• Users Online: 1091
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 

 Table of Contents  
Year : 2016  |  Volume : 7  |  Issue : 3  |  Page : 101-104

Midline diastema

Department of Orthodontics, Saveetha Dental College, Chennai, Tamil Nadu, India

Date of Web Publication18-Oct-2016

Correspondence Address:
M Ketaki Kamath
D5, Sneha Sadan, #3 Karpagam Avenue, Chennai - 600 028, Tamil Nadu
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2349-5243.192532

Rights and Permissions

Midline diastema is a space between the maxillary and/or mandibular central incisors. Midline diastema can be due to various causes such as genetic, environmental, and so on. Proper history taking and correct diagnosis of the etiology of the diastema is essential to ensure that the orthodontic correction is successful, and no future relapse takes place. The presence of diastema between the central incisors in the adult patient has esthetics and malocclusion concerns.

Keywords: Etiology; midline diastema; stability

How to cite this article:
Kamath M K, Arun A V. Midline diastema. Int J Orthod Rehabil 2016;7:101-4

How to cite this URL:
Kamath M K, Arun A V. Midline diastema. Int J Orthod Rehabil [serial online] 2016 [cited 2024 Feb 26];7:101-4. Available from: https://www.orthodrehab.org/text.asp?2016/7/3/101/192532

  Introduction Top

Angle described the dental midline diastema as a rather common form of incomplete occlusion characterized by a space between the maxillary and less frequently the mandibular central incisors. [1]

Broadbent described the maxillary midline diastema in growing children as unaesthetically pleasing and termed it as the "ugly duckling" stage of dental development. He considered this stage as a phase which underwent spontaneous closure with the complete eruption of lateral incisors and canines. [2]

For some individuals, the diastema does not close spontaneously. [3]

The extent and the cause of the diastema must be properly evaluated. Proper case selection, appropriate treatment selection, adequate patient cooperation, and good oral hygiene are crucial to the treatment success. [4]

Clinical diagnosis is important and should compulsorily include a radiographic examination. During the "ugly duckling" phase, the long axes of the roots of the maxillary central and lateral incisors converge toward [5] and which often misguides practitioners to a diagnosis of a diastema caused by a hypertrophic labial frenum. [6]

Enlarged labial frena have been considered to be a contributing factor for a majority of persistent diastemas, but this has now been attributed only to the small proportion of cases. Other etiologies related to diastema include oral habits, muscular imbalances, physical obstructions, abnormal maxillary arch structure, and various dental anomalies. [4]

According to Taylor, 98% children 6 years of age presented with a midline diastema. As age increased, the percentage of diastema significantly decreased being 48.7% of children in the age group of 10-11 years old and 7% in the age group of 12-18 years. [7]

Effective treatment of diastema requires an accurate diagnosis of its etiology and a treatment plan that is related to that specific etiology, including medical and dental histories, radiographic and clinical examinations and probably tooth-size evaluations. [4]

  Etiology and Effective Treatment Options Top

Timing of the treatment is important to achieve satisfactory results. Most of the researchers do not advise tooth movement until the eruption of the permanent canines. [8] However, in selected cases, where very large diastemas exist, early treatment can be contemplated.

  Genetics Top

"Heritability" is defined as the ratio of the total genotypic diversity to the total phenotypic diversity with values ranging from 0 to 1. [9]

Gass et al. noted that heritability of midline diastema was 0.32% for the white population and 0.04% for the black population. [10]

Incomplete palatal fusion and cystic formations have been attributed to the cause of midline diastema. [11]

Many other authors like Gardiner [12] and Schmitt et al. [13] suggested that genetics could be a cause for midline diastema.

