Introduction
============

Microdontia is a rare phenomenon. The term microdontia (microdentism, microdontism) is defined as the condition of having abnormally small teeth \[[@B1]\]. According to Boyle, \"in general microdontia, the teeth are small, the crowns short, and normal contact areas between the teeth are frequently missing\" \[[@B2]\] Shafer, Hine, and Levy \[[@B3]\] divided microdontia into three types: (1) Microdontia involving only a single tooth; (2) relative generalized microdontia due to relatively small teeth in large jaws and (3) true generalized microdontia, in which all the teeth are smaller than normal. According to these authors, aside from its occurrence in some cases of pituitary dwarfism, true generalized microdontia is exceedingly rare. Microdontia of a single tooth can be further classified into (1) microdontia of the whole tooth, (2) microdontia of the crown of the tooth, and (3) microdontia of the root alone \[[@B4]\].

Involvement of the entire dentition is rare and been reported in radiation or chemotherapeutic treatment during the developmental stage of the teeth \[[@B5]\], pituitary dwarfism \[[@B3]\] and Fanconi\'s anemia \[[@B6]\]. The syndromes associated with microdontia are Gorlin-Chaudhry-Moss syndrome, Williams\'s syndrome, Chromosome d/u, 45X \[Ullrich-Turner syndrome\], Chromosome 13\[trisomy 13\], Rothmund-Thomson syndrome, Hallermann-Streiff, Orofaciodigital syndrome (type 3), Oculo-mandibulo-facial syndrome, Tricho-Rhino-Phalangeal, type1 Branchio-oculo-facial syndrome.

Supernumerary teeth are defined as any supplementary tooth or tooth substance in addition to usual configuration of twenty deciduous and thirty two permanent teeth \[[@B7]\]. Classification of supernumerary teeth may be based on position or morphology. Positional variations include anterior mesiodens, para-premolars, para-molars and disto-molars. Variations in morphology consist of supplemental and rudimentary types \[[@B8]\].

Supernumerary teeth are common in the maxillary anterior region although supernumerary teeth have been reported in the incisor region of the mandible are very rare. Although supernumerary teeth have been reported in the incisor region of the mandible, they are very rare \[[@B9]-[@B14]\].

Conditions, in which supernumery teeth found, are cleidocranial dysplesia, cleft lip and cleft palate \[[@B15]\]. Syndromes associated with supernumery teeth are Familial adenomatous polyposis \[Gardner\'s\], Apert, Klippel-Trenaunay-Weber, Craniometaphyseal dysplasia, Trisomy 21\[Down\'s\], Nance-Horan, Orofaciodigital syndrome (type 3), Sturge-weber and Tricho-Rhino-Phalangeal, type1.

In the case described here is a bizarre generalized microdontia involving the entire dentition along with mandibular mesiodens without any other apparent systemic conditions.

Case Report
===========

The patient was a 12 year old boy, only child of consanguineous parents, reported to the department of pedodontics and preventive dentistry with the complaint of small teeth. Parents noted small teeth ever since the eruption of permanent teeth. No abnormalities were reported, however, in their extended family.

Physical examination
--------------------

Physical growth was within normal limits. The patient was of normal in stature, appearance, height, and weight for his age. Upon examination of the limbs, hands, skin, hair, nails and eyes were all appeared normal. No abnormality was noted in neck, back, muscles, cranium and joints as well. Intellectual and scholastic performance was also normal. His medical history was unremarkable; no other abnormalities were noted in the history apart from the difficult delivery. The child was examined and found to be free of any gross abnormalities.

His blood profile was normal. Serum calcium, phosphorous and alkaline phosphatase levels were also normal. Endocrinological investigation was carried out to rule in or out the possibility of hormonal disorder, and the results were within normal limits.

Intraoral examination
---------------------

The intraoral soft tissues were healthy, but the teeth were abnormal in size and shape (Figure [1](#F1){ref-type="fig"} and [2](#F2){ref-type="fig"}). Diagnostic casts were obtained to aid in diagnosis (Figure [3](#F3){ref-type="fig"}). Patient was in permanent dentition, teeth present were small in size. The patient had normal occlusion with excessive spacing between the teeth. Fully erupted mandibular mesiodens was present between the central incisors.

