The combined use of computer-guided, minimally invasive, flapless corticotomy and clear aligners as a novel approach to moderate crowding: a case report

The aim of this case report was to describe an innovative orthodontic treatment method that combined surgical and orthodontic techniques. The novel method was used to achieve a positive result in a case of moderate crowding by employing a computer-guided piezocision procedure followed by the use of clear aligners. A 23-year-old woman had a malocclusion with moderate crowding. Her periodontal indices, oral health-related quality of life (OHRQoL), and treatment time were evaluated. The treatment included interproximal corticotomy cuts extending through the entire thickness of the cortical layer, without a fullthickness flap reflection. This was achieved with a three-dimensionally printed surgical guide using computer-aided design and computer-aided manufacturing. Orthodontic force was applied to the teeth immediately after surgery by using clear appliances for better control of tooth movement. The total treatment time was 8 months. The periodontal indices improved after crowding correction, but the oral health impact profile showed a slight deterioration of OHRQoL during the 3 days following surgery. At the 2-year retention follow-up, the stability of treatment was excellent. The reduction in surgical time and patient discomfort, increased periodontal safety and patient acceptability, and accurate control of orthodontic movement without the risk of losing anchorage may encourage the use of this combined technique in appropriate cases

Mirror imaging of impacted and supernumerary teeth in dizygotic twins: a case report

Background: Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered during the clinical examination as a casual finding on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. Mirror imaging in twins has been reported frequently in relation to several unilateral dental anomalies including mesiodens. This phenomenon is the appearance of an asymmetrical feature or anomaly occurring on the right side of one twin but on the left side of the other twin. The event of mesiodens mirror imaging in monozygotic twins has been described in literature. Results: This is the first reported case of mesiodens mirror imaging in dizygotic twins. The described mesiodens caused the eruption failure of maxillary permanent incisors. The supernumerary teeth were removed to facilitate the spontaneous eruption of the impacted permanent maxillary incisors. Clinical Implications: Studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. Clinical and radiographic examinations provide a correct therapeutic approach

Etiological factors in second mandibular molar impaction

Objectives: The impaction of the second mandibular molar (MM2) has recently become more prevalent. Several etiological hypothesis have been proposed to investigate the association between skeletal features and impaction of MM2. The aims of this study were to analyze the skeletal features in patients with MM2 impaction and the association between arrested eruption of MM2 and the presence of the third mandibular molar (MM3). Study Design: In this retrospective study 48 subjects from 3,530 Caucasian orthodontic patients with MM2 impaction were included in a study group (SG) and compared to a control group (CG) of 200 subjects without MM2 impaction. Panoramic radiographs evaluated the presence or absence of the MM3 germ. Cephalometric analysis was performed to evaluate linear and angular skeletal values. For the statistical analysis, descriptive statistics, Student'fs t-test, 'Ô2 test and odds ratio (OR) were used. Results: The paired comparisons between SG and CG showed in cephalometric analysis both a reduced mandibular gonial angle (ArGoMe) and lowered Jarabak'fs polygon value with a statistically significant difference (P. 0.05). MM3 was statistically significant associated (P. 0.05) with MM2 impaction but it is not a risk factor (OR 0.817). Conclusions: Subjects with MM2 impaction show a vertical condylar growth direction. MM3 is not a risk factor for MM2 impaction

