Nonsyndromic Hypodontia and Associated Developmental Dental Anomalies in Siblings: A Case Series and a Review

Abstract

A dental anomaly is any deviation from normal tooth development, affecting the number, size, form, position, or structure of one or more teeth. Examining affected family members can enhance our understanding of the genetic factors involved in both normal and abnormal dental development. Hypodontia is a common dental anomaly characterized by the congenital absence of one or more teeth. It may exhibit a familial pattern associated with certain dental anomalies in siblings. The two main treatment modalities for hypodontia are space opening for prosthetic replacement of the missing tooth or space closure, which underscores the need for an interdisciplinary approach of management. This case series aims to present the clinical dental features and treatment modalities of 10 siblings from 5 families who exhibited hypodontia and other nonsyndromic dental anomalies with malocclusion. A thorough literature review on familial and genetic basis of hypodontia and associated dental anomalies in siblings is also presented.

Keywords

hypodontia - dental anomalies - malocclusion - siblings

Introduction

Normal development and eruption of teeth are crucial for the normal physiological development of the craniofacial complex and dental occlusion.[1] Odontogenesis commences in the 6th week of intrauterine life, whereby genetics control teeth position, number, size, shape, and structure.[2] This process follows distinct stages of initiation, morphogenesis, differentiation, and eruption under the influence of complex interactions at the molecular level between oral ectoderm of the first pharyngeal arch and the underlying ectomesenchyme of neural crest.[3] These interactions are regulated by several signaling molecules and their receptors such as bone morphogenetic protein, transforming growth factor-β, hedgehog protein, fibroblast growth factor, wingless (Wnt), and epidermal growth factor.[4] [5]

Any interruption of the normal process of odontogenesis due to genetic and/or environmental factors may result in dental anomalies depending on the odontogenic stage in which this interruption occurs,[6] [7] [8] affecting tooth number (agenesis), size (microdontia and macrodontia), or position (impaction).[9]

Nonsyndromic dental anomalies are considered genetically and phenotypically heterogeneous conditions.[10] Even though the field of genetics is rapidly progressing, our understanding of the etiology of dental anomalies is far from complete. It is still very challenging to connect a single genetic defect with a specific dental anomaly. Even a single genetic defect can be variably expressed across individuals,[4] [11] and different family members may present with heterogeneous phenotypic manifestations.[8]

Tooth agenesis (hypodontia) is the developmental absence of primary or secondary teeth that results from disturbances during the initial stages of tooth formation.[12] [13] Hypodontia can be classified into mild (one to two missing teeth), moderate (three to six missing teeth), and severe (six or more missing teeth).[14] This anomaly is often nonsyndromic, and it is the most common craniofacial congenital malformation.[15] [16] Excluding third molars the estimated prevalence is 1.6 to 20.9%, according to the population studied.[17] [18] [19] [20] [21] [22] Common features of hypodontia include microdontia and delayed tooth development. The most commonly affected teeth are maxillary lateral incisors and mandibular second premolars with an estimated prevalence of 0.8 to 4.5%.[23]

Hypodontia has an adverse impact on quality of life,[24] attributed to the associated aesthetic, functional, and psychological limitations, complicated by increased financial burden.[25] It is often clinically challenging, due to the prolonged treatment time and compromised outcomes. Therefore, early prediction of this condition is useful through identification of genetic and environmental factors followed by development of appropriate preventive and treatment strategies.[26]

This study aims to describe hypodontia and other nonsyndromic dental anomalies identified in 10 siblings of 5 families. Diagnostic techniques and orthodontic management of associated malocclusion will be described in detail. A thorough literature review on this topic will be presented with a focus on heredity and clinical outcomes.

Case Reports

Study Group and Design

This study was approved by the Ethical Committee of the School of Dentistry at the University of Jordan (IRB No. 610/2013/10) and all methods were performed in accordance with the World Medical Declaration of Helsinki.

