Amelogenesis imperfecta and localised aggressive periodontitis: A rare clinical entity.

This case report presents two female patients whose chief complaint was discoloration of teeth. On careful clinical examination it was found that the patients had features of amelogenesis imperfecta and localised aggressive periodontitis. This article will give an insight of clinical and radiographic features of amelogenesis imperfecta with localised aggressive periodontitis, which is a rare clinical entity.

INTRODUCTION

Enamel hypoplasia (EH) is a defect in tooth enamel that results in less quantity of enamel than normal.[1]

The defect can be a small pit or dent in the tooth or can be so widespread that the entire tooth is small and/or malformed. This type of defect may cause tooth sensitivity, may be unsightly or may be more susceptible to dental caries. EH can occur on a single tooth or on multiple teeth. It can appear white, yellow or brownish in color with a rough or pitted surface. In some cases, the quality of the enamel is affected as well as the quantity.

Environmental and genetic factors that interfere with tooth formation are thought to be responsible for EH. This includes trauma to the teeth and jaws, intubation of premature infants, infections during pregnancy or infancy, poor pre-natal and post-natal nutrition, hypoxia, exposure to toxic chemicals and a variety of hereditary disorders. Frequently, the cause of EH in a particular child is difficult to determine.[2]

This case report presents with two cases of amelogenesis imperfecta as an example of a hereditary disorder.

CASE REPORTS

Case 1

A 14–year-old female patient visited the Department of Periodontics at the Oxford Dental College and Hospital with a chief complaint of discoloration of teeth. The patient reported that her teeth were at this state from the time of eruption and her deciduous teeth too had appeared the same. She was systemically healthy and gave a family history that revealed her mother and younger sister also had similar discoloration of teeth. The patient did not have any para-functional habit. Her oral hygiene habits involved brushing once a day using a medium brush with the horizontal method of brushing.

Intraoral hard tissue examination revealed presence of full complement of teeth. All teeth had yellowish discoloration with some patches of brown color in a few teeth. The patient had a class I malocclusion with a cross bite in relation to the first premolar on both sides. The occlusal surface of both the upper and lower molars showed severe attrition as a result of which the dentine was exposed. The second premolars of both the upper and lower jaws showed varying degrees of attrition [Figure 1a–e].

Figure 1

(a) Upper and lower teeth showing brownish discoloration. Gingiva appears moderately inflamed (b) Moderate gingival inflammation in relation to the interdental papilla of upper and lower premolars, also note the crossbite between the upper and lower right first premolars (c) Moderate gingival inflammation in relation to the interdental papilla of upper and lower premolars, also note the crossbite between upper and lower left first premolars (d) Severe attrition in upper right and left first molars with dentine being exposed (e) Severe attrition in lower first and second molars on both the sides with dentine being exposed (f) Deep periodontal pocket measuring 8 mm in relation to mesial surface of 36 (g) Deep periodontal pocket measuring 8 mm in relation to mesial surface of 46 (h) Orthopantomogram showing pulp stones with most of the teeth, loss of cusp tips with respect to the upper and lower molars. Bone loss in relation to the mesial surfaces of all the first molars, indicative of localised aggressive periodontitis (i) Functional and esthetic rehabilitation of patient's teeth with ceramic crowns

The oral hygiene status of the patient was good with minimal plaque scores. The gingiva showed minimal inflammation. On detailed periodontal examination there were deep periodontal pockets in relation to the mesial surface of all the first molars. There was no furcation involvement and mobility associated with these teeth [Figure 1f and g].

An orthopantomogram and an intraoral periapical radiographs in relation to all the first molars were taken. The orthopantomogram revealed that the enamel was very thin generally and even absent in relation to the molars of both upper and lower jaw. The dentine appeared normal and distinct from the enamel. All the molars showed the presence of pulpal calcifications in the pulp chamber [Figure 1h].

A diagnosis of amelogenesis imperfecta and localised aggressive periodontitis were made after a detailed examination of the teeth and periodontium. The diagnosis of amelogenesis imperfecta was further supported by the family history.

