Multiple odontogenic keratocysts in Ehlers-Danlos syndrome: a rare case report.

BACKGROUND: An odontogenic keratocyst is a lesion characterized by aggressive and infiltrative growth. The lesion is characterized by the existence of satellite microcysts (microtumours) and frequent recurrence (up to 30%). Ehlers-Danlos syndrome is a condition in which collagen production or its post-translational modifications are affected. Defects in connective tissues cause symptoms, which range from mild joint hypermobility to life-threatening complications. CASE PRESENTATION: We present an extremely rare case of an 11-year old girl with Ehlers-Danlos syndrome and coexistence of multiple odontogenic keratocysts. CONCLUSIONS: This case shows mainly atypical or rare association between multiple odontogenic keratocysts and Ehlers-Danlos syndrome.

Odontogenic keratocysts in the Basal Cell Nevus (Gorlin-Goltz) Syndrome associated with paresthesia of the lower jaw: Case report, retrospective analysis of a representative Czech cohort and recommendations for the early diagnosis.

OBJECTIVES: Identification of early presenting signs of the Basal Cell Nevus (BCNS; synonyme Gorlin-Goltz) syndrome, which is associated with a principal triad of multiple basal cell nevi, jaw odontogenic keratocysts, and skeletal anomalies, in stomatological and neurological practices. Proposal of multidisciplinary diagnostic algorithm comprising other medical specialists, including pathology, imaging, laboratory and molecular analyses based on the study outcomes. DESIGN: Case report of a male patient reporting paresthesia of their lower jaw, with right facial asymmetry (maxilla and mandible) and radiological detection of large osteolytic lesions in both jaws, including a retrospective analysis of a representative Czech cohort with BCNS from within the last decade. SETTING: Clinical, imaging and laboratory analyses were carried out at a national tertiary centre. RESULTS: A multidisciplinary clinical approach followed by surgical management lead to the identification of odontogenic cysts, which were substantiated by histological examination. DNA sequencing of the PTCH1 gene detected a c.2929dupT resulting in p. Tyr977Leufs*16 pathogenic variant. This finding confirmed the clinical and laboraoty diagnosis of BCNS. Parental DNA analysis showed that this causal genetic defect arose de novo. Surgical management and orthodontic therapy were successful. CONCLUSIONS: Analysis of the reported case and retrospective data analysis provided evidence that paresthesia of the lower jaw should be considered as one of the early presenting signs of this rare disorder in stomatological and neurological practice. Obtained results allowed us to formulate recommendations for diagnostic practice in stomatology and neurology.

[Difficulties in differential diagnosis of dentin dysplasia. Case report]. / A dentin dysplasia differenciáldiagnosztikai nehézségei. Esetismertetés.

In cases of periapical lesions of unknown origin we have to keep in mind the possibility of dentin dysplasia. From the differential diagnostic point of view of differential diagnosis it is important to recognize this disease as it significantly influences the treatment modality. It is an anomaly of unknown etiology that could affect both deciduous and permanent dentition. Dentin dysplasia presentation varies clinically and radiologically. A rare manifestation which affects 1: 100000 patients is spontaneously occurring either as periapical abscess or odontogenic cyst. The affected teeth could become mobile and eventually lost. Dentin dysplasia is a genetic disease which shows autosomal dominant inheritance and characterized by abnormal formation of dentin structure which occurs during tooth development. For this article we have reviewed available literature and PubMed database. Dentin dysplasia increases the risk of early tooth loss and associated with it esthetic and functional disturbances. As a result it can influence the psychological and social status of the patients and affect their quality of life.

Man with macrocephaly, learning disability and multiple basal cell carcinomas.

Gorlin syndrome is a rare genetic condition in which patients may develop medulloblastomas, jaw cysts and basal cell carcinomas and show congenital skeletal malformations. If left undiagnosed, Gorlin syndrome can have a number of negative consequences. Early diagnosis and good follow-up is important for all patients with rare disorders. We wish to make doctors and dentists aware of Gorlin syndrome so that, whenever the syndrome is suspected or a patient has been diagnosed, the patient is referred for assessment, treatment and follow-up by specialists who know the disorder well. Dermatology departments at university hospitals and departments of medical genetics have a key role to play in assessment and follow-up. A national support group for Gorlin syndrome has been established, consisting of a dermatologist, oncologist, geneticist, paediatrician, specialist dentist, ophthalmologist, orthopaedic surgeon, plastic surgeon, oral and maxillofacial surgeon and counsellors. Patients, relatives and health professionals can contact the Centre for Rare Disorders directly for information about Gorlin syndrome, or to be put in touch with members of the group.