![**Intra oral view of the upper arch**.](1746-160X-7-19-1){#F1}

![**Intra oral view of the lower arch**.](1746-160X-7-19-2){#F2}

![**Diagnostic casts showing the morphology of the teeth**.](1746-160X-7-19-3){#F3}

The anterior teeth lacked normal size in all dimensions. Most of the anterior teeth were \"peg-shaped\" without the typical variation in mesiodistal and labiolingual dimensions. Almost all the maxillary anterior teeth did not have lingual pits whereas mandibular central and lateral incisors had prominent pits on the lingual surfaces. The posterior teeth were also small and exhibited a short occlusogingival dimension. Overall, the dentition was smaller than that of the average adult (Table [1](#T1){ref-type="table"} and [2](#T2){ref-type="table"}). Orthopantomogram or the Intra oral periapical radigraph could not be taken because the patient was not able to afford.

###### 

Comparison of buccolingual/labiolingual and mesiodistal crown dimensions with an anatomic average\* of the right side maxillary and mandibular teeth

  ----------------------------------------------------------------------------------------------------------------------------------------------
  Right side   Central incisor   Lateral incisor   Canine        First premolar   Second premolar   First molar    Second molar   Total
  ------------ ----------------- ----------------- ------------- ---------------- ----------------- -------------- -------------- --------------
  Maxillary    [MD]{.ul}\        [MD]{.ul}\        [MD]{.ul}\    [MD]{.ul}\       [MD]{.ul}\        [MD]{.ul}\     [MD]{.ul}\     [MD]{.ul}\
               LL                LL                LL            BL               BL                BL             BL             LL/BL

                                                                                                                                  

  Average      [8.5]{.ul}\       [6.5]{.ul}\       [7.5]{.ul}\   [7.0]{.ul}\      [7.0]{.ul}\       [10.0]{.ul}\   [9.0]{.ul}\    [55.5]{.ul}\
               7.0               6.0               8.0           9.0              9.0               11.0           11.0           61.0

                                                                                                                                  

  Patient      [7.5]{.ul}\       [4.7]{.ul}\       [6.9]{.ul}\   [6.4]{.ul}\      [6.5]{.ul}\       [9.5]{.ul}\    [8.7]{.ul}\    [50.2]{.ul}\
               6.1               5.6               7.4           7.8              7.7               10.4           10.9           55.9

                                                                                                                                  

  Mandible     [MD]{.ul}\        [MD]{.ul}\        [MD]{.ul}\    [MD]{.ul}\       [MD]{.ul}\        [MD]{.ul}\     [MD]{.ul}\     [MD]{.ul}\
               LL                LL                LL            BL               BL                BL             BL             LL/BL

                                                                                                                                  

  Average      [5.0]{.ul}\       [5.5]{.ul}\       [7.0]{.ul}\   [7.0]{.ul}\      [7.0]{.ul}\       [11.0]{.ul}\   [10.5]{.ul}\   [53.0]{.ul}\
               6.0               6.5               7.5           7.5              8.0               10.5           10.0           56.0

                                                                                                                                  

  Patient      [4.4]{.ul}\       [5.2]{.ul}\       [6.6]{.ul}\   [6.7]{.ul}\      [6.8]{.ul}\       [10.7]{.ul}\   [9.9]{.ul}\    [50.3]{.ul}\
               5.6               5.8               7.1           7.3              7.7               10.3           9.4            53.2
  ----------------------------------------------------------------------------------------------------------------------------------------------

Measurements in millimeters were taken at widest portion of clinical crown on diagnostic casts. \*Anatomic average taken from Wheeler, R. C.: Textbook of Dental Anatomy and Physiology, ed. 7, Philadelphia, 1993, W. B. Saunders Company, pp. 25.