Routine orthodontic diagnostic records (photographs, dental casts, and orthopantomogram) were collected from all patients. Depending on the skeletal and dental features of malocclusion, either space closure or space opening followed by prosthesis was adopted.

Clinical Case Reviews and Treatments

The developmental dental problems of 10 patients are presented in [Table 1].

Table 1 Patients' characteristics including demographic data, developmental dental anomalies, and characteristics of malocclusion

Patients	Family	Sex	Age	Developmental dental anomalies and malocclusion
				Tooth agenesis	Tooth size defect	Tooth impaction	Retained deciduous teeth	Incisal relationship	Central line shift	Median diastema	Other findings
P1	Family 1	F	16 y	#12	#22 microdontia	None	None	Class I	Upper 2 mm to the right	3 mm	Moderately crowded lower labial segment
P2		M	13 y	None	#12 macrodontia #22 microdontia	None	None	Class III	Upper 1.5 mm to the left	1.5 mm	Reduced overbite and overjet
P3	Family 2	F	13 y	#45	None	None	#85	Class I	Upper 2 mm to the left	None	#41 poor prognosis
P4		F	15 y	None	None	#13 palatally, #45	#53	Class I	Lower 1.5 mm to the right	None	None
P5	Family 3	M	12 y	#12 #22 #18 #28	None	None	#52 #62	Class III with anterior crossbite	None	None	Generalized delay in the dental development
P6		M	14 y	#22 #18 #28	#12 microdontia	None	#63	Class II div 2 with deep overbite	None	None	Delayed eruption of #35 and #45
P7	Family 4	F	16 y	#35 #45 #18	None	None	#75	Class I	Lower 2.5 mm to the right	None	Moderately crowded lower labial segment
P8		F	18 y	#45	None	#13 and #23 palatally #35	#53, #63, #75	Class I	Lower 1.5 mm to the right	1 mm	Crowded upper and lower labial segments
P9	Family 5	M	13 y	#12	None	None	None	Class III with anterior crossbite	Upper 2.5 mm to the right	None	Delayed eruption of #13 and #23 with spaced upper labial segment
P10		F	10 y	None	None	#23 severe horizontally	None	Class III with anterior crossbite	None	None	None

Abbreviations: F, female; M, male.

Family1 (Patients 1 and 2)

Patient 1 ([Fig. 1]), a 16-year-old female, presented with a spaced upper labial segment. She had class I malocclusion, agenesis of the upper right permanent lateral incisor (URL), microdontia of the upper left lateral incisor (ULL), and 3mm diastema in the upper arch. There was minimal skeletal discrepancy therefore no lateral cephalogram was necessary. The buccal segment relationship was class I bilaterally with average overbite/overjet and a moderately crowded lower labial segment. The upper centerline was shifted to the right by 2 mm as a direct result of URL agenesis. Based on the associated class I skeletal pattern, class I buccal segment relationship on both sides, a spaced upper arch, and a mesially inclined upper right canine (UR3), treatment plan consisted of opening space for an implant to replace the URL. The treatment objectives were to align and level the teeth, distalize the (UR3) to achieve a class I relationship, correct the upper centerline shift, create space to restore the missing URL, and parallelize the adjacent roots for the implant site.

Fig. 1 (A) Pretreatment photos for patient 1, the patient presented with class I malocclusion complicated by tooth agenesis that affected the upper right permanent lateral incisor, with microdontia of the upper left lateral incisor. (B) Fixed orthodontic appliance (FOA) in place. (C) Orthopantomogram (OPG) taken during treatment to confirm root parallelism of adjacent teeth for placement of an implant in the space of missing upper right permanent lateral incisor. (D) Posttreatment records, implant placement postponed until the patient is 18 and the space was retained using a vacuum-formed appliance with prosthetic upper right lateral incisor.

Treatment included fitting an upper and lower fixed orthodontic appliance (FOA). Eighteen months into treatment a panoramic radiograph confirmed root parallelism. The appliance was removed, and a vacuum-formed retainer with a prosthetic URL was used for retention for 6 months. This was followed by a temporary bridge and a new retainer.

