Dissertation committee:
Τσιχλάκης Κωνσταντίνος, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Ιατρού Ιωάννης, Ομότιμος Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Χαλαζωνίτης Δημήτριος, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Νικητάκης Νικόλαος, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Περισανίδης Χρήστος, Καθηγητής, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Δοντά Αικατερίνη, Αναπληρώτρια Καθηγήτρια, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Θεολόγη-Λυγιδάκη Κωνσταντίνα, Επίκουρη Καθηγήτρια, Τμήμα Οδοντιατρικής, Σχολή Επιστημών Υγείας, ΕΚΠΑ
Summary:
INTRODUCTION: Clefts affecting the lip, the maxilla and the palate represent the most common congenital craniofacial disorder. Alveolar cleft is characterized by a pyramid-shaped deficit, which extends over the alveolar process, towards the hard palate and the nasal cavity, frequently leading to oronasal communication and presence of fistula. Alveolar cleft repair is a crucial step in the course of the treatment plan. Secondary osteoplasty with autologous bone grafting, during the mixed dentition, before the eruption of the permanent canine in the area, is preferred in most cases. By alveolar cleft repair the continuity of the maxilla is restored through a bony bridge and the oral and nasal cavities are separated. Furthermore, the development of the dental arch is supported. The successful integration and the preservation of the dimensions of the graft are assessed with special scales, traditionally based only on plain radiographs. Obviously, plain radiographs cannot evaluate accurately the dimensions of the bony bridge and they are characterized by various imaging problems. Moreover, the success of the surgical intervention may be overestimated to some degree.
Computed tomography, which has been applied in alveolar cleft patients in the last 20 years, attempts to address these weaknesses. Most recent studies propose the use of cone-beam computed tomography (CBCT), which offers three-dimensional imaging of the alveolar bone, with significantly reduced radiation dose. None of the measuring systems based on computed tomography is particularly popular among the scientific community. Moreover, there is no single success scale that takes into consideration all dimensions of the bony bridge.
AIM: The aim of this doctoral thesis was the evaluation of the success of alveolar cleft repair with a novel scale using CBCT. This scale measures the height and the width of the bony bridge, as well as the level of the nasal floor. The success rate according to the new scale was compared to the one by Bergland and Enemark scales. The effect of various demographic, presurgical, surgical and postsurgical parameters on the outcome was also investigated.
MATERIAL AND METHODS: The material of the study were the young patients treated for alveolar clefts, with secondary osteoplasty, between 1995-2016, at the University Department of Oral and Maxillofacial Surgery of “P. & A. Kyriakou” Children’s Hospital in Athens. Alveolar clefts were either unilateral or bilateral and the follow-up at least one year after bone grafting.
The charts of the patients were collected and reviewed retrospectively. The following demographic, presurgical and surgical parameters were recorded: age at surgery, gender, follow-up, unilateral or bilateral alveolar cleft, cleft palate, volume of bone deficit, presurgical orthodontics, erupted canine, lateral incisor missing or extracted, origin and form of bone autograft, graft revision. At the recall appointment, each patient was examined clinically and radiographically. In bilateral cases, each cleft site was evaluated separately. Postsurgical orthodontics was applied in all patients. The following postsurgical parameters were recorded: residual oronasal fistula, spontaneous or orthodontically-assisted eruption of the previously unerupted canine, preservation or closure of the space of a missing or extracted lateral incisor.
Each patient was referred for a periapical radiograph in the cleft site, for evaluation of the success of alveolar cleft repair using the Bergland and Enemark scales. Moreover, each patient was referred for a CBCT of the maxilla, for evaluation of the success of alveolar cleft repair using a novel semiquantitative scale. The height of the bony bridge (score H0-H4), the width of the bony bridge (score W0-W2) and the level of the nasal floor (score N0-N4) were measured, in relation to the adjacent teeth. For the bone height and the level of the nasal floor, multiple coronal slices were analyzed, and the adjacent roots were divided into four equal quarters. For the bone width, an axial slice was analyzed, and each case was evaluated for having a bony bridge more or less than half the width of the adjacent roots. Consequently, with this scale, each case was assigned three scores, which were summed to form a total score of 0-10. Furthermore, total scores 9-10 were defined as success and total scores 0-8 as failure.
Statistically, the agreement between the new scale and the Bergland and Enemark scales, on defining success versus failure of alveolar cleft repair, was measured. Moreover, univariate analysis was done, evaluating possible associations between the various demographic, presurgical, surgical and postsurgical parameters and the new success scale.
RESULTS: 44 patients, with 53 alveolar cleft sites were included in study. According to the new scale, for the bone height (H), scores H4 (43.4%) and H3 (26.4%) were most commonly reported. For the bone width (W), scores W2 (66%) and W1 (32.1%) were most commonly reported. For the nasal floor (N), scores N4 (84.9%) and N3 (9.4%) were most commonly reported. Total score 10 was assigned in 35.8% of the cases, total score 9 in 24.5%, total score 8 in 5.7%, total score 7 in 9.4%, total score 6 in 22.6% and total score 0 in 1.9% of the cases. Sixty point four percent (60.4%) of the cases was defined as successful (total scores 9-10) and 39.6% was defined as failed (total scores 0-8). Moderate (kappa=0.511) and substantial (kappa=0.718) agreement, on defining success, was reported, between the new scale and the Bergland and Enemark scale, respectively. Moderate (kappa=0.526) agreement, on defining bone height, was reported, between the new scale and the Enemark scale. Statistically significant positive correlation was found between the new success scale and the closure of the space of a missing or extracted lateral incisor. Statistically significant negative correlation was found between the new success scale and the age at surgery, the graft revision and the presence of residual fistula. No other statistically significant correlations were detected.
CONCLUSIONS: Computed tomography should be considered a valid approach for the post-surgical follow-up of alveolar cleft patients. The novel success scale, for evaluating alveolar cleft repair using CBCT, takes into consideration all dimensions of the bony bridge and provides a single threshold for successful results. Traditional scales, based on plain radiographs, cannot provide such accurate and analytical data.
