907 D3000 new imprint Word template Vol 13, No 1 (2025) ISSN 2167-8677 (online) DOI 10.5195/d3000/2025.907 http://dentistry3000.pitt.edu Treatment of Non Syndromic Hypodontia Associated with Generalized Microdontia with Fiber Reinforced Resin Composite Bridges Atoosa Nobakht, Sara Nabizadeh, Ladan Ranjbar Omrani Dental Research Center, School of Den2stry, Tehran University Medical Center, Tehran, Iran Abstract Gene9c and environmental factors are the causes of dental anomalies during tooth mor- phogenesis. Microdon9a may appear as three types: single tooth, mul9ple teeth in both jaws, and true generalized microdon9a (TGM), in which all teeth are smaller. Congenitally missing teeth is referred as hypodon9a. This condi9on might be combined with specific syndromes. This paper proposes that generalized microdon9a, without any apparent sys- temic associa9on, can be treated by direct composite restora9ons. Open Access Cita%on: Nobakht A, et al. (2025) Treatment of Non Syn- dromic Hypodon%a Associated with Generalized Micro- don%a with Fiber Reinforced Composite Bridges. Den%s- try 3000. 1:a001 doi:10.5195/d3000.2025.907 Received: April 15, 2025 Accepted: May 5, 2025 Published: June 27, 2025 Copyright: ©2025 Nobakht A, et al. This is an open ac- cess ar%cle licensed under a Crea%ve Commons AWribu- %on Work 4.0 United States License. Email: saranabizadeh1993@gmail.com Introduc)on The phenomenon of microdontia is de- scribed as an abnormal state of small teeth [1]. Boyle et al. characterized this phenome- non as ‘small dental size, normal short crowns, commonly missing teeth’s contact areas’ [2]. Levy, Hine, and Shafer [3] classi- Fied microdontia as 1) Microdontia including only one tooth; 2) Relative generalized mi- crodontia because of huge jaws, and 3) True generalized microdontia which all teeth are affected. True generalized microdontia is a rare condition and is often related to other syndromes, such as Rieger anomaly, oro- faciodigital syndrome (type 3), oculo-man- dibulo-facial syndrome, and pituitary dwarf- ism [4]. It has also been reported in radiation or chemotherapeutic treatment during the developmental stage of the teeth [5]. Hypodontia is deFined as the absence of 1 to 5 teeth excluding the 3rd molars [4]. Hypo- dontia might be present separately or as a part of genetic or chromosomal faults like Down syndrome or Hereditary Ectodermal Dysplasia (HED) [6-8]. Hypodontia, like ano- dontia, is often associated with general disorders, but there are rare cases of non- syndromic hypodontia in clinically healthy patients. Factors that cause hypodontia are not fully understood, but some authors showed that there are some environmental factors that may favor this disorder [9]. The overall prevalence of hypodontia is found to be 6.4% [10]. 1. Hypodontia usually requires complex treat- ments, associated with lifelong mainte- nance. The treatment depends on the pat- tern of tooth absence, the amount of re- mainig spaces, the presence of malocclusion and patient habits. Minimal invasion, esthet- ics, and cost are some of the important fac- tors that can affect the treatment plan . A conventional porcelain-fused metal bridge is the most invasive treatment in terms of the tooth reduction. The resin-bonded Fixed par- tial denture (FPD) is a valid treatment option in selected cases. Traditionally, metal alloy has been used as the material for the frame- work, but Fiber-reinforced composite (FRC) is advocated today for their favorable elastic modulus as compared to metals and better adhesion of the composite luting agent to the framework. The FRC bridges are adhesive, minimally invasive, and economic restora- tions that can be used for single visit replace- ment of a missing tooth. A review of the den- tal literature suggests that the FRC prosthe- ses have good longevity, especially those which are made by the direct technique [11]. 