Patient 2 ([Fig. 2]), 13-year-old brother of patient 1, presented with spaced and rotated teeth in the upper labial segment. He presented with class III malocclusion, macrodontia of URL, microdontia of ULL, and 1.5 mm diastema in the upper arch. There was minimal skeletal discrepancy therefore no lateral cephalogram was necessary. The buccal segment relationship was class I bilaterally with reduced overbite and overjet. The upper centerline was shifted to the left by 1.5 mm as a direct result of the upper laterals size discrepancy. The patient and parents declined the option of enamel reduction of the URL and building up the left one, and preferred alignment with a short course of FOA. Therefore, the treatment objectives included aligning and leveling the teeth, restoring overjet and overbite to normal values, and accepting tooth size and centerline discrepancies. The treatment included fitting of upper and lower FOAs for 6 months, and the treatment objectives were successfully achieved. Afterward, a vacuum-formed retainer was provided.

Fig. 2 (A) Pretreatment photos for patient 2, the patient presented with class III malocclusion complicated by macrodontia of upper right lateral incisor, microdontia of upper left lateral incisor, and reduced overbite and overjet. (B) End of treatment records where teeth were aligned and leveled, overbite and overjet were normalized, no adjustment in the size of UR1, and UR2 upon patient's request.

Family 2 (Patients 3 and 4)

Patient 3 ([Fig. 3]), a 13-year-old female, presented with crowded upper and lower arches with multiple rotations. She had class I malocclusion, agenesis of the lower right second premolar (LR5), retained right deciduous second molar, and a root-canal treated lower right central incisor (LRCi) with poor prognosis. The buccal segment relationship on the right side was class I and quarter unit class III on the left side. The canine relationship was class II on the right side and class I on the left side with the upper centerline shifted to the left by 2 mm. Treatment consisted of extracting the upper right first premolar (UR4), lower right second primary molar, and (LRCi) to align and level the teeth, distalize the upper right canine (UR3) to achieve a class I relationship, and utilize all available spaces to alleviate crowding while also correcting the upper centerline. The goal was to position the (LLCi) at the center of the lower arch while also accepting a mild increase in overjet and overbite. Treatment involved fitting an FOA for both the upper and lower arches. After 25 months of treatment, all objectives were successfully achieved, the appliance was removed, and a vacuum-formed retainer was used for retention.

Fig. 3 (A) Pretreatment records for patient 3, the patient presented with class I malocclusion complicated by tooth agenesis of the lower right second premolar, with a retained deciduous second molar on the same side, the orthopantomogram (OPG) shows a root canal treated lower right central with poor prognosis. (B) Treatment plan started with extraction of #14, #41, and #85 then fixed orthodontic appliance (FOA) was fitted in place.

Patient 4 ([Fig. 4]), sister of patient 3, aged 15, presented with class I malocclusion and severely impacted and palatally displaced UR3 with a retained URC. The LR5 was impacted, due to early loss of its predecessor. The lower centerline was shifted to the right by 1.5 mm. Treatment consisted of extracting URC and surgical exposure of UR3, performing orthodontic traction with the use of an FOA to align and level the teeth, and open space for both the UR3 and LR5. FOA for the upper and lower arches were placed. After 30 months of treatment, all objectives were successfully achieved, the FOA was removed, and a vacuum-formed retainer was used for retention.

Fig. 4 (A) Pretreatment records for patient 4, the patient presented with class I malocclusion complicated by retained upper right deciduous canine. The orthopantomogram (OPG) shows a severely impacted and palatally displaced upper right permanent canine and impacted lower right second premolar. (B) Treatment plan included extraction of the retained deciduous and surgical exposure of the impacted canine, fixed orthodontic appliance (FOA) was then used to open space for tooth #45 and to move the exposed canine toward the line of the arch.