The treatment involved scaling and root planing, followed by antibiotic therapy with 100 mg Doxycycline (loading dose 200 mg on the first day followed by 100 mg once a day for 13 days). Periodontal flap surgery was done in relation to 36 and 46. Bio-Oss™ bone graft was placed in both the sites to attempt regeneration in relation to the intrabony defects in relation to these teeth. The probing depths in relation to the upper first molars reduced following non-surgical therapy and so further periodontal surgery was not needed. After 3 months of completion of the periodontal therapy, the patient's teeth were restored with full ceramic crowns. The patient was on a regular maintenance programme and has been followed up for 3 years [Figure 1i].

Case 2

A 19-year-old female patient presented with discoloration and sensitivity of teeth. The teeth were discolored since eruption, and the deciduous teeth presented the same problem before they were exfoliated. The patient was apparently systemically healthy except for slight growth retardation.

Hard tissue examination showed all teeth except the 3rd molars to be present. The teeth were brown and pitted, with the enamel presenting a cheesy consistency in the cervical areas of many teeth. Most teeth in the mouth were carious and the oral hygiene was generally poor. The gingiva was erythematous in all marginal and papillary areas with a soft and edematous consistency, with bleeding on probing in all areas. Exudation was positive in the anterior and bicuspid areas of the maxillary and mandibular arches. Deep pockets >10 mm were present in the upper central incisor region. The upper right first molar exhibited severe mobility with grade 3 furcation involvement. The mandibular teeth did not show any significant probing depths [Figure 2a–c].

Figure 2

(a) Note the absence of enamel in the upper and lower teeth and complete absence of Cuspal tips in the lower teeth due to severe attrition. (b) Proximal caries in relation to mesial surfaces of both the upper lateral incisors. Presence of deep periodontal pocket in relation to the distal surface of right central incisor (c) The gingiva appears moderately inflammed with bulbous interdental papillae and rolled margins. Presence of deep periodontal pocket in relation to the distal surface of left central incisor

On radiographic examination the teeth generally had a thin layer of enamel, in relation to the upper and lower molars the enamel was absent due to severe attrition. The lower left first molar presented with horizontal bone loss and the upper incisors and right first molar presented with vertical bone loss [Figure 3].

Figure 3

Orthopantomogram shows proximal caries in relation to lower first molars and initial bone loss in relation to the distal surfaces of both molars

Based upon these clinical findings a diagnosis of localized aggressive periodontitis associated with amelogenesis imperfecta was given. For unknown reasons the patient, however, did not return for the treatment.

DISCUSSION

Amelogenesis imperfecta is a composite of hereditary disorders that primarily affects enamel of both deciduous and permanent teeth. There is no systemic involvement. Studies have reported the prevalence of amelogenesis imperfecta to be 1 out of 700 to 1 out of 14000 depending on the population examined. Many cases are inherited as autosomal dominant, autosomal recessive or as an X-linked trait. There can be three basic types namely hypoplastic (60 to 70%), hypomaturation type (20 to 40%), and hypocalcification type (7%). Witkop and Sauk sub classified amelogenesis imperfecta as shown in Table 1.[34]

Table 1

Classification of amelogenesis imperfecta by Witkop and Sauk

The clinical presentation depends on the type of amelogenesis imperfecta; varying from the mild hypomaturation ‘snow capped’ enamel to the more severe hereditary hypoplastic with thin, hard enamel, which has a yellow brown appearance. In the hypoplastic type, the enamel is well mineralized but its amount is reduced. The teeth appear to be normally hard, although the enamel in the deeper portions may be poorly mineralized. Schulze C recorded that the teeth could be yellow, yellowish red, or yellow-brown. Radiographs exhibit a thin peripheral out line of radio dense enamel, and low or absent cusps. In the hypomaturation type, the affected teeth exhibit mottled, opaque white, brown-yellow discoloured enamel, which is softer than normal. In radiographs the thickness of enamel is normal but density is the same as that of dentine. The hypocalcified type shows pigmented, softened, and easily detectable enamel. Radiographs show that enamel thickness is normal but its density is even lesser than that of dentine.[5]

In this report the first patient's teeth were conformed to the description of hypoplastic type of amelogenesis imperfecta, both clinically and radiographically. The second patient's teeth conferred to the description of hypomineralized type of amelogenesis imperfecta because of the cheesy consistency and ease with which the enamel could be detached.