[Pediatric keratocystic odontogenic tumor and nevoid basal cell carcinoma syndrome. Predictive factors for recurrence and aggressiveness]. / Tumeurs kératokystiques odontogènes de l'enfant et syndrome de Gorlin. Comment expliquer les récidives et l'agressivité des lésions ?

INTRODUCTION: Keratocystic odontogenic tumors (KOT), as complications in Nevoid Basal Cell Carcinoma Syndrome (NBCCS), occur early (before 20 years of age) and are usually more aggressive. The aim of this retrospective study was to determine the clinical, histological, and genetic phenotype, of these lesions and to define predictive features of aggressiveness. PATIENTS AND METHODS: We retrospectively studied five patients presenting with one or several KOT with NBCCS. We collected their clinical, radiological, and therapeutic data, rate of recurrence or new localization. Anatomopathological examinations were reviewed systematically. Somatic PTCH, SMO and SMAD 4 sequencing were completed. RESULTS: The average age at diagnosis was 11.2 years. The average number of KOT was 3.2 most often located in the molar region. All the cysts were enucleated. Anatomopathological examination revealed the presence of satellite cysts and daughter cysts and epithelial expansion in more than 80% of cases. No somatic mutation was observed among KOT. DISCUSSION: KOT develop in the first 10 years, in patients presenting with NBCCS, and recurrence is observed in the second and third decade. KOT are typically aggressive and have a tendency to recur, especially in patients with NBCCS. Anatomopathological examination may be predictive of the lesion's aggressiveness. Understanding the genetic and immunological mechanisms should open the way for new medical treatment.

Multidisciplinary approaches to odontogenic lesions.

PURPOSE OF REVIEW: To give an overview of technical considerations and relevant literature in the management odontogenic pathology with involvement of the maxillary sinus. RECENT FINDINGS: Infections, cysts, benign neoplasms (odontogenic and nonodontogenic), and inflammatory conditions impact the maxillary sinus in various ways, could result in significant expansion within the maxillary sinus and significant infections. SUMMARY: This manuscript provides an overview of common pathologic entities of the oral cavity proper that impacts the maxillary sinus health, with discussion of the role of the otorhinolaryngologist and the dental specialist.

[Recurrent maxillo-mandibular odontogenic keratocysts: prevention and treatment]. / Kératokystes odontogéniques maxillo-mandibulaires récidivants: prévention et traitement.

Keratocyst is an odontogenic cyst with an aggressive clinical behavior and a high recurrence rate. Our work describes a 62 year-old patient with Gorlin's syndrome presenting advanced recurrent maxillo-mandibular keratocysts. He already had multiple resections of these lesions. Early diagnosis and treatment of keratocysts is crucial to reduce the extension of the cysts and minimize their malignant transformation especially when they are part of a Gorlin's syndrome.

Recurrence of nonsyndromic odontogenic keratocyst after marsupialization and delayed enucleation vs. enucleation alone: a systematic review and meta-analysis.

PURPOSE: This study was conducted in order to determine whether marsupialization before definitive enucleation of nonsyndromic odontogenic keratocysts (OKCs) is capable of decreasing the recurrence rate more effectively than just enucleation. METHODS: We searched MEDLINE, Web of Science, Scopus, and Cochrane Library, until August 5th of 2017 for original studies reporting on the treatment of OKCs with and without previous marsupialization and the related recurrence rate. All records and data were independently assessed, meta-analysis was performed, and the odds ratio of recurrence was the effect measure; P value for the summary effect of < 0.05 was considered statistically significant. RESULTS: The 748 records retrieved were reduced to 6 studies to be qualitatively assessed and 5 studies were included in the meta-analysis. The overall odds ratio of 0.57 [0.25-1.28] of the pooled values pointed that marsupialization reduced the recurrence rate in comparison to just enucleation; however, the P value showed that there is no strong evidence to support this statement. CONCLUSIONS: Marsupialization followed by enucleation after 12 to 18 months reduces the recurrence rate, but more studies are necessary to support this statement.

