, college of dental sciences, Davangere, complaining of spacing between teeth in the upper and lower front region. A detailed history was undertaken with the patient and his legal guardian, who revealed her past medical history, was non-contributory and family history revealed that she was born to non-consanguineous marriage parents with normal delivery and mother did not suffer from any disease during pregnancy, none of the family member had congenitally missing teeth. The patient had no history of trauma but had severe aesthetic dissatisfaction which resulted in several social problems.

On general physical examination her height and weight were normal according to her age and she was well oriented and active. On extra oral examination she was normal in her facial appearance and did not show any physical or skeletal abnormality. She had a mild concave profile, a mild reduction of the lower third of facial height, with a marked nasolabial angle and procumbent lip contours; however, the facial symmetry was not affected. No clicking or crepitus of the temporomandibular joint was detected and masticatory muscles were not sensitive upon palpation.

On intra oral examination, soft tissues examination was normal. Oral hygiene was considered satisfactory. Hard tissue examination revealed presence of erupted 11 permanent teeth and 8 overeretained primary teeth (11,21,24,37,34,33,31,41,42,44,47) 63 and 83 were in grade II mobility. The remaining permanent teeth were missing clinically; she also had upper midline diastema between permanent central incisors, generalized spacing and underdeveloped alveolar ridges in the anterior mandibular region. In addition, no parafunctional habit was present. Suspecting the congenital absence of permanent teeth panoramic radiograph was taken which showed missing teeth; 12,16,17,22,26,27,32,35,36,43,46 [Figure 1], [Figure 2]. There was absence of dental caries and no previous treatment for the missing teeth was done.

A provisional diagnosis of partial anodontia was given with differential diagnosis of ectodermal dysplasia; Rieger syndrome and Witkop syndrome were considered. In view of the oligodontia of permanent teeth, a detailed examination was done to rule out syndromes associated with oligodontia. Paediatric consultation was taken regarding general health status of the patient. Complete set of investigations were done. Routine examination of blood including serum calcium, alkaline phosphate, TSH, T3, T4 was done. The findings of these investigations were within normal range. During physical examination, hairs were not thin and sparse, nails were not brittle and no difficulty in perspiration was seen, which ruled out absence of ectodemaldysplsia. On occular examination, no signs of glaucoma was seen, ruling out Rieger syndrome and Van Der Woude syndrome was ruled out as there was no associated cleft palate or any mucosal cysts in lower lip. Final diagnosis of Non-syndromic partial anodontia/oligodontia was given.

Full mouth rehabilitation was planned; the teeth present were abnormal in morphology and were aesthetically restored after extraction of mobile teeth. The restorations of the defective teeth were carried out in stages. Each treatment session lasted between 1 and 2 hrs depending on the patient’s tolerance and acceptability toward treatment. Problems encountered when attempting to restore the palatal or lingual sites of the affected teeth using composite with free-hand technique so as to create a proper anatomical contour and to obtain a homogenous thickness of the material used. To overcome this, alginate impressions of both the dentitions were taken and stone casts were made. The defective areas of the tooth structure on the stone casts were filled and reconstructed anatomically using inlay wax [Figure 3]. Over the contoured cast, secondary impression was made and final cast was poured with stone.

The reconstructed stone casts were sent to the laboratory for fabrication of transparent thermoform “Biostar” templates that conform to the anatomical shape of the reconstructed crowns. A 0.5mm thickness transparent thermoforming disc made of copolyester was heated up to 170ºc for 50 s and, once the disc softened, it was pressed onto the stone casts. The pressed templates were allowed to cool and later removed and trimmed [Figure 4]. The produced templates act as crown formers to reconstruct the defective teeth. Initially, the upper four permanent incisors were restored. Minimal tooth structure was removed in order to provide additional retentive element to aid adhesion of the restorative material.

Adequate volume of composite material was packed into the template that corresponds to the desired area of teeth to be restored. The template was then placed over the affected teeth and light cured. Upon curing, the template was removed from the teeth and the restored areas were examined for any defectiveness. The composite restorations were polished and contoured using a combination of rotary discs of various grades of polishing burs to create aesthetically pleasing restorations. Due to congenitally missing 43 there was a wide gap present between 42 and 44 which was aesthetically not pleasing even after restoring all 4 lower anteriors.

Therefore fabrication of a fiber reinforced composite (FRC-RIBBOND) space maintainer using the acrylic tooth was planned. An acrylic crown of desired size and form was selected. Horizontal groove was made in the middle third of the crown palatal to at nearly 2-mm depth using a round diamond bur (No. 8) to accommodate the thickness and width of Ribbond. The required length of the fiber (Ribbond) was measured using dental floss between the adjacent teeth extending from distal surface of 42–44. Enamel on the lingual surfaces of both the acrylic crown and adjacent teeth were etched with 37% phosphoric acid for 20 s (Scotchbond Etchant; 3M ESPE, St Paul, MN, USA). The fiber soaked in bonding agent was adapted using a tweezer onto the acrylic crown to ensure that it fits into the groove and light cured.

