Prevalence of Congenitally Missing Lateral Incisors and Peg Laterals in Patients Receiving Orthodontic Treatment

Introduction: Maxillary lateral incisor is a common congenitally missing tooth in the oral cavity. Maxillary lateral incisor is also the most common varying tooth in form than any other tooth. The objective of the study is to estimate the prevalence of congenitally missing maxillary lateral incisors and peg laterals in patients receiving orthodontic treatment. Materials & Method: This is a cross sectional retrospective study carried out among 204 orthodontic patients. Panoramic radiographs taken during the diagnostic procedure of orthodontic treatment was used to confirm the presence or absence of lateral incisors. The presence of peg laterals was determined by dental casts. Result: Prevalence of missing maxillary lateral incisors and peg laterals was found 2.5% and 3.9% respectively. Prevalence of missing lateral in male was 5.7% while among female no missing laterals were observed. Prevalence of peg laterals in male and female was 1.1% and 6% respectively. Among the missing lateral incisors, prevalence of bilaterally missing lateral incisors was 60% while prevalence of both right and left unilateral missing laterals was 20%. Among the peg laterals, bilateral peg laterals were present in 50% patients, followed by left unilateral 37.5% and right unilateral 12.5% peg laterals. Conclusion: The present study shows higher prevalence of peg laterals than missing lateral incisors. Prevalence of missing lateral incisors was higher in male and prevalence of peg laterals was higher in female. Prevalence of bilaterally missing laterals and bilateral peg laterals was higher than unilateral presentation.


INTRODUCTION
lateral incisors and peg laterals in patients receiving orthodontic treatment. belonged to Muslim community( Figure 1).

MATERIALS AND METHOD
Prevalence of missing maxillary lateral incisors and peg laterals was 2.5% (5) and 3.9% (8) respectively ( Figure 2 and Figure 3) which shows that prevalence of peg laterals in orthodontic patients was higher than missing lateral incisors.
Distribution of the missing laterals and peg laterals according to the site is shown in Figure 4 and Figure 5.
Prevalence of missing lateral in male was 5.7% (5) while among female no missing laterals were observed.
Prevalence of missing lateral incisors was higher in male which was statistically significant(p<0.05). Prevalence of peg laterals in male and female was 1.1% (1) and 6% (7) respectively. Prevalence of peg laterals was higher in female which was statistically significant (p<0.05). Among the patients with missing laterals 100% (5) were male and among the patients of peg laterals 25% (2) were male and 75% (6) were female. Furthermore, 40% (2) of missing lateral cases and 12.5%(1) peg lateral cases were associated with other missing teeth. showing a prevalence of 20.7%. 5 Maxillary lateral incisor is the second most frequently missing tooth, followed by the mandibular second premolar, maxillary second premolar and mandibular incisor. 11 In the present study prevalence of missing laterals was 2.5% (5) (Figure 2). Prevalence among male was 5.7% (5) while prevalence among female was 0. All the patients having missing lateral incisors were male. Frequency of the missing lateral incisors has been found 0.3% to 11.3% in different populations. 3 In a study done in Portuguese population prevalence of missing lateral incisors was found 1.3%. 2 The prevalence for missing maxillary lateral incisors was 1.91% in dental patients in study done by Arandi NZ et al. 7 In the same study prevalenceof missing lateral incisors in males was 1.7% and in females was 2.1% which is in contrast with our study. 7 In a similar study done in orthodontic patients prevalence of missing lateral incisor was 9.42%. 3 In contrast to our findings, of patients with agenesis, 44.12% were female and 55.88% were male. 3 In another study done in Iranian population the prevalence of missing maxillary lateral incisor was 18.94%. 12 Prevalence of missing teeth was found in 12.6% of the patient receiving orthodontic treatment in a tertiary care center of Nepal. Among the missing teeth maxillary lateral incisors were found to be the most commonly missing tooth excluding third molars. 9 These finding demonstrate there is great variation in prevalence of missing lateral in incisors in different population.

DISCUSSION
Prevalence of bilateral missing laterals was 60% (3)  suggest that that bilateral missing lateral is more common than unilateral expression.
In the present study the prevalence of peg lateral in orthodontic patient was found 3.9% (8) (Figure3). Among the patients having peg laterals 25%(2) were male and 6(75%) were female. In similar studies done on orthodontic patients the prevalence of peg laterals was found 1.3% and 5.26% respectively. 3,4 In a systematic meta-analysis of prevalence of the peg lateral incisors, prevalence in general population, dental patients and orthodontic patients were pooled at 1.6%, 1.9% and 2.7% respectively. 13 These studies also demonstrate higher prevalence in female compared to male which was also observed in our study. 3,4,13 In the present study, among the total peg laterals observed bilateral peg laterals was present in 50% (4) which was followed by left unilateral 37.5%(3) and right unilateral 12.5%(1) peg lateral. Similar to these findings other studies also show higher prevalence of bilateral peg lateral followed by unilateral left and right peg lateral. 3,4 Congenitally missing lateral incisors whether unilateral or bilateral may affect the self-esteem and social relationships of the affected individual along with some esthetic and functional problems. Absence of maxillary lateral incisors may also cause a diastema between the central incisors, spacing between permanent incisor and canine, mesial migration of canines, midline shift in case of a unilateral missing tooth. 6 Similarly peg laterals also pose esthetic and functional problems. Early recognition of a tooth agenesis is helpful in order to provide adequate treatment and prevent a developing malocclusion. 4 Treatment of missing lateral and peg laterals can include orthodontic space opening or closure before prosthetic therapy, using adhesive restorative techniques, removable or fixed partial dentures, implant supported restorations, or combinations of this approaches. 1 The data in this study is from a single institution so it may have some limitations. Hence a multi-centric data with larger sample size may overcome this limitation.

CONCLUSION
The present study shows higher prevalence of peg laterals than missing lateral incisors. Prevalence of missing lateral incisor was higher in male. Prevalence of peg lateral was higher in female. Prevalence of bilaterally missing laterals and bilateral peg laterals was higher than unilateral presentation.

ACKNOWLEDGEMENT
We would like to acknowledge Dr Sanzee Silwal, Dr Puja Shah, Dr Asal Acharya, Dr Anju Agrawal, Dr Diwash Adhikari and Dr Ravi Ranjan Kumar Rajak for their contributions in data collection.