###### 

Comparison of buccolingual/labiolingual and mesiodistal crown dimensions with an anatomic average\* of the left side maxillary and mandibular teeth

  ---------------------------------------------------------------------------------------------------------------------------------------------
  Left side   Central incisor   Lateral incisor   Canine        First premolar   Second premolar   First molar    Second molar   Total
  ----------- ----------------- ----------------- ------------- ---------------- ----------------- -------------- -------------- --------------
  Maxillary   [MD]{.ul}\        [MD]{.ul}\        [MD]{.ul}\    [MD]{.ul}\       [MD]{.ul}\        [MD]{.ul}\     [MD]{.ul}\     [MD]{.ul}\
              LL                LL                LL            BL               BL                BL             BL             LL/BL

                                                                                                                                 

  Average     [8.5]{.ul}\       [6.5]{.ul}\       [7.5]{.ul}\   [7.0]{.ul}\      [7.0]{.ul}\       [10.0]{.ul}\   [9.0]{.ul}\    [55.5]{.ul}\
              7.0               6.0               8.0           9.0              9.0               11.0           11.0           61.0

                                                                                                                                 

  Patient     [7.2]{.ul}\       [4.5]{.ul}\       [7.1]{.ul}\   [6.2]{.ul}\      [6.3]{.ul}\       [9.3]{.ul}\    [8.7]{.ul}\    [49.3]{.ul}\
              5.8               5.4               7.5           7.6              7.7               10.2           10.9           52.1

                                                                                                                                 

  Mandible    [MD]{.ul}\        [MD]{.ul}\        [MD]{.ul}\    [MD]{.ul}\       [MD]{.ul}\        [MD]{.ul}\     [MD]{.ul}\     [MD]{.ul}\
              LL                LL                LL            BL               BL                BL             BL             LL/BL

                                                                                                                                 

  Average     [5.0]{.ul}\       [5.5]{.ul}\       [7.0]{.ul}\   [7.0]{.ul}\      [7.0]{.ul}\       [11.0]{.ul}\   [10.5]{.ul}\   [53.0]{.ul}\
              6.0               6.5               7.5           7.5              8.0               10.5           10.0           56.0

                                                                                                                                 

  Patient     [4.2]{.ul}\       [5.3]{.ul}\       [6.7]{.ul}\   [6.7]{.ul}\      [6.8]{.ul}\       [10.7]{.ul}\   [9.6]{.ul}\    [50.0]{.ul}\
              5.7               6.1               7.3           7.2              7.7               10.2           8.9            53.1
  ---------------------------------------------------------------------------------------------------------------------------------------------

Measurements in millimeters were taken at widest portion of clinical crown on diagnostic casts. \*Anatomic average taken from Wheeler, R. C.: Textbook of Dental Anatomy and Physiology, ed. 7, Philadelphia, 1993, W. B. Saunders Company, pp. 25.

The simultaneous presence of microdontia and supernumery teeth is been reported in the Cleidocranial dysplasia, Craniometadiaphyseal dysplasia, Dermoodontodysplasia, Hypodontia and nail dysgenesis, Orofaciodigital syndrome type 3 and Tricho-rhino-phalangeal syndrome type 1. However in this case, except for the dental abnormality in the form of generalized microdontia and the presence of fully erupted mandibular mesiodens between the central incisors were found and no other clinical features observed, therefore all the syndrome associated with the simultaneous presence of microdontia and supernumery teeth were ruled out along with Taurodontism, microdontia, and dens invaginatus as well as Distal symphalangism, hypoplastic carpal bones, microdontia, dental pulp stones, narrowed zygomatic arch (Table [3](#T3){ref-type="table"}).

###### 

Comparison of conditions associated with the simultaneous presence of microdontia and supernumery teeth along with taurodontism, microdontia, and dens invaginatus as well as distal symphalangism, hypoplastic carpal bones, microdontia, dental pulp stones, narrowed zygomatic arch.