L’espansione del palato: uno studio prospettico a coorte parallela

Introduzione: Lo studio delle anomalie trasversali in difetto del mascellare superiore, con particolare riferimento al paziente in crescita, è un tema centrale della letteratura ortodontica, per le complesse correlazioni con numerose condizioni patologiche e disfunzionali, oltre che per i molteplici fattori eziologici che le caratterizzano. Lo scopo primario del presente progetto di ricerca è stato condurre uno studio prospettico a coorte parallela per valutare gli effetti dento-alveolari, scheletrici e sulle vie aeree di due diverse tipologie di espansori rapidi palatali: su bande (Hyrax) e su miniviti. Gli scopi secondari sono stati valutare gli effetti sui tessuti parodontali, l’alterazione dello stato di salute orale e la percezione del dolore mediante la compilazione di una serie di strumenti di valutazione. Materiali e Metodi: 36 pazienti (16 femmine e 20 maschi) con un’età media 12.3 anni (deviazione standard 0.82) sono stati divisi randomicamente in 2 gruppi. Il Gruppo A è stato trattato con un apparecchiatura tipo Hyrax, il Gruppo B è stato trattato con un dispositivo scheletrico su miniviti computer-guidate. E’ stata utilizzata la stessa tipologia di vite di espansione ed eseguito lo stesso protocollo di attivazione della vite. Sugli esami CBCT pre-trattamento e post-trattamento (6 mesi di follow-up) sono state eseguite misurazioni lineari ed angolari per valutare gli effetti scheletrici, dento-alveolari e parodontali dei dispositivi di espansione palatale. Sono state somministrate due scale per la valutazione del dolore durante la fase attiva di espansione palatale: la Graphic Rating Scale (GRS) e la scala di Wong-Baker (FPS). L’ Oral Health Impact Profile (OHIP-14) è stato utilizzato per valutare l’impatto dell’espansione rapida palatale sulla qualità della vita correlata allo stato di salute del cavo orale (OHRQoL), prima del trattamento, a 3 giorni e a 7 giorni di follow-up. L’analisi statistica descrittiva, il T test di Student, e il coefficiente di correlazione di Pearson sono stati utilizzati. La significatività è stata settata per valori di P≤ 0.05. Risultati: Dei 36 pazienti trattati, 10 sono stati censurati. Nei rimanenti 26 pazienti è stato osservato, in entrambi i gruppi, un aumento delle dimensioni trasversali scheletriche delle strutture naso-mascellari indagate; tale aumento è stato maggiore e statisticamente significativo, nel gruppo di pazienti trattati con espansore ad ancoraggio scheletrico (P≤0.05). Inoltre, è stato registrato in entrambi i gruppi, un aumento dei diametri trasversali dento-alveolari maggiore, ma non statisticamente significativo, nel gruppo trattato con espansore a supporto dentale. Per quanto riguarda l’effetto dento-alveolare di inclinazione del primo molare mascellare è stata registrata una vestibolo-inclinazione di tale elemento dentario nei pazienti trattati con espansore a supporto dentale con una differenza statisticamente significativa tra i due gruppi (P≤0.05). In relazione al dolore e all’OHRQoL non ci sono state differenze statisticamente significative nei livelli di dolore tra i due gruppi, ad eccezione di un maggior dolore e impatto sullo stato di salute orale durante primo giorno di attivazione della vite dell’espansore nel gruppo trattato con espansore ad ancoraggio scheletrico (GRS, P =0.01*;FPS, P <0.01*). Conclusioni: I dispositivi a supporto scheletrico permettono di ottenere un maggior incremento trasversale delle strutture scheletriche naso-mascellari riducendo i contro-effetti dento-alveolari tipici dei dispositivi di espansione a supporto dentale. L’intensità del dolore percepito dal paziente è maggiore nei pazienti trattati con espansore a supporto scheletrico, solo nel primo giorno di attivazione della vite del dispositivo. Non ci sono state differenze statisticamente significative tra i due tipi di trattamento in termini del loro impatto sull’ OHRQOL

Miniscrew-supported distal jet versus conventional distal jet appliance : a pilot study

Maxillary molar distalization is the most frequently used nonextraction treatment in the correction of Class II malocclusion. The use of traditional intra-oral devices shows unreliable results. Nowadays the use of miniscrew-supported appliances helps prevent anchorage loss. The aim of this pilot study is to compare the amount of upper first molar distalization and the dentoalveolar side effects using traditional distal jet appliance and miniscrew-supported distal jet appliance. 20 patients were randomly assigned to receive a treatment with miniscrew-supported distal jet appliance (Group A) or with traditional distal jet appliance (Group B). To ensure a safe and minimally invasive miniscrew insertion a surgical guide was used. Digital models and lateral cephalograms were obtained and analyzed before orthodontic treatment and at 6-month follow-up. Intergroup differences were determined using T- test. The significance was set at p ?0.05. The intra-operator reliability was evaluated using a 2 sample T-test. The difference was not statistically significant (P ?0.05 ), demonstrating an intra-operator reliability. In Group A, a greater maxillary first molar distalization was recorded (P=0.002). Considering the dentoalveolar side effects, in Group A, a spontaneous distalization of the first premolars and a retroclination of central incisors were determined. In Group B, the first premolars tipped mesially with a proclination of the maxillary central incisors. Miniscrew-supported distal jet appliance achieved a greater first molar distalization at 6-month follow-up and did not cause dento-alveolar side effects, such as the mesial drift of the premolars and the incisors

Can computer-guided surgery help orthodontics in miniscrew insertion and corticotomies? A narrative review

Orthodontics has considerably increased the use of technology combined with surgery as a tool to improve dental movements in terms of predictability, acceleration of movement, and fewer side effects. To achieve these goals miniscrews and corticotomy were introduced. The digital workflow permits an increase in the accuracy of surgical and orthodontic setups. The tool that transfers the information is the CAD/CAM (Computer-Aided Design/ Computer-Aided Manufacturing) template. The aim of this review is to illustrate the use of computer-guided surgery in orthodontics regarding miniscrews and piezocision. The search strategy was a combination of Medical Subject Headings (Mesh) and free text words for PubMed. A total of 27 articles were included in this review: 16 concerned miniscrews and 11 concerned corticotomy. The current need for faster treatments, the improved systems of anchorage, and the evolution of imaging technologies require operators to be knowledgeable of the digital workflow. CAD/CAM templates allow greater precision and predictability of miniscrew insertion even if in the hands of less experienced clinicians and permit a better orientation and depth of the cortical incision. In conclusion, digital planning makes surgery faster and easier and allows for the identification and correction of any potential problem before the procedure

