Authors : Dr. Arun Garg, Dr. Krishna Nayak
Cleft lip and palate is one of the most common congenital anomalies of the face and an orthodontist plays an integral role in the multidisciplinary team approach required for the management of these patients. With a cleft lip and palate patient, the tendency is to concentrate on the growth of the maxilla and to forget that the mandibular growth and its direction are equally important and may enhance or hurt efforts to achieve good facial profile relationships as well as desirable occlusal relationships. The position, growth and configuration of the lower jaw are equally important to the aesthetic appearance of the face.
The objective of the present study is to evaluate the variation of mandibular morphology and spatial position in cleft lip and palate patients when compared to a control group through lateral cephalometric radiographs.
Subjects and Methods:
Materials for the study were the lateral cephalomatric radiographs of 38 patients who reported to department of orthodontics and dentofacial orthopaedics. All patients displayed cleft lip and palate, all in permanent dentition and without a history of pre-orthodontic treatment. Non growing individuals were selected to standardise the influence of growth.
(Mean age): 19 years and 04 months-- Males
19 years and 03 months-- Females
consisted of 45 adult (20 females and 25 males) without any gross malocclusion and all were in the permanent dentition
(Mean age): 17 years and 07 months -- Males
17 years and 02 months-- Females
Lateral cephalograms were taken and various cephalometric parameters (both linear and angular) were used to evaluate them.
Cephalometric landmarks (Figure 1)
Following measurements were made (Figure 2)
3) Spatial position of Mandible in relation to Anterior Cranial Fossa
Two way analysis of variance was used to observe the difference between group means. Comparisons between the cleft group and control group were undertaken with large sample test.
|Cephalometric Parameter||Non Cleft (N = 45)||Cleft Lip And Palate(N = 38)||Differences In Mean|
|Go – Gn||81.9||5.11||75.3||6.03||6.6|
|Co – Go||63.6||4.69||55.7||6.1||7.9|
|Co – Gn||128.1||6.70||120.6||8.0||7.4|
|Go – Gn||1.98||Significant|
|Co – Go||1.98||Significant|
|Co – Gn||1.98||Significant|
Analysis of the results shows significant difference in structure and spatial relation of the mandible in cleft lip and palate individuals when compared to the non-cleft individuals. This is in agreement with Jain1, Horowitz2and Bishara3.
In the cleft group the mandibular dimension at the level of the ramus (S-Go, Co-Go), the body (Go-Gn) and the total length (Co-Gn) was found to be smaller. The mandible showed besides the short ramus and body length, a more vertical growth pattern. These findings can be confirmed by decreased posterior facial height (S-Go), greater anterior facial height (N-Me), more obtuse gonial angle (Co-Go-Me) and a downward and backward rotation of the mandible relative to the cranial base (Sn-Go-Gn).This is in agreement with the previous studies done by Hayashi4, Smahel5, Clarke6, Roth7and Rantha8 and many other similar studies.
Concerning the antero-posterior spatial relationship of mandible to the cranial base (SNB), cleft group showed a significant posterior repositioning of the mandible when compared to subjects without clefts. This is due to greater downward and backward rotation of the mandible, leading to a more posterior position of landmark B. During the mixed dentition period when the maxillary segments are displaced medially, tongue cannot be accommodated in its normal position in the palate. The position acquired by the tongue becomes decisive for the pattern of further development of the maxilla as well as the mandible. Here if the nasal respiration is impeded the tongue may assume a low position to facilitate normal respiration. If the tongue in the low position does not rest under the occlusal surface of the maxillary teeth, the alveolar height will increase, resulting in a progressive lowering of the mandible, a more open gonial angle and a more retruded position of the chin. The shorter mandibular length is being attempted to be compensated by a short cranial base length. Besides the shorter ramus and body lengths, a more vertical growth pattern is seen in cleft group.
Not only is the extent or amount of lower jaw growth but also the direction of mandibular growth is important and deserves equal consideration while deciding what orthodontics can do to improve the function as well as the facial appearance of the cleft lip and palate individual .Clinically, such knowledge can be helpful in estimating the eventual mandibular position following growth and providing improved insight into treatment modalities that might be best suited for any individual patient. In formulating a treatment plan of any growing patient, it is mandatory for the operator to know about the growth and development of the craniofacial skeleton and thus predict with various methods as to what the final outcome will be without any treatment. For growth predictions in cleft lip and palate cases, one needs to know the altered pattern of growth which has taken place in all dimensions.
A cleft lip and palate patient usually show a retrognathic or concave profile and is managed with a reverse pull headgear with simultaneous palatal expansion appliances. In such cases, it is to be determined, whether the mandible should be held back during the above treatment and if so, how long to achieve an acceptable maxillo - mandibular relationship and hence an acceptable profile. Usually, in non growing patients who need an orthodontic - orthognathic approach to correct the concave profile, the morphology and spatial position of maxilla and mandible should be known to determine, how much to decompensate, which arch to do surgery, in which direction and the amount of push back or advancement to be made.
It is believed that there are many roads leading to Rome, hence it is to be accepted that many different treatment strategies and techniques may produce good results. Choosing from more than one approach may open the door to a better understanding of the various treatment strategies and their applications. This option should encourage us to explore more unorthodox ideas and approaches.
Care for the individual with a cleft continues throughout the life time of that individual. Levels of clinical success have improved a lot over the years and achieving ideal results is becoming a more frequent possibility. Orthodontics in all ages plays a valuable role in striving to achieve ideal results in the rehabilitation of the cleft lip and palate individual.