  Taurodontism, microdontia, and dens invaginatus    Cleidocranial dysplasia                            Craniometadiaphyseal dysplasia                     Dermoodontodysplasia                    Hypodontia and nail dysgenesis                   Orofaciodigital syndrome type 3                    Tricho-rhino-phalangeal syndrome type 1          Distal symphalangism, hypoplastic carpal bones, microdontia, dental pulp stones, narrowed zygomatic arch
  -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- --------------------------------------- ------------------------------------------------ -------------------------------------------------- ------------------------------------------------ ----------------------------------------------------------------------------------------------------------
  Generalized microdontia                            Autosomal dominant                                 Autosomal recessive                                Autosomal dominant                      Autosomal dominant                               Autosomal recessive                                Autosomal dominant                               Autosomal dominant
  Taurodontism of first permanent molars             Chromosome 6                                       Macrocephaly                                       Dry skin                                Chromosome 4                                     Thin/hyperconvex/hypoplastic nails                 Autosomal recessive                              Absent/small nails
  Multiple teeth with one or more dens invaginatus   Arm p                                              Frontal bossing                                    Ichthyosis                              Arm p                                            Prominent occiput                                  Chromosome 8                                     Microdontia
  X-linked recessive inheritance                     Normal height (with skeletal dysplasia)            Large fontanelle                                   Thin skin                               Dry skin                                         Frontal bossing                                    Arm q                                            Other dental abnormality
                                                     Short stature - postnatal                          Prominent eyes                                     Pigmented naevi                         Fine hair                                        Round face                                         Normal height (with skeletal dysplasia)          Abnormal clinical features of the limbs
                                                     Absent/small nails                                 Mandibular hyperostosis/sclerosis                  Abnormal hair texture                   Brittle hair/trichorrhexis nodosa/pili torti     Hypertelorism                                      Short stature - postnatal                        Brachydactyly
                                                     Macrocephaly                                       Optic nerve abnormality/atrophy                    Sparse/absent scalp hair - localised    Sparse/absent scalp hair - generalised           Down-slanting palpebral fissures                   Decreased body hair/hypotrichosis                Irregularities of length/shape of fingers
                                                     Flat occiput (brachycephaly)                       Microdontia                                        Abnormal nails                          Absent/small nails                               Other orbital abnormality                          Decreased hair pigmentation - general            Syndactyly of fingers
                                                     Frontal bossing                                    Abnormal tooth position/malocclusion/open bite     Midface hypoplasia/flat/short midface   Thin/hyperconvex/hypoplastic nails               Paresis of ocular muscles/squint                   Decreased hair pigmentation - patchy             Short foot (including brachydactyly)
                                                     Wide sutures/delayed fusion of sutures             Missing permanent teeth/retained deciduous teeth   Micrognathia/agnathia/retrognathia      Dysplastic/grooved/thick/discoloured nails       Other eye movement disorder                        Fine hair                                        Syndactyly (other than minimal 2nd and 3rd toes)
                                                     Large fontanelle                                   Anodontia/oligodontia                              Microdontia                             Depressed premaxillary region                    Broad/bulbous nasal tip                            Brittle hair/trichorrhexis nodosa/pili torti     Irregular length or shape of toes
                                                     Facies significantly abnormal                      Natal/neonatal teeth                               Anodontia/oligodontia                   Midface hypoplasia/flat/short midface            Cleft soft palate/bifid uvula/submucous cleft      Sparse/absent scalp hair - generalised           Other skull abnormality
                                                     Small face                                         Supernumerary teeth                                Supernumerary teeth                     Micrognathia/agnathia/retrognathia               Microdontia                                        High hairline - front                            Absent/small/hypoplastic carpals
                                                     Hypertelorism                                      Dental caries                                      Other dental abnormality                Absent/decreased eyebrows/lateral thinning       Abnormal tooth position/malocclusion/open bite     Thin/hyperconvex/hypoplastic nails               Symphalangism
                                                     Prominent supraorbital ridges                      Low set ears                                       Simian creases                          Absent/decreased lashes                          Supernumerary teeth                                Dysplastic/grooved/thick/discoloured nails       Cone shaped epiphyses
                                                     Depressed premaxillary region                      Scoliosis                                          Dislocated hip                          Everted/protruding lips                          Cleft/notched tongue                               Broad/bifid nails                                Symphalangism
                                                     Midface hypoplasia/flat/short midface              Bowed limbs                                                                                Tooth crown shape abnormality                    Hamartoma/other tumours of the mouth               Frontal bossing                                  Cone-shaped epiphyses of middle phalanges
                                                     Prognathism                                        Mental retardation of any degree                                                           Microdontia                                      Other abnormality of tongue/gingivae/mucosa        High forehead                                    
                                                     Depressed nasal bridge                             Boney sclerosis of any type                                                                Abnormal tooth position/malocclusion/open bite   Low set ears                                       Facies significantly abnormal                    
                                                     Paramedian/lateral cleft lip (uni/bilateral)       Multiple fractures/increased boney fragility                                               Delayed eruption of teeth                        Tragus abnormal                                    Long face                                        
                                                     Cleft soft palate/bifid uvula/submucous cleft      Enchondroma/radiolucencies - localized                                                     Anodontia/oligodontia                            Pectus excavatum (funnel chest)                    Grooved/dimpled chin                             
                                                     High vaulted and narrow palate                     Lytic/lucent lesions of bone                                                               Supernumerary teeth                              Abnormally placed nipples                          Micrognathia/agnathia/retrognathia               
                                                     [Microdontia]{.ul}                                 Fibrous dysplasia of bone                                                                                                                   Thoracolumbar general kyphosis                     Medial flare of eyebrows                         