2. Fiber-reinforced technology was initially used as a splint material for periodontally in- volved teeth and to stabilize avulsed teeth. Nowadays, it is used to replace anterior or posterior teeth [12]. There are some condi- tions that need to be checked before the FRC composite treatment. Some of these are listed below: 3. Medical situations that can affect oral health such as uncontrolled diabetes [13], the length of edentulous space, loading on the pontic and the technique which was used [14]. There are two types of techniques for this treatment, direct and indirect. The direct technique excludes the need of laborator and can be done in one session [15]. The indirect technique success is related to the skills of the technician and cost more [16]. To give the Fiber better properties, they create meshes with multiple Fiber orientations sev- eral times. This can be achieved in one of two Treatment of Non Syndromic HypodonGa Associated with Generalized MicrodonGa with Fiber Reinforced Resin Composite Bridges Vol 13, No 1 (2025) DOI 10.5195/d3000/2025.907 http://dentistry3000.pitt.edu 2 ways: either by placing unidirectional Fibers in multiple directions or by using a braided or woven fabric [12]. Authors, in this case report deliberate treat- ment of a rare case of generalized microdon- tia with hypodontia not associated with sys- temic conditions or syndromes with a Fiber re-inforced composite bridge. Narra)ve A 22-year-old female patient was referred to the restorative dentistry department of Teh- ran University of Medical Sciences, com- plaining of small teeth and spaces between them. During the registration of patient his- tory, her brother showed the same abnor- mality, where the small teeth had been noted by the parent during permanent tooth erup- tion without any other abnormalities. There- fore, the heredity possibility was considered. No gross abnormality was noted in the phys- ical examination. The patient’s medical his- tory was unremarkable. After checking the patient’s medical records; alkaline phospha- tase, phosphorous, serum calcium, and her hormonal levels including growth hormone, thyroxin, and cortisol revealed normal val- ues. Intraoral examination revealed normal soft tissues, while abnormal shape and size of the teeth and missing teeth number 12, 14, 15, 22, 24, 25, 34, 35, 44, and 45 was rec- orded. In contrast retained deciduous teeth number 52, 54, 55, 63, 64, 65, 73, and 83 was seen in mouth. Total residual teeth were found less in size than normal permanent teeth, and other clinical Findings were: Abnormal occlusion with excessive interdental spaces (Class III Angle classiFication of occlusion), proclined upper anterior segment with spacing, de- creased overbite( anterior open bite) and class III molar relation on the right and left side (mandibular prognathism). The First steps of the author’s management were diag- nosis and treatment plan through making and evaluating the diagnostic casts. The pos- terior and anterior teeth were short and had small clinical crowns. Mesiodistal dimension of teeth was measured from the diagnostic casts for the erupted teeth (Table 1). The pa- tient’s photographs and radiography are shown in Figure 1. Regarding the data collected earlier with a systematic assessment that revealed a lack of signiFicant abnormalities, the Final diagnosis was Non-syndromic occurrence of hypodon- tia and true generalized microdontia. The consultations from orthodontic, peri- dontic and prosthodontic departments were taken. Beacause of patient’s age and number of involved teeth, the preparation for crowns or overlays seemed to be invasive and would cost a fortune. Also patient couldn’t afford the orthodontic treatment and demanded a treatment with shorter period of time. Af- teral it was decided to reconstruct the pa- tients teeth with composite veneers and Fi- ber re-inforced resin composite bridges. 4. The First step was to register occlusal rec- ords of patient and mounting dental casts in an articalutor as it is shown in Figure 2. 5. After mounting, diagnostic was up was done by inlay wax and a clear mold was fabricated to ease the procedure of composite recon- struction (Figure 3). 6. SolaFill M90 universal A1 4g Trent Dent Products Ltd, London, United Kingdom, Meta P& Bond 5g Meta Biomedical Republic of Korea Bonding Agent and Rib- bond® ribbon United States was used for the reconstruction (Table 2). 7. In the upper right segment, the tooth num- ber 55 was heavily decayed, so it was ex- tracted. FRC bridge was fabricated to replace tooth 55 with abutments of teeth 16 and 54. Teeth number 11,13 and 52 were prepared for composite veneer. Teeth dimensions were corrected to become more esthetic. 8. In the upper left segment, tooth number 22 was missed and the deciduous tooth number 63 was present. The deciduous canine was reshaped by composite veneer to lateral and teeth number 21,64 and 65 were treated by composite veneer to have better width to height relations (which was 0.8). 