The other dental manifestations include pulpal calcification, taurodontism, root malformation, impaction of permanent teeth, progressive root and crown resorption, congenital missing teeth, and anterior open bite. The first patient's radiograph showed presence of pulpal calcifications in most of the teeth. The second patient had spacing between the teeth and carious lesions.[5]

Histologically there is a disturbance in the differentiation or visibility of ameloblasts in the hypoplastic type, and this is reflected in defects in matrix formation up to and includes total absence of matrix. In the hypocalcification type, there are defects of matrix structure and of mineral deposition. Finally in the hypomaturation types, there are alterations in enamel rod and rod sheath structures.[6]

The diagnosis is made by eliminating environmental factors like fluorosis, trauma, exanthematous fevers, hypocalcemia, or hypoplasia due to calcium deficiency as a possible cause, recognising the in heritance pattern, and phenotype. Radiographs including full mouth intraoral periapical radiographs, orthopantomogram will play a vital role in diagnosing the difference in density of enamel in amelogenesis imperfecta and normal patients along with dentine thickness, density, pulp canals, and root length.[7]

Treatment planning for patients with amelogenesis imperfecta is related to the age, socioeconomic factors, the type, and severity of the disorder and intraoral structures. An interdisciplinary approach may be required to evaluate, diagnose, and resolve the esthetic problem. As was done with the first case where the patient underwent prosthetic rehabilitation for esthetic and functional purpose.[7]

Localised aggressive periododntitis previously known as localised juvenile periodontitis is one of the rapidly progressive periodontal diseases. It is characterised by pattern of rapid vertical loss of alveolar bone around more than one permanent tooth mainly the permanent first molars and incisors. The severity of the destruction is not proportional to the mass of plaque or calculus present.[89]

Clinical picture of localised aggressive periodontitis is characterised by an insidious onset during the circumpubertal period. The most striking feature is that during the early stage there is lack of clinical sign of inflammation. There is severe periodontal destruction which is evidenced by deep periodontal pocket formation, tooth mobility, and pathological migration. In advanced stages diastema formation, sensitivity to thermal and tactile stimuli from denuded root surface may appear. Deep dull radiating pain may occur with mastication due to irritation of supporting structures.[1011]

Radiographic findings show vertical bone loss in relation to the first molars and/or incisors. In the classic localised juvenile periodontitis; an arc shape bone loss pattern is seen extending from the distal of the second premolar to the mesial of the second molar.

The diagnosis is made based on clinical examination, radiographic appearance, and lack of systemic involvement. Treatment of localised aggressive periodontitis involves the combination of scaling and root planing along with systemic antibiotic therapy followed by periodontal flap surgery in areas of persisting deep pockets. Teeth with hopeless periodontal prognosis are usually extracted.

Amelogenesis imperfecta with localised aggressive periodontitis is a rare clinical entity. A linkage study on a dentinogenesis imperfecta-III kindred with juvenile periodontitis (JP) has also suggested that this disease may be linked to the long arm (q) of human chromosome 4. Furthermore, the autosomal domininant local hypoplastic form of amelogenesis imperfecta has also been recently linked to a 15.2 cM region of human chromosome 4 in the region 4q11-4q13. The proposal is based on the following hypotheses: that mutations within the human ameloblastin (AMBN) gene localized to 4q21 causes the local hypoplastic form of ADAI. Thus suggesting that there may be a genetic link between amelogenesis imperfecta and localized aggressive periodontitis, this however needs further investigation.[12]