[Odontogenic keratocyst related to a Gorlin syndrome: a case report]. / Kératokystes odontogènes dans le cadre d'un syndrome de Gorlin: à propos d'un cas clinique.

We are reporting here, the case of a 9 years old boy with Gorlin syndrome diagnosis. Current knowledge on this syndrome is reviewed.

An Update of Gorlin-Goltz Syndrome.

Gorlin-Goltz syndrome encompasses a variety of clinical signs and symptoms including important oral manifestations which general dental practitioners should be aware of. In light of the risk of malignancy it is important to be aware of this syndrome and recognise the need for early referral for multidisciplinary management. This paper aims to discuss Gorlin-Goltz syndrome, the pathophysiology of the condition and address the wide range of clinical manifestations. The author will pay particular attention to the oral manifestations of the condition and the management of such anomalies.

Deep neck infection in patients with and without human immunodeficiency virus: a comparison of clinical features, complications, and outcomes.

We retrospectively studied the clinical features, complications, and outcomes of deep neck infections in 31 adult patients with the human immunodeficiency virus (HIV) (HIV group) and 192 patients without (non-HIV group). In the HIV group, the cause was more likely to be odontogenic (21 (68%) compared with 90 (47%); odds ratio (OR) 2.38; 95% CI 1.06 to 5.32). In both groups, the parapharyngeal, submandibular, and masticator spaces, were those most often involved. However, in the HIV group, Ludwig's angina was common, and was the main cause of airway obstruction. Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa were most often isolated in the HIV group. Upper airway obstruction tended to be more common in the HIV group (5/31 compared with 13/192). These patients also had a higher risk of other complications (sepsis, mediastinitis, jugular vein thrombosis, and pneumonia) (6/31 compared with 12/192; OR 3.60; 95% CI 1.24 to 10.45), a higher mortality rate (3/31 compared with 2/192), and longer hospital stay (19days compared with 16 days). Factors associated with an increased risk of complications in this group were an age of 55 years or over and a CD4 count of less than 350 cells/mm3. Deep neck infections in these patients are more severe. Dental health care, appropriate empirical antibiotics, early detection, and management of the airway and complications, may improve outcomes.

Glandular Odontogenic Cyst in Maxilla: A Case Series.

Glandular odontogenic cyst is rare phenomenon with 0.012% to 0.03% frequency of all jaw cysts and worldwide prevalence of 0.17%. Diagnosis of Glandular odontogenic cyst, well known for its aggressive growth potential and high rate of recurrence, is very crucial. This report presents cases of two 50-year old individuals with Glandular odontogenic cyst presenting as a radiolucent lesion of maxilla. Final diagnosis was made on the basis of histopathological features and further confirmed by immunohistochemical analysis. Keywords: histology; immunohistochemistry; odontogenic cyst.

Angiogenesis concept in odontogenic keratocyst: A comparative study.

CONTEXT: Recent reports have indicated that angiogenesis possibly affects the biologic behavior of the lesions. AIM: Given the different clinical behaviors of odontogenic keratocyst (OKC), the present study was undertaken to evaluate the concept of angiogenesis in pathogenesis and clinical behavior of OKC. SETTING AND DESIGN: This experimental study was carried out on 22 and 24 samples of OKCs and dentigerous cysts (DCs), respectively. METHODS: Immunohistochemical staining was approached using CD34 and vascular endothelial growth factor (VEGF) antibodies. The expression of VEGF was first reported by determining the counts of stained cells, including epithelial cells, fibroblasts, and endothelial cells, followed by the percentage of stained cells in each sample based on a 0-2 scoring system. The counts of CD34+ cells were reported in each group in the form of means ± standard deviations. In addition, the patterns of blood vessels in the samples prepared from the walls of both cysts were evaluated. STATISTICAL ANALYSIS USED: Mann-Whitney U-test, Chi-squared test, and t-test were used for analysis of data, and statistical significance was defined at p < 0.05. RESULTS: The expression percentage and scores of VEGF and the mean expression rate of CD34 were significantly higher in OKCs than DCs (p = 0.045, 0.000, and p = 0.58). Finally, there was a strong correlation between the expressions of the two markers in the samples (Correlation coefficient = 0.766). CONCLUSION: The present results indicate the angiogenesis may play an important role in the pathogenesis and the unique clinical behavior of OKC.