Family 3 (Patient 5 and 6)

Patient 5 ([Fig. 5]), a 12-year-old male, complained of small incisors in the upper arch. He presented with a mild class III malocclusion in the mixed dentition, anterior crossbite, agenesis of upper third molars, URL, and ULL, with their predecessors retained. There was a radiographic evidence of generalized delay in dental development in both arches with an estimated dental age of 9 years. Therefore, treatment consisted of extracting the upper primary lateral incisors and correcting the anterior crossbite using a simple removable appliance. We monitored the eruption of the maxillary canines during this phase. Subsequently, we introduced an FOA to reposition the upper canines in place of the missing upper laterals while preserving space and bone by retaining the upper deciduous canines. As the patient proceeded into adulthood, and bone growth ceased, the next phase of treatment involved extracting the upper deciduous canines and moving the permanent canines into their normal position, thereby creating space for implants to replace the missing upper laterals.

Fig. 5 (A) Pretreatment records for patient 5, the patient presented with class III malocclusion in the mixed dentition with anterior crossbite complicated by retained upper deciduous lateral incisors. Orthopantomogram (OPG) showed agenesis of permanent upper right and left lateral incisors. Lateral cephalometric radiograph revealed a class I skeletal relationship with ANB (angle between A point, B point and nasion) = 2.44 degrees (0–4 degrees range) and WITS (University of Witwatersrand, Johannesburg, South Africa, and represents the distance between points A and B measured on the occlusal plane) = −0.36 mm (−1 to 1 range). (B) After correction of anterior crossbite using removable appliance, fixed orthodontic appliance (FOA) was fitted to reposition the upper permanent canines in place of missing laterals.

Patient 6 ([Fig. 6]), 14-year old brother of patient 5, complained of a spaced upper labial segment. He presented with a class II division 2 malocclusion with a deep overbite, microdontia of the URL, agenesis of the ULL, retained upper left deciduous canine, delayed eruption of the LR5 and LL5, and agenesis of the upper third molars, while the (UL3) was erupting mesial to its normal position. Taking age into consideration, treatment objectives were restricted to teeth aligning and leveling, reducing overbite, preserving the upper left primary canine, and closing spaces in the upper arch while creating room for the lower second premolars to erupt. In adulthood, the plan involved extracting the upper left deciduous canine and moving the (UL3) to the correct position, while also preparing space for an implant to replace the missing ULL.

Fig. 6 (A) Pretreatment records for patient 6, the patient presented with class II division 2 malocclusion with deep overbite complicated by microdontia of the upper right permanent lateral incisor with a retained upper left deciduous canine, the orthopantomogram (OPG) shows missing upper left permanent lateral incisor. (B) Fixed orthodontic appliance (FOA) in place.

Family 4 (Patients 7 and 8)

Patient 7 ([Fig. 7]), a 16-year-old female, complained of crowded and rotated teeth in the lower labial segment. She presented with a class I malocclusion, crowded lower labial segment, agenesis of the LR5 and LL5, and agenesis of the upper right third molar. The retention of the lower left deciduous second molar and loss of the right counterpart resulted in lower centerline shift to the right by 2.5 mm. Given the bilateral quarter class III molar relationship, treatment approach was to close the spaces in the lower arch. We explained to the patient that this would require a lengthy treatment using an FOA, with the advantage of eliminating the need for future implants. Treatment objectives were to align and level the teeth, use the space in the lower arch to relieve crowding, correct the lower centerline shift, and achieve a full unit class III molar relationship. The FOA was utilized for 28 months, successfully closing the spaces in the lower arch. Afterward, a vacuum-formed retainer was used for retention.

Fig. 7 (A) Pretreatment records for patient 7, the patient presented with class I malocclusion with crowded labial segments and retained lower left deciduous second molar. The orthopantomogram (OPG) showed developmentally absent right and left mandibular second premolars. (B) Treatment plan was space closure in the spaces of missing premolars in the lower arch to relieve crowding, the pictures show successful space closure in the lower arch.

