*3.6.2 Impacted canines*

The canines on the cleft side are often palatally impacted. It has been suggested that the impaction may be due to the palatal collapse of the maxillary lateral segment [89] or related to the genetic factor responsible for CLP [91].

Lai et al. suggested that when the lateral incisor is located distal to the cleft, it can provide guidance for the eruption of the adjacent canine [47].

## *3.6.3 Ectopic eruption*

Ectopic eruption of teeth, including transposition has also been reported in patients with CLP [62, 90, 92, 93].

**11**

*Dental Development and Anomalies in Cleft Lip and Palate*

Since a high prevalence of dental anomalies was found at the region of the cleft, these anomalies may be attributed to the cleft itself or to the early surgical correction of the defects. The severity of these anomalies also appears to be related to the

As the increased prevalence of dental anomalies was also found in the noncleft region, it was postulated that dental anomalies in CLP patients were affected by common developmental mechanisms that involved non-fusion of orofacial processes and the persistence of orofacial clefts during embryonic and foetal formation. Extensive studies on orofacial clefting have linked genetic susceptibility, signalling pathways and transcription factors in the regulation of -lip, palate and

Multiple disruptions in development of a number of body tissues including the dental lamina result in frequent occurrences of dental anomalies together with and

This has led to several studies investigating the presence of dental anomalies in parents and siblings of CLP children, of which, the results have been conflicting to date. Both Jordan et al. [53] and Schroeder and Green [54] reported a higher than normal frequency of occurrence of dental anomalies in the siblings of affected CLP individuals than in the general population. More recently, Eerens et al. reported significantly higher frequency of hypodontia and asymmetric tooth formation in both cleft and unaffected sibling groups compared with normal controls [41].

On the other hand, Woolf et al. observed that the incidence of maxillary lateral incisor abnormalities in parents' dentition was similar to non-cleft controls [58]. Mills et al. demonstrated no significant differences in the oral and facial defects

Anderson and Moss similarly found no evidence to suggest that parents of CLP children have a higher incidence of dental abnormalities than the general population and suggested that the genes carried by the non-cleft parents of CLP cases do not produce dental manifestations [60]. This could be because the genetics of odontogenesis is complex and is influenced by many factors, genes, epigenetics, and

It has been well-documented in the literature that CLP patients often present with delayed dental development and tooth eruption, asymmetric tooth formation and dental anomalies like hypodontia, supernumerary teeth, malformed or missing lateral incisor at the cleft region. However, there are minor controversies regarding gender differences, teeth most commonly affected, and differences in the develop-

The coming together of genetic, epigenetic and environmental factors seem to play an important role in the sequential pathway of orofacial and dental formation. Cell differentiation, proliferation and migration, as well as timing and fusion impact on the development of the lip, palate and dentition. Perturbations in the highly orchestrated mechanisms result in orofacial, dental and systemic organ defects.

several other visceral and skeletal anomalies in CLP children [41, 98, 99].

*DOI: http://dx.doi.org/10.5772/intechopen.88310*

**3.7 Aetiology of dental anomalies**

*3.7.1 Cleft defect and surgical trauma*

dentition development [94–97].

between cleft and non-cleft families [59].

environmental factors [60, 100, 101].

ment of maxillary and mandibular teeth.

**4. Conclusion**

severity of the cleft.

*3.7.2 Genetic factors*