  Hypertrophic Labial Frenum Top

The most common factor associated with maxillary midline diastema is a hypertrophic labial frenum. [14],[15]

A maxillary midline diastema may be caused by the attachment of the labial frenum into the notch in the alveolar bone so that a band of heavy fibrous tissue lies between the central incisors. [15] The two central incisors may erupt widely parted from one another, and the rim of bone surrounding each tooth may not extend till the median suture. In such cases, bone is not deposited inferior to the frenum. A V-shaped bony cleft exists between the two central incisors, and an "abnormal" frenum attachment typically results. [16] Transseptal fibers fail to multiply across the midline cleft, and space might never close. [17]

According to Angle, [18] the maxillary midline diastema is caused by a high labial frenum, but the stability of space closure is not influenced by frenum excision. Sicher [19] and Gardiner [12] also supported this view.

This was contradicted by Tait who stated that high frenum is an effect and not a cause for the incidence of diastema. [20]

Ceremello compared the frena of two groups, one with diastemas and the other without. [18] He found no association between frenum attachment and diastema width, between frenum width and diastema, or between frenum height and frenum width. Dewel established the same results in a similar study. [21]

The blanching test is a simple investigative assessment to predict whether a normal tight contact is a present between the central incisors. [22]

  Peg Laterals Top

Bolton discrepancy (tooth-size discrepancy) is an alternative cause of midline diastema regularly reported in the literature. Bishara, [23] Becker, [24] and Oesterle and Shellhart [25] termed tooth-size discrepancy as one of the main causes for maxillary midline diastema. According to them, the presence of peg-shaped lateral incisors results in distal tipping of central incisors, hence producing the midline diastema. [23],[24],[25]

Midline diastema caused due to peg laterals can be closed, and the space required for restoration of the peg-shaped lateral can be obtained by moving the peg lateral into position between the central incisor and the cuspid. [26],[27]

  Anterior Traumatic Bite Top

Excessive anterior overbite is another chief causative factor for midline diastema. [28] Trauma to the maxillary anteriors from the mandibular incisors causes the maxillary incisors to procline resulting in an increase in the upper arch circumference, leading to diastema.

When there is no Bolton discrepancy and the patient has an Angle's Class I occlusion, an increase in the anterior overbite outcome will either increase the upper arch circumference leading to diastema or anterior mandibular crowding. This occurrence is due to the wedge-shaped lingual surface of upper central incisors. [28] Excessive anterior overbite can be due to a disproportionate vertical alveolar growth of the mandibular or the maxillary incisors, the insufficient vertical dimension of posterior occlusion (molars) and skeletal conditions such as augmented ramal height. [28]

  Oral Habits Top

Finger sucking and/or abnormal tongue movement may result in interincisal spacing.

According to Proffit and Fields, [29] tongue position at rest may have a bigger impact on tooth position compared to tongue pressure, as the tongue only temporarily contacts the lingual surface of the anterior teeth while thrusting. The tongue pushes the anterior teeth to a forward position, increasing the circumference which results in spacing.

  Supernumerary Teeth Top

A mesiodens is a supernumerary tooth which occurs in the midline between the two maxillary central incisors. [30] A mesiodens accounts for 80% of all supernumerary teeth.

The presence of a mesiodens can inhibit the close approximation of the central incisors resulting in a midline diastema and can also give way to several other complications such as impaction, delayed and ectopic eruption of adjacent teeth, crowding, axial rotation, displacement, radicular resorption of adjacent teeth, and dentigerous cyst. [31]

Russel and Folwarczna have recommended the extraction of a mesiodens in the early mixed dentition period. According to them, this will aid in improved alignment of teeth and will also minimize the requirement for orthodontic treatment. [32] However, some authors such as Mitchell and Bennett prefer the late extraction of mesiodens when the adjacent permanent incisors have finished their root formation. [33]

Developmental cysts in the orofacial midline

An odontogenic keratocyst can develop in the maxilla and can dislodge teeth, leading to spacing in the anterior region. [34] A median palatal cyst is another midline structure which is a rare cyst commencing from the epithelium trapped along the line of fusion of the lateral palatal maxillary process during growth. [35],[36]