Analysis of odontogenic cysts of the jaws.

In this study 850 cases of odontogenic cysts of the jaws, treated in Kaunas University of Medicine Hospital during the period of 1986-2004, were analyzed in order to evaluate the incidence of these cysts and other aspects of clinical and therapeutic interest such as their clinical features, changes they caused in the facial and mandible structures, and the teeth that had caused the pathology. Case histories of 455 men and 395 women had been analyzed. The age of the patients varied from 4 to 87 years, with the average of 35.8. More than half of the diagnosed cysts (63%) were present in the maxilla, 37% of them--in the mandible. The common complaints of the patients were bump, swelling, pain, discharge leaking from the fistula or alveolus after tooth extraction, increased teeth mobility, paresthesia; changes in the maxillofacial system - intraoral or facial asymmetry, inflated bone with sensation of an egg shell cracking revealed under palpation, swelling at the mucofacial fold, mobile teeth and fistula. While comparing the causative groups of antagonistic teeth in the maxilla and mandible, we found the proportion to be (in order from the right to the left): molars--1:1, premolars 1.3:1, fore teeth--3.3:1, fore teeth 3.8:1, premolars 1.2:1, molars 0.7:1. Odontogenic cysts may be present in both sexes; maxillary cysts are 1.5 times as frequent as mandibular cysts. The pathology may equally affect both sides of jaws, most cysts being diagnosed in the maxillary fore teeth area from tooth 13 to tooth 23. The following pairs of changes in maxillofacial system are frequently present: inflated body of bone or alveolus--increased mobility of teeth; the formed fistula--swelling at the mucofacial fold, swelling at the mucofacial fold--pain. The applied treatment of cysts was surgical--cystotomy or cystectomy.

Rapid cystic development in relation with an impacted lower third molar: a case report.

Cystic changes can arise in relation with unerupted lower third molars. This case report describes a large odontogenic keratocyst (OKC) which developed rapidly and aggressively over a short period of 2 years and presented with acute symptoms. The development of a large OKC over the mandible is evidenced by radiographs taken 2 years apart. The OKC was enucleated and the residual cavity was treated with Carnoy's solution and packed with bismuth iodoform paraffin paste dressing. The impacted third molar and second molar associated with the lesion were also extracted. This case illustrates how rapidly a cyst can develop in association with a previously asymptomatic, unerupted tooth and how quickly a radiographic diagnosis can become out of date. As such, the authors recommend the use of repeated radiographs for monitoring unerupted teeth at a tighter time frame of 6 to 12 months.

Diagnóstico precoce e tratamento da síndrome de Gorlin-Goltz: acompanhamento de oito anos / Diagnóstico precoz y tratamiento del síndrome de Gorlin-Goltz: seguimiento de ocho años / Early diagnosis and treatment of Gorlin-Goltz syndrome: eight-year follow-up

RESUMO Introdução: A síndrome de Gorlin-Goltz, conhecida também como síndrome do Carcinoma Basocelular Nevóide, é um transtorno hereditário autossômico dominante de alta penetrância e expressividade variável. Foi primeiramente descrita por Jarisch em 1894 e, em 1960 Gorlin e Goltz relacionaram o conjunto de doença de casos anteriormente relatados na literatura, concluindo que se tratava de uma síndrome caracterizada por uma tríade (carcinomas basocelulares, queratocistos odontogênicos múltiplos e anomalias esqueléticas). Atualmente, sabe-se que um amplo espectro de outras manifestações sistêmicas pode estar presente como neurológicas, oftálmicas, genitais, cardiovasculares e endócrinas. Objetivo: O presente artigo tem como objetivo relatar um caso clínico de síndrome de Gorlin-Goltz com proservação de oito anos, bem como destacar a importância do Cirurgião-Dentista no diagnóstico precoce e tratamento da síndrome. Caso clínico: Paciente 10 anos, sexo masculino, compareceu em fevereiro de 2004 ao Serviço de Estomatologia e Cirurgia Bucomaxilofacial da Santa Casa de Misericórdia de São Felix, Bahia, Brasil, acompanhado de sua avó, que relatava a seguinte queixa: "Os dentes do meu neto estão tortos". Ao exame físico foi observado aumento do volume do lado direito da face, hipertelorismo, base nasal larga, bossa frontal, leve prognatismo mandibular e dedos dos pés encurtados. Ao exame físico intrabucal foram identificados dentes fora de posição e desvio de linha média. O paciente foi acompanhado por 8 anos e, durante este tempo, foram realizados exames imaginológicos observando grandes áreas de lesões radiolúcidas com recidiva. O diagnóstico conclusivo de Queratocisto Odontogênico foi então comprovado no exame histopatológico, a hipótese diagnóstica de síndrome de Gorlin-Goltz foi então confirmada. O paciente foi encaminhado para avaliação genética e atualmente encontra-se em proservação na Universidade Estadual de Feira de Santana, Bahia. Conclusão: É essencial o acompanhamento multidisciplinar e a longo prazo nos casos dessa síndrome, oferecendo melhor qualidade de vida a esses pacientes(AU)