                                                     Developmental defect of enamel                     Wide diaphyses (undertubulation)                                                                                                            Irregularities of length/shape of fingers          Absent/decreased eyebrows/lateral thinning       
                                                     Tooth discolouration                               Submetaphyseal undermodelling/expansion                                                                                                     Syndactyly of fingers                              Absent/decreased lashes                          
                                                     Delayed eruption of teeth                          Thin cortex of diaphyses                                                                                                                    Polydactyly - postaxial (ulnar)/type unspecified   Long/large nose                                  
                                                     Missing permanent teeth/retained deciduous teeth   Bowing of long bones                                                                                                                        Abnormal palmar dermatoglyphics/skin creases       Broad nasal bridge (see telecanthus)             
                                                     Supernumerary teeth                                Cartilage tongues of metaphyses - localized                                                                                                 Polydactyly of feet - postaxial/type unspecified   High nasal bridge                                
                                                     Dental cysts/tumours                               Hyperostosis/thickened/sclerotic calvarium                                                                                                  Syndactyly (other than minimal 2nd and 3rd toes)   Broad/bulbous nasal tip                          
                                                     Deafness - conductive                              Absent/abnormal sinuses                                                                                                                     Cranial nerve/nuclei                               Hypoplastic/small nostrils                       
                                                     Other hearing abnormality                          Wormian bones                                                                                                                               Mental retardation - moderate/severe               Abnormal columella                               
                                                     Narrow/sloping shoulder/hypermobile shoulders      Sclerotic/hyperostotic facial bones                                                                                                         Hypotonia                                          Thin lips                                        
                                                     Pectus excavatum (funnel chest)                    Other skull abnormality                                                                                                                     Movement disorder - dystonia/chorea/tremor/spasm   Long philtrum                                    
                                                     Bell-shaped chest                                  Hyperostotic/wide clavicle                                                                                                                  EEG abnormality                                    Deeply grooved philtrum                          
                                                     Thoracolumbar general kyphosis                     Abnormal rib structure including fusion                                                                                                     Short sternum                                      Microdontia                                      
                                                     Gibbus/localised kyphosis                          Widened ribs                                                                                                                                                                                   Abnormal tooth position/malocclusion/open bite   
                                                     Scoliosis                                          Irregular shape of pubic and ischial bones                                                                                                                                                     Supernumerary teeth                              
                                                     Hyperextensible/hypermobile joints                 Absent/hypoplastic/short femur                                                                                                                                                                 Anteverted/prominent/bat ears                    
                                                     Small hand                                         Femora short/deformed/bowed                                                                                                                                                                    Long/large ear                                   
                                                     Brachydactyly                                      Other abnormal femur                                                                                                                                                                           Pectus carinatum (pigeon chest)                  
                                                     Seizures of any type                               Bow legs - genu varum                                                                                                                                                                          Thoracolumbar general kyphosis                   
                                                     Hypotonia                                                                                                                                                                                                                                         Scoliosis                                        
                                                     Imperforate anus/anal stenosis                                                                                                                                                                                                                    Hyperextensible/hypermobile joints               
                                                     Horseshoe/fused/ectopic kidneys                                                                                                                                                                                                                   Small hand                                       
                                                     Hypospadias/epispadias                                                                                                                                                                                                                            Brachydactyly                                    
                                                     Undescended/ectopic testes                                                                                                                                                                                                                        Clinodactyly of 5th finger                       
                                                     Wilms tumour                                                                                                                                                                                                                                      Terminal hypoplasia fingers                      
                                                     Delayed skeletal maturation                                                                                                                                                                                                                       Spindle shaped/tapered fingers                   
                                                     Poorly ossified calvarium/Soft skull                                                                                                                                                                                                              Ulnar deviation of fingers                       