9. In the lower right segment, teeth number 34 and 35 were missing and the deciduous ca- nine tooth (tooth number 73) was present. For the replacement of premolars, Fiber re- inforced composite bridge was utilized. The bridge beneFits from abutment teeth number 33 and 36. In the lower left segment, teeth number 44 and 45 were missing and the deciduous ca- nine tooth(number 83) was present in mouth. For the replacement of premolars, a Fiber re-inforced composite bridge was used. The teeth number 43 and 56 were abut- ments. These treatments are shown graph- ically in Table 3. The post treatment photographs is illus- trated in Figure 4. A 1mm width and depth box was prepared on each abutment teeth. Then teeth were prepared for bonding and a thin layer of composite was placed on tooth. After that the Ribbond has been wet with the bonding agent and was placed from one abutment to the other. Then a thin layer of composite was placed lingual to the Ribbond. After placing the second layer of Rebbond, it was covered with composite and cured. The occlusal relationships were adjusted so that the resin bridge pontics had light con- tact in centric relation and were out of con- tact in lateral and protrusive movements. Discussion development [17]. Microdontia is a dental disorder in the form of teeth that are smaller than normal teeth [18]. Microdontia is pre- sent in three forms, (1) Microdontia includes only one tooth; (2) Relative generalized mi- crodontia because of small teeth related to huge jaws and (3) True generalized micro- dontia when there are total abnormal small teeth (3). Although it can affect primary and permanent teeth, microdontia is more com- mon in permanent teeth and can cause ab- normal spacing.12 Microdontia can cause a diastema between the involved tooth and the adjacent tooth so that it has the potential to become an area for trapped food debris or food impaction that has the potential to cause caries and periodontal disease [19]. Hypodontia can be represented as, with the exception of the third molar, a state of devel- opmentally missing single or more dental primary or secondary teeth [4]. Hypodontia, like anodontia, is often associated with gen- eral disorders, but there are rare cases of non-syndromic hypodontia in clinically healthy patients. Factors that cause hypo- dontia are not fully understood, but some au- thors showed that there are some environ- mental factors that may favor this disorder [9]. Treatment of these conditions is aimed at addressing the aesthetics issue of the pa- tient and this can present a number of chal- lenges which may require a multidiscipli- nary approach in its management (20). Treatment options for the comprehensive management of microdontia, which may also include hypodontia, vary but broadly include the following: 1. Orthodontic treatment – to idealise tooth position of the microdont tooth or teeth 2. Restorative treatment – using direct and indirect techniques on the microdont tooth or teeth 3. Joint orthodontics and restorative treat- ment 4. Extraction of the microdont tooth or teeth and orthodontics and tooth replacement if required 5. Extraction and tooth replacement 6. No treatment – which is unlikely to be ac- ceptable [20]. Composite based restorations can be used as a reversible material to build-up the mor- phology of the microdont tooth or teeth [21]. Direct composite has been shown to be aes- thetic, non-invasive, well-tolerated by pulpal tissue, minimally abrasive to opposing teeth and easy to repair, however, it is prone to staining/discolouration, accelerated wear rate of material in comparison to metal and ceramic based material, bulk fractures, Treatment of Non Syndromic HypodonGa Associated with Generalized MicrodonGa with Fiber Reinforced Resin Composite Bridges Vol 13, No 1 (2025) DOI 10.5195/d3000/2025.907 http://dentistry3000.pitt.edu 3 complexity and technique sensitive [22]. Di- rect composite veneers can provide ade- quate aesthetics and studies have shown that direct composite can be just as aesthetic as porcelain [23]. Fiber-reinforced compo- site resin (FRC) bridges are a conservative alternative method for the replacement of missing teeth. The abutment teeth can be conserved with a minimally invasive prepa- ration, thereby ensuring