RESUMEN Introducción: El síndrome de Gorlin-Goltz, conocido también como síndrome del carcinoma basocelular nevoide, es un trastorno hereditario autosómico dominante de alta penetración y expresividad variable. En 1960, Gorlin y Goltz relacionaron el conjunto de enfermedades de casos con anterioridad informados en la literatura, y concluyeron que se trataba de un síndrome caracterizado por una tríada (carcinomas basocelulares, queratocistos odontogénicos múltiples y anomalías esqueléticas). Actualmente, se conoce que un amplio espectro de otras manifestaciones sistémicas puede estar presente, como neurológicas, oftálmicas, genitales, cardiovasculares y endocrinas. Objetivo: describir un caso clínico de síndrome de Gorlin-Goltz con seguimiento de ocho años, así como destacar la importancia del dentista en el diagnóstico precoz y tratamiento del síndrome. Caso clínico: Paciente de 10 años, de sexo masculino, acudió en febrero de 2004 al Servicio de Estomatología y Cirugía Maxilofacial de la Santa Casa de Misericordia de São Félix, Bahia, Brasil, acompañado de su abuela, que refería: "Los dientes de mi nieto están torcidos". En el examen físico se observó aumento del volumen del lado derecho de la cara, hipertelorismo, base nasal ancha, bóveda frontal, leve prognatismo mandibular y dedos de los pies acortados. En el examen físico intrabucal se identificaron dientes fuera de posición y desviación de línea media. El paciente tuvo seguimiento por ocho años y durante este tiempo se realizaron exámenes imaginológicos en los que se observaron grandes áreas de lesiones radiolúcidas con recidiva. El diagnóstico conclusivo de queratocisto odontogénico fue comprobado en el examen histopatológico; la hipótesis diagnóstica del síndrome de Gorlin-Goltz fue entonces confirmada. El paciente fue dirigido para evaluación genética y actualmente se encuentra en seguimiento en la Universidad Estadual de Feira de Santana, Bahia. Conclusiones: Es esencial el seguimiento multidisciplinario y a largo plazo en los casos de este síndrome, a fin de ofrecer mejor calidad de vida a esos pacientes(AU)

ABSTRACT Introduction: Gorlin-Goltz syndrome, also known as nevoid basal cell carcinoma syndrome, is an autosomal dominant inherited disorder of high level penetrance and variable expressiveness. In 1960 Gorlin and Goltz listed the disease cases previously reported in the literature, concluding that it was a triad syndrome (basal cell carcinomas, multiple odontogenic keratocysts and skeletal anomalies). It is now known that a broad spectrum of other systemic manifestations may be present, such as neurological, ophthalmic, genital, cardiovascular and endocrine. Objective: Describe a clinical case of Gorlin-Goltz syndrome and its eight-year follow-up, and highlight the importance of the dentist in the early diagnosis and treatment of the syndrome. Case report: A 10-year-old male patient attended the Oral and Maxillofacial Surgery Service of Santa Casa de Misericordia Hospital in Sao Felix, Bahia, Brazil, in February 2004, accompanied by his grandmother, who reported that her grandson's teeth "were crooked". Physical examination revealed an increase in the volume of the right side of the face, hypertelorism, broad nasal base, frontal bossing, mild mandibular prognathism and shortened toes, whereas oral examination found ill-positioned teeth and midline deviation. The patient was followed up for eight years, and during this time imaging tests were performed which showed large areas of recurrent radiolucent lesions. Diagnosis of odontogenic keratocyst was verified by histopathological examination, confirming the diagnostic hypothesis of Gorlin-Goltz syndrome. The patient was referred for genetic evaluation and is currently being followed up at the State University of Feira de Santana, Bahia. Conclusions: Multidisciplinary long-term follow-up is essential in cases of this syndrome to improve the quality of life of patients(AU)

The pathology of head and neck tumors: cysts of the jaws, part 12.