                                                     Absent/abnormal sinuses                                                                                                                                                                                                                           Other hand abnormality                           
                                                     Wormian bones                                                                                                                                                                                                                                     Mental retardation of any degree                 
                                                     Platybasia/basilar impression                                                                                                                                                                                                                     Abnormal cardiovascular structure/function       
                                                     Enlarged foramen magnum                                                                                                                                                                                                                           Winged/other abnormal scapula (See Shoulder)     
                                                     Small/absent scapula                                                                                                                                                                                                                              Coxa vara                                        
                                                     Winged/other abnormal scapula (See Shoulder)                                                                                                                                                                                                      Cone shaped epiphyses                            
                                                     Absent/hypoplastic clavicles                                                                                                                                                                                                                      Small femoral head epiphyses                     
                                                     Pseudarthrosis of clavicle                                                                                                                                                                                                                        Flat femoral head epiphyses                      
                                                     Short ribs (circumferential)                                                                                                                                                                                                                      Deformed/irregular femoral head epiphyses        
                                                     Under-/unossified sternum                                                                                                                                                                                                                         Broad femoral neck                               
                                                     Hypoplastic/absent ribs                                                                                                                                                                                                                           Cone-shaped epiphyses of proximal phalanges      
                                                     Dorsal wedging of vertebral bodies                                                                                                                                                                                                                Some phalanges short and deformed                
                                                     Narrow/trapezoid iliac wings (lack of flare)                                                                                                                                                                                                      Cone-shaped epiphyses of middle phalanges        
                                                     Horizontal/flat acetabular roof                                                                                                                                                                                                                   Cone-shaped epiphyses of distal phalanges        
                                                     Delayed ossification of pubic and ischial bones                                                                                                                                                                                                                                                    
                                                     Open pubic symphysis in adults                                                                                                                                                                                                                                                                     
                                                     Coxa valga                                                                                                                                                                                                                                                                                         
                                                     Coxa vara                                                                                                                                                                                                                                                                                          
                                                     Dislocated hip                                                                                                                                                                                                                                                                                     
                                                     Cone shaped epiphyses                                                                                                                                                                                                                                                                              
                                                     Fibulae a-/hypoplastic/under-/unossified                                                                                                                                                                                                                                                           
                                                     Cone-shaped epiphyses of proximal phalanges                                                                                                                                                                                                                                                        
                                                     Cone-shaped epiphyses of middle phalanges                                                                                                                                                                                                                                                          
                                                     All middle phalanges short/deformed                                                                                                                                                                                                                                                                
                                                     Cone-shaped epiphyses of distal phalanges                                                                                                                                                                                                                                                          
                                                     All distal phalanges short/deformed                                                                                                                                                                                                                                                                