Evaluation of alveolar cortical bone thickness and density for orthodontic mini-implant placement

Objective: Mini-implant stability is primarily related to bone quality and quantity. This study evaluated alveolar cortical bone thickness and density differences between interradicular sites at different levels from the alveolar crest, and assessed the differences between adolescents (12-18 years of age) and adults (19-50 years of age), males and females, upper and lower arch, anterior and posterior region of jaws and buccal and oral side. Study Design: In this retrospective study, 48 Computed Tomography scans, performed for oral surgery purposes were selected from dental records of 3,223 Caucasian orthodontic patients. The SimPlant software (Materialise, Leuven, Belgium) was used to measure cortical bone thickness and density at 13 interradicular sites and four bone levels ( 2,4,6 and 8 mm ). For the statistical analysis descriptive statistics, Student's t-test and Pearson correlation coefficient were used. Results: Statistically significant differences in alveolar cortical bone thickness and density between age, gender, sites and sides were found (P<0.05). The Pearson correlation coefficient demonstrated a significant linear increasing of thickness and density from crest to base of alveolar crest (P.0.05). Conclusion. Adults show a thicker alveolar cortical bone than adolescents. Alveolar cortical bone thickness and density were greater in males than in females, in mandible than in maxilla, in the posterior region than the anterior, in oral than buccal side. There is an increase of thickness and density from crest to base of alveolar crest

Morphological and topographical characteristics of posterior supernumerary molar teeth: an epidemiological study on 25,186 subjects

Objectives: To investigate the prevalence , gender difference , arch , morphology and position within the arch of supernumerary molar (SM) teeth in a referred Italian Caucasian population. Study D esign: Records of 25,186 young patients were evaluated. Only data related to supernumerary teeth in the posterior region of the jaws were analyzed. The diagnosis of hyperdontia was formulated during the clinical and radiological examinations based on panoramic radiographs. Statistical analysis was conducted at level of subjects in the assessment of prevalence of SMs and sex ratio. Statistical analysis was conducted at level of teeth according to their morphological and topographic characteristics. The analysis of association between supernumerary morphology and arch, between supernumerary position and arch and between morphology and position was performed using the χ2 test (P≤ 0.05). Results: 61 posterior supernumerary teeth were found in 45 patients. The male to female ratio was 2.5:1 ;the mean age was 21.23 (IC:95%).The SMs were found more frequently in the maxilla (62.3%) than in the mandible; supernumerary teeth (60.7%) were more frequent than supplemental teeth. The SMs were mostly of tuberculate shape (56.8%) and paramolars teeth (64.9%) were more common than distomolars. 54% of teeth were erupted in the arch. No statistically significant relationship were found between the supernumerary teeth shape and the arch ( P = 0.087) , between supernumerary teeth position and the arch ( P =0.511) and between morphology and position ( P =0.216). Conclusions: Epidemiological studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. In this retrospective study the prevalence of SMs was 0.18%. SMs were more frequent in males and in the maxilla. Supernumerary were more frequent than supplemental; the conical morphology and paramolar position were the most common shape and position

Impaction of permanent mandibular second molar: a retrospective study

Objective: To determine the prevalence of impacted mandibular second molar (MM2) and the association between MM2 impaction and crowding. The clinical significance of the angle between first and second mandibular molar and of the space between the first mandibular molar (MM1) and the anterior margin of mandibular ramus in MM2 impaction were also evaluated. Material and Methods: In this retrospective study , from the dental records of 2,945 caucasian young orthodontics patients, 40 subjects with MM2 impaction were included in a study group (SG) and compared with a control group (CG) of 200 subjects without MM2 impactions. The crowding, the angle of inclination of MM2, the distance between MM1 and mandibular ramus, the canine and molar relationships, and the lower centre line discrepancy were measured. For the statistical analysis , descriptive statistics and t-Student for independent sample groups were used. Results: The prevalence of impacted MM2 was 1.36%. The independent-Samples t-Test between SG and CG showed: the presence of crowding (P<=0.001), an higher angle values of MM2 inclination (P<=0.001) and a smaller distance between MM1 and the anterior margin of mandibular ramus (P<=0.001) in the SG. Conclusion: The impaction of MM2 is a relatively rare occurrence in orthodontic caucasian populations. The crowding, a higher angle values of MM2 inclination and a reduced distance between MM1 and the anterior margin of mandibular ramus, at the time of one third of MM2 root formation (T1), characterize MM2 impaction

Comparision of profile macro-estethic perception among orthodontists, dentistry students, orthodontic patients and surgical orthodontic patients

The patient?s needs should guide the orthodontist in choosing the most appropriate therapy. The purpose of the present survey was to compare the esthetic perception of the facial profile by orthodontists (O), dentistry students (DS), orthodontic patient