Patient 8 ([Fig. 8]), 18-year old sister of patient 7, complained of crowded upper and lower labial segments. She presented with class I malocclusion, congenitally missing LR5, impaction of the UR3, UL3, and LL5. The upper permanent canines were palatally displaced with retained upper deciduous canines and lower left second deciduous molar. The lower centerline was shifted to the right by 1.5 mm. Treatment consisted of extracting all retained primary teeth, surgical exposure, and alignment of the upper permanent canines. FOA was used to align and level then open space for upper permanent canines and LL5 and review their eruption. The LL5 erupted spontaneously, nevertheless, the upper permanent canines required lengthy orthodontic traction. The treatment lasted 29 months and the patient received a vacuum-formed retainer at the end of the treatment.

Fig. 8 (A) Pretreatment records for patient 8, the patient presented with class I malocclusion complicated by retained 53 and 63 and retained 75, the orthopantomogram (OPG) shows 13, 23, and 35 are impacted. Lateral cephalometric radiograph revealed a class III skeletal relationship with ANB (angle between A point, B point and nasion) = 6.65 degrees (0–4 degrees range) and WITS (University of Witwatersrand, Johannesburg, South Africa, and represents the distance between points A and B measured on the occlusal plane) = −4.31 mm (−1 to 1 range). (B) Mid-treatment records after extraction of retained 53, 54, and 75 and the use of fixed orthodontic appliance (FOA) to move the exposed canines toward the line of the arch.

Family 5 (Patients 9 and 10)

Patient 9 ([Fig. 9]), a 13-year-old male, presented with concerns about the upper labial segment spacing and a reversed bite. He had a class III malocclusion, anterior crossbite, absent URL, and delayed eruption of UR3 and UL3, causing a 2.5-mm shift of upper centerline to the right. Despite the relatively early decision to consider an implant, absence of retained upper deciduous teeth, the anterior crossbite, the class III skeletal pattern, and impacted upper permanent canines have all supported the need for early intervention. Therefore, it was necessary to plan space opening in the upper arch to facilitate the eruption of the upper permanent canines and correct the anterior crossbite. The patient and parents were informed of the potential disadvantages of early space opening by distalizing the permanent canine, which would result in the right lateral incisor area lacking the natural tooth stimulus. This situation could potentially compromise the quality and quantity of bone in the future implant area. An FOA was fitted for nearly 30 months. Subsequently, the patient was provided with a vacuum-formed retainer containing a prosthetic tooth in place of the missing URL for 6 months. This was followed by the placement of a temporary bridge and a new retainer to maintain the treatment results.

Fig. 9 (A) Pretreatment records for patient 9, the patient presented with class III malocclusion and anterior crossbite complicated by delayed eruption of 13 and 23. The orthopantomogram (OPG) shows agenesis of 12. Lateral cephalometric radiograph revealed a class III skeletal relationship with ANB (angle between A point, B point and nasion) = 1.96 degrees (0–4 degrees range) and WITS (University of Witwatersrand, Johannesburg, South Africa, and represents the distance between points A and B measured on the occlusal plane) = −4.87 mm (−1 to 1 range). (B) Posttreatment records show successful eruption of 13 and 23 into the line of the arch, a temporary bridge was used with a prosthetic tooth in the place of 12 until the patient is old enough for an implant.

Patient 10 ([Fig. 10]), 10-year old sister of patient 9, also complained of a reversed bite. She presented with a class III malocclusion and had a normal physiological dental development, except for the UL3, which exhibited severe horizontal impaction with an increased angle to the midline. Due to the severity of this impaction, treatment was initiated with a simple removable appliance for anterior expansion to correct the anterior crossbite and monitor the position of the UL3. After successfully completing the removable appliance stage, a second panoramic radiograph was taken, which displayed promising progress in the position of UL3. An FOA was then placed to align and level the teeth, restore overjet and overbite to normal values, create space for the UL3, and prepare for surgical exposure. Progress of the FOA treatment was excellent, and she completed treatment in only 24 months. At the end of the treatment, she was provided with a vacuum-formed retainer to prevent relapse.