that the technique is reversible, and FRC bridge treatment can be performed in a single visit [24]. The treatment plan, in this case, was to sub- stitute the missing teeth and interdental space closure with resin composite material to promote the aesthetics look, the mastica- tion efFicacy, and the pronunciation of the words to restore the patient’s esthetics and functions. Regarding the unpleasantness of the patient’s smile and the inadequacy of her esthetic, these reasons made her unhappy with her appearance. Different treatment methods are suggested for partial hypodon- tia; however, the treatment plans should be adjusted, rendering the severity of the anom- aly in a way that makes the maximum pleas- ing outcome. Follow ups within 3,6 and 12 months were done and the evaluation of the restorations and periodontal health was ex- amined each time. Follow ups showed pleas- ant results. Conclusion In this case, dental Findings are rarely seen and with negative hereditary history. Differ- ent clinical appearance of syndromic and non-syndromic incidence of dental anoma- lies is arguing, and more investigations are needed. This study supports that different modulations in treatment plans can be al- tered and performed to ascertain esthetics and dental functions in the future and reduce the difFiculties associated with hypodontia and microdontia. References 1. Laundau S. International dictionary of medicine and biology. 1. New York: John Wiley & Sons; 1986. p. 1717. 2. Boyle PE. Kronfeld's Histopathology of the Teeth and their Surrounding Structures. 3. Phila- delphia: Lea& Febiger; 1955. p. 14. 3. Shafer WG, Hine MK, Levy BM. A Textbook of Oral Pathology. 1. Philadelphia: W. B. Saunders Co; 1958. p. 26. 4. Chen, Yuan et al. “Non-syndromic occurrence of true generalized microdontia with hypodontia: A case report.” Medicine vol. 98,26 (2019): e16283. doi:10.1097/MD.0000000000016283 5. Van der waal I, Van der kwast WAM. Oral pathol- ogy. Chicago: Quintessence Publishing Co. Inc; 1988. Developmental anomalies and eruption dis- turbances and some acquired disorders of the teeth; p. 114. 6. Vastardis H. The genetics of human tooth agen- esis: new discoveries for understanding dental anomalies. Am J Orthod Dentofacial Orthop, 2000, 117(6):650–656. 7. de Moraes ME, de Moraes LC, Dotto GN, Dotto PP, dos Santos LR. Dental anomalies in patients with Down syndrome. Braz Dent J, 2007, 18(4):346–350. 8. Zarrinnia K, Bassiouny MA. Combined aplasia of maxillary jirst molars and lateral incisors: a case report and mana Herman NG, Moss SJ. Anodontia of the permanent dentition: 9. Mărgărit, Ruxandra et al. “Non-syndromic famil- ial hypodontia: rare case reports and literature re- view.” Romanian journal of morphology and em- bryology = Revue roumaine de morphologie et em- bryologie vol. 60,4 (2019): 1355-1360. 10. K. Khalaf, J. Miskelly, E. Voge, and T. V. Macfar- lane, “Prevalence of hypodontia and associated factors: a systematic review and meta-analy- sis,” Journal of Orthodontics, vol. 41, no. 4, pp. 299– 316, 2020. 11. Muhamad, Abu-Hussein & Abdulgani, Az- zaldeen & Mai, Abdulgani. (2017). Ortho-Prostho Management of Hypodontia Using Fibre-Rein- forced Composite Resin Bridge: An Interdiscipli- nary Approach. 10.9790/0853-1606100810. 12. Escobedo Martıńez MF, Rodrıǵuez López S, Valdés Fontela J, Olay Garcıá S, Mauvezıń Quevedo M. A New Technique for Direct Fabrication of Fi- ber-Reinforced Composite Bridge: A Long-Term Clinical Observation. Dentistry Journal. 2020; 8(2):48. https://doi.org/10.3390/dj8020048 13. Isola, G.; Matarese, G.; Ramaglia, L.; Pedullà, E.; Rapisarda, E.; Iorio-Siciliano, V. Association be- tween periodontitis and glycosylated haemoglo- bin before diabetes onset: A cross-sectional study. Clin. Oral Investig. 2019, 1–10. 14. Goguta, L.M.; Candea, A.; Lungeanu, D.; Frandes, M.; Jivanescu, A. Direct Fiber-Reinforced Interim Fixed Partial Dentures: Six-Year Survival Study. J. Prosthodont. Off. J. Am. Coll. Prostho- dont. 2019, 28, 604–608. 15. Singh, K.; Gupta, N.; Unnikrishnan, N.; Kapoor, V.; Arora, D.; Khinnavar, P.K. A Conservative Treat- ment Approach to Replacing a Missing Anterior Tooth. Case Rep. Dent. 2014, 14, 10–12. 16. Benito, P.P.; Trushkowsky, R.D.; Magid, K.S.; David, S.B. Fiber-reinforced framework in con- junction with porcelain veneers for the esthetic re- placement of a congenitally missing maxillary lat- eral incisor: A case study. Oper. Dent. 2012, 37, 576–583. 