A diagnosis of non-syndromic occurance of true generalized microdontia with mandibular mesiodens was made as no systemic condition was observed. The fully erupted mandibular mesiodens was extracted under local anesthesia in order to correct midline and to facilitate the orthodontic treatment.

Discussion
==========

The initiating factor or factors responsible for microdontia remain obscure. Mutation in developmental regularity genes are known to cause variety of dental defects \[[@B16]\]. Both genetic and environmental factors are involved in the complex etiology of microdontia. Genetic factors probably play a role in the formation of microdontia. Although the proband was the only child, the presence of consanguinity in the form of both parents being maternal first cousins could suggest recessive or polygenic inheritance.

The development of a tooth has been shown to have ectodermal, mesodermal, and neural crest contributions. The variation in size of a particular tooth arises during the period when the form of the tooth is being determined by the enamel organ and the sheath of hertwig at the bell stage of enamel organ. The determination of the form of the crown is thought to be related to different regions of the oral epithelium or to the ectomesenchyme. Studies have shown that different regions of the oral epithelium rather than the underlying ectomesenchyme are initially responsible for the shape of the crown \[[@B17]\]. Bones dating from the Middle Ages which were excavated at Alborg, Denmark proved evidence for generalized microdontia resulting from intrauterine growth retardation \[[@B18]\].

On the basis of visual documentation, the patient in the current case seems to have been more severely affected in all his teeth which exhibited aberrant morphology and all were smaller than normal. MEDLINE search in the English dental literature for true generalized microdontia revealed zero search results. Although child\'s mother had difficult delivery, it was insignificant and neither microdontia nor mesiodens has been reported in the literature.

The prevalence of mesiodens varies between 0.09 and 2.05% in different studies. In permanent dentition, a 0.15 to 3.8% incidence of mesiodens has been reported \[[@B19]\]. Erupted supernumerary teeth in the mandible are rare, is about 0.01% which indicated marked low value \[[@B20]\]. Supernumerary teeth in the mandible anterior region in this case is fully erupted which is unusual.

Sexual dimorphism is reported by most authors with males being more commonly affected. Hogstrum and Andersson \[[@B21]\] reported a 2:1 ratio of sex distribution. A study of supernumerary teeth in Asian school children found a greater male to female distribution of 6.5:1 for Hong Kong children \[[@B22]\] which indicates that supernumery teeth is more common in males than females which is consistent in our case.

Non-syndromic multiple supernumerary teeth occur most frequently in the mandible region especially premolar region followed by molar and anterior region \[[@B9]\]. Few cases of non-syndrome multiple supernumery teeth have been reported \[[@B23],[@B24]\] however in the present case non-syndromic single supernumerary tooth was observed in the mandibular anterior region.

Evidence regarding etiology of mesiodens indicates that genetic susceptibility together with environmental factors might increase the activity of dental lamina leading to formation of the extra tooth/teeth \[[@B19]\]. A number of theories have been proposed as regards the causes of the occurrence of supernumerary teeth: 1\] Atavism theory \[[@B8],[@B24],[@B25]\] 2\] Independent hyperactivity of the dental lamina \[[@B24],[@B25]\] and 3\] Dichotomy of the tooth bud are also suggested as a possible etiological factors \[[@B8],[@B25]\]. However, none of these theories alone offers a sufficient explanation for this phenomenon.

Since mesiodens may interfere with normal occlusal development, in the present case an early diagnosis could have prevented the lower diastema formation. Early diagnosis and treatment of patients with supernumerary teeth are important to prevent or minimize complications.

As the patient did not show any abnormal systemic manifestations, all the syndrome associated with the dental anomalies were ruled out. The simultaneous presence of supernumerary teeth and the generalized microdontia is very rare. To our knowledge, this is the first such case of non-syndromic occurance of true generalized microdontia in association with mandibular mesiodens. Such unusual nature of dental anomaly has not been reported so far in the literature.

Conclusion
==========

The dental finding seen in this case is certainly rare. The case is also sporadic, with no positive family history. The wide variation in clinical manifestations in cases of non-syndromic occurrence of dental anomalies is challenging and is an area for further research. Mesiodens are familiar to pediatric dentists and orthodontists as one of the more common anomalies to affect the developing dentition and it demands a multidisciplinary assessment.

Consent
=======

Written informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests
===================

The authors declare that they have no competing interests.

Authors\' contributions
=======================

SB and SK drafted the manuscript paper, analysed the patient\'s history and contributed to the writing of the final version as well as extracted the mesiodens. Each author reviewed the paper for content and contributed to the writing of the manuscript. All authors approved the final report.

Acknowledgements
================

The authors also wish to thank the patient and their family for their contribution to this article. Written consent for publication was obtained from the patient\'s parent.