Thereafter, it was coated with flowable resin (3M, ESPE) and light cured (Elipar 2500, Halogen Curings Light; 3M ESPE) from multiple directions for 20 s, which increased the mechanical strength of the space maintainer. Fiber-adapted acrylic crown was then positioned in the edentulous space and adapted to the adjacent teeth. Flowable composite application was initiated starting from the distal aspects of 42 – 44 and cured. This enabled us to stabilize the acrylic crown and check for its correct position. After confirming the correct position, the remaining fiber was coated with composite and cured. Finally, occlusion was adjusted; finishing and polishing (Sof-Lex; 3M ESPE) was performed [Figure 5]. The patient was informed about the importance of good oral hygiene and regular follow up. Follow up of 6 months revealed good retention and satisfactory esthetics [Figure 6].

Discussion:

Oligodontia (severe partial anodontia) is a developmental dental anomaly refers to congenital lack of more than six teeth excluding third molars. The exact etiology for oligodontia is unknown. Various factors have been described in the literature.¹¹ Oligodontia condition should not be neglected as it may result in various disturbances like abnormal occlusion, altered facial appearance which may cause psychological distress, difficulty in mastication and speech especially during the formative age. Thus early diagnosis and treatment of these patients is very important.

The treatment of oligodontia could be challenging if there are several missing teeth and malocclusion present. Treatment planning should take into account the age of the patient, number and condition of retained teeth, number of missing teeth, condition of supporting tissues, the occlusion and interocclusal space.¹² The treatment should be planned thoughly as it needs multidisciplinary appoarch. Treatment options include orthodontic therapy, speech therapy, implants, adhesive techniques, removable partial prostheses, fixed prostheses and over dentures to ensure adequate and durable results.^13,14 Most young patients require the fabrication of a partial denture as an interim procedure before definitive restoration is planned. Early treatment improves speech and masticatory function in addition to psychological implications that may greatly help in regaining self-confidence of the young patient.

Prosthodontic rehabilitation is fundamental in these situations that allow the child to lead a normal life without damaging self-esteem or psychological development and ensuring that behavior remains unaffected.¹⁵ The prosthetic rehabilitation using complete dentures had lot of benefits including better social acceptance, self-esteem and restoring normal functional demands of the patient such as chewing as showed in case report by Manu R et.al.¹⁶ The age of the patient for the present case was carefully considered, since younger adults require special attention with regard to their psychological and emotional condition, and particularly the anatomical changes related to facial growth.

In the present case, the patient was in an early adolescent stage. The posterior teeth were still in the erupting phases and, therefore, restoration of the defective teeth with permanent and complex restorations was contraindicated. Composite restorative material was selected as a suitable replacement of the defective structures because of its esthetics and high sustainability and also it provides excellent conservative transitional treatment.¹⁷ Initially, the defective anterior teeth were restored using a free-hand technique. However, due to small inaccessibility on the palatal and lingual aspects of the teeth, it was not possible to carry out proper restorations. The time spent to restore a single tooth was prolonged and each restored tooth needed more trimming and polishing. Thus, these templates act as an adjunct to allow easy restoration of the defective teeth. Similarly with the present report, this template method has also been proven successfully in a case report by Sockalingam et.al.¹⁸

Satisfactory restorations of the lost teeth space present in between mandibular anterior teeth was a challenge to the paediatric dentist as there are limited treatment options in children.¹⁹ While long-term single tooth replacement options such as conventional fixed bridges, resin bonded dentures, removable dentures, and single tooth implants may be the treatment choice for adults, they have limited use in children. As in growing children, gingival and bone architecture undergoes changes demanding provisional restorations to achieve good esthetics and maintain edentulous space until definitive restoration is planned.²⁰ For the success of single tooth restoration bonding of the restoration to adjacent teeth is important. So grooving, use of etching, and bonding procedures increase retention.¹⁹ In the present case, a groove was made on the lingual surface of the acrylic tooth, 42 and 44 to enhance maximum adhesion, durability, and also to provide mechanical support.

Acrylic restoration provides several advantages such as desirable esthetics (a sense of natural feeling), ease of use, and direct bonding to tooth structure with reduced cost. Besides, it provided better gingival health (lesser plaque retention), greater patient–parent satisfaction, and less clinical time in acquisition of natural crown anatomy.¹⁹ Minimally invasive adhesive restorations using Ribbond was selected in the present case, as it is an ultrahigh molecular weight polyethylene fiber having virtually no memory, translucent, colorless and disappears within the composite or acrylic without show through offering excellent esthetics. Hence, it adapts to the contours of the teeth and dental arch. Children with oligodontia appear to have worse oral health related quality of life than children with dental decay and malocclusion.²¹ However long-term studies are required to evaluate their prolonged use.

Conclusion:

1. Child patient suffering from oligodontia may have severe functional, esthetic and psychological problems especially during the early years of life as reported in the present case.
2. Thus, these thermoformed templates act as an adjunct to allow easy restoration of the defective teeth.
3. The FRC space maintainer technique described in this case can satisfactorily restore esthetics and function and hence suggested as an alternative to conventional techniques. However, it can be considered as an interim treatment until a definitive restoration can be performed.

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