17. W.R. Profjit The development of orthodontic problems W.R. Profjit (Ed.), Contemporary ortho- dontics (2nd ed.), Mosby, St Louis (1997), p. 110 18. Malleshi S, Basappa S, Negi S, Irshad A, Nair S. The Unusual Peg Shaped Mandibular Central Inci- sor – Report of Two Cases. J Res Pract Dent. 2014;2014:1–6. 19. Rahmah KA, Riyanti E, Yohana W. Prevalence of Microdontia in People with Down Syndrome: A Rapid Review. Journal of International Dental & Medical Research. 2022 Jul 1;15(3). 20. Laverty DP, Thomas MB. The restorative man- agement of microdontia. British dental journal. 2016 Aug;221(4):160-6. 21. Asher C, Lewis D H . The integration of ortho- dontic and restorative procedures in cases with missing maxillary incisors. Br Dent J 1986; 160: 241–245. 22. Mehta S, Banerji S, Millar B, Suarez-Feito J . Cur- rent concepts on the management of tooth wear: Part 4. An overview of the restorative techniques and dental materials commonly applied for the management of tooth wear. Br Dent J 2012; 212: 169–171. 23. Nalbandian S, Millar B J . The effect of veneers on cosmetic improvement. Br Dent J 2009; 207: E3; discussion 72–73. 24. Heo G, Lee EH, Kim JW, Cho KM, Park SH. Fiber- reinforced composite resin bridges: an alternative method to treat root-fractured teeth. Restorative Dentistry & Endodontics. 2019 Nov 4;45(1). Treatment of Non Syndromic HypodonGa Associated with Generalized MicrodonGa with Fiber Reinforced Resin Composite Bridges Vol 13, No 1 (2025) DOI 10.5195/d3000/2025.907 http://dentistry3000.pitt.edu 4 10. 11. Figure 1. Patient’s pre-treatment photographs and radiography. Treatment of Non Syndromic HypodonGa Associated with Generalized MicrodonGa with Fiber Reinforced Resin Composite Bridges Vol 13, No 1 (2025) DOI 10.5195/d3000/2025.907 http://dentistry3000.pitt.edu 5 Table 1. Measurements of the erupted teeth dimensions mesio-distally and bucco-lingually/labio-lingually and the values of anatomic averages for the permanent teeth in the maxilla and mandible (measures in millimeters). Central incisor (MD/LL) Lateral incisor (MD/LL) Canine (MD/LL) 1st premolar (MD/BL) 2nd premolar (MD/BL) 1st molar (MD/BL) 2nd molar (MD/BL) Maxillary ∗ Average 8.6/7.1 7.0/6.4 7.9/8.2 7.2/9.5 6.7/9.3 10.1/11.3 9.6/11.4 Right 6.8/3.6 Missing 6.4/Nm 5.9/Nm 6.5/Nm 7.3/8.3 7.9/Nm Left 7.0/3.9 Missing 6.6/Nm 6/Nm 5.4/Nm 7.6/8.5 8.7/Nm Mandible ∗ Average 5.4/5.8 6.1/6.3 7.0/7.1 7.1/7.1 7.1/8.4 11.2/10.6 10.7/10.5 Right 4.0/3.5 4.6/3.5 5.7/Nm 6.2/Nm 6.4/Nm 8.1/7.1 7.9/Nm Left 4.3/3.6 4.4/3.5 5.5/Nm 5.9/Nm 6.3/Nm 7.9/7.7 8.6/Nm *Values taken from Xin, P. Textbook of dental anatomy and physiology, ed. 7, Beijing, 2012, People’s Medical Publishing House, pp. 46-47 NM=not measured. BL = buccolingual, LL = labiolingual, MD =mesiodistal Figure 2. Register occlusal records of patient and mounting dental casts in an articalutor. Treatment of Non Syndromic HypodonGa Associated with Generalized MicrodonGa with Fiber Reinforced Resin Composite Bridges Vol 13, No 1 (2025) DOI 10.5195/d3000/2025.907 http://dentistry3000.pitt.edu 6 Figure 3. Diagnostic by inlay wax and fabrication a clear mold to ease the procedure of composite reconstruction. Table 2. Materials used in the case. Material Composition Meta P&Bond 5g Bis-GMA, PMGDM, 2-Hydroxyethylmethacrylate, Ethyl alcohols SolaFil M90 A1 4g 1,4-Butandioldimethacrylate Urethandimethacrylate Bis-GMA Ribbond® Ultra-high molecular weight polyethylene Fibers Table 3. Treatment graphic. FR C br id ge a bu tm en t Ex tr ac tio n (d ec ay ) FR C br id ge a bu tm en t Co m po si te v en ee r Co m po si te v en ee r Co m po si te v en ee r Co m po si te v en ee r Re sh sa pe to la te ra l Co m po si te v en ee r Co m po si te v en ee r 18 17 16 55 54 13 52 11 21 63 23 64 65 26 27 28 48 47 46 missing 43 83 42 41 31 32 73 33 missing 36 37 38 12 . FR C br id ge a bu t- m en t po nt ic 13 . FR C br id ge a bu t- m en t Co m po si te ve - ne er Co m po si te v e - ne er Co m po si te ve - ne er Co m po si te ve - ne er Co m po si te ve - ne er 14 . FR C br id ge a bu t- m en t po nt ic 15 . FR C br id ge a bu t- m en t Treatment of Non Syndromic HypodonGa Associated with Generalized MicrodonGa with Fiber Reinforced Resin Composite Bridges Vol 13, No 1 (2025) DOI 10.5195/d3000/2025.907 http://dentistry3000.pitt.edu 7 16. Figure 4. Post treatment photographs.