Abnormal maxillary arch structure

Tooth size discrepancies are caused by disproportionately large maxillary arch or bony defects that impede approximation of the incisors. [4] The presence of large jaws and normal or small teeth can be attributed to inherited characteristics. However, in a few cases, it can be due to endocrine imbalances. Conditions such as acromegaly can cause unusually large jaws comparative to the teeth size. Normal-sized jaws and small teeth can also result in generalized spacing. [37]

Muscular imbalances in the oral region

The dentition is in equilibrium between the various forces from the intraoral and extraoral soft tissues. The muscular imbalance in the oral region can disrupt this balance and cause the teeth to move until the forces achieve a new equilibrium. In patients with hypotonic lips, the teeth may drift and remain in a labial or buccal position owing to the tongue pressure which leads to wide, ovoid arches deprived of interproximal teeth contact. [38]

  Diagnosis and Treatment Top

Because of the likelihood for multiple etiologies, the diagnosis of a diastema must be founded on systematic medical/dental history, clinical inspection, and radiographic assessment. A nominal diastema treatment requires the precise diagnosis of its etiology and a medication that is appropriate to that specific etiology including medical and dental histories, radiographic and clinical examinations and also tooth-size evaluations. [4] Diagnostic study models also may be essential for analysis.

The treatment objectives are principally attributed to esthetic and psychological reasons rather than functional reasons. Although it is frequently the case, treatment plan should not be selected empirically but should rather be based on adequate scientific documentation. The ideal treatment should deal not only with the diastema but also with the cause of the diastema. Regardless of the selected treatment, of the stability of treatment results has always been deliberated. [39]

Various techniques can be used for diastema closure. Some of the methods that have been proposed for the closure of unaesthetic diastemas involve the usage of fixed or removable appliances, elastics, composite build-ups and brass wires placed around the central incisors and gradually tightened until the diastema is closed. [40]

Stability after diastema closure

Relapse is a major factor to be considered in the treatment of midline diastema. Meticulous diagnosis and elimination of the etiology is the key to gaining a stable result. Long-term use of retainers or the use of permanent bonded lingual retainers have been encouraged, especially in cases with large diastema. [41],[42],[43],[44] Large pretreatment diastema and the existence of at least one family member with a related condition increases the risk of relapse. [45]