The jaws are unique bones of the skeleton because of their intimate involvement with tooth and facial development. Abnormal sequelae of these developmental processes may give rise to cystic lesions later in life. This paper reviews the pathogenesis, clinical features, and behavior of these odontogenic and nonodontogenic cysts. Justification is found for the exclusion of the globulomaxillary, midmandibular, and midpalatine cysts from a current classification. Emphasis is placed on the importance and controversy surrounding the odontogenic keratocyst.

The role of endotoxin and cytokines in the pathogenesis of odontogenic cysts.

Odontogenic cysts arise from tooth-forming epithelial residues. The stimulus for the formation of radicular cysts is thought to be endotoxin released from the infected necrotic tooth pulp. However, in keratocysts and follicular cysts, such a stimulus is not present. In order to investigate what drives the cyst epithelium to proliferate, explant media and fluids from 16 radicular cysts, eight keratocysts and seven follicular cysts and explant media from four specimens of non-inflamed gingival tissue were examined for the presence of endotoxin and cytokines. Cyst fluids were also cultured for 72 h in anaerobic and aerobic conditions to detect micro-organisms. Endotoxin from three different bacteria, cytokines [interleukin-(IL) 1 alpha, IL-1 beta and IL-6] as well as prostaglandin E2 (PGE2) were tested in an epithelial cell-proliferation assay. As the cyst epithelium is supported by a connective tissue capsule, the effect of fibroblast culture media on epithelial cell proliferation was also investigated. The results showed significantly higher concentrations of endotoxin in radicular cyst fluid than in the keratocyst or the follicular cyst. None of the cyst fluids contained micro-organisms. Immunoassays demonstrated the presence of IL-1 alpha and -6 in all fluids and explants tested; IL-1 beta was only found in the inflammatory radicular cysts. However, reverse transcriptase-polymerase chain reaction showed that mRNAs for IL-1 alpha, -1 beta and -6 were present in all cyst types. Proliferation studies indicated that endotoxin and the cytokines had a mitogenic effect on epithelia at low concentrations; PGE2 had very little effect at low concentrations, and had an inhibitory effect at high concentrations. Cyst fibroblast culture media had a mitogenic effect on the epithelia that was enhanced by the presence of endotoxin.

The incidence of cysts and tumors around impacted third molars.

The objective of this retrospective analysis was to determine the incidence of the development of cysts and tumors around third molars and to discuss some relevant issues in relation to the removal of asymptomatic, impacted third molars. 9994 impacted third molars, removed in 7582 patients, formed the basis of this study. The analysis revealed 231 cysts (2.31%) and 79 tumors (0.79%), including 7 benign tumors (0.77%) and two malignant tumors (0.02%). The incidence of cysts and tumors around impacted third molars was 3.10%.

Production of amelogenin by enamel epithelium of Hertwig's root sheath.

OBJECTIVE: To study the multiple potentials of differentiating odontogenic epithelial cells. STUDY DESIGN: Bilateral first and second maxillary molars of 30 immature rats were perforated into the pulp chambers with a round bur. The pulps were observed histologically and immunohistochemically for amelogenin 3, 7, and 14 days after the perforation. RESULTS: On day 7, the enamel epithelium of Hertwig's root sheath migrated and formed oval-shaped epithelial islands that resembled epithelial rests of Malassez. On day 14, the islands consisted of epithelial cells with large nuclei and cytoplasm partially surrounded by a subsequently formed osteodentin and cementum. Immunoreactivity for amelogenin was observed in the large epithelial cells and in the area between the cells as well as the calcified tissues. Some of the enamel epithelium resembling columnar ameloblasts of the enamel organ were also positive for amelogenin. CONCLUSIONS: The enamel epithelium of Hertwig's root sheath appeared to differentiate into ameloblasts and produce amelogenin.