Fig. 10 (A) Pretreatment records for patient 10, the patient presented with class III malocclusion with anterior crossbite, the orthopantomogram (OPG) shows 23 is horizontally impacted. (B) Mid-treatment records after successful expansion of the upper arch with a removable appliance and fitting of fixed orthodontic appliance (FOA). (C) End of treatment records showing successful traction of the upper left canine into the line of the arch.

Discussion

The role of heredity in hypodontia was investigated in some studies by genetic analysis,[27] [28] [29] however, the majority of studies employed clinical techniques only.[23] [30] [31] [32] Previous research explained in detail the familial and/or genetic basis of hypodontia and its association with other dental anomalies in siblings like changes in tooth size, impaction, or short roots.[31]

Numerous studies have investigated families and twins to expand the understanding of the etiology of the inherited nonsyndromic teeth disorders.[10] [33] [34] [35] The majority of these studies have suggested the possibility of all modes of inheritance being responsible for dental anomalies, such as autosomal dominant, autosomal recessive, and sex-linked inheritance.[4] Inherited factors linked to a specific dental anomaly when present in a certain family, they do not always completely penetrate and express that dental anomaly(s). Rather, they may show a reduced or incomplete penetrance, or may result in variable expressions. Reduced penetrance is manifested by a milder form of the dental anomaly, while an incomplete penetrance may result in skipping of these anomalies across generations in the same family. Conversely, if these inherited factors exhibit variable expressions, different forms of dental anomalies will eventually result in the same family. One explanation for this inconsistency of genetic expression is that variable local, systemic, and environmental factors can regulate genetic functions and manifestations.[4] [8] [11]

Alvesalo and Portin investigated agenesis, peg-shaped, and microdontia of the upper lateral incisors in families and concluded that agenesis followed an autosomal dominant inheritance pattern, whereas peg-shaped and microdontia were regarded as a variable expression of the same gene.[36] Previous studies on twins also confirmed that an association exists between tooth agenesis and microdontia.[37] [38]

Following segregation analyses in several family studies, tooth agenesis was found to be a single-gene defect with an autosomal dominant mode of inheritance, along with incomplete penetrance and variable expressivity. A study that analyzed 214 family members for genetic linkage, and investigated incisor-premolar agenesis concluded similar results, whereby an autosomal dominant inheritance pattern was confirmed, with reduced penetrance and an association with several other dental anomalies (microdontia of the upper lateral incisors, ectopic canines, taurodontism, and rotated premolars).[10] Conversely, Ahmad et al examining a single family in Pakistan, further reported an autosomal recessive trait of inheritance for tooth agenesis that was associated with various dental anomalies.[33]

Dental care for all patients should ideally start as soon as the eruption of the primary dentition. This is even more important for patients with missing teeth. Treatment includes one of two options: close spaces or open spaces for prosthetic replacement. However, there are several early interventions that could simplify and enhance success of future comprehensive management. For patients where space closure of the missing teeth is the treatment of choice, timely extraction of selected primary and/or permanent teeth with spontaneous tooth movement could reduce the amount of orthodontic tooth movement needed and therefor reduce the complexity and duration of future orthodontic treatment. On the other hand, for patients where opening spaces for prosthetic replacement of the missing tooth is the treatment of choice, maintaining the deciduous teeth in place as long as it takes is crucial to guarantee excellent soft tissue and bone quality and quantity for a successful future treatment.