  Conclusion Top

Considering the different views related to uneventful dental development, it is concluded that an initial presence of midline diastema is not a matter of concern. However, when the diastema is larger than 2.7 mm even after the eruption of lateral incisors, orthodontic intervention may be necessary. Timing often is significant to achieve satisfactory results. Several etiological factors are conveyed and debated in literature, and no single etiological factor is decided upon for the development of a midline diastema. Elimination of the etiologic agent usually can be commenced on diagnosis and after the adequate development of the central incisors. Tooth movement usually is postponed until the eruption of the permanent canines, but can begin premature in certain cases with very large diastemas. Retention procedure should be subject to the size and the etiology of the midline diastema.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Andrews LF. The six keys to normal occlusion. Am J Orthod 1972;62:296-309.  Back to cited text no. 1
Broadbent BH. Ontogenic development of occlusion. Angle Orthod 1941;11:223-41.  Back to cited text no. 2
Broadbent BH. The face of the normal child (diagnosis, development). Angle Orthod 1937;7:183-208.  Back to cited text no. 3
Huang WJ, Creath CJ. The midline diastema: A review of its etiology and treatment. Pediatr Dent 1995;17:171-9.  Back to cited text no. 4
Higley LB. Maxillary labial frenum and midline diastema. ASDC J Dent Child 1969;36:413-4.  Back to cited text no. 5
Madruga AE, Michalski CZ, Tanaka O. Midmaxillary interíndsal diastema and its relationship to the superior labial frenum. Rev ABO Natl 2005;12:360-4.  Back to cited text no. 6
Taylor JE. Clinical observations relating to the normal and abnormal frenum labii superians. Am J Orthod 1939;25:646-60.  Back to cited text no. 7
Baum AT. The midline diastema. J Oral Med 1966;21:30-9.  Back to cited text no. 8
Moullas AT. Maxillary midline diastema: A contemporary review. Hellenic Orthod Rev 2005;8:93-103.  Back to cited text no. 9
Gass JR, Valiathan M, Tiwari HK, Hans MG, Elston RC. Familial correlations and heritability of maxillary midline diastema. Am J Orthod Dentofacial Orthop 2003;123:35-9.  Back to cited text no. 10
Stubley R. The influence of transseptal fibers on incisor position and diastema formation. Am J Orthod 1976;70:645-62.  Back to cited text no. 11
Gardiner JH. Midline spaces. Dent Pract Dent Rec 1967;17:287-97.  Back to cited text no. 12
Schmitt E, Gillenwater JY, Kelly TE. An autosomal dominant syndrome of radial hypoplasia, triphalangeal thumbs, hypospadias, and maxillary diastema. Am J Med Genet 1982;13:63-9.  Back to cited text no. 13
Kaimenyi JT. Occurrence of midline diastema and frenum attachments amongst school children in Nairobi, Kenya. Indian J Dent Res 1998;9:67-71.  Back to cited text no. 14
Adams CP. The relation of spacing of the upper central incisors to abnormal labial frenum and other features of the dento-facial complex. Dent Pract Dent Rec 1954;74:72-86.  Back to cited text no. 15
Dewel BF. The labial frenum, midline diastema, and palatine papilla: A clinical analysis. Dent Clin North Am 1966:175-84.  Back to cited text no. 16
Edwards JG. The diastema, the frenum, the frenectomy: A clinical study. Am J Orthod 1977;71:489-508.  Back to cited text no. 17
Angle EH. In: Treatment of Malocclusion of the Teeth. 7 th ed. Philadelphia: S.S. White Dental Manufacturing Co.; 1907. p. 167.  Back to cited text no. 18
Sicher H. Oral Anatomy. 2 nd ed. St. Louis: CV Mosby Company; 1952. p. 73-5.  Back to cited text no. 19
Tait CH. The median frenum of the upper lip and its influence on the spacing of the upper central incisor teeth. Dent Cosm 1934;76:991-2.  Back to cited text no. 20
Ceremello PJ. The superior labial frenum and the midline diastema and their relation to growth and development of the oral structures. Am J Orthod 1933;39:120-39.  Back to cited text no. 21
Koora K, Muthu MS, Rathna PV. Spontaneous closure of midline diastema following frenectomy. J Indian Soc Pedod Prev Dent 2007;25:23-6.  Back to cited text no. 22
[PUBMED]  Medknow Journal  
Bishara SE. Management of diastemas in orthodontics. Am J Orthod 1972;61:55-63.  Back to cited text no. 23
Becker A. The median diastema. Dent Clin North Am 1978;22:685-710.  Back to cited text no. 24
Oesterle LJ, Shellhart WC. Maxillary midline diastemas: A look at the causes. J Am Dent Assoc 1999;130:85-94.  Back to cited text no. 25
Miller WB, McLendon WJ, Hines FB 3 rd . Two treatment approaches for missing or peg-shaped maxillary lateral incisors: A case study on identical twins. Am J Orthod Dentofacial Orthop 1987;92:249-56.  Back to cited text no. 26
Counihan D. The orthodontic restorative management of the peg-lateral. Dent Update 2000;27:250-6.  Back to cited text no. 27
Nielsen IL. Vertical malocclusions : e0 tiology, development, diagnosis and some aspects of treatment. Angle Orthod 1991;61:247-60.  Back to cited text no. 28
Proffit WR, Fields HW. Contemporary Orthodontics. 2 nd ed. St. Louis: Mosby Yearbook; 1993. p. 467.  Back to cited text no. 29
Sykaras SN. Mesiodens in primary and permanent dentitions. Report of a case. Oral Surg Oral Med Oral Pathol 1975;39:870-4.  Back to cited text no. 30
Liu JF. Characteristics of premaxillary supernumerary teeth: A survey of 112 cases. ASDC J Dent Child 1995;62:262-5.  Back to cited text no. 31
Russell KA, Folwarczna MA. Mesiodens - Diagnosis and management of a common supernumerary tooth. J Can Dent Assoc 2003;69:362-6.  Back to cited text no. 32
Mitchell L, Bennett TG. Supernumerary teeth causing delayed eruption - A retrospective study. Br J Orthod 1992;19:41-6.  Back to cited text no. 33
Neville BW, Damm DD, Brock T. Odontogenic keratocysts of the midline maxillary region. J Oral Maxillofac Surg 1997;55:340-4.  Back to cited text no. 34
Hadi U, Younes A, Ghosseini S, Tawil A. Median palatine cyst: An unusual presentation of a rare entity. Br J Oral Maxillofac Surg 2001;39:278-81.  Back to cited text no. 35
Manzon S, Graffeo M, Philbert R. Median palatal cyst: Case report and review of literature. J Oral Maxillofac Surg 2009;67:926-30.  Back to cited text no. 36
Abraham R, Kamath G. Midline diastema and its aetiology - A review. Dent Update 2014;41:457-60, 462-4.  Back to cited text no. 37
Lamberton CM, Reichart PA, Triratananimit P. Bimaxillary protrusion as a pathologic problem in the Thai. Am J Orthod 1980;77:320-9.  Back to cited text no. 38
Gkantidis N, Kolokitha OE, Topouzelis N. Management of maxillary midline diastema with emphasis on etiology. J Clin Pediatr Dent 2008;32:265-72.  Back to cited text no. 39
Tanaka OM, Clabaugh R 3 rd, Sotiropoulos GG. Management of a relapsed midline diastema in one visit. J Clin Orthod 2012;46:570-1.  Back to cited text no. 40
Durbin DD. Relapse and the need for permanent fixed retention. J Clin Orthod 2001;35:723-7.  Back to cited text no. 41
Bearn DR. Bonded orthodontic retainers: A review. Am J Orthod Dentofacial Orthop 1995;108:207-13.  Back to cited text no. 42
Mulligan TF. Diastema closure and long-term stability. J Clin Orthod 2003;37:560-74.  Back to cited text no. 43
Zachrisson BU. Important aspects of long-term stability. J Clin Orthod 1997;31:562-83.  Back to cited text no. 44
Shashua D, Artun J. Relapse after orthodontic correction of maxillary median diastema: A follow-up evaluation of consecutive cases. Angle Orthod 1999;69:257-63.  Back to cited text no. 45