Treatment plans for patients with tooth agenesis should be customized to the aesthetic and functional needs of every patient. There is no ideal treatment for all cases with hypodontia, as the treatment plan is influenced by the severity of tooth agenesis (number of missing teeth), the affected arch, the position of missing tooth within the arch, space condition of the arches, skeletal pattern, amount of overjet, buccal segment relationship, and many other skeletal and occlusal features. In this case series, patients with hypodontia in the upper arch who presented with skeletal class I or III and a spaced upper arch, opening the space for prosthetic replacement could be the treatment of choice as shown in patients 1, 5, 6, and 9. For example in patient 1, space opening to replace the missing URL enhanced centerline correction and closure of the diastema while retracting the canine on the hypodontia side into class I to facilitate canine guidance on function. In patient 5, who had missing URL and ULL, and patient 9, who had a missing URL, space opening contributed to the correction of class III malocclusion and elimination of the reversed overjet. Patient 6 (brother of patient 5) had missing ULL and retained left deciduous canine, indicating spaced arch, therefore, space opening would maintain class I relationship of the buccal segment and distalization of the canine on that side to achieve normal canine guidance on function. Space opening may have favorable outcomes of shorter and less complicated orthodontic treatment course, achieving canine guidance on function, and eliminating the need to reshape and build up teeth to camouflage the missing tooth. Nevertheless, it is an expensive option where the missing tooth must be replaced with an implant or a bridge that requires lifetime maintenance and potential compromised gingival health.[16] [26] [39] [40] [41]

On the other hand, for patients with hypodontia in the lower arch with the class I or III skeletal pattern and crowded lower arch, space closure may represent the treatment of choice (patients 3 and 7). Patient 7 presented with missing LR5 and LL5 with crowding, while patient 3 had a missing LR5, where in both cases space closure contributed to relief of crowding and alignment of teeth while maintaining appropriate buccal occlusion. More recently and with the development of temporary anchorage devices (miniscrews), space closure is more clinically feasible, and associated with favorable outcomes such as treatment initiation in adolescence, eliminating the need for the prosthetic replacement, and enhanced gingival health of natural dentition.[39] [40] [41] [42]

Treatment plans for managing missing teeth of hypodontia patients are complex and require an interdisciplinary approach, which is usually associated with a financial burden. Therefore, an experienced team of dental specialists should be involved in the treatment process.[14] [43] Goals of treatment should address obstacles to oral health care, particularly in low resource settings where lack of public awareness and cost of dental treatment represent two major barriers to dental attendance.[44]

Early and periodic dental visits are recommended for siblings that have a familial history of dental anomalies such as hypodontia. This is to provide them with optimum preventive dental treatment specially designed to address dental anomalies in a timely and cost-effective manner.

Conclusion

Hypodontia may exhibit a familial pattern associated with certain dental anomalies in siblings; however, the multifactorial etiology of dental anomalies may result in different clinical manifestations. Some members of the same family will be affected with more severe versions of the anomaly or will have a greater number of teeth involved, while other members will suffer from other forms of dental anomalies. Further, due to the complexity and variability of genetic and environmental factors influencing dental anomalies, generalization of our findings to broader populations may not be possible. Therefore, further research is needed to address these limitations and enhance our understanding of hypodontia and associated dental anomalies. On the other hand, an interdisciplinary approach involving orthodontic, pediatric, and restorative dentists should be adopted to tackle challenges in the management of dental anomalies such as hypodontia.

Conflict of Interest

None declared.

Authors' Contributions

M.A.-A.: Conceptualization, investigation, writing – original draft, supervision, and project administration. N.D.O.: Writing – review and editing. N.A.-S.: Data curation, writing – original draft, and visualization. H.T.: Data curation, writing – original draft, and visualization. N.A.: Data curation and resources. R.E.: Data curation and resources.

Ethical Approval

This study was approved by the Ethical Committee of the School of Dentistry at the University of Jordan (IRB No. 610/2013/10) and was conducted in accordance with the World Medical Declaration of Helsinki.

Patients' Consent

Written and verbal informed consent was obtained from each parent (or guardian) for two distinct purposes: their child's participation in the research study and their child's clinical examination and treatment. Parents (or guardians) were explicitly informed that participation in the research study was voluntary and would not affect the examination or treatment their child would receive.

Data Availability Statement

Data associated with the study has not been deposited into a publicly available repository and data will be made available by the first author upon request.

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Publication History

Article published online:
23 January 2025