This article has been cited by
1 Associations among the occurrence or types of maxillary canine impaction, labial frenum attachment types, lateral incisor anomalies, and midline diastema in patients with and without impaction: A case-control study
Mohamad Ali Ranjbaran, Farzin Aslani, Alireza Jafari-Naeimi, Vahid Rakhshan
International Orthodontics. 2023; 21(2): 100743
[Pubmed] | [DOI]
2 Early removal of supernumeraries to close a midline diastema: a case report
Laura Brooks, Kelly Smorthit, Jonathan Sandler
Orthodontic Update. 2023; 16(1): 46
[Pubmed] | [DOI]
3 Ön Bölge Orta Hat Diastemasi: Etyoloji ve Tedavi Seçenekleri- Olgu Raporu
Aysenur ÇELIK, Sinem AKGÜL, Oya BALA
Selcuk Dental Journal. 2022; 9(4): 64
[Pubmed] | [DOI]
4 Midline diastema: A brief overview of its aetiology and management
Sneha Lopes
BDJ Student. 2022; 29(3): 26
[Pubmed] | [DOI]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  In this article
Etiology and Eff...
Hypertrophic Lab...
Peg Laterals
Anterior Traumat...
Oral Habits
Supernumerary Teeth
Diagnosis and Tr...

 Article Access Statistics
    PDF Downloaded1770    
    Comments [Add]    
    Cited by